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1,689	How is CHIKV propagated to humans?	2,476	[ "primarily by Aedes aegypti, the infamous yellow fever propagator" ]	[ "Chikungunya: A Potentially Emerging Epidemic?\n\nhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC2860491/\n\nSHA: f7c3160bef4169d29e2a8bdd79dd6e9056d4774c\n\nAuthors: Thiboutot, Michelle M.; Kannan, Senthil; Kawalekar, Omkar U.; Shedlock, Devon J.; Khan, Amir S.; Sarangan, Gopalsamy; Srikanth, Padma; Weiner, David B.; Muthumani, Karuppiah\nDate: 2010-04-27\nDOI: 10.1371/journal.pntd.0000623\nLicense: cc-by", "Abstract: Chikungunya virus is a mosquito-borne emerging pathogen that has a major health impact in humans and causes fever disease, headache, rash, nausea, vomiting, myalgia, and arthralgia. Indigenous to tropical Africa, recent large outbreaks have been reported in parts of South East Asia and several of its neighboring islands in 2005–07 and in Europe in 2007. Furthermore, positive cases have been confirmed in the United States in travelers returning from known outbreak areas. Currently, there is no vaccine or antiviral treatment. With the threat of an emerging global pandemic, the peculiar problems associated with the more immediate and seasonal epidemics warrant the development of an effective vaccine. In this review, we summarize the evidence supporting these concepts.", "Text: Chikungunya virus (CHIKV), a mosquito-borne pathogen listed by National Institute of Allergy and Infectious Diseases (NIAID) as a Category C Priority Pathogen that causes Chikungunya fever (CHIKF), has been spreading throughout Asia, Africa, and parts of Europe in recent times [1, 2, 3] . CHIKV is an arthropod-borne virus (arbovirus) and is transmitted to humans primarily by Aedes aegypti, the infamous yellow fever propagator [4, 5] . CHIKV infection is marked by severe joint pain, contorting its victims into unusual postures [6] . The disease gets its name from the Kimakonde vernacular language of Tanzania and Mozambique, and the word chikungunya means ''that which contorts or bends up'' and translates in Swahili to ''the illness of the bended walker'' [7, 8, 9] . In Africa, CHIKV is maintained in a sylvatic cycle among forest-dwelling Aedes spp. mosquitoes, wild primates, squirrels, birds, and rodents ( Figure 1 ) [10] . In Asia, the disease is vectored by Ae. aegypti and Ae.", "albopictus [11] . Transmission in Asia occurs in an urban cycle whereby the mosquito spreads the disease from an infected human to an uninfected human, following an epidemiological pattern similar to dengue fever [12] .", "The 2005-2006 epidemic of CHIKV in La Reunion islands in the Indian Ocean, spurred the discovery of a new vector species, Ae. albopictus [5] . Wrecking over one-third of the island's population, this epidemic peaked its devastation between January and February 2006, when over 46,000 cases came into light every week, including 284 deaths [5, 13] . Ae. albopictus is common in urban areas of the United States and is already flourishing in 36 states, raising grave concerns to the immunologically naive populace of the United States [14] .\n\nAccordingly, this review elaborately details the epidemiology and global expansion of CHIKV, describes its clinical features and pathogenesis and its symptoms and complications, and finally nominates a possible vaccine approach against CHIKV infection.", "CHIKV has been isolated into three genotypes based on phylogenetic studies. These genotypes, based on the gene sequences of an Envelope protein (E1), are Asian, East/Central/ South African, and West African [4, 11, 15] . Using phylogenetic models, Cherian et al. estimate that the Asian genotype of CHIKV emerged between 50 and 310 y ago, and the West and East African genotypes diverged between 100 and 840 y ago [15] . Since then, CHIKV has come a long way, with several mutations incorporated, and has continued to wreak epidemics in several regions. Recent activities of CHIKV include the Indian epidemic in 2005-2006, which was followed by a sudden explosion of cases in 2007. An estimated 1.3 million people across 13 states were reported to be infected in India [12, 16] , and CHIKV was also widespread in Malaysia, Sri Lanka, and Indonesia [17] . In July-August of 2007, CHIKV was reported in Italy, probably brought in by travelers from CHIKV-prone regions of India, Africa, and Indian", "Ocean islands such as Mauritius, Madagascar, and Seychelles. Few of the Italian isolates were found to have evolved from the Kerala isolate, which was associated with a A226V shift in E1 gene that represents a successful evolutionary adaptation in the mosquito vector similar to the ones observed in Reunion Island [2, 18, 19] .", "In recent times, with an increase in global travel, the risk for spreading CHIKV to non-endemic regions has heightened [1] . Several travelers have brought CHIKV home with them after visiting areas with actively infected populations [12, 20] . Such cases have been documented in European countries, Australia, Asia, and the United States [8, 21] . The United States has already reported at least twelve cases of travel-associated CHIKV, while France has reported 850 cases, and the United Kingdom 93 [8, 14] . Beyond this, CHIKV-infected travelers have also been diagnosed in Australia, Belgium, Canada, Czech Republic, French Guiana, Germany, Hong Kong, Italy, Japan, Kenya, Malaysia, Martinique, Norway, Switzerland, and Sri Lanka [21] . Some travelers were viremic, worrying public health officials about the spread of CHIKV to new areas [1, 8] .", "The incubation time for CHIKV is relatively short, requiring only 2-6 d with symptoms usually appearing 4-7 d post-infection [22] . Vazeille et al. detected CHIKV in the salivary glands of Ae. albopictus only 2 d after infection [5] . Upon infection, CHIKF tends to present itself in two phases. The first stage is acute, while the second stage, experienced by most but not all, is persistent, causing disabling polyarthritis. Characteristics of the acute phase include an abrupt onset of fever, arthralgia, and in some cases, maculopapular rash [6, 23] . The acute phase causes such intense joint and muscular pain that makes movement very difficult and prostrates its victims [6, 20] .", "Ninety-five percent of infected adults are symptomatic after infection, and of these, most become disabled for weeks to months as a result of decreased dexterity, loss of mobility, and delayed reaction. Eighteen months after disease onset, 40% of patients are found to still have anti-CHIKV IgM [6, 18, 23, 24] . The chronic stage of CHIKF is characterized by polyarthralgia that can last from weeks to years beyond the acute stage [6] . CHIKV has been shown to attack fibroblasts, explaining the involvement of muscles, joints, and skin connective tissues. The high number of nociceptive nerve endings found within the joints and muscle connective tissues can explain pain associated with CHIKF [25, 26] .", "More than 50% of patients who suffer from severe CHIKF are over 65 y old, and more than 33% of them die. Most adults who suffer from severe CHIKF have underlying medical conditions [6, 24, 27] . The other group that is disproportionately affected by severe CHIKV is children. Other complications associated with CHIKV, from most common to least common, include respiratory failure, cardiovascular decompensation, meningoencephalitis, severe acute hepatitis, severe cutaneous effects, other central nervous system problems, and kidney failure [6, 18, 20, 23, 24, 26, 27] .", "CHIKV undertakes a complex replication cycle upon host infection (Figure 2 ), which makes its genome susceptible to mutations [28, 29] . For instance, Ae. aegypti, responsible for epidemics in Kenya, Comoros, and Seychelles, carried CHIKV with an alanine in the 226 position of the E1 gene (E1-A226) [4, 18] . However, when the virus struck La Reunion Islands, a decline in population of Ae. aegypti, due to massive dichlorodiphenyltrichloroethane usage and dearth of Ae. albopictus species' www.plosntds.org population, resulted in an ecological pressure, favoring replacement of alanine at position 226 with valine (E1-A226V) [5] . This mutation allowed CHIKV's secondary vector species, Ae. albopictus, to supplement Ae. aegypti as its primary vector [5] .", "Within a year, the E1-A226V mutation was present in La Reunion Island, and Ae. albopictus apparently vectored the large epidemic infecting 34% of La Reunion Island's population [5] . All of the CHIKV strains isolated from Mayotte carried the E1-A226V mutation, and the mutation was also found in Madagascar in 2007 [5] . The E1-A226V mutation was not present at the beginning of the Indian Ocean Islands outbreak (before September 2005). However, more than 90% of later viral strains found there had incorporated the mutation (December-March 2006), indicating a genotype switch during the winter season [5, 18, 20] .", "The E1-A226V mutation also enabled an increase in infectivity of Ae. albopictus when compared to its infectivity of Ae. aegypti [4, 11, 18, 30] , and with several factors taken together, Ae. albopictus has become the new preferred and more lethal vector for CHIKV [4, 5, 11] . In fact, Tsetsarkin et al. found that a Green Fluorescent Protein tagged E1-A226V virus was 100 times more infective to Ae. albopictus than it was to Ae. aegypti [4] . In all the Indian Ocean Islands, Ae. albopictus became the main vector for CHIKV within 1-2 y after CHIKV was introduced to the region [31] .", "Of note is that Ae. aegypti has most likely been established in North America for over 300 y, while Ae. albopictus has been in many areas of the US, since 1985, primarily in Florida [32] and since then has expanded its range in the country. Reiskind et al. set out to determine if Ae. aegypti and Ae. albopictus mosquitoes captured in Florida were susceptible to CHIKV infection by a La Reunion isolate [32] . Each mosquito tested was highly susceptible to infection by a full-length infectious clone of the La Réunion Island isolate, CHIKV LR2006 OPY1 strain. Even though the Ae. albopictus strains were more susceptible to infection, overall ecology and differences in human biting patterns need to be studied further Characteristically, there are two rounds of translation: (+) sense genomic RNA (49S9 = 11.7 kb) acts directly as mRNA and is partially translated (59 end) to produce non-structural proteins (nsp's). These proteins are responsible for replication and formation of a complementary", "(2) strand, the template for further (+) strand synthesis. Subgenomic mRNA (26 S = 4.1 kb) replication occurs through the synthesis of full-length (2) intermediate RNA, which is regulated by nsp4 and p123 precursor in early infection and later by mature nsp's. Translation of the newly synthesized sub-genomic RNA results in production of structural proteins such as Capsid and protein E2-6k-E1 (from 39 end of genome). Assembly occurs at the cell surface, and the envelope is acquired as the virus buds from the cell and release and maturation almost simultaneous occurred. Replication occurs in the cytoplasm and is very rapid (,4 h) [28, 29] . doi:10.1371/journal.pntd.0000623.g002 www.plosntds.org to gain a more accurate understanding of a potential CHIKV epidemic in the US [32] .", "During the 7 d preceding birth, no human mother has been reported to transmit the disease vertically. However, about 50% of newborns delivered while the mother was infected with CHIKV contracted the disease from their mother, despite the method of delivery. Furthermore, there have been instances of CHIKV transmission from mother to fetus causing congenital illness and fetal death [33] .", "During the 2005-2006 La Reunion Island outbreaks, Ramful et al. discovered that mothers could transmit CHIKV to their progeny during the perinatal period (Day 24 to Day +1) [33, 34] , and it is associated with a high degree of morbidity. By mean Day 4 of life, all of the neonates were symptomatic for CHIKV, exhibiting common CHIKF symptoms. Six neonates were confirmed to have contracted CHIKV and developed mengoencephalitis. Of those mothers who, during the La Reunion Island epidemic, were infected long before delivery, only three fetal deaths were reported [12, 33] . Ramful et al. theorized that motherto-child transmission most likely happens transplacentally shortly before delivery [33] . A similar study by Gerardin et al. reported nineteen cases of neonatal infection associated with intrapartum maternal viremia that progressed to develop encephalitis owing to vertical transmission from infected mothers [34] .", "Clinical and epidemiological similarities with dengue fever make CHIKV diagnosis difficult, which may lead physicians to misdiagnose CHIKV as dengue fever; therefore, the incidence of CHIKV may actually be higher than currently believed (Table 1 ) [6, 12, 35] .", "The amount of time elapsed since disease onset is the most critical parameter when choosing a diagnostic test. CHIKV can be detected and isolated by culturing with mosquito cells (C6/36), Vero cells (mammalian), or in mice [26] . However, this method can take at least a week and only achieves a high sensitivity during the viremic phase, which usually only lasts up to 48 h after the bite. Five days post-infection, the viral isolation approach has a low sensitivity but is still the preferred method for detecting the CHIKV strain [12, 26, 31, 35] . RT-PCR on the other hand is a faster and more sensitive method that can be used within the first week of disease onset [26] , and it is currently the most sensitive method for detecting and quantifying viral mRNA [4, 36] .", "Classic serological detection, by assays such as ELISA [37] , immunofluorescence [5, 38] , complement binding, and haemagglutination inhibition [39] , constitutes the second diagnostic tool used for biological diagnosis of CHIKV infection. These proven techniques are useful for detection of Antigen in mosquitoes during epidemiological studies. These assays detect virus-specific IgM and IgG, however the sensitivity and specificity of these assays has been poorly characterized. Viral competence, or the potential of viral infection and transmission, is an important parameter that can be quantified by ELISA, viral culture, and PCR.", "A study by Ng et al. showed biomarkers indicative of severe CHIKV infection [40] . They found decreased levels of RANTES and increased levels of Interleukin-6 (IL-6) and Interleukin-1b (IL-1b) that could be sued for CHIKV detection in patients as indicators of CHIKV-driven cytokine storm. Couderc et al. demonstrate another cytokine, type-I IFN, as a key player in the progression to CHIKV infection [26] . Using an IFN-a/b null mouse model, they demonstrated evidence of muscles, joints, and skin as privileged CHIKV targets, which is consistent with human pathology. Although Ng et al. concluded that RANTES levels were significantly suppressed in severe CHIKF patients [40] , interestingly, an increase in levels of RANTES has been observed in dengue infection [41] . Since the symptoms of CHIKF mimic those of dengue fever, results obtained from this study strongly suggest that RANTES could be a potential distinctive biomarker that differentiates between these two clinically similar", "diseases.", "There are no approved antiviral treatments currently available for CHIKV [1, 3, 12, 42] . Currently, CHIKF is treated symptomatically, usually with non-steroidal anti-inflammatory drugs or steroids, bed rest, and fluids. Movement and mild exercise are thought to decrease stiffness and morning arthralgia, but heavy exercise may exacerbate rheumatic symptoms. Corticosteroids may be used in cases of debilitating chronic CHIKV infection. There is a debate about the appropriateness of chloroquine as treatment for unresolved, non-steroidal anti-inflammatory drugresistant arthritis [43] . A study showed that viral production was www.plosntds.org drastically reduced at 16 h post-infection after treatment with 100 mM dec-RVKR-cmk (Decanoyl-Arg-Val-Lys-Arg-chloromethylketone), a furine inhibitor [42, 44] . Chloroquine acted by raising the pH, blocking low pH-dependent entry of virus into the cell. It is important to note that dec-RVKR-cmk or chloroquine only inhibited viral spreading from cell", "to cell, not CHIKV replication once it had entered the cell [43] . However, most would agree that the best weapon against CHIKV is prevention. A live CHIKV vaccine developed by the United States reached phase II clinical trial encompassing 59 healthy volunteers [45] . Eight percent of the volunteers experienced transient arthralgia, while 98% of the volunteers had seroconversion [45] . However, live CHIKV vaccines are still questionable. One cannot discount the risk of a live vaccine possibly inducing chronic rheumatism. Also, there is the question as to whether widespread use among the public could trigger mosquito transmission or lead to chronic infection or viral reversion [1] .", "An alternative approach would be to produce a chimeric vaccine against CHIKV. Wang et al. developed a chimeric alphavirus vaccine that is uniformly attenuated and does not cause reactogenicity in mice [3] . Three different versions of this vaccine were made using three different backbone vectors: Venezuelan equine encephalitis virus (VEEV) attenuated vaccine strain T-83, naturally attenuated eastern equine encephalitis virus (EEEV), and attenuated Sindbis virus (SINV). In short, CHIKV structural proteins were engineered into the backbones of the aforementioned vaccines to produce the chimeras [3] . These chimeras were found to stimulate a strong humoral immunity, and even at doses of 5.3-5.8 log 10 PFU, they did not trigger reactogenicity. When vaccinated mice were challenged with CHIKV, neither adult nor neonatal mice gained weight, had fever, or displayed signs of neurological illness. Upon comparison of the chimeras with the Army181/25 vaccine, the Army vaccine resulted in higher", "levels of viremia and replication in the joints of neonatal mice. Because the joints are known targets of CHIKV, Wang et al. noted their vaccine might avoid the negative reactogenic side effects of the Army vaccine. After being subcutaneously vaccinated with 5.3-5.8 log 10 PFU of the chimeric vaccines, mice produced strong neutralizing antibody titers. The VEEV and EEEV chimeras yielded higher neutralizing antibody titers than the SINV chimera without being more virulent. On top of this, the VEEV and EEEV CHIKV chimeras seemed to be more immunogenic than the Army vaccine despite the chimeras' lower viremia and replication in the joints of neonatal mice [3] .", "Tiwari et al. [46] adopted a different strategy using formalin inactivated CHIKV in combination with alhydrogel (Aluminum Hydroxide) as an adjuvant. This study clearly suggests that this vaccine elicits both humoral and cell-mediated immune responses in mice, providing its immunogenic potential. A recent study by Couderc et al. [47] showed passive immunization as a potential treatment for CHIKV infection. Using purified immunoglobulin extracted from convalescent CHIKV patients, they demonstrated effective neutralizing activity against CHIKV infection both in vitro and in vivo. This thereby establishes a potential preventive and therapeutic approach to combat CHIKV infection. Pathogenesis studies conducted with related alpha virus, like RRV, have shown the role of macrophages in persistence on infection [48] . They also demonstrated the role of RRV-specific CD8 T cells in clearing viral load in infected patients, thereby warranting similar investigations with CHIKV and the importance", "of investigating a cell-mediated immune response-based vaccine against CHIKV [49] .", "There are always certain risks associated with live attenuated or inactivated viral vaccines [50] . One way to avoid these potential problems is to construct a consensus-based DNA vaccine. DNA based vaccines have an improved safety profile as compared to live or attenuated vaccines [51, 52] . A consequence of CHIKV's rapid evolution is difficulty in constructing a vaccine that will be able to Figure 3 . Levels of CHIKV-specific IgG in mice immunized with CHIKV vaccines. Each group of C57BL/6 mice (n = 5) was immunized with 12.5 mg of pVax1 control vector or CHIKV vaccine plasmids as indicated at 0 and 2 wk. Mice were bled 2 wk after each immunization, and each group's serum pool was diluted to 1:100 and 1:500 for reaction with specific vaccine constructs. Serum was incubated for 1 h at 37uC on 96-well plates coated with 2 mg/ml of respective CHIKV peptides, and antibody was detected using anti-mouse IgG-HRP and OD was measured at 405 nm. doi:10.1371/journal.pntd.0000623.g003", "www.plosntds.org effectively protect large populations from multiple strains of the virus. One of the strengths of DNA consensus vaccines is its ability to induce cross-reactive immune responses against the three distinct phylogenetic groups of CHIKV. Also DNA-based vaccines can be produced more rapidly than protein-based vaccines.", "Recently, Muthumani et al. constructed a vaccine that was shown to induce both humoral and cellular immunity in vivo in 3-4-wk-old female C57/BL6 mice [49] . These mice were immunized using an in vivo electroporation method to deliver the vaccine into the quadriceps muscle. The consensus construct was designed against E1, E2, and the core protein capsid. To design the construct, they aligned 21 sequences of CHIKV isolated between 1952 and 2006, using strains from differing countries, including La Reunion Island. The most common nucleotide among the sequences was chosen at each position to be used in the consensus construct, taking care not to alter the reading frame. They conducted codon and RNA optimization, added a strong Kozak sequence, and substituted signal peptide with an immunoglobulin E leader sequence to improve vaccine efficacy.", "After immunizing the mice, spleens were harvested along with serum and tested to determine antibody titer. After three immunizations, consensus E1, E2, and C vaccines were shown to induce T-cell immune responses leading to strong IFN-c responses and proliferation in C57/BL6 mice. Furthermore, when compared with control mice, immunized mice had higher total IgG levels as well as higher anti-E1 specific, anti-E2 specific, and anti-C specific IgG antibodies, suggesting a strong humoral immune response ( Figure 3 ) and also specificity for the antigens encoded in the vaccine constructs ( Figure 4 ). Because of its promising results and the need for a safer vaccine, this consensus DNA vaccine deserves further investigation. Determining longevity of protective effects of the vaccine and persistence of antibody and IFN-c responses could be the next step of investigation. Challenged studies of immunized mice must also be carried out.", "CHIKV mosquito-borne disease has caused massive outbreaks for at least half a century but is no longer confined to the www.plosntds.org developing nations. It began to encroach into the boundaries of the developing world. As a result, the NIAID has designated CHIKV as a Category C pathogen alongside the influenza and SARS-CoV viruses [3] . Realization of the potential severity of this disease is exigent; for instance, if used as a biological weapon, the world economy could be severely crippled; if enough members of the armed forces were to become infected during a military deployment, military operations could be significantly affected. Efforts to monitor the disease will only provide minimal warning in a global society, and steps to prevent the morbidity and mortality associated with pandemic are imperative [21, 31] . Despite the gravity of its infectious potency and the fear of it being a potential biological weapon, there is currently no vaccine for CHIKV infections. Live", "attenuated vaccine trials were carried out in 2000, but funding for the project was discontinued. Newer approaches such as DNA vaccines appear promising over conventional strategies like live attenuated or inactivated virus and thus call for further investigation. Recent advances such electroporation delivery and incorporation of adjuvants has boosted DNA vaccine efficacy [51, 53] . Despite the low antibody response to DNA vaccines, other numerous advantages have overshadowed these minor drawbacks (Table 2) , the most important one being the ability to induce both humoral and cellular immune responses [51, 54] .", "Judging by recent success, such as the immunogenic construct developed by Muthumani et al., DNA vaccines could play a major role in combating CHIKV [49] . Vaccines are literally a critical component of CHIKV disease control and therefore research in this area is highly encouraged. The dramatic spread of dengue viruses (DENV) throughout tropical America since 1980 via the same vectors and human hosts underscores the risk to public health in the Americas. The adverse events associated with the current live vaccine are well documented [55] . Realizing these drawbacks, earnest efforts should be taken to develop new strategies to forestall further spread and complications." ]	[ 2 ]	3,829	5,688
1,689	From what language the disease gets its name?	2,478	[ "Kimakonde vernacular language of Tanzania and Mozambique" ]	[ "Chikungunya: A Potentially Emerging Epidemic?\n\nhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC2860491/\n\nSHA: f7c3160bef4169d29e2a8bdd79dd6e9056d4774c\n\nAuthors: Thiboutot, Michelle M.; Kannan, Senthil; Kawalekar, Omkar U.; Shedlock, Devon J.; Khan, Amir S.; Sarangan, Gopalsamy; Srikanth, Padma; Weiner, David B.; Muthumani, Karuppiah\nDate: 2010-04-27\nDOI: 10.1371/journal.pntd.0000623\nLicense: cc-by", "Abstract: Chikungunya virus is a mosquito-borne emerging pathogen that has a major health impact in humans and causes fever disease, headache, rash, nausea, vomiting, myalgia, and arthralgia. Indigenous to tropical Africa, recent large outbreaks have been reported in parts of South East Asia and several of its neighboring islands in 2005–07 and in Europe in 2007. Furthermore, positive cases have been confirmed in the United States in travelers returning from known outbreak areas. Currently, there is no vaccine or antiviral treatment. With the threat of an emerging global pandemic, the peculiar problems associated with the more immediate and seasonal epidemics warrant the development of an effective vaccine. In this review, we summarize the evidence supporting these concepts.", "Text: Chikungunya virus (CHIKV), a mosquito-borne pathogen listed by National Institute of Allergy and Infectious Diseases (NIAID) as a Category C Priority Pathogen that causes Chikungunya fever (CHIKF), has been spreading throughout Asia, Africa, and parts of Europe in recent times [1, 2, 3] . CHIKV is an arthropod-borne virus (arbovirus) and is transmitted to humans primarily by Aedes aegypti, the infamous yellow fever propagator [4, 5] . CHIKV infection is marked by severe joint pain, contorting its victims into unusual postures [6] . The disease gets its name from the Kimakonde vernacular language of Tanzania and Mozambique, and the word chikungunya means ''that which contorts or bends up'' and translates in Swahili to ''the illness of the bended walker'' [7, 8, 9] . In Africa, CHIKV is maintained in a sylvatic cycle among forest-dwelling Aedes spp. mosquitoes, wild primates, squirrels, birds, and rodents ( Figure 1 ) [10] . In Asia, the disease is vectored by Ae. aegypti and Ae.", "albopictus [11] . Transmission in Asia occurs in an urban cycle whereby the mosquito spreads the disease from an infected human to an uninfected human, following an epidemiological pattern similar to dengue fever [12] .", "The 2005-2006 epidemic of CHIKV in La Reunion islands in the Indian Ocean, spurred the discovery of a new vector species, Ae. albopictus [5] . Wrecking over one-third of the island's population, this epidemic peaked its devastation between January and February 2006, when over 46,000 cases came into light every week, including 284 deaths [5, 13] . Ae. albopictus is common in urban areas of the United States and is already flourishing in 36 states, raising grave concerns to the immunologically naive populace of the United States [14] .\n\nAccordingly, this review elaborately details the epidemiology and global expansion of CHIKV, describes its clinical features and pathogenesis and its symptoms and complications, and finally nominates a possible vaccine approach against CHIKV infection.", "CHIKV has been isolated into three genotypes based on phylogenetic studies. These genotypes, based on the gene sequences of an Envelope protein (E1), are Asian, East/Central/ South African, and West African [4, 11, 15] . Using phylogenetic models, Cherian et al. estimate that the Asian genotype of CHIKV emerged between 50 and 310 y ago, and the West and East African genotypes diverged between 100 and 840 y ago [15] . Since then, CHIKV has come a long way, with several mutations incorporated, and has continued to wreak epidemics in several regions. Recent activities of CHIKV include the Indian epidemic in 2005-2006, which was followed by a sudden explosion of cases in 2007. An estimated 1.3 million people across 13 states were reported to be infected in India [12, 16] , and CHIKV was also widespread in Malaysia, Sri Lanka, and Indonesia [17] . In July-August of 2007, CHIKV was reported in Italy, probably brought in by travelers from CHIKV-prone regions of India, Africa, and Indian", "Ocean islands such as Mauritius, Madagascar, and Seychelles. Few of the Italian isolates were found to have evolved from the Kerala isolate, which was associated with a A226V shift in E1 gene that represents a successful evolutionary adaptation in the mosquito vector similar to the ones observed in Reunion Island [2, 18, 19] .", "In recent times, with an increase in global travel, the risk for spreading CHIKV to non-endemic regions has heightened [1] . Several travelers have brought CHIKV home with them after visiting areas with actively infected populations [12, 20] . Such cases have been documented in European countries, Australia, Asia, and the United States [8, 21] . The United States has already reported at least twelve cases of travel-associated CHIKV, while France has reported 850 cases, and the United Kingdom 93 [8, 14] . Beyond this, CHIKV-infected travelers have also been diagnosed in Australia, Belgium, Canada, Czech Republic, French Guiana, Germany, Hong Kong, Italy, Japan, Kenya, Malaysia, Martinique, Norway, Switzerland, and Sri Lanka [21] . Some travelers were viremic, worrying public health officials about the spread of CHIKV to new areas [1, 8] .", "The incubation time for CHIKV is relatively short, requiring only 2-6 d with symptoms usually appearing 4-7 d post-infection [22] . Vazeille et al. detected CHIKV in the salivary glands of Ae. albopictus only 2 d after infection [5] . Upon infection, CHIKF tends to present itself in two phases. The first stage is acute, while the second stage, experienced by most but not all, is persistent, causing disabling polyarthritis. Characteristics of the acute phase include an abrupt onset of fever, arthralgia, and in some cases, maculopapular rash [6, 23] . The acute phase causes such intense joint and muscular pain that makes movement very difficult and prostrates its victims [6, 20] .", "Ninety-five percent of infected adults are symptomatic after infection, and of these, most become disabled for weeks to months as a result of decreased dexterity, loss of mobility, and delayed reaction. Eighteen months after disease onset, 40% of patients are found to still have anti-CHIKV IgM [6, 18, 23, 24] . The chronic stage of CHIKF is characterized by polyarthralgia that can last from weeks to years beyond the acute stage [6] . CHIKV has been shown to attack fibroblasts, explaining the involvement of muscles, joints, and skin connective tissues. The high number of nociceptive nerve endings found within the joints and muscle connective tissues can explain pain associated with CHIKF [25, 26] .", "More than 50% of patients who suffer from severe CHIKF are over 65 y old, and more than 33% of them die. Most adults who suffer from severe CHIKF have underlying medical conditions [6, 24, 27] . The other group that is disproportionately affected by severe CHIKV is children. Other complications associated with CHIKV, from most common to least common, include respiratory failure, cardiovascular decompensation, meningoencephalitis, severe acute hepatitis, severe cutaneous effects, other central nervous system problems, and kidney failure [6, 18, 20, 23, 24, 26, 27] .", "CHIKV undertakes a complex replication cycle upon host infection (Figure 2 ), which makes its genome susceptible to mutations [28, 29] . For instance, Ae. aegypti, responsible for epidemics in Kenya, Comoros, and Seychelles, carried CHIKV with an alanine in the 226 position of the E1 gene (E1-A226) [4, 18] . However, when the virus struck La Reunion Islands, a decline in population of Ae. aegypti, due to massive dichlorodiphenyltrichloroethane usage and dearth of Ae. albopictus species' www.plosntds.org population, resulted in an ecological pressure, favoring replacement of alanine at position 226 with valine (E1-A226V) [5] . This mutation allowed CHIKV's secondary vector species, Ae. albopictus, to supplement Ae. aegypti as its primary vector [5] .", "Within a year, the E1-A226V mutation was present in La Reunion Island, and Ae. albopictus apparently vectored the large epidemic infecting 34% of La Reunion Island's population [5] . All of the CHIKV strains isolated from Mayotte carried the E1-A226V mutation, and the mutation was also found in Madagascar in 2007 [5] . The E1-A226V mutation was not present at the beginning of the Indian Ocean Islands outbreak (before September 2005). However, more than 90% of later viral strains found there had incorporated the mutation (December-March 2006), indicating a genotype switch during the winter season [5, 18, 20] .", "The E1-A226V mutation also enabled an increase in infectivity of Ae. albopictus when compared to its infectivity of Ae. aegypti [4, 11, 18, 30] , and with several factors taken together, Ae. albopictus has become the new preferred and more lethal vector for CHIKV [4, 5, 11] . In fact, Tsetsarkin et al. found that a Green Fluorescent Protein tagged E1-A226V virus was 100 times more infective to Ae. albopictus than it was to Ae. aegypti [4] . In all the Indian Ocean Islands, Ae. albopictus became the main vector for CHIKV within 1-2 y after CHIKV was introduced to the region [31] .", "Of note is that Ae. aegypti has most likely been established in North America for over 300 y, while Ae. albopictus has been in many areas of the US, since 1985, primarily in Florida [32] and since then has expanded its range in the country. Reiskind et al. set out to determine if Ae. aegypti and Ae. albopictus mosquitoes captured in Florida were susceptible to CHIKV infection by a La Reunion isolate [32] . Each mosquito tested was highly susceptible to infection by a full-length infectious clone of the La Réunion Island isolate, CHIKV LR2006 OPY1 strain. Even though the Ae. albopictus strains were more susceptible to infection, overall ecology and differences in human biting patterns need to be studied further Characteristically, there are two rounds of translation: (+) sense genomic RNA (49S9 = 11.7 kb) acts directly as mRNA and is partially translated (59 end) to produce non-structural proteins (nsp's). These proteins are responsible for replication and formation of a complementary", "(2) strand, the template for further (+) strand synthesis. Subgenomic mRNA (26 S = 4.1 kb) replication occurs through the synthesis of full-length (2) intermediate RNA, which is regulated by nsp4 and p123 precursor in early infection and later by mature nsp's. Translation of the newly synthesized sub-genomic RNA results in production of structural proteins such as Capsid and protein E2-6k-E1 (from 39 end of genome). Assembly occurs at the cell surface, and the envelope is acquired as the virus buds from the cell and release and maturation almost simultaneous occurred. Replication occurs in the cytoplasm and is very rapid (,4 h) [28, 29] . doi:10.1371/journal.pntd.0000623.g002 www.plosntds.org to gain a more accurate understanding of a potential CHIKV epidemic in the US [32] .", "During the 7 d preceding birth, no human mother has been reported to transmit the disease vertically. However, about 50% of newborns delivered while the mother was infected with CHIKV contracted the disease from their mother, despite the method of delivery. Furthermore, there have been instances of CHIKV transmission from mother to fetus causing congenital illness and fetal death [33] .", "During the 2005-2006 La Reunion Island outbreaks, Ramful et al. discovered that mothers could transmit CHIKV to their progeny during the perinatal period (Day 24 to Day +1) [33, 34] , and it is associated with a high degree of morbidity. By mean Day 4 of life, all of the neonates were symptomatic for CHIKV, exhibiting common CHIKF symptoms. Six neonates were confirmed to have contracted CHIKV and developed mengoencephalitis. Of those mothers who, during the La Reunion Island epidemic, were infected long before delivery, only three fetal deaths were reported [12, 33] . Ramful et al. theorized that motherto-child transmission most likely happens transplacentally shortly before delivery [33] . A similar study by Gerardin et al. reported nineteen cases of neonatal infection associated with intrapartum maternal viremia that progressed to develop encephalitis owing to vertical transmission from infected mothers [34] .", "Clinical and epidemiological similarities with dengue fever make CHIKV diagnosis difficult, which may lead physicians to misdiagnose CHIKV as dengue fever; therefore, the incidence of CHIKV may actually be higher than currently believed (Table 1 ) [6, 12, 35] .", "The amount of time elapsed since disease onset is the most critical parameter when choosing a diagnostic test. CHIKV can be detected and isolated by culturing with mosquito cells (C6/36), Vero cells (mammalian), or in mice [26] . However, this method can take at least a week and only achieves a high sensitivity during the viremic phase, which usually only lasts up to 48 h after the bite. Five days post-infection, the viral isolation approach has a low sensitivity but is still the preferred method for detecting the CHIKV strain [12, 26, 31, 35] . RT-PCR on the other hand is a faster and more sensitive method that can be used within the first week of disease onset [26] , and it is currently the most sensitive method for detecting and quantifying viral mRNA [4, 36] .", "Classic serological detection, by assays such as ELISA [37] , immunofluorescence [5, 38] , complement binding, and haemagglutination inhibition [39] , constitutes the second diagnostic tool used for biological diagnosis of CHIKV infection. These proven techniques are useful for detection of Antigen in mosquitoes during epidemiological studies. These assays detect virus-specific IgM and IgG, however the sensitivity and specificity of these assays has been poorly characterized. Viral competence, or the potential of viral infection and transmission, is an important parameter that can be quantified by ELISA, viral culture, and PCR.", "A study by Ng et al. showed biomarkers indicative of severe CHIKV infection [40] . They found decreased levels of RANTES and increased levels of Interleukin-6 (IL-6) and Interleukin-1b (IL-1b) that could be sued for CHIKV detection in patients as indicators of CHIKV-driven cytokine storm. Couderc et al. demonstrate another cytokine, type-I IFN, as a key player in the progression to CHIKV infection [26] . Using an IFN-a/b null mouse model, they demonstrated evidence of muscles, joints, and skin as privileged CHIKV targets, which is consistent with human pathology. Although Ng et al. concluded that RANTES levels were significantly suppressed in severe CHIKF patients [40] , interestingly, an increase in levels of RANTES has been observed in dengue infection [41] . Since the symptoms of CHIKF mimic those of dengue fever, results obtained from this study strongly suggest that RANTES could be a potential distinctive biomarker that differentiates between these two clinically similar", "diseases.", "There are no approved antiviral treatments currently available for CHIKV [1, 3, 12, 42] . Currently, CHIKF is treated symptomatically, usually with non-steroidal anti-inflammatory drugs or steroids, bed rest, and fluids. Movement and mild exercise are thought to decrease stiffness and morning arthralgia, but heavy exercise may exacerbate rheumatic symptoms. Corticosteroids may be used in cases of debilitating chronic CHIKV infection. There is a debate about the appropriateness of chloroquine as treatment for unresolved, non-steroidal anti-inflammatory drugresistant arthritis [43] . A study showed that viral production was www.plosntds.org drastically reduced at 16 h post-infection after treatment with 100 mM dec-RVKR-cmk (Decanoyl-Arg-Val-Lys-Arg-chloromethylketone), a furine inhibitor [42, 44] . Chloroquine acted by raising the pH, blocking low pH-dependent entry of virus into the cell. It is important to note that dec-RVKR-cmk or chloroquine only inhibited viral spreading from cell", "to cell, not CHIKV replication once it had entered the cell [43] . However, most would agree that the best weapon against CHIKV is prevention. A live CHIKV vaccine developed by the United States reached phase II clinical trial encompassing 59 healthy volunteers [45] . Eight percent of the volunteers experienced transient arthralgia, while 98% of the volunteers had seroconversion [45] . However, live CHIKV vaccines are still questionable. One cannot discount the risk of a live vaccine possibly inducing chronic rheumatism. Also, there is the question as to whether widespread use among the public could trigger mosquito transmission or lead to chronic infection or viral reversion [1] .", "An alternative approach would be to produce a chimeric vaccine against CHIKV. Wang et al. developed a chimeric alphavirus vaccine that is uniformly attenuated and does not cause reactogenicity in mice [3] . Three different versions of this vaccine were made using three different backbone vectors: Venezuelan equine encephalitis virus (VEEV) attenuated vaccine strain T-83, naturally attenuated eastern equine encephalitis virus (EEEV), and attenuated Sindbis virus (SINV). In short, CHIKV structural proteins were engineered into the backbones of the aforementioned vaccines to produce the chimeras [3] . These chimeras were found to stimulate a strong humoral immunity, and even at doses of 5.3-5.8 log 10 PFU, they did not trigger reactogenicity. When vaccinated mice were challenged with CHIKV, neither adult nor neonatal mice gained weight, had fever, or displayed signs of neurological illness. Upon comparison of the chimeras with the Army181/25 vaccine, the Army vaccine resulted in higher", "levels of viremia and replication in the joints of neonatal mice. Because the joints are known targets of CHIKV, Wang et al. noted their vaccine might avoid the negative reactogenic side effects of the Army vaccine. After being subcutaneously vaccinated with 5.3-5.8 log 10 PFU of the chimeric vaccines, mice produced strong neutralizing antibody titers. The VEEV and EEEV chimeras yielded higher neutralizing antibody titers than the SINV chimera without being more virulent. On top of this, the VEEV and EEEV CHIKV chimeras seemed to be more immunogenic than the Army vaccine despite the chimeras' lower viremia and replication in the joints of neonatal mice [3] .", "Tiwari et al. [46] adopted a different strategy using formalin inactivated CHIKV in combination with alhydrogel (Aluminum Hydroxide) as an adjuvant. This study clearly suggests that this vaccine elicits both humoral and cell-mediated immune responses in mice, providing its immunogenic potential. A recent study by Couderc et al. [47] showed passive immunization as a potential treatment for CHIKV infection. Using purified immunoglobulin extracted from convalescent CHIKV patients, they demonstrated effective neutralizing activity against CHIKV infection both in vitro and in vivo. This thereby establishes a potential preventive and therapeutic approach to combat CHIKV infection. Pathogenesis studies conducted with related alpha virus, like RRV, have shown the role of macrophages in persistence on infection [48] . They also demonstrated the role of RRV-specific CD8 T cells in clearing viral load in infected patients, thereby warranting similar investigations with CHIKV and the importance", "of investigating a cell-mediated immune response-based vaccine against CHIKV [49] .", "There are always certain risks associated with live attenuated or inactivated viral vaccines [50] . One way to avoid these potential problems is to construct a consensus-based DNA vaccine. DNA based vaccines have an improved safety profile as compared to live or attenuated vaccines [51, 52] . A consequence of CHIKV's rapid evolution is difficulty in constructing a vaccine that will be able to Figure 3 . Levels of CHIKV-specific IgG in mice immunized with CHIKV vaccines. Each group of C57BL/6 mice (n = 5) was immunized with 12.5 mg of pVax1 control vector or CHIKV vaccine plasmids as indicated at 0 and 2 wk. Mice were bled 2 wk after each immunization, and each group's serum pool was diluted to 1:100 and 1:500 for reaction with specific vaccine constructs. Serum was incubated for 1 h at 37uC on 96-well plates coated with 2 mg/ml of respective CHIKV peptides, and antibody was detected using anti-mouse IgG-HRP and OD was measured at 405 nm. doi:10.1371/journal.pntd.0000623.g003", "www.plosntds.org effectively protect large populations from multiple strains of the virus. One of the strengths of DNA consensus vaccines is its ability to induce cross-reactive immune responses against the three distinct phylogenetic groups of CHIKV. Also DNA-based vaccines can be produced more rapidly than protein-based vaccines.", "Recently, Muthumani et al. constructed a vaccine that was shown to induce both humoral and cellular immunity in vivo in 3-4-wk-old female C57/BL6 mice [49] . These mice were immunized using an in vivo electroporation method to deliver the vaccine into the quadriceps muscle. The consensus construct was designed against E1, E2, and the core protein capsid. To design the construct, they aligned 21 sequences of CHIKV isolated between 1952 and 2006, using strains from differing countries, including La Reunion Island. The most common nucleotide among the sequences was chosen at each position to be used in the consensus construct, taking care not to alter the reading frame. They conducted codon and RNA optimization, added a strong Kozak sequence, and substituted signal peptide with an immunoglobulin E leader sequence to improve vaccine efficacy.", "After immunizing the mice, spleens were harvested along with serum and tested to determine antibody titer. After three immunizations, consensus E1, E2, and C vaccines were shown to induce T-cell immune responses leading to strong IFN-c responses and proliferation in C57/BL6 mice. Furthermore, when compared with control mice, immunized mice had higher total IgG levels as well as higher anti-E1 specific, anti-E2 specific, and anti-C specific IgG antibodies, suggesting a strong humoral immune response ( Figure 3 ) and also specificity for the antigens encoded in the vaccine constructs ( Figure 4 ). Because of its promising results and the need for a safer vaccine, this consensus DNA vaccine deserves further investigation. Determining longevity of protective effects of the vaccine and persistence of antibody and IFN-c responses could be the next step of investigation. Challenged studies of immunized mice must also be carried out.", "CHIKV mosquito-borne disease has caused massive outbreaks for at least half a century but is no longer confined to the www.plosntds.org developing nations. It began to encroach into the boundaries of the developing world. As a result, the NIAID has designated CHIKV as a Category C pathogen alongside the influenza and SARS-CoV viruses [3] . Realization of the potential severity of this disease is exigent; for instance, if used as a biological weapon, the world economy could be severely crippled; if enough members of the armed forces were to become infected during a military deployment, military operations could be significantly affected. Efforts to monitor the disease will only provide minimal warning in a global society, and steps to prevent the morbidity and mortality associated with pandemic are imperative [21, 31] . Despite the gravity of its infectious potency and the fear of it being a potential biological weapon, there is currently no vaccine for CHIKV infections. Live", "attenuated vaccine trials were carried out in 2000, but funding for the project was discontinued. Newer approaches such as DNA vaccines appear promising over conventional strategies like live attenuated or inactivated virus and thus call for further investigation. Recent advances such electroporation delivery and incorporation of adjuvants has boosted DNA vaccine efficacy [51, 53] . Despite the low antibody response to DNA vaccines, other numerous advantages have overshadowed these minor drawbacks (Table 2) , the most important one being the ability to induce both humoral and cellular immune responses [51, 54] .", "Judging by recent success, such as the immunogenic construct developed by Muthumani et al., DNA vaccines could play a major role in combating CHIKV [49] . Vaccines are literally a critical component of CHIKV disease control and therefore research in this area is highly encouraged. The dramatic spread of dengue viruses (DENV) throughout tropical America since 1980 via the same vectors and human hosts underscores the risk to public health in the Americas. The adverse events associated with the current live vaccine are well documented [55] . Realizing these drawbacks, earnest efforts should be taken to develop new strategies to forestall further spread and complications." ]	[ 2 ]	3,829	5,688
1,689	What is the word Chikungunya mean?	2,479	[ "'that which contorts or bends up'" ]	[ "Chikungunya: A Potentially Emerging Epidemic?\n\nhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC2860491/\n\nSHA: f7c3160bef4169d29e2a8bdd79dd6e9056d4774c\n\nAuthors: Thiboutot, Michelle M.; Kannan, Senthil; Kawalekar, Omkar U.; Shedlock, Devon J.; Khan, Amir S.; Sarangan, Gopalsamy; Srikanth, Padma; Weiner, David B.; Muthumani, Karuppiah\nDate: 2010-04-27\nDOI: 10.1371/journal.pntd.0000623\nLicense: cc-by", "Abstract: Chikungunya virus is a mosquito-borne emerging pathogen that has a major health impact in humans and causes fever disease, headache, rash, nausea, vomiting, myalgia, and arthralgia. Indigenous to tropical Africa, recent large outbreaks have been reported in parts of South East Asia and several of its neighboring islands in 2005–07 and in Europe in 2007. Furthermore, positive cases have been confirmed in the United States in travelers returning from known outbreak areas. Currently, there is no vaccine or antiviral treatment. With the threat of an emerging global pandemic, the peculiar problems associated with the more immediate and seasonal epidemics warrant the development of an effective vaccine. In this review, we summarize the evidence supporting these concepts.", "Text: Chikungunya virus (CHIKV), a mosquito-borne pathogen listed by National Institute of Allergy and Infectious Diseases (NIAID) as a Category C Priority Pathogen that causes Chikungunya fever (CHIKF), has been spreading throughout Asia, Africa, and parts of Europe in recent times [1, 2, 3] . CHIKV is an arthropod-borne virus (arbovirus) and is transmitted to humans primarily by Aedes aegypti, the infamous yellow fever propagator [4, 5] . CHIKV infection is marked by severe joint pain, contorting its victims into unusual postures [6] . The disease gets its name from the Kimakonde vernacular language of Tanzania and Mozambique, and the word chikungunya means ''that which contorts or bends up'' and translates in Swahili to ''the illness of the bended walker'' [7, 8, 9] . In Africa, CHIKV is maintained in a sylvatic cycle among forest-dwelling Aedes spp. mosquitoes, wild primates, squirrels, birds, and rodents ( Figure 1 ) [10] . In Asia, the disease is vectored by Ae. aegypti and Ae.", "albopictus [11] . Transmission in Asia occurs in an urban cycle whereby the mosquito spreads the disease from an infected human to an uninfected human, following an epidemiological pattern similar to dengue fever [12] .", "The 2005-2006 epidemic of CHIKV in La Reunion islands in the Indian Ocean, spurred the discovery of a new vector species, Ae. albopictus [5] . Wrecking over one-third of the island's population, this epidemic peaked its devastation between January and February 2006, when over 46,000 cases came into light every week, including 284 deaths [5, 13] . Ae. albopictus is common in urban areas of the United States and is already flourishing in 36 states, raising grave concerns to the immunologically naive populace of the United States [14] .\n\nAccordingly, this review elaborately details the epidemiology and global expansion of CHIKV, describes its clinical features and pathogenesis and its symptoms and complications, and finally nominates a possible vaccine approach against CHIKV infection.", "CHIKV has been isolated into three genotypes based on phylogenetic studies. These genotypes, based on the gene sequences of an Envelope protein (E1), are Asian, East/Central/ South African, and West African [4, 11, 15] . Using phylogenetic models, Cherian et al. estimate that the Asian genotype of CHIKV emerged between 50 and 310 y ago, and the West and East African genotypes diverged between 100 and 840 y ago [15] . Since then, CHIKV has come a long way, with several mutations incorporated, and has continued to wreak epidemics in several regions. Recent activities of CHIKV include the Indian epidemic in 2005-2006, which was followed by a sudden explosion of cases in 2007. An estimated 1.3 million people across 13 states were reported to be infected in India [12, 16] , and CHIKV was also widespread in Malaysia, Sri Lanka, and Indonesia [17] . In July-August of 2007, CHIKV was reported in Italy, probably brought in by travelers from CHIKV-prone regions of India, Africa, and Indian", "Ocean islands such as Mauritius, Madagascar, and Seychelles. Few of the Italian isolates were found to have evolved from the Kerala isolate, which was associated with a A226V shift in E1 gene that represents a successful evolutionary adaptation in the mosquito vector similar to the ones observed in Reunion Island [2, 18, 19] .", "In recent times, with an increase in global travel, the risk for spreading CHIKV to non-endemic regions has heightened [1] . Several travelers have brought CHIKV home with them after visiting areas with actively infected populations [12, 20] . Such cases have been documented in European countries, Australia, Asia, and the United States [8, 21] . The United States has already reported at least twelve cases of travel-associated CHIKV, while France has reported 850 cases, and the United Kingdom 93 [8, 14] . Beyond this, CHIKV-infected travelers have also been diagnosed in Australia, Belgium, Canada, Czech Republic, French Guiana, Germany, Hong Kong, Italy, Japan, Kenya, Malaysia, Martinique, Norway, Switzerland, and Sri Lanka [21] . Some travelers were viremic, worrying public health officials about the spread of CHIKV to new areas [1, 8] .", "The incubation time for CHIKV is relatively short, requiring only 2-6 d with symptoms usually appearing 4-7 d post-infection [22] . Vazeille et al. detected CHIKV in the salivary glands of Ae. albopictus only 2 d after infection [5] . Upon infection, CHIKF tends to present itself in two phases. The first stage is acute, while the second stage, experienced by most but not all, is persistent, causing disabling polyarthritis. Characteristics of the acute phase include an abrupt onset of fever, arthralgia, and in some cases, maculopapular rash [6, 23] . The acute phase causes such intense joint and muscular pain that makes movement very difficult and prostrates its victims [6, 20] .", "Ninety-five percent of infected adults are symptomatic after infection, and of these, most become disabled for weeks to months as a result of decreased dexterity, loss of mobility, and delayed reaction. Eighteen months after disease onset, 40% of patients are found to still have anti-CHIKV IgM [6, 18, 23, 24] . The chronic stage of CHIKF is characterized by polyarthralgia that can last from weeks to years beyond the acute stage [6] . CHIKV has been shown to attack fibroblasts, explaining the involvement of muscles, joints, and skin connective tissues. The high number of nociceptive nerve endings found within the joints and muscle connective tissues can explain pain associated with CHIKF [25, 26] .", "More than 50% of patients who suffer from severe CHIKF are over 65 y old, and more than 33% of them die. Most adults who suffer from severe CHIKF have underlying medical conditions [6, 24, 27] . The other group that is disproportionately affected by severe CHIKV is children. Other complications associated with CHIKV, from most common to least common, include respiratory failure, cardiovascular decompensation, meningoencephalitis, severe acute hepatitis, severe cutaneous effects, other central nervous system problems, and kidney failure [6, 18, 20, 23, 24, 26, 27] .", "CHIKV undertakes a complex replication cycle upon host infection (Figure 2 ), which makes its genome susceptible to mutations [28, 29] . For instance, Ae. aegypti, responsible for epidemics in Kenya, Comoros, and Seychelles, carried CHIKV with an alanine in the 226 position of the E1 gene (E1-A226) [4, 18] . However, when the virus struck La Reunion Islands, a decline in population of Ae. aegypti, due to massive dichlorodiphenyltrichloroethane usage and dearth of Ae. albopictus species' www.plosntds.org population, resulted in an ecological pressure, favoring replacement of alanine at position 226 with valine (E1-A226V) [5] . This mutation allowed CHIKV's secondary vector species, Ae. albopictus, to supplement Ae. aegypti as its primary vector [5] .", "Within a year, the E1-A226V mutation was present in La Reunion Island, and Ae. albopictus apparently vectored the large epidemic infecting 34% of La Reunion Island's population [5] . All of the CHIKV strains isolated from Mayotte carried the E1-A226V mutation, and the mutation was also found in Madagascar in 2007 [5] . The E1-A226V mutation was not present at the beginning of the Indian Ocean Islands outbreak (before September 2005). However, more than 90% of later viral strains found there had incorporated the mutation (December-March 2006), indicating a genotype switch during the winter season [5, 18, 20] .", "The E1-A226V mutation also enabled an increase in infectivity of Ae. albopictus when compared to its infectivity of Ae. aegypti [4, 11, 18, 30] , and with several factors taken together, Ae. albopictus has become the new preferred and more lethal vector for CHIKV [4, 5, 11] . In fact, Tsetsarkin et al. found that a Green Fluorescent Protein tagged E1-A226V virus was 100 times more infective to Ae. albopictus than it was to Ae. aegypti [4] . In all the Indian Ocean Islands, Ae. albopictus became the main vector for CHIKV within 1-2 y after CHIKV was introduced to the region [31] .", "Of note is that Ae. aegypti has most likely been established in North America for over 300 y, while Ae. albopictus has been in many areas of the US, since 1985, primarily in Florida [32] and since then has expanded its range in the country. Reiskind et al. set out to determine if Ae. aegypti and Ae. albopictus mosquitoes captured in Florida were susceptible to CHIKV infection by a La Reunion isolate [32] . Each mosquito tested was highly susceptible to infection by a full-length infectious clone of the La Réunion Island isolate, CHIKV LR2006 OPY1 strain. Even though the Ae. albopictus strains were more susceptible to infection, overall ecology and differences in human biting patterns need to be studied further Characteristically, there are two rounds of translation: (+) sense genomic RNA (49S9 = 11.7 kb) acts directly as mRNA and is partially translated (59 end) to produce non-structural proteins (nsp's). These proteins are responsible for replication and formation of a complementary", "(2) strand, the template for further (+) strand synthesis. Subgenomic mRNA (26 S = 4.1 kb) replication occurs through the synthesis of full-length (2) intermediate RNA, which is regulated by nsp4 and p123 precursor in early infection and later by mature nsp's. Translation of the newly synthesized sub-genomic RNA results in production of structural proteins such as Capsid and protein E2-6k-E1 (from 39 end of genome). Assembly occurs at the cell surface, and the envelope is acquired as the virus buds from the cell and release and maturation almost simultaneous occurred. Replication occurs in the cytoplasm and is very rapid (,4 h) [28, 29] . doi:10.1371/journal.pntd.0000623.g002 www.plosntds.org to gain a more accurate understanding of a potential CHIKV epidemic in the US [32] .", "During the 7 d preceding birth, no human mother has been reported to transmit the disease vertically. However, about 50% of newborns delivered while the mother was infected with CHIKV contracted the disease from their mother, despite the method of delivery. Furthermore, there have been instances of CHIKV transmission from mother to fetus causing congenital illness and fetal death [33] .", "During the 2005-2006 La Reunion Island outbreaks, Ramful et al. discovered that mothers could transmit CHIKV to their progeny during the perinatal period (Day 24 to Day +1) [33, 34] , and it is associated with a high degree of morbidity. By mean Day 4 of life, all of the neonates were symptomatic for CHIKV, exhibiting common CHIKF symptoms. Six neonates were confirmed to have contracted CHIKV and developed mengoencephalitis. Of those mothers who, during the La Reunion Island epidemic, were infected long before delivery, only three fetal deaths were reported [12, 33] . Ramful et al. theorized that motherto-child transmission most likely happens transplacentally shortly before delivery [33] . A similar study by Gerardin et al. reported nineteen cases of neonatal infection associated with intrapartum maternal viremia that progressed to develop encephalitis owing to vertical transmission from infected mothers [34] .", "Clinical and epidemiological similarities with dengue fever make CHIKV diagnosis difficult, which may lead physicians to misdiagnose CHIKV as dengue fever; therefore, the incidence of CHIKV may actually be higher than currently believed (Table 1 ) [6, 12, 35] .", "The amount of time elapsed since disease onset is the most critical parameter when choosing a diagnostic test. CHIKV can be detected and isolated by culturing with mosquito cells (C6/36), Vero cells (mammalian), or in mice [26] . However, this method can take at least a week and only achieves a high sensitivity during the viremic phase, which usually only lasts up to 48 h after the bite. Five days post-infection, the viral isolation approach has a low sensitivity but is still the preferred method for detecting the CHIKV strain [12, 26, 31, 35] . RT-PCR on the other hand is a faster and more sensitive method that can be used within the first week of disease onset [26] , and it is currently the most sensitive method for detecting and quantifying viral mRNA [4, 36] .", "Classic serological detection, by assays such as ELISA [37] , immunofluorescence [5, 38] , complement binding, and haemagglutination inhibition [39] , constitutes the second diagnostic tool used for biological diagnosis of CHIKV infection. These proven techniques are useful for detection of Antigen in mosquitoes during epidemiological studies. These assays detect virus-specific IgM and IgG, however the sensitivity and specificity of these assays has been poorly characterized. Viral competence, or the potential of viral infection and transmission, is an important parameter that can be quantified by ELISA, viral culture, and PCR.", "A study by Ng et al. showed biomarkers indicative of severe CHIKV infection [40] . They found decreased levels of RANTES and increased levels of Interleukin-6 (IL-6) and Interleukin-1b (IL-1b) that could be sued for CHIKV detection in patients as indicators of CHIKV-driven cytokine storm. Couderc et al. demonstrate another cytokine, type-I IFN, as a key player in the progression to CHIKV infection [26] . Using an IFN-a/b null mouse model, they demonstrated evidence of muscles, joints, and skin as privileged CHIKV targets, which is consistent with human pathology. Although Ng et al. concluded that RANTES levels were significantly suppressed in severe CHIKF patients [40] , interestingly, an increase in levels of RANTES has been observed in dengue infection [41] . Since the symptoms of CHIKF mimic those of dengue fever, results obtained from this study strongly suggest that RANTES could be a potential distinctive biomarker that differentiates between these two clinically similar", "diseases.", "There are no approved antiviral treatments currently available for CHIKV [1, 3, 12, 42] . Currently, CHIKF is treated symptomatically, usually with non-steroidal anti-inflammatory drugs or steroids, bed rest, and fluids. Movement and mild exercise are thought to decrease stiffness and morning arthralgia, but heavy exercise may exacerbate rheumatic symptoms. Corticosteroids may be used in cases of debilitating chronic CHIKV infection. There is a debate about the appropriateness of chloroquine as treatment for unresolved, non-steroidal anti-inflammatory drugresistant arthritis [43] . A study showed that viral production was www.plosntds.org drastically reduced at 16 h post-infection after treatment with 100 mM dec-RVKR-cmk (Decanoyl-Arg-Val-Lys-Arg-chloromethylketone), a furine inhibitor [42, 44] . Chloroquine acted by raising the pH, blocking low pH-dependent entry of virus into the cell. It is important to note that dec-RVKR-cmk or chloroquine only inhibited viral spreading from cell", "to cell, not CHIKV replication once it had entered the cell [43] . However, most would agree that the best weapon against CHIKV is prevention. A live CHIKV vaccine developed by the United States reached phase II clinical trial encompassing 59 healthy volunteers [45] . Eight percent of the volunteers experienced transient arthralgia, while 98% of the volunteers had seroconversion [45] . However, live CHIKV vaccines are still questionable. One cannot discount the risk of a live vaccine possibly inducing chronic rheumatism. Also, there is the question as to whether widespread use among the public could trigger mosquito transmission or lead to chronic infection or viral reversion [1] .", "An alternative approach would be to produce a chimeric vaccine against CHIKV. Wang et al. developed a chimeric alphavirus vaccine that is uniformly attenuated and does not cause reactogenicity in mice [3] . Three different versions of this vaccine were made using three different backbone vectors: Venezuelan equine encephalitis virus (VEEV) attenuated vaccine strain T-83, naturally attenuated eastern equine encephalitis virus (EEEV), and attenuated Sindbis virus (SINV). In short, CHIKV structural proteins were engineered into the backbones of the aforementioned vaccines to produce the chimeras [3] . These chimeras were found to stimulate a strong humoral immunity, and even at doses of 5.3-5.8 log 10 PFU, they did not trigger reactogenicity. When vaccinated mice were challenged with CHIKV, neither adult nor neonatal mice gained weight, had fever, or displayed signs of neurological illness. Upon comparison of the chimeras with the Army181/25 vaccine, the Army vaccine resulted in higher", "levels of viremia and replication in the joints of neonatal mice. Because the joints are known targets of CHIKV, Wang et al. noted their vaccine might avoid the negative reactogenic side effects of the Army vaccine. After being subcutaneously vaccinated with 5.3-5.8 log 10 PFU of the chimeric vaccines, mice produced strong neutralizing antibody titers. The VEEV and EEEV chimeras yielded higher neutralizing antibody titers than the SINV chimera without being more virulent. On top of this, the VEEV and EEEV CHIKV chimeras seemed to be more immunogenic than the Army vaccine despite the chimeras' lower viremia and replication in the joints of neonatal mice [3] .", "Tiwari et al. [46] adopted a different strategy using formalin inactivated CHIKV in combination with alhydrogel (Aluminum Hydroxide) as an adjuvant. This study clearly suggests that this vaccine elicits both humoral and cell-mediated immune responses in mice, providing its immunogenic potential. A recent study by Couderc et al. [47] showed passive immunization as a potential treatment for CHIKV infection. Using purified immunoglobulin extracted from convalescent CHIKV patients, they demonstrated effective neutralizing activity against CHIKV infection both in vitro and in vivo. This thereby establishes a potential preventive and therapeutic approach to combat CHIKV infection. Pathogenesis studies conducted with related alpha virus, like RRV, have shown the role of macrophages in persistence on infection [48] . They also demonstrated the role of RRV-specific CD8 T cells in clearing viral load in infected patients, thereby warranting similar investigations with CHIKV and the importance", "of investigating a cell-mediated immune response-based vaccine against CHIKV [49] .", "There are always certain risks associated with live attenuated or inactivated viral vaccines [50] . One way to avoid these potential problems is to construct a consensus-based DNA vaccine. DNA based vaccines have an improved safety profile as compared to live or attenuated vaccines [51, 52] . A consequence of CHIKV's rapid evolution is difficulty in constructing a vaccine that will be able to Figure 3 . Levels of CHIKV-specific IgG in mice immunized with CHIKV vaccines. Each group of C57BL/6 mice (n = 5) was immunized with 12.5 mg of pVax1 control vector or CHIKV vaccine plasmids as indicated at 0 and 2 wk. Mice were bled 2 wk after each immunization, and each group's serum pool was diluted to 1:100 and 1:500 for reaction with specific vaccine constructs. Serum was incubated for 1 h at 37uC on 96-well plates coated with 2 mg/ml of respective CHIKV peptides, and antibody was detected using anti-mouse IgG-HRP and OD was measured at 405 nm. doi:10.1371/journal.pntd.0000623.g003", "www.plosntds.org effectively protect large populations from multiple strains of the virus. One of the strengths of DNA consensus vaccines is its ability to induce cross-reactive immune responses against the three distinct phylogenetic groups of CHIKV. Also DNA-based vaccines can be produced more rapidly than protein-based vaccines.", "Recently, Muthumani et al. constructed a vaccine that was shown to induce both humoral and cellular immunity in vivo in 3-4-wk-old female C57/BL6 mice [49] . These mice were immunized using an in vivo electroporation method to deliver the vaccine into the quadriceps muscle. The consensus construct was designed against E1, E2, and the core protein capsid. To design the construct, they aligned 21 sequences of CHIKV isolated between 1952 and 2006, using strains from differing countries, including La Reunion Island. The most common nucleotide among the sequences was chosen at each position to be used in the consensus construct, taking care not to alter the reading frame. They conducted codon and RNA optimization, added a strong Kozak sequence, and substituted signal peptide with an immunoglobulin E leader sequence to improve vaccine efficacy.", "After immunizing the mice, spleens were harvested along with serum and tested to determine antibody titer. After three immunizations, consensus E1, E2, and C vaccines were shown to induce T-cell immune responses leading to strong IFN-c responses and proliferation in C57/BL6 mice. Furthermore, when compared with control mice, immunized mice had higher total IgG levels as well as higher anti-E1 specific, anti-E2 specific, and anti-C specific IgG antibodies, suggesting a strong humoral immune response ( Figure 3 ) and also specificity for the antigens encoded in the vaccine constructs ( Figure 4 ). Because of its promising results and the need for a safer vaccine, this consensus DNA vaccine deserves further investigation. Determining longevity of protective effects of the vaccine and persistence of antibody and IFN-c responses could be the next step of investigation. Challenged studies of immunized mice must also be carried out.", "CHIKV mosquito-borne disease has caused massive outbreaks for at least half a century but is no longer confined to the www.plosntds.org developing nations. It began to encroach into the boundaries of the developing world. As a result, the NIAID has designated CHIKV as a Category C pathogen alongside the influenza and SARS-CoV viruses [3] . Realization of the potential severity of this disease is exigent; for instance, if used as a biological weapon, the world economy could be severely crippled; if enough members of the armed forces were to become infected during a military deployment, military operations could be significantly affected. Efforts to monitor the disease will only provide minimal warning in a global society, and steps to prevent the morbidity and mortality associated with pandemic are imperative [21, 31] . Despite the gravity of its infectious potency and the fear of it being a potential biological weapon, there is currently no vaccine for CHIKV infections. Live", "attenuated vaccine trials were carried out in 2000, but funding for the project was discontinued. Newer approaches such as DNA vaccines appear promising over conventional strategies like live attenuated or inactivated virus and thus call for further investigation. Recent advances such electroporation delivery and incorporation of adjuvants has boosted DNA vaccine efficacy [51, 53] . Despite the low antibody response to DNA vaccines, other numerous advantages have overshadowed these minor drawbacks (Table 2) , the most important one being the ability to induce both humoral and cellular immune responses [51, 54] .", "Judging by recent success, such as the immunogenic construct developed by Muthumani et al., DNA vaccines could play a major role in combating CHIKV [49] . Vaccines are literally a critical component of CHIKV disease control and therefore research in this area is highly encouraged. The dramatic spread of dengue viruses (DENV) throughout tropical America since 1980 via the same vectors and human hosts underscores the risk to public health in the Americas. The adverse events associated with the current live vaccine are well documented [55] . Realizing these drawbacks, earnest efforts should be taken to develop new strategies to forestall further spread and complications." ]	[ 2 ]	3,829	5,688
1,689	What does Chikungunya mean in Swahili?	2,480	[ "the illness of the bended walker" ]	[ "Chikungunya: A Potentially Emerging Epidemic?\n\nhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC2860491/\n\nSHA: f7c3160bef4169d29e2a8bdd79dd6e9056d4774c\n\nAuthors: Thiboutot, Michelle M.; Kannan, Senthil; Kawalekar, Omkar U.; Shedlock, Devon J.; Khan, Amir S.; Sarangan, Gopalsamy; Srikanth, Padma; Weiner, David B.; Muthumani, Karuppiah\nDate: 2010-04-27\nDOI: 10.1371/journal.pntd.0000623\nLicense: cc-by", "Abstract: Chikungunya virus is a mosquito-borne emerging pathogen that has a major health impact in humans and causes fever disease, headache, rash, nausea, vomiting, myalgia, and arthralgia. Indigenous to tropical Africa, recent large outbreaks have been reported in parts of South East Asia and several of its neighboring islands in 2005–07 and in Europe in 2007. Furthermore, positive cases have been confirmed in the United States in travelers returning from known outbreak areas. Currently, there is no vaccine or antiviral treatment. With the threat of an emerging global pandemic, the peculiar problems associated with the more immediate and seasonal epidemics warrant the development of an effective vaccine. In this review, we summarize the evidence supporting these concepts.", "Text: Chikungunya virus (CHIKV), a mosquito-borne pathogen listed by National Institute of Allergy and Infectious Diseases (NIAID) as a Category C Priority Pathogen that causes Chikungunya fever (CHIKF), has been spreading throughout Asia, Africa, and parts of Europe in recent times [1, 2, 3] . CHIKV is an arthropod-borne virus (arbovirus) and is transmitted to humans primarily by Aedes aegypti, the infamous yellow fever propagator [4, 5] . CHIKV infection is marked by severe joint pain, contorting its victims into unusual postures [6] . The disease gets its name from the Kimakonde vernacular language of Tanzania and Mozambique, and the word chikungunya means ''that which contorts or bends up'' and translates in Swahili to ''the illness of the bended walker'' [7, 8, 9] . In Africa, CHIKV is maintained in a sylvatic cycle among forest-dwelling Aedes spp. mosquitoes, wild primates, squirrels, birds, and rodents ( Figure 1 ) [10] . In Asia, the disease is vectored by Ae. aegypti and Ae.", "albopictus [11] . Transmission in Asia occurs in an urban cycle whereby the mosquito spreads the disease from an infected human to an uninfected human, following an epidemiological pattern similar to dengue fever [12] .", "The 2005-2006 epidemic of CHIKV in La Reunion islands in the Indian Ocean, spurred the discovery of a new vector species, Ae. albopictus [5] . Wrecking over one-third of the island's population, this epidemic peaked its devastation between January and February 2006, when over 46,000 cases came into light every week, including 284 deaths [5, 13] . Ae. albopictus is common in urban areas of the United States and is already flourishing in 36 states, raising grave concerns to the immunologically naive populace of the United States [14] .\n\nAccordingly, this review elaborately details the epidemiology and global expansion of CHIKV, describes its clinical features and pathogenesis and its symptoms and complications, and finally nominates a possible vaccine approach against CHIKV infection.", "CHIKV has been isolated into three genotypes based on phylogenetic studies. These genotypes, based on the gene sequences of an Envelope protein (E1), are Asian, East/Central/ South African, and West African [4, 11, 15] . Using phylogenetic models, Cherian et al. estimate that the Asian genotype of CHIKV emerged between 50 and 310 y ago, and the West and East African genotypes diverged between 100 and 840 y ago [15] . Since then, CHIKV has come a long way, with several mutations incorporated, and has continued to wreak epidemics in several regions. Recent activities of CHIKV include the Indian epidemic in 2005-2006, which was followed by a sudden explosion of cases in 2007. An estimated 1.3 million people across 13 states were reported to be infected in India [12, 16] , and CHIKV was also widespread in Malaysia, Sri Lanka, and Indonesia [17] . In July-August of 2007, CHIKV was reported in Italy, probably brought in by travelers from CHIKV-prone regions of India, Africa, and Indian", "Ocean islands such as Mauritius, Madagascar, and Seychelles. Few of the Italian isolates were found to have evolved from the Kerala isolate, which was associated with a A226V shift in E1 gene that represents a successful evolutionary adaptation in the mosquito vector similar to the ones observed in Reunion Island [2, 18, 19] .", "In recent times, with an increase in global travel, the risk for spreading CHIKV to non-endemic regions has heightened [1] . Several travelers have brought CHIKV home with them after visiting areas with actively infected populations [12, 20] . Such cases have been documented in European countries, Australia, Asia, and the United States [8, 21] . The United States has already reported at least twelve cases of travel-associated CHIKV, while France has reported 850 cases, and the United Kingdom 93 [8, 14] . Beyond this, CHIKV-infected travelers have also been diagnosed in Australia, Belgium, Canada, Czech Republic, French Guiana, Germany, Hong Kong, Italy, Japan, Kenya, Malaysia, Martinique, Norway, Switzerland, and Sri Lanka [21] . Some travelers were viremic, worrying public health officials about the spread of CHIKV to new areas [1, 8] .", "The incubation time for CHIKV is relatively short, requiring only 2-6 d with symptoms usually appearing 4-7 d post-infection [22] . Vazeille et al. detected CHIKV in the salivary glands of Ae. albopictus only 2 d after infection [5] . Upon infection, CHIKF tends to present itself in two phases. The first stage is acute, while the second stage, experienced by most but not all, is persistent, causing disabling polyarthritis. Characteristics of the acute phase include an abrupt onset of fever, arthralgia, and in some cases, maculopapular rash [6, 23] . The acute phase causes such intense joint and muscular pain that makes movement very difficult and prostrates its victims [6, 20] .", "Ninety-five percent of infected adults are symptomatic after infection, and of these, most become disabled for weeks to months as a result of decreased dexterity, loss of mobility, and delayed reaction. Eighteen months after disease onset, 40% of patients are found to still have anti-CHIKV IgM [6, 18, 23, 24] . The chronic stage of CHIKF is characterized by polyarthralgia that can last from weeks to years beyond the acute stage [6] . CHIKV has been shown to attack fibroblasts, explaining the involvement of muscles, joints, and skin connective tissues. The high number of nociceptive nerve endings found within the joints and muscle connective tissues can explain pain associated with CHIKF [25, 26] .", "More than 50% of patients who suffer from severe CHIKF are over 65 y old, and more than 33% of them die. Most adults who suffer from severe CHIKF have underlying medical conditions [6, 24, 27] . The other group that is disproportionately affected by severe CHIKV is children. Other complications associated with CHIKV, from most common to least common, include respiratory failure, cardiovascular decompensation, meningoencephalitis, severe acute hepatitis, severe cutaneous effects, other central nervous system problems, and kidney failure [6, 18, 20, 23, 24, 26, 27] .", "CHIKV undertakes a complex replication cycle upon host infection (Figure 2 ), which makes its genome susceptible to mutations [28, 29] . For instance, Ae. aegypti, responsible for epidemics in Kenya, Comoros, and Seychelles, carried CHIKV with an alanine in the 226 position of the E1 gene (E1-A226) [4, 18] . However, when the virus struck La Reunion Islands, a decline in population of Ae. aegypti, due to massive dichlorodiphenyltrichloroethane usage and dearth of Ae. albopictus species' www.plosntds.org population, resulted in an ecological pressure, favoring replacement of alanine at position 226 with valine (E1-A226V) [5] . This mutation allowed CHIKV's secondary vector species, Ae. albopictus, to supplement Ae. aegypti as its primary vector [5] .", "Within a year, the E1-A226V mutation was present in La Reunion Island, and Ae. albopictus apparently vectored the large epidemic infecting 34% of La Reunion Island's population [5] . All of the CHIKV strains isolated from Mayotte carried the E1-A226V mutation, and the mutation was also found in Madagascar in 2007 [5] . The E1-A226V mutation was not present at the beginning of the Indian Ocean Islands outbreak (before September 2005). However, more than 90% of later viral strains found there had incorporated the mutation (December-March 2006), indicating a genotype switch during the winter season [5, 18, 20] .", "The E1-A226V mutation also enabled an increase in infectivity of Ae. albopictus when compared to its infectivity of Ae. aegypti [4, 11, 18, 30] , and with several factors taken together, Ae. albopictus has become the new preferred and more lethal vector for CHIKV [4, 5, 11] . In fact, Tsetsarkin et al. found that a Green Fluorescent Protein tagged E1-A226V virus was 100 times more infective to Ae. albopictus than it was to Ae. aegypti [4] . In all the Indian Ocean Islands, Ae. albopictus became the main vector for CHIKV within 1-2 y after CHIKV was introduced to the region [31] .", "Of note is that Ae. aegypti has most likely been established in North America for over 300 y, while Ae. albopictus has been in many areas of the US, since 1985, primarily in Florida [32] and since then has expanded its range in the country. Reiskind et al. set out to determine if Ae. aegypti and Ae. albopictus mosquitoes captured in Florida were susceptible to CHIKV infection by a La Reunion isolate [32] . Each mosquito tested was highly susceptible to infection by a full-length infectious clone of the La Réunion Island isolate, CHIKV LR2006 OPY1 strain. Even though the Ae. albopictus strains were more susceptible to infection, overall ecology and differences in human biting patterns need to be studied further Characteristically, there are two rounds of translation: (+) sense genomic RNA (49S9 = 11.7 kb) acts directly as mRNA and is partially translated (59 end) to produce non-structural proteins (nsp's). These proteins are responsible for replication and formation of a complementary", "(2) strand, the template for further (+) strand synthesis. Subgenomic mRNA (26 S = 4.1 kb) replication occurs through the synthesis of full-length (2) intermediate RNA, which is regulated by nsp4 and p123 precursor in early infection and later by mature nsp's. Translation of the newly synthesized sub-genomic RNA results in production of structural proteins such as Capsid and protein E2-6k-E1 (from 39 end of genome). Assembly occurs at the cell surface, and the envelope is acquired as the virus buds from the cell and release and maturation almost simultaneous occurred. Replication occurs in the cytoplasm and is very rapid (,4 h) [28, 29] . doi:10.1371/journal.pntd.0000623.g002 www.plosntds.org to gain a more accurate understanding of a potential CHIKV epidemic in the US [32] .", "During the 7 d preceding birth, no human mother has been reported to transmit the disease vertically. However, about 50% of newborns delivered while the mother was infected with CHIKV contracted the disease from their mother, despite the method of delivery. Furthermore, there have been instances of CHIKV transmission from mother to fetus causing congenital illness and fetal death [33] .", "During the 2005-2006 La Reunion Island outbreaks, Ramful et al. discovered that mothers could transmit CHIKV to their progeny during the perinatal period (Day 24 to Day +1) [33, 34] , and it is associated with a high degree of morbidity. By mean Day 4 of life, all of the neonates were symptomatic for CHIKV, exhibiting common CHIKF symptoms. Six neonates were confirmed to have contracted CHIKV and developed mengoencephalitis. Of those mothers who, during the La Reunion Island epidemic, were infected long before delivery, only three fetal deaths were reported [12, 33] . Ramful et al. theorized that motherto-child transmission most likely happens transplacentally shortly before delivery [33] . A similar study by Gerardin et al. reported nineteen cases of neonatal infection associated with intrapartum maternal viremia that progressed to develop encephalitis owing to vertical transmission from infected mothers [34] .", "Clinical and epidemiological similarities with dengue fever make CHIKV diagnosis difficult, which may lead physicians to misdiagnose CHIKV as dengue fever; therefore, the incidence of CHIKV may actually be higher than currently believed (Table 1 ) [6, 12, 35] .", "The amount of time elapsed since disease onset is the most critical parameter when choosing a diagnostic test. CHIKV can be detected and isolated by culturing with mosquito cells (C6/36), Vero cells (mammalian), or in mice [26] . However, this method can take at least a week and only achieves a high sensitivity during the viremic phase, which usually only lasts up to 48 h after the bite. Five days post-infection, the viral isolation approach has a low sensitivity but is still the preferred method for detecting the CHIKV strain [12, 26, 31, 35] . RT-PCR on the other hand is a faster and more sensitive method that can be used within the first week of disease onset [26] , and it is currently the most sensitive method for detecting and quantifying viral mRNA [4, 36] .", "Classic serological detection, by assays such as ELISA [37] , immunofluorescence [5, 38] , complement binding, and haemagglutination inhibition [39] , constitutes the second diagnostic tool used for biological diagnosis of CHIKV infection. These proven techniques are useful for detection of Antigen in mosquitoes during epidemiological studies. These assays detect virus-specific IgM and IgG, however the sensitivity and specificity of these assays has been poorly characterized. Viral competence, or the potential of viral infection and transmission, is an important parameter that can be quantified by ELISA, viral culture, and PCR.", "A study by Ng et al. showed biomarkers indicative of severe CHIKV infection [40] . They found decreased levels of RANTES and increased levels of Interleukin-6 (IL-6) and Interleukin-1b (IL-1b) that could be sued for CHIKV detection in patients as indicators of CHIKV-driven cytokine storm. Couderc et al. demonstrate another cytokine, type-I IFN, as a key player in the progression to CHIKV infection [26] . Using an IFN-a/b null mouse model, they demonstrated evidence of muscles, joints, and skin as privileged CHIKV targets, which is consistent with human pathology. Although Ng et al. concluded that RANTES levels were significantly suppressed in severe CHIKF patients [40] , interestingly, an increase in levels of RANTES has been observed in dengue infection [41] . Since the symptoms of CHIKF mimic those of dengue fever, results obtained from this study strongly suggest that RANTES could be a potential distinctive biomarker that differentiates between these two clinically similar", "diseases.", "There are no approved antiviral treatments currently available for CHIKV [1, 3, 12, 42] . Currently, CHIKF is treated symptomatically, usually with non-steroidal anti-inflammatory drugs or steroids, bed rest, and fluids. Movement and mild exercise are thought to decrease stiffness and morning arthralgia, but heavy exercise may exacerbate rheumatic symptoms. Corticosteroids may be used in cases of debilitating chronic CHIKV infection. There is a debate about the appropriateness of chloroquine as treatment for unresolved, non-steroidal anti-inflammatory drugresistant arthritis [43] . A study showed that viral production was www.plosntds.org drastically reduced at 16 h post-infection after treatment with 100 mM dec-RVKR-cmk (Decanoyl-Arg-Val-Lys-Arg-chloromethylketone), a furine inhibitor [42, 44] . Chloroquine acted by raising the pH, blocking low pH-dependent entry of virus into the cell. It is important to note that dec-RVKR-cmk or chloroquine only inhibited viral spreading from cell", "to cell, not CHIKV replication once it had entered the cell [43] . However, most would agree that the best weapon against CHIKV is prevention. A live CHIKV vaccine developed by the United States reached phase II clinical trial encompassing 59 healthy volunteers [45] . Eight percent of the volunteers experienced transient arthralgia, while 98% of the volunteers had seroconversion [45] . However, live CHIKV vaccines are still questionable. One cannot discount the risk of a live vaccine possibly inducing chronic rheumatism. Also, there is the question as to whether widespread use among the public could trigger mosquito transmission or lead to chronic infection or viral reversion [1] .", "An alternative approach would be to produce a chimeric vaccine against CHIKV. Wang et al. developed a chimeric alphavirus vaccine that is uniformly attenuated and does not cause reactogenicity in mice [3] . Three different versions of this vaccine were made using three different backbone vectors: Venezuelan equine encephalitis virus (VEEV) attenuated vaccine strain T-83, naturally attenuated eastern equine encephalitis virus (EEEV), and attenuated Sindbis virus (SINV). In short, CHIKV structural proteins were engineered into the backbones of the aforementioned vaccines to produce the chimeras [3] . These chimeras were found to stimulate a strong humoral immunity, and even at doses of 5.3-5.8 log 10 PFU, they did not trigger reactogenicity. When vaccinated mice were challenged with CHIKV, neither adult nor neonatal mice gained weight, had fever, or displayed signs of neurological illness. Upon comparison of the chimeras with the Army181/25 vaccine, the Army vaccine resulted in higher", "levels of viremia and replication in the joints of neonatal mice. Because the joints are known targets of CHIKV, Wang et al. noted their vaccine might avoid the negative reactogenic side effects of the Army vaccine. After being subcutaneously vaccinated with 5.3-5.8 log 10 PFU of the chimeric vaccines, mice produced strong neutralizing antibody titers. The VEEV and EEEV chimeras yielded higher neutralizing antibody titers than the SINV chimera without being more virulent. On top of this, the VEEV and EEEV CHIKV chimeras seemed to be more immunogenic than the Army vaccine despite the chimeras' lower viremia and replication in the joints of neonatal mice [3] .", "Tiwari et al. [46] adopted a different strategy using formalin inactivated CHIKV in combination with alhydrogel (Aluminum Hydroxide) as an adjuvant. This study clearly suggests that this vaccine elicits both humoral and cell-mediated immune responses in mice, providing its immunogenic potential. A recent study by Couderc et al. [47] showed passive immunization as a potential treatment for CHIKV infection. Using purified immunoglobulin extracted from convalescent CHIKV patients, they demonstrated effective neutralizing activity against CHIKV infection both in vitro and in vivo. This thereby establishes a potential preventive and therapeutic approach to combat CHIKV infection. Pathogenesis studies conducted with related alpha virus, like RRV, have shown the role of macrophages in persistence on infection [48] . They also demonstrated the role of RRV-specific CD8 T cells in clearing viral load in infected patients, thereby warranting similar investigations with CHIKV and the importance", "of investigating a cell-mediated immune response-based vaccine against CHIKV [49] .", "There are always certain risks associated with live attenuated or inactivated viral vaccines [50] . One way to avoid these potential problems is to construct a consensus-based DNA vaccine. DNA based vaccines have an improved safety profile as compared to live or attenuated vaccines [51, 52] . A consequence of CHIKV's rapid evolution is difficulty in constructing a vaccine that will be able to Figure 3 . Levels of CHIKV-specific IgG in mice immunized with CHIKV vaccines. Each group of C57BL/6 mice (n = 5) was immunized with 12.5 mg of pVax1 control vector or CHIKV vaccine plasmids as indicated at 0 and 2 wk. Mice were bled 2 wk after each immunization, and each group's serum pool was diluted to 1:100 and 1:500 for reaction with specific vaccine constructs. Serum was incubated for 1 h at 37uC on 96-well plates coated with 2 mg/ml of respective CHIKV peptides, and antibody was detected using anti-mouse IgG-HRP and OD was measured at 405 nm. doi:10.1371/journal.pntd.0000623.g003", "www.plosntds.org effectively protect large populations from multiple strains of the virus. One of the strengths of DNA consensus vaccines is its ability to induce cross-reactive immune responses against the three distinct phylogenetic groups of CHIKV. Also DNA-based vaccines can be produced more rapidly than protein-based vaccines.", "Recently, Muthumani et al. constructed a vaccine that was shown to induce both humoral and cellular immunity in vivo in 3-4-wk-old female C57/BL6 mice [49] . These mice were immunized using an in vivo electroporation method to deliver the vaccine into the quadriceps muscle. The consensus construct was designed against E1, E2, and the core protein capsid. To design the construct, they aligned 21 sequences of CHIKV isolated between 1952 and 2006, using strains from differing countries, including La Reunion Island. The most common nucleotide among the sequences was chosen at each position to be used in the consensus construct, taking care not to alter the reading frame. They conducted codon and RNA optimization, added a strong Kozak sequence, and substituted signal peptide with an immunoglobulin E leader sequence to improve vaccine efficacy.", "After immunizing the mice, spleens were harvested along with serum and tested to determine antibody titer. After three immunizations, consensus E1, E2, and C vaccines were shown to induce T-cell immune responses leading to strong IFN-c responses and proliferation in C57/BL6 mice. Furthermore, when compared with control mice, immunized mice had higher total IgG levels as well as higher anti-E1 specific, anti-E2 specific, and anti-C specific IgG antibodies, suggesting a strong humoral immune response ( Figure 3 ) and also specificity for the antigens encoded in the vaccine constructs ( Figure 4 ). Because of its promising results and the need for a safer vaccine, this consensus DNA vaccine deserves further investigation. Determining longevity of protective effects of the vaccine and persistence of antibody and IFN-c responses could be the next step of investigation. Challenged studies of immunized mice must also be carried out.", "CHIKV mosquito-borne disease has caused massive outbreaks for at least half a century but is no longer confined to the www.plosntds.org developing nations. It began to encroach into the boundaries of the developing world. As a result, the NIAID has designated CHIKV as a Category C pathogen alongside the influenza and SARS-CoV viruses [3] . Realization of the potential severity of this disease is exigent; for instance, if used as a biological weapon, the world economy could be severely crippled; if enough members of the armed forces were to become infected during a military deployment, military operations could be significantly affected. Efforts to monitor the disease will only provide minimal warning in a global society, and steps to prevent the morbidity and mortality associated with pandemic are imperative [21, 31] . Despite the gravity of its infectious potency and the fear of it being a potential biological weapon, there is currently no vaccine for CHIKV infections. Live", "attenuated vaccine trials were carried out in 2000, but funding for the project was discontinued. Newer approaches such as DNA vaccines appear promising over conventional strategies like live attenuated or inactivated virus and thus call for further investigation. Recent advances such electroporation delivery and incorporation of adjuvants has boosted DNA vaccine efficacy [51, 53] . Despite the low antibody response to DNA vaccines, other numerous advantages have overshadowed these minor drawbacks (Table 2) , the most important one being the ability to induce both humoral and cellular immune responses [51, 54] .", "Judging by recent success, such as the immunogenic construct developed by Muthumani et al., DNA vaccines could play a major role in combating CHIKV [49] . Vaccines are literally a critical component of CHIKV disease control and therefore research in this area is highly encouraged. The dramatic spread of dengue viruses (DENV) throughout tropical America since 1980 via the same vectors and human hosts underscores the risk to public health in the Americas. The adverse events associated with the current live vaccine are well documented [55] . Realizing these drawbacks, earnest efforts should be taken to develop new strategies to forestall further spread and complications." ]	[ 2 ]	3,829	5,688
1,689	How is CHIKV maintained in Africa?	2,481	[ "in a sylvatic cycle among forest-dwelling Aedes spp. mosquitoes, wild primates, squirrels, birds, and rodents" ]	[ "Chikungunya: A Potentially Emerging Epidemic?\n\nhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC2860491/\n\nSHA: f7c3160bef4169d29e2a8bdd79dd6e9056d4774c\n\nAuthors: Thiboutot, Michelle M.; Kannan, Senthil; Kawalekar, Omkar U.; Shedlock, Devon J.; Khan, Amir S.; Sarangan, Gopalsamy; Srikanth, Padma; Weiner, David B.; Muthumani, Karuppiah\nDate: 2010-04-27\nDOI: 10.1371/journal.pntd.0000623\nLicense: cc-by", "Abstract: Chikungunya virus is a mosquito-borne emerging pathogen that has a major health impact in humans and causes fever disease, headache, rash, nausea, vomiting, myalgia, and arthralgia. Indigenous to tropical Africa, recent large outbreaks have been reported in parts of South East Asia and several of its neighboring islands in 2005–07 and in Europe in 2007. Furthermore, positive cases have been confirmed in the United States in travelers returning from known outbreak areas. Currently, there is no vaccine or antiviral treatment. With the threat of an emerging global pandemic, the peculiar problems associated with the more immediate and seasonal epidemics warrant the development of an effective vaccine. In this review, we summarize the evidence supporting these concepts.", "Text: Chikungunya virus (CHIKV), a mosquito-borne pathogen listed by National Institute of Allergy and Infectious Diseases (NIAID) as a Category C Priority Pathogen that causes Chikungunya fever (CHIKF), has been spreading throughout Asia, Africa, and parts of Europe in recent times [1, 2, 3] . CHIKV is an arthropod-borne virus (arbovirus) and is transmitted to humans primarily by Aedes aegypti, the infamous yellow fever propagator [4, 5] . CHIKV infection is marked by severe joint pain, contorting its victims into unusual postures [6] . The disease gets its name from the Kimakonde vernacular language of Tanzania and Mozambique, and the word chikungunya means ''that which contorts or bends up'' and translates in Swahili to ''the illness of the bended walker'' [7, 8, 9] . In Africa, CHIKV is maintained in a sylvatic cycle among forest-dwelling Aedes spp. mosquitoes, wild primates, squirrels, birds, and rodents ( Figure 1 ) [10] . In Asia, the disease is vectored by Ae. aegypti and Ae.", "albopictus [11] . Transmission in Asia occurs in an urban cycle whereby the mosquito spreads the disease from an infected human to an uninfected human, following an epidemiological pattern similar to dengue fever [12] .", "The 2005-2006 epidemic of CHIKV in La Reunion islands in the Indian Ocean, spurred the discovery of a new vector species, Ae. albopictus [5] . Wrecking over one-third of the island's population, this epidemic peaked its devastation between January and February 2006, when over 46,000 cases came into light every week, including 284 deaths [5, 13] . Ae. albopictus is common in urban areas of the United States and is already flourishing in 36 states, raising grave concerns to the immunologically naive populace of the United States [14] .\n\nAccordingly, this review elaborately details the epidemiology and global expansion of CHIKV, describes its clinical features and pathogenesis and its symptoms and complications, and finally nominates a possible vaccine approach against CHIKV infection.", "CHIKV has been isolated into three genotypes based on phylogenetic studies. These genotypes, based on the gene sequences of an Envelope protein (E1), are Asian, East/Central/ South African, and West African [4, 11, 15] . Using phylogenetic models, Cherian et al. estimate that the Asian genotype of CHIKV emerged between 50 and 310 y ago, and the West and East African genotypes diverged between 100 and 840 y ago [15] . Since then, CHIKV has come a long way, with several mutations incorporated, and has continued to wreak epidemics in several regions. Recent activities of CHIKV include the Indian epidemic in 2005-2006, which was followed by a sudden explosion of cases in 2007. An estimated 1.3 million people across 13 states were reported to be infected in India [12, 16] , and CHIKV was also widespread in Malaysia, Sri Lanka, and Indonesia [17] . In July-August of 2007, CHIKV was reported in Italy, probably brought in by travelers from CHIKV-prone regions of India, Africa, and Indian", "Ocean islands such as Mauritius, Madagascar, and Seychelles. Few of the Italian isolates were found to have evolved from the Kerala isolate, which was associated with a A226V shift in E1 gene that represents a successful evolutionary adaptation in the mosquito vector similar to the ones observed in Reunion Island [2, 18, 19] .", "In recent times, with an increase in global travel, the risk for spreading CHIKV to non-endemic regions has heightened [1] . Several travelers have brought CHIKV home with them after visiting areas with actively infected populations [12, 20] . Such cases have been documented in European countries, Australia, Asia, and the United States [8, 21] . The United States has already reported at least twelve cases of travel-associated CHIKV, while France has reported 850 cases, and the United Kingdom 93 [8, 14] . Beyond this, CHIKV-infected travelers have also been diagnosed in Australia, Belgium, Canada, Czech Republic, French Guiana, Germany, Hong Kong, Italy, Japan, Kenya, Malaysia, Martinique, Norway, Switzerland, and Sri Lanka [21] . Some travelers were viremic, worrying public health officials about the spread of CHIKV to new areas [1, 8] .", "The incubation time for CHIKV is relatively short, requiring only 2-6 d with symptoms usually appearing 4-7 d post-infection [22] . Vazeille et al. detected CHIKV in the salivary glands of Ae. albopictus only 2 d after infection [5] . Upon infection, CHIKF tends to present itself in two phases. The first stage is acute, while the second stage, experienced by most but not all, is persistent, causing disabling polyarthritis. Characteristics of the acute phase include an abrupt onset of fever, arthralgia, and in some cases, maculopapular rash [6, 23] . The acute phase causes such intense joint and muscular pain that makes movement very difficult and prostrates its victims [6, 20] .", "Ninety-five percent of infected adults are symptomatic after infection, and of these, most become disabled for weeks to months as a result of decreased dexterity, loss of mobility, and delayed reaction. Eighteen months after disease onset, 40% of patients are found to still have anti-CHIKV IgM [6, 18, 23, 24] . The chronic stage of CHIKF is characterized by polyarthralgia that can last from weeks to years beyond the acute stage [6] . CHIKV has been shown to attack fibroblasts, explaining the involvement of muscles, joints, and skin connective tissues. The high number of nociceptive nerve endings found within the joints and muscle connective tissues can explain pain associated with CHIKF [25, 26] .", "More than 50% of patients who suffer from severe CHIKF are over 65 y old, and more than 33% of them die. Most adults who suffer from severe CHIKF have underlying medical conditions [6, 24, 27] . The other group that is disproportionately affected by severe CHIKV is children. Other complications associated with CHIKV, from most common to least common, include respiratory failure, cardiovascular decompensation, meningoencephalitis, severe acute hepatitis, severe cutaneous effects, other central nervous system problems, and kidney failure [6, 18, 20, 23, 24, 26, 27] .", "CHIKV undertakes a complex replication cycle upon host infection (Figure 2 ), which makes its genome susceptible to mutations [28, 29] . For instance, Ae. aegypti, responsible for epidemics in Kenya, Comoros, and Seychelles, carried CHIKV with an alanine in the 226 position of the E1 gene (E1-A226) [4, 18] . However, when the virus struck La Reunion Islands, a decline in population of Ae. aegypti, due to massive dichlorodiphenyltrichloroethane usage and dearth of Ae. albopictus species' www.plosntds.org population, resulted in an ecological pressure, favoring replacement of alanine at position 226 with valine (E1-A226V) [5] . This mutation allowed CHIKV's secondary vector species, Ae. albopictus, to supplement Ae. aegypti as its primary vector [5] .", "Within a year, the E1-A226V mutation was present in La Reunion Island, and Ae. albopictus apparently vectored the large epidemic infecting 34% of La Reunion Island's population [5] . All of the CHIKV strains isolated from Mayotte carried the E1-A226V mutation, and the mutation was also found in Madagascar in 2007 [5] . The E1-A226V mutation was not present at the beginning of the Indian Ocean Islands outbreak (before September 2005). However, more than 90% of later viral strains found there had incorporated the mutation (December-March 2006), indicating a genotype switch during the winter season [5, 18, 20] .", "The E1-A226V mutation also enabled an increase in infectivity of Ae. albopictus when compared to its infectivity of Ae. aegypti [4, 11, 18, 30] , and with several factors taken together, Ae. albopictus has become the new preferred and more lethal vector for CHIKV [4, 5, 11] . In fact, Tsetsarkin et al. found that a Green Fluorescent Protein tagged E1-A226V virus was 100 times more infective to Ae. albopictus than it was to Ae. aegypti [4] . In all the Indian Ocean Islands, Ae. albopictus became the main vector for CHIKV within 1-2 y after CHIKV was introduced to the region [31] .", "Of note is that Ae. aegypti has most likely been established in North America for over 300 y, while Ae. albopictus has been in many areas of the US, since 1985, primarily in Florida [32] and since then has expanded its range in the country. Reiskind et al. set out to determine if Ae. aegypti and Ae. albopictus mosquitoes captured in Florida were susceptible to CHIKV infection by a La Reunion isolate [32] . Each mosquito tested was highly susceptible to infection by a full-length infectious clone of the La Réunion Island isolate, CHIKV LR2006 OPY1 strain. Even though the Ae. albopictus strains were more susceptible to infection, overall ecology and differences in human biting patterns need to be studied further Characteristically, there are two rounds of translation: (+) sense genomic RNA (49S9 = 11.7 kb) acts directly as mRNA and is partially translated (59 end) to produce non-structural proteins (nsp's). These proteins are responsible for replication and formation of a complementary", "(2) strand, the template for further (+) strand synthesis. Subgenomic mRNA (26 S = 4.1 kb) replication occurs through the synthesis of full-length (2) intermediate RNA, which is regulated by nsp4 and p123 precursor in early infection and later by mature nsp's. Translation of the newly synthesized sub-genomic RNA results in production of structural proteins such as Capsid and protein E2-6k-E1 (from 39 end of genome). Assembly occurs at the cell surface, and the envelope is acquired as the virus buds from the cell and release and maturation almost simultaneous occurred. Replication occurs in the cytoplasm and is very rapid (,4 h) [28, 29] . doi:10.1371/journal.pntd.0000623.g002 www.plosntds.org to gain a more accurate understanding of a potential CHIKV epidemic in the US [32] .", "During the 7 d preceding birth, no human mother has been reported to transmit the disease vertically. However, about 50% of newborns delivered while the mother was infected with CHIKV contracted the disease from their mother, despite the method of delivery. Furthermore, there have been instances of CHIKV transmission from mother to fetus causing congenital illness and fetal death [33] .", "During the 2005-2006 La Reunion Island outbreaks, Ramful et al. discovered that mothers could transmit CHIKV to their progeny during the perinatal period (Day 24 to Day +1) [33, 34] , and it is associated with a high degree of morbidity. By mean Day 4 of life, all of the neonates were symptomatic for CHIKV, exhibiting common CHIKF symptoms. Six neonates were confirmed to have contracted CHIKV and developed mengoencephalitis. Of those mothers who, during the La Reunion Island epidemic, were infected long before delivery, only three fetal deaths were reported [12, 33] . Ramful et al. theorized that motherto-child transmission most likely happens transplacentally shortly before delivery [33] . A similar study by Gerardin et al. reported nineteen cases of neonatal infection associated with intrapartum maternal viremia that progressed to develop encephalitis owing to vertical transmission from infected mothers [34] .", "Clinical and epidemiological similarities with dengue fever make CHIKV diagnosis difficult, which may lead physicians to misdiagnose CHIKV as dengue fever; therefore, the incidence of CHIKV may actually be higher than currently believed (Table 1 ) [6, 12, 35] .", "The amount of time elapsed since disease onset is the most critical parameter when choosing a diagnostic test. CHIKV can be detected and isolated by culturing with mosquito cells (C6/36), Vero cells (mammalian), or in mice [26] . However, this method can take at least a week and only achieves a high sensitivity during the viremic phase, which usually only lasts up to 48 h after the bite. Five days post-infection, the viral isolation approach has a low sensitivity but is still the preferred method for detecting the CHIKV strain [12, 26, 31, 35] . RT-PCR on the other hand is a faster and more sensitive method that can be used within the first week of disease onset [26] , and it is currently the most sensitive method for detecting and quantifying viral mRNA [4, 36] .", "Classic serological detection, by assays such as ELISA [37] , immunofluorescence [5, 38] , complement binding, and haemagglutination inhibition [39] , constitutes the second diagnostic tool used for biological diagnosis of CHIKV infection. These proven techniques are useful for detection of Antigen in mosquitoes during epidemiological studies. These assays detect virus-specific IgM and IgG, however the sensitivity and specificity of these assays has been poorly characterized. Viral competence, or the potential of viral infection and transmission, is an important parameter that can be quantified by ELISA, viral culture, and PCR.", "A study by Ng et al. showed biomarkers indicative of severe CHIKV infection [40] . They found decreased levels of RANTES and increased levels of Interleukin-6 (IL-6) and Interleukin-1b (IL-1b) that could be sued for CHIKV detection in patients as indicators of CHIKV-driven cytokine storm. Couderc et al. demonstrate another cytokine, type-I IFN, as a key player in the progression to CHIKV infection [26] . Using an IFN-a/b null mouse model, they demonstrated evidence of muscles, joints, and skin as privileged CHIKV targets, which is consistent with human pathology. Although Ng et al. concluded that RANTES levels were significantly suppressed in severe CHIKF patients [40] , interestingly, an increase in levels of RANTES has been observed in dengue infection [41] . Since the symptoms of CHIKF mimic those of dengue fever, results obtained from this study strongly suggest that RANTES could be a potential distinctive biomarker that differentiates between these two clinically similar", "diseases.", "There are no approved antiviral treatments currently available for CHIKV [1, 3, 12, 42] . Currently, CHIKF is treated symptomatically, usually with non-steroidal anti-inflammatory drugs or steroids, bed rest, and fluids. Movement and mild exercise are thought to decrease stiffness and morning arthralgia, but heavy exercise may exacerbate rheumatic symptoms. Corticosteroids may be used in cases of debilitating chronic CHIKV infection. There is a debate about the appropriateness of chloroquine as treatment for unresolved, non-steroidal anti-inflammatory drugresistant arthritis [43] . A study showed that viral production was www.plosntds.org drastically reduced at 16 h post-infection after treatment with 100 mM dec-RVKR-cmk (Decanoyl-Arg-Val-Lys-Arg-chloromethylketone), a furine inhibitor [42, 44] . Chloroquine acted by raising the pH, blocking low pH-dependent entry of virus into the cell. It is important to note that dec-RVKR-cmk or chloroquine only inhibited viral spreading from cell", "to cell, not CHIKV replication once it had entered the cell [43] . However, most would agree that the best weapon against CHIKV is prevention. A live CHIKV vaccine developed by the United States reached phase II clinical trial encompassing 59 healthy volunteers [45] . Eight percent of the volunteers experienced transient arthralgia, while 98% of the volunteers had seroconversion [45] . However, live CHIKV vaccines are still questionable. One cannot discount the risk of a live vaccine possibly inducing chronic rheumatism. Also, there is the question as to whether widespread use among the public could trigger mosquito transmission or lead to chronic infection or viral reversion [1] .", "An alternative approach would be to produce a chimeric vaccine against CHIKV. Wang et al. developed a chimeric alphavirus vaccine that is uniformly attenuated and does not cause reactogenicity in mice [3] . Three different versions of this vaccine were made using three different backbone vectors: Venezuelan equine encephalitis virus (VEEV) attenuated vaccine strain T-83, naturally attenuated eastern equine encephalitis virus (EEEV), and attenuated Sindbis virus (SINV). In short, CHIKV structural proteins were engineered into the backbones of the aforementioned vaccines to produce the chimeras [3] . These chimeras were found to stimulate a strong humoral immunity, and even at doses of 5.3-5.8 log 10 PFU, they did not trigger reactogenicity. When vaccinated mice were challenged with CHIKV, neither adult nor neonatal mice gained weight, had fever, or displayed signs of neurological illness. Upon comparison of the chimeras with the Army181/25 vaccine, the Army vaccine resulted in higher", "levels of viremia and replication in the joints of neonatal mice. Because the joints are known targets of CHIKV, Wang et al. noted their vaccine might avoid the negative reactogenic side effects of the Army vaccine. After being subcutaneously vaccinated with 5.3-5.8 log 10 PFU of the chimeric vaccines, mice produced strong neutralizing antibody titers. The VEEV and EEEV chimeras yielded higher neutralizing antibody titers than the SINV chimera without being more virulent. On top of this, the VEEV and EEEV CHIKV chimeras seemed to be more immunogenic than the Army vaccine despite the chimeras' lower viremia and replication in the joints of neonatal mice [3] .", "Tiwari et al. [46] adopted a different strategy using formalin inactivated CHIKV in combination with alhydrogel (Aluminum Hydroxide) as an adjuvant. This study clearly suggests that this vaccine elicits both humoral and cell-mediated immune responses in mice, providing its immunogenic potential. A recent study by Couderc et al. [47] showed passive immunization as a potential treatment for CHIKV infection. Using purified immunoglobulin extracted from convalescent CHIKV patients, they demonstrated effective neutralizing activity against CHIKV infection both in vitro and in vivo. This thereby establishes a potential preventive and therapeutic approach to combat CHIKV infection. Pathogenesis studies conducted with related alpha virus, like RRV, have shown the role of macrophages in persistence on infection [48] . They also demonstrated the role of RRV-specific CD8 T cells in clearing viral load in infected patients, thereby warranting similar investigations with CHIKV and the importance", "of investigating a cell-mediated immune response-based vaccine against CHIKV [49] .", "There are always certain risks associated with live attenuated or inactivated viral vaccines [50] . One way to avoid these potential problems is to construct a consensus-based DNA vaccine. DNA based vaccines have an improved safety profile as compared to live or attenuated vaccines [51, 52] . A consequence of CHIKV's rapid evolution is difficulty in constructing a vaccine that will be able to Figure 3 . Levels of CHIKV-specific IgG in mice immunized with CHIKV vaccines. Each group of C57BL/6 mice (n = 5) was immunized with 12.5 mg of pVax1 control vector or CHIKV vaccine plasmids as indicated at 0 and 2 wk. Mice were bled 2 wk after each immunization, and each group's serum pool was diluted to 1:100 and 1:500 for reaction with specific vaccine constructs. Serum was incubated for 1 h at 37uC on 96-well plates coated with 2 mg/ml of respective CHIKV peptides, and antibody was detected using anti-mouse IgG-HRP and OD was measured at 405 nm. doi:10.1371/journal.pntd.0000623.g003", "www.plosntds.org effectively protect large populations from multiple strains of the virus. One of the strengths of DNA consensus vaccines is its ability to induce cross-reactive immune responses against the three distinct phylogenetic groups of CHIKV. Also DNA-based vaccines can be produced more rapidly than protein-based vaccines.", "Recently, Muthumani et al. constructed a vaccine that was shown to induce both humoral and cellular immunity in vivo in 3-4-wk-old female C57/BL6 mice [49] . These mice were immunized using an in vivo electroporation method to deliver the vaccine into the quadriceps muscle. The consensus construct was designed against E1, E2, and the core protein capsid. To design the construct, they aligned 21 sequences of CHIKV isolated between 1952 and 2006, using strains from differing countries, including La Reunion Island. The most common nucleotide among the sequences was chosen at each position to be used in the consensus construct, taking care not to alter the reading frame. They conducted codon and RNA optimization, added a strong Kozak sequence, and substituted signal peptide with an immunoglobulin E leader sequence to improve vaccine efficacy.", "After immunizing the mice, spleens were harvested along with serum and tested to determine antibody titer. After three immunizations, consensus E1, E2, and C vaccines were shown to induce T-cell immune responses leading to strong IFN-c responses and proliferation in C57/BL6 mice. Furthermore, when compared with control mice, immunized mice had higher total IgG levels as well as higher anti-E1 specific, anti-E2 specific, and anti-C specific IgG antibodies, suggesting a strong humoral immune response ( Figure 3 ) and also specificity for the antigens encoded in the vaccine constructs ( Figure 4 ). Because of its promising results and the need for a safer vaccine, this consensus DNA vaccine deserves further investigation. Determining longevity of protective effects of the vaccine and persistence of antibody and IFN-c responses could be the next step of investigation. Challenged studies of immunized mice must also be carried out.", "CHIKV mosquito-borne disease has caused massive outbreaks for at least half a century but is no longer confined to the www.plosntds.org developing nations. It began to encroach into the boundaries of the developing world. As a result, the NIAID has designated CHIKV as a Category C pathogen alongside the influenza and SARS-CoV viruses [3] . Realization of the potential severity of this disease is exigent; for instance, if used as a biological weapon, the world economy could be severely crippled; if enough members of the armed forces were to become infected during a military deployment, military operations could be significantly affected. Efforts to monitor the disease will only provide minimal warning in a global society, and steps to prevent the morbidity and mortality associated with pandemic are imperative [21, 31] . Despite the gravity of its infectious potency and the fear of it being a potential biological weapon, there is currently no vaccine for CHIKV infections. Live", "attenuated vaccine trials were carried out in 2000, but funding for the project was discontinued. Newer approaches such as DNA vaccines appear promising over conventional strategies like live attenuated or inactivated virus and thus call for further investigation. Recent advances such electroporation delivery and incorporation of adjuvants has boosted DNA vaccine efficacy [51, 53] . Despite the low antibody response to DNA vaccines, other numerous advantages have overshadowed these minor drawbacks (Table 2) , the most important one being the ability to induce both humoral and cellular immune responses [51, 54] .", "Judging by recent success, such as the immunogenic construct developed by Muthumani et al., DNA vaccines could play a major role in combating CHIKV [49] . Vaccines are literally a critical component of CHIKV disease control and therefore research in this area is highly encouraged. The dramatic spread of dengue viruses (DENV) throughout tropical America since 1980 via the same vectors and human hosts underscores the risk to public health in the Americas. The adverse events associated with the current live vaccine are well documented [55] . Realizing these drawbacks, earnest efforts should be taken to develop new strategies to forestall further spread and complications." ]	[ 2 ]	3,829	5,688
1,689	What is it vectored by, in Asia?	2,482	[ "Ae. aegypti and Ae. albopictus" ]	[ "Chikungunya: A Potentially Emerging Epidemic?\n\nhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC2860491/\n\nSHA: f7c3160bef4169d29e2a8bdd79dd6e9056d4774c\n\nAuthors: Thiboutot, Michelle M.; Kannan, Senthil; Kawalekar, Omkar U.; Shedlock, Devon J.; Khan, Amir S.; Sarangan, Gopalsamy; Srikanth, Padma; Weiner, David B.; Muthumani, Karuppiah\nDate: 2010-04-27\nDOI: 10.1371/journal.pntd.0000623\nLicense: cc-by", "Abstract: Chikungunya virus is a mosquito-borne emerging pathogen that has a major health impact in humans and causes fever disease, headache, rash, nausea, vomiting, myalgia, and arthralgia. Indigenous to tropical Africa, recent large outbreaks have been reported in parts of South East Asia and several of its neighboring islands in 2005–07 and in Europe in 2007. Furthermore, positive cases have been confirmed in the United States in travelers returning from known outbreak areas. Currently, there is no vaccine or antiviral treatment. With the threat of an emerging global pandemic, the peculiar problems associated with the more immediate and seasonal epidemics warrant the development of an effective vaccine. In this review, we summarize the evidence supporting these concepts.", "Text: Chikungunya virus (CHIKV), a mosquito-borne pathogen listed by National Institute of Allergy and Infectious Diseases (NIAID) as a Category C Priority Pathogen that causes Chikungunya fever (CHIKF), has been spreading throughout Asia, Africa, and parts of Europe in recent times [1, 2, 3] . CHIKV is an arthropod-borne virus (arbovirus) and is transmitted to humans primarily by Aedes aegypti, the infamous yellow fever propagator [4, 5] . CHIKV infection is marked by severe joint pain, contorting its victims into unusual postures [6] . The disease gets its name from the Kimakonde vernacular language of Tanzania and Mozambique, and the word chikungunya means ''that which contorts or bends up'' and translates in Swahili to ''the illness of the bended walker'' [7, 8, 9] . In Africa, CHIKV is maintained in a sylvatic cycle among forest-dwelling Aedes spp. mosquitoes, wild primates, squirrels, birds, and rodents ( Figure 1 ) [10] . In Asia, the disease is vectored by Ae. aegypti and Ae.", "albopictus [11] . Transmission in Asia occurs in an urban cycle whereby the mosquito spreads the disease from an infected human to an uninfected human, following an epidemiological pattern similar to dengue fever [12] .", "The 2005-2006 epidemic of CHIKV in La Reunion islands in the Indian Ocean, spurred the discovery of a new vector species, Ae. albopictus [5] . Wrecking over one-third of the island's population, this epidemic peaked its devastation between January and February 2006, when over 46,000 cases came into light every week, including 284 deaths [5, 13] . Ae. albopictus is common in urban areas of the United States and is already flourishing in 36 states, raising grave concerns to the immunologically naive populace of the United States [14] .\n\nAccordingly, this review elaborately details the epidemiology and global expansion of CHIKV, describes its clinical features and pathogenesis and its symptoms and complications, and finally nominates a possible vaccine approach against CHIKV infection.", "CHIKV has been isolated into three genotypes based on phylogenetic studies. These genotypes, based on the gene sequences of an Envelope protein (E1), are Asian, East/Central/ South African, and West African [4, 11, 15] . Using phylogenetic models, Cherian et al. estimate that the Asian genotype of CHIKV emerged between 50 and 310 y ago, and the West and East African genotypes diverged between 100 and 840 y ago [15] . Since then, CHIKV has come a long way, with several mutations incorporated, and has continued to wreak epidemics in several regions. Recent activities of CHIKV include the Indian epidemic in 2005-2006, which was followed by a sudden explosion of cases in 2007. An estimated 1.3 million people across 13 states were reported to be infected in India [12, 16] , and CHIKV was also widespread in Malaysia, Sri Lanka, and Indonesia [17] . In July-August of 2007, CHIKV was reported in Italy, probably brought in by travelers from CHIKV-prone regions of India, Africa, and Indian", "Ocean islands such as Mauritius, Madagascar, and Seychelles. Few of the Italian isolates were found to have evolved from the Kerala isolate, which was associated with a A226V shift in E1 gene that represents a successful evolutionary adaptation in the mosquito vector similar to the ones observed in Reunion Island [2, 18, 19] .", "In recent times, with an increase in global travel, the risk for spreading CHIKV to non-endemic regions has heightened [1] . Several travelers have brought CHIKV home with them after visiting areas with actively infected populations [12, 20] . Such cases have been documented in European countries, Australia, Asia, and the United States [8, 21] . The United States has already reported at least twelve cases of travel-associated CHIKV, while France has reported 850 cases, and the United Kingdom 93 [8, 14] . Beyond this, CHIKV-infected travelers have also been diagnosed in Australia, Belgium, Canada, Czech Republic, French Guiana, Germany, Hong Kong, Italy, Japan, Kenya, Malaysia, Martinique, Norway, Switzerland, and Sri Lanka [21] . Some travelers were viremic, worrying public health officials about the spread of CHIKV to new areas [1, 8] .", "The incubation time for CHIKV is relatively short, requiring only 2-6 d with symptoms usually appearing 4-7 d post-infection [22] . Vazeille et al. detected CHIKV in the salivary glands of Ae. albopictus only 2 d after infection [5] . Upon infection, CHIKF tends to present itself in two phases. The first stage is acute, while the second stage, experienced by most but not all, is persistent, causing disabling polyarthritis. Characteristics of the acute phase include an abrupt onset of fever, arthralgia, and in some cases, maculopapular rash [6, 23] . The acute phase causes such intense joint and muscular pain that makes movement very difficult and prostrates its victims [6, 20] .", "Ninety-five percent of infected adults are symptomatic after infection, and of these, most become disabled for weeks to months as a result of decreased dexterity, loss of mobility, and delayed reaction. Eighteen months after disease onset, 40% of patients are found to still have anti-CHIKV IgM [6, 18, 23, 24] . The chronic stage of CHIKF is characterized by polyarthralgia that can last from weeks to years beyond the acute stage [6] . CHIKV has been shown to attack fibroblasts, explaining the involvement of muscles, joints, and skin connective tissues. The high number of nociceptive nerve endings found within the joints and muscle connective tissues can explain pain associated with CHIKF [25, 26] .", "More than 50% of patients who suffer from severe CHIKF are over 65 y old, and more than 33% of them die. Most adults who suffer from severe CHIKF have underlying medical conditions [6, 24, 27] . The other group that is disproportionately affected by severe CHIKV is children. Other complications associated with CHIKV, from most common to least common, include respiratory failure, cardiovascular decompensation, meningoencephalitis, severe acute hepatitis, severe cutaneous effects, other central nervous system problems, and kidney failure [6, 18, 20, 23, 24, 26, 27] .", "CHIKV undertakes a complex replication cycle upon host infection (Figure 2 ), which makes its genome susceptible to mutations [28, 29] . For instance, Ae. aegypti, responsible for epidemics in Kenya, Comoros, and Seychelles, carried CHIKV with an alanine in the 226 position of the E1 gene (E1-A226) [4, 18] . However, when the virus struck La Reunion Islands, a decline in population of Ae. aegypti, due to massive dichlorodiphenyltrichloroethane usage and dearth of Ae. albopictus species' www.plosntds.org population, resulted in an ecological pressure, favoring replacement of alanine at position 226 with valine (E1-A226V) [5] . This mutation allowed CHIKV's secondary vector species, Ae. albopictus, to supplement Ae. aegypti as its primary vector [5] .", "Within a year, the E1-A226V mutation was present in La Reunion Island, and Ae. albopictus apparently vectored the large epidemic infecting 34% of La Reunion Island's population [5] . All of the CHIKV strains isolated from Mayotte carried the E1-A226V mutation, and the mutation was also found in Madagascar in 2007 [5] . The E1-A226V mutation was not present at the beginning of the Indian Ocean Islands outbreak (before September 2005). However, more than 90% of later viral strains found there had incorporated the mutation (December-March 2006), indicating a genotype switch during the winter season [5, 18, 20] .", "The E1-A226V mutation also enabled an increase in infectivity of Ae. albopictus when compared to its infectivity of Ae. aegypti [4, 11, 18, 30] , and with several factors taken together, Ae. albopictus has become the new preferred and more lethal vector for CHIKV [4, 5, 11] . In fact, Tsetsarkin et al. found that a Green Fluorescent Protein tagged E1-A226V virus was 100 times more infective to Ae. albopictus than it was to Ae. aegypti [4] . In all the Indian Ocean Islands, Ae. albopictus became the main vector for CHIKV within 1-2 y after CHIKV was introduced to the region [31] .", "Of note is that Ae. aegypti has most likely been established in North America for over 300 y, while Ae. albopictus has been in many areas of the US, since 1985, primarily in Florida [32] and since then has expanded its range in the country. Reiskind et al. set out to determine if Ae. aegypti and Ae. albopictus mosquitoes captured in Florida were susceptible to CHIKV infection by a La Reunion isolate [32] . Each mosquito tested was highly susceptible to infection by a full-length infectious clone of the La Réunion Island isolate, CHIKV LR2006 OPY1 strain. Even though the Ae. albopictus strains were more susceptible to infection, overall ecology and differences in human biting patterns need to be studied further Characteristically, there are two rounds of translation: (+) sense genomic RNA (49S9 = 11.7 kb) acts directly as mRNA and is partially translated (59 end) to produce non-structural proteins (nsp's). These proteins are responsible for replication and formation of a complementary", "(2) strand, the template for further (+) strand synthesis. Subgenomic mRNA (26 S = 4.1 kb) replication occurs through the synthesis of full-length (2) intermediate RNA, which is regulated by nsp4 and p123 precursor in early infection and later by mature nsp's. Translation of the newly synthesized sub-genomic RNA results in production of structural proteins such as Capsid and protein E2-6k-E1 (from 39 end of genome). Assembly occurs at the cell surface, and the envelope is acquired as the virus buds from the cell and release and maturation almost simultaneous occurred. Replication occurs in the cytoplasm and is very rapid (,4 h) [28, 29] . doi:10.1371/journal.pntd.0000623.g002 www.plosntds.org to gain a more accurate understanding of a potential CHIKV epidemic in the US [32] .", "During the 7 d preceding birth, no human mother has been reported to transmit the disease vertically. However, about 50% of newborns delivered while the mother was infected with CHIKV contracted the disease from their mother, despite the method of delivery. Furthermore, there have been instances of CHIKV transmission from mother to fetus causing congenital illness and fetal death [33] .", "During the 2005-2006 La Reunion Island outbreaks, Ramful et al. discovered that mothers could transmit CHIKV to their progeny during the perinatal period (Day 24 to Day +1) [33, 34] , and it is associated with a high degree of morbidity. By mean Day 4 of life, all of the neonates were symptomatic for CHIKV, exhibiting common CHIKF symptoms. Six neonates were confirmed to have contracted CHIKV and developed mengoencephalitis. Of those mothers who, during the La Reunion Island epidemic, were infected long before delivery, only three fetal deaths were reported [12, 33] . Ramful et al. theorized that motherto-child transmission most likely happens transplacentally shortly before delivery [33] . A similar study by Gerardin et al. reported nineteen cases of neonatal infection associated with intrapartum maternal viremia that progressed to develop encephalitis owing to vertical transmission from infected mothers [34] .", "Clinical and epidemiological similarities with dengue fever make CHIKV diagnosis difficult, which may lead physicians to misdiagnose CHIKV as dengue fever; therefore, the incidence of CHIKV may actually be higher than currently believed (Table 1 ) [6, 12, 35] .", "The amount of time elapsed since disease onset is the most critical parameter when choosing a diagnostic test. CHIKV can be detected and isolated by culturing with mosquito cells (C6/36), Vero cells (mammalian), or in mice [26] . However, this method can take at least a week and only achieves a high sensitivity during the viremic phase, which usually only lasts up to 48 h after the bite. Five days post-infection, the viral isolation approach has a low sensitivity but is still the preferred method for detecting the CHIKV strain [12, 26, 31, 35] . RT-PCR on the other hand is a faster and more sensitive method that can be used within the first week of disease onset [26] , and it is currently the most sensitive method for detecting and quantifying viral mRNA [4, 36] .", "Classic serological detection, by assays such as ELISA [37] , immunofluorescence [5, 38] , complement binding, and haemagglutination inhibition [39] , constitutes the second diagnostic tool used for biological diagnosis of CHIKV infection. These proven techniques are useful for detection of Antigen in mosquitoes during epidemiological studies. These assays detect virus-specific IgM and IgG, however the sensitivity and specificity of these assays has been poorly characterized. Viral competence, or the potential of viral infection and transmission, is an important parameter that can be quantified by ELISA, viral culture, and PCR.", "A study by Ng et al. showed biomarkers indicative of severe CHIKV infection [40] . They found decreased levels of RANTES and increased levels of Interleukin-6 (IL-6) and Interleukin-1b (IL-1b) that could be sued for CHIKV detection in patients as indicators of CHIKV-driven cytokine storm. Couderc et al. demonstrate another cytokine, type-I IFN, as a key player in the progression to CHIKV infection [26] . Using an IFN-a/b null mouse model, they demonstrated evidence of muscles, joints, and skin as privileged CHIKV targets, which is consistent with human pathology. Although Ng et al. concluded that RANTES levels were significantly suppressed in severe CHIKF patients [40] , interestingly, an increase in levels of RANTES has been observed in dengue infection [41] . Since the symptoms of CHIKF mimic those of dengue fever, results obtained from this study strongly suggest that RANTES could be a potential distinctive biomarker that differentiates between these two clinically similar", "diseases.", "There are no approved antiviral treatments currently available for CHIKV [1, 3, 12, 42] . Currently, CHIKF is treated symptomatically, usually with non-steroidal anti-inflammatory drugs or steroids, bed rest, and fluids. Movement and mild exercise are thought to decrease stiffness and morning arthralgia, but heavy exercise may exacerbate rheumatic symptoms. Corticosteroids may be used in cases of debilitating chronic CHIKV infection. There is a debate about the appropriateness of chloroquine as treatment for unresolved, non-steroidal anti-inflammatory drugresistant arthritis [43] . A study showed that viral production was www.plosntds.org drastically reduced at 16 h post-infection after treatment with 100 mM dec-RVKR-cmk (Decanoyl-Arg-Val-Lys-Arg-chloromethylketone), a furine inhibitor [42, 44] . Chloroquine acted by raising the pH, blocking low pH-dependent entry of virus into the cell. It is important to note that dec-RVKR-cmk or chloroquine only inhibited viral spreading from cell", "to cell, not CHIKV replication once it had entered the cell [43] . However, most would agree that the best weapon against CHIKV is prevention. A live CHIKV vaccine developed by the United States reached phase II clinical trial encompassing 59 healthy volunteers [45] . Eight percent of the volunteers experienced transient arthralgia, while 98% of the volunteers had seroconversion [45] . However, live CHIKV vaccines are still questionable. One cannot discount the risk of a live vaccine possibly inducing chronic rheumatism. Also, there is the question as to whether widespread use among the public could trigger mosquito transmission or lead to chronic infection or viral reversion [1] .", "An alternative approach would be to produce a chimeric vaccine against CHIKV. Wang et al. developed a chimeric alphavirus vaccine that is uniformly attenuated and does not cause reactogenicity in mice [3] . Three different versions of this vaccine were made using three different backbone vectors: Venezuelan equine encephalitis virus (VEEV) attenuated vaccine strain T-83, naturally attenuated eastern equine encephalitis virus (EEEV), and attenuated Sindbis virus (SINV). In short, CHIKV structural proteins were engineered into the backbones of the aforementioned vaccines to produce the chimeras [3] . These chimeras were found to stimulate a strong humoral immunity, and even at doses of 5.3-5.8 log 10 PFU, they did not trigger reactogenicity. When vaccinated mice were challenged with CHIKV, neither adult nor neonatal mice gained weight, had fever, or displayed signs of neurological illness. Upon comparison of the chimeras with the Army181/25 vaccine, the Army vaccine resulted in higher", "levels of viremia and replication in the joints of neonatal mice. Because the joints are known targets of CHIKV, Wang et al. noted their vaccine might avoid the negative reactogenic side effects of the Army vaccine. After being subcutaneously vaccinated with 5.3-5.8 log 10 PFU of the chimeric vaccines, mice produced strong neutralizing antibody titers. The VEEV and EEEV chimeras yielded higher neutralizing antibody titers than the SINV chimera without being more virulent. On top of this, the VEEV and EEEV CHIKV chimeras seemed to be more immunogenic than the Army vaccine despite the chimeras' lower viremia and replication in the joints of neonatal mice [3] .", "Tiwari et al. [46] adopted a different strategy using formalin inactivated CHIKV in combination with alhydrogel (Aluminum Hydroxide) as an adjuvant. This study clearly suggests that this vaccine elicits both humoral and cell-mediated immune responses in mice, providing its immunogenic potential. A recent study by Couderc et al. [47] showed passive immunization as a potential treatment for CHIKV infection. Using purified immunoglobulin extracted from convalescent CHIKV patients, they demonstrated effective neutralizing activity against CHIKV infection both in vitro and in vivo. This thereby establishes a potential preventive and therapeutic approach to combat CHIKV infection. Pathogenesis studies conducted with related alpha virus, like RRV, have shown the role of macrophages in persistence on infection [48] . They also demonstrated the role of RRV-specific CD8 T cells in clearing viral load in infected patients, thereby warranting similar investigations with CHIKV and the importance", "of investigating a cell-mediated immune response-based vaccine against CHIKV [49] .", "There are always certain risks associated with live attenuated or inactivated viral vaccines [50] . One way to avoid these potential problems is to construct a consensus-based DNA vaccine. DNA based vaccines have an improved safety profile as compared to live or attenuated vaccines [51, 52] . A consequence of CHIKV's rapid evolution is difficulty in constructing a vaccine that will be able to Figure 3 . Levels of CHIKV-specific IgG in mice immunized with CHIKV vaccines. Each group of C57BL/6 mice (n = 5) was immunized with 12.5 mg of pVax1 control vector or CHIKV vaccine plasmids as indicated at 0 and 2 wk. Mice were bled 2 wk after each immunization, and each group's serum pool was diluted to 1:100 and 1:500 for reaction with specific vaccine constructs. Serum was incubated for 1 h at 37uC on 96-well plates coated with 2 mg/ml of respective CHIKV peptides, and antibody was detected using anti-mouse IgG-HRP and OD was measured at 405 nm. doi:10.1371/journal.pntd.0000623.g003", "www.plosntds.org effectively protect large populations from multiple strains of the virus. One of the strengths of DNA consensus vaccines is its ability to induce cross-reactive immune responses against the three distinct phylogenetic groups of CHIKV. Also DNA-based vaccines can be produced more rapidly than protein-based vaccines.", "Recently, Muthumani et al. constructed a vaccine that was shown to induce both humoral and cellular immunity in vivo in 3-4-wk-old female C57/BL6 mice [49] . These mice were immunized using an in vivo electroporation method to deliver the vaccine into the quadriceps muscle. The consensus construct was designed against E1, E2, and the core protein capsid. To design the construct, they aligned 21 sequences of CHIKV isolated between 1952 and 2006, using strains from differing countries, including La Reunion Island. The most common nucleotide among the sequences was chosen at each position to be used in the consensus construct, taking care not to alter the reading frame. They conducted codon and RNA optimization, added a strong Kozak sequence, and substituted signal peptide with an immunoglobulin E leader sequence to improve vaccine efficacy.", "After immunizing the mice, spleens were harvested along with serum and tested to determine antibody titer. After three immunizations, consensus E1, E2, and C vaccines were shown to induce T-cell immune responses leading to strong IFN-c responses and proliferation in C57/BL6 mice. Furthermore, when compared with control mice, immunized mice had higher total IgG levels as well as higher anti-E1 specific, anti-E2 specific, and anti-C specific IgG antibodies, suggesting a strong humoral immune response ( Figure 3 ) and also specificity for the antigens encoded in the vaccine constructs ( Figure 4 ). Because of its promising results and the need for a safer vaccine, this consensus DNA vaccine deserves further investigation. Determining longevity of protective effects of the vaccine and persistence of antibody and IFN-c responses could be the next step of investigation. Challenged studies of immunized mice must also be carried out.", "CHIKV mosquito-borne disease has caused massive outbreaks for at least half a century but is no longer confined to the www.plosntds.org developing nations. It began to encroach into the boundaries of the developing world. As a result, the NIAID has designated CHIKV as a Category C pathogen alongside the influenza and SARS-CoV viruses [3] . Realization of the potential severity of this disease is exigent; for instance, if used as a biological weapon, the world economy could be severely crippled; if enough members of the armed forces were to become infected during a military deployment, military operations could be significantly affected. Efforts to monitor the disease will only provide minimal warning in a global society, and steps to prevent the morbidity and mortality associated with pandemic are imperative [21, 31] . Despite the gravity of its infectious potency and the fear of it being a potential biological weapon, there is currently no vaccine for CHIKV infections. Live", "attenuated vaccine trials were carried out in 2000, but funding for the project was discontinued. Newer approaches such as DNA vaccines appear promising over conventional strategies like live attenuated or inactivated virus and thus call for further investigation. Recent advances such electroporation delivery and incorporation of adjuvants has boosted DNA vaccine efficacy [51, 53] . Despite the low antibody response to DNA vaccines, other numerous advantages have overshadowed these minor drawbacks (Table 2) , the most important one being the ability to induce both humoral and cellular immune responses [51, 54] .", "Judging by recent success, such as the immunogenic construct developed by Muthumani et al., DNA vaccines could play a major role in combating CHIKV [49] . Vaccines are literally a critical component of CHIKV disease control and therefore research in this area is highly encouraged. The dramatic spread of dengue viruses (DENV) throughout tropical America since 1980 via the same vectors and human hosts underscores the risk to public health in the Americas. The adverse events associated with the current live vaccine are well documented [55] . Realizing these drawbacks, earnest efforts should be taken to develop new strategies to forestall further spread and complications." ]	[ 14 ]	3,829	5,688
1,689	How does the transmission in Asia occur?	2,483	[ "in an urban cycle whereby the mosquito spreads the disease from an infected human to an uninfected human, following an epidemiological pattern similar to dengue fever" ]	[ "Chikungunya: A Potentially Emerging Epidemic?\n\nhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC2860491/\n\nSHA: f7c3160bef4169d29e2a8bdd79dd6e9056d4774c\n\nAuthors: Thiboutot, Michelle M.; Kannan, Senthil; Kawalekar, Omkar U.; Shedlock, Devon J.; Khan, Amir S.; Sarangan, Gopalsamy; Srikanth, Padma; Weiner, David B.; Muthumani, Karuppiah\nDate: 2010-04-27\nDOI: 10.1371/journal.pntd.0000623\nLicense: cc-by", "Abstract: Chikungunya virus is a mosquito-borne emerging pathogen that has a major health impact in humans and causes fever disease, headache, rash, nausea, vomiting, myalgia, and arthralgia. Indigenous to tropical Africa, recent large outbreaks have been reported in parts of South East Asia and several of its neighboring islands in 2005–07 and in Europe in 2007. Furthermore, positive cases have been confirmed in the United States in travelers returning from known outbreak areas. Currently, there is no vaccine or antiviral treatment. With the threat of an emerging global pandemic, the peculiar problems associated with the more immediate and seasonal epidemics warrant the development of an effective vaccine. In this review, we summarize the evidence supporting these concepts.", "Text: Chikungunya virus (CHIKV), a mosquito-borne pathogen listed by National Institute of Allergy and Infectious Diseases (NIAID) as a Category C Priority Pathogen that causes Chikungunya fever (CHIKF), has been spreading throughout Asia, Africa, and parts of Europe in recent times [1, 2, 3] . CHIKV is an arthropod-borne virus (arbovirus) and is transmitted to humans primarily by Aedes aegypti, the infamous yellow fever propagator [4, 5] . CHIKV infection is marked by severe joint pain, contorting its victims into unusual postures [6] . The disease gets its name from the Kimakonde vernacular language of Tanzania and Mozambique, and the word chikungunya means ''that which contorts or bends up'' and translates in Swahili to ''the illness of the bended walker'' [7, 8, 9] . In Africa, CHIKV is maintained in a sylvatic cycle among forest-dwelling Aedes spp. mosquitoes, wild primates, squirrels, birds, and rodents ( Figure 1 ) [10] . In Asia, the disease is vectored by Ae. aegypti and Ae.", "albopictus [11] . Transmission in Asia occurs in an urban cycle whereby the mosquito spreads the disease from an infected human to an uninfected human, following an epidemiological pattern similar to dengue fever [12] .", "The 2005-2006 epidemic of CHIKV in La Reunion islands in the Indian Ocean, spurred the discovery of a new vector species, Ae. albopictus [5] . Wrecking over one-third of the island's population, this epidemic peaked its devastation between January and February 2006, when over 46,000 cases came into light every week, including 284 deaths [5, 13] . Ae. albopictus is common in urban areas of the United States and is already flourishing in 36 states, raising grave concerns to the immunologically naive populace of the United States [14] .\n\nAccordingly, this review elaborately details the epidemiology and global expansion of CHIKV, describes its clinical features and pathogenesis and its symptoms and complications, and finally nominates a possible vaccine approach against CHIKV infection.", "CHIKV has been isolated into three genotypes based on phylogenetic studies. These genotypes, based on the gene sequences of an Envelope protein (E1), are Asian, East/Central/ South African, and West African [4, 11, 15] . Using phylogenetic models, Cherian et al. estimate that the Asian genotype of CHIKV emerged between 50 and 310 y ago, and the West and East African genotypes diverged between 100 and 840 y ago [15] . Since then, CHIKV has come a long way, with several mutations incorporated, and has continued to wreak epidemics in several regions. Recent activities of CHIKV include the Indian epidemic in 2005-2006, which was followed by a sudden explosion of cases in 2007. An estimated 1.3 million people across 13 states were reported to be infected in India [12, 16] , and CHIKV was also widespread in Malaysia, Sri Lanka, and Indonesia [17] . In July-August of 2007, CHIKV was reported in Italy, probably brought in by travelers from CHIKV-prone regions of India, Africa, and Indian", "Ocean islands such as Mauritius, Madagascar, and Seychelles. Few of the Italian isolates were found to have evolved from the Kerala isolate, which was associated with a A226V shift in E1 gene that represents a successful evolutionary adaptation in the mosquito vector similar to the ones observed in Reunion Island [2, 18, 19] .", "In recent times, with an increase in global travel, the risk for spreading CHIKV to non-endemic regions has heightened [1] . Several travelers have brought CHIKV home with them after visiting areas with actively infected populations [12, 20] . Such cases have been documented in European countries, Australia, Asia, and the United States [8, 21] . The United States has already reported at least twelve cases of travel-associated CHIKV, while France has reported 850 cases, and the United Kingdom 93 [8, 14] . Beyond this, CHIKV-infected travelers have also been diagnosed in Australia, Belgium, Canada, Czech Republic, French Guiana, Germany, Hong Kong, Italy, Japan, Kenya, Malaysia, Martinique, Norway, Switzerland, and Sri Lanka [21] . Some travelers were viremic, worrying public health officials about the spread of CHIKV to new areas [1, 8] .", "The incubation time for CHIKV is relatively short, requiring only 2-6 d with symptoms usually appearing 4-7 d post-infection [22] . Vazeille et al. detected CHIKV in the salivary glands of Ae. albopictus only 2 d after infection [5] . Upon infection, CHIKF tends to present itself in two phases. The first stage is acute, while the second stage, experienced by most but not all, is persistent, causing disabling polyarthritis. Characteristics of the acute phase include an abrupt onset of fever, arthralgia, and in some cases, maculopapular rash [6, 23] . The acute phase causes such intense joint and muscular pain that makes movement very difficult and prostrates its victims [6, 20] .", "Ninety-five percent of infected adults are symptomatic after infection, and of these, most become disabled for weeks to months as a result of decreased dexterity, loss of mobility, and delayed reaction. Eighteen months after disease onset, 40% of patients are found to still have anti-CHIKV IgM [6, 18, 23, 24] . The chronic stage of CHIKF is characterized by polyarthralgia that can last from weeks to years beyond the acute stage [6] . CHIKV has been shown to attack fibroblasts, explaining the involvement of muscles, joints, and skin connective tissues. The high number of nociceptive nerve endings found within the joints and muscle connective tissues can explain pain associated with CHIKF [25, 26] .", "More than 50% of patients who suffer from severe CHIKF are over 65 y old, and more than 33% of them die. Most adults who suffer from severe CHIKF have underlying medical conditions [6, 24, 27] . The other group that is disproportionately affected by severe CHIKV is children. Other complications associated with CHIKV, from most common to least common, include respiratory failure, cardiovascular decompensation, meningoencephalitis, severe acute hepatitis, severe cutaneous effects, other central nervous system problems, and kidney failure [6, 18, 20, 23, 24, 26, 27] .", "CHIKV undertakes a complex replication cycle upon host infection (Figure 2 ), which makes its genome susceptible to mutations [28, 29] . For instance, Ae. aegypti, responsible for epidemics in Kenya, Comoros, and Seychelles, carried CHIKV with an alanine in the 226 position of the E1 gene (E1-A226) [4, 18] . However, when the virus struck La Reunion Islands, a decline in population of Ae. aegypti, due to massive dichlorodiphenyltrichloroethane usage and dearth of Ae. albopictus species' www.plosntds.org population, resulted in an ecological pressure, favoring replacement of alanine at position 226 with valine (E1-A226V) [5] . This mutation allowed CHIKV's secondary vector species, Ae. albopictus, to supplement Ae. aegypti as its primary vector [5] .", "Within a year, the E1-A226V mutation was present in La Reunion Island, and Ae. albopictus apparently vectored the large epidemic infecting 34% of La Reunion Island's population [5] . All of the CHIKV strains isolated from Mayotte carried the E1-A226V mutation, and the mutation was also found in Madagascar in 2007 [5] . The E1-A226V mutation was not present at the beginning of the Indian Ocean Islands outbreak (before September 2005). However, more than 90% of later viral strains found there had incorporated the mutation (December-March 2006), indicating a genotype switch during the winter season [5, 18, 20] .", "The E1-A226V mutation also enabled an increase in infectivity of Ae. albopictus when compared to its infectivity of Ae. aegypti [4, 11, 18, 30] , and with several factors taken together, Ae. albopictus has become the new preferred and more lethal vector for CHIKV [4, 5, 11] . In fact, Tsetsarkin et al. found that a Green Fluorescent Protein tagged E1-A226V virus was 100 times more infective to Ae. albopictus than it was to Ae. aegypti [4] . In all the Indian Ocean Islands, Ae. albopictus became the main vector for CHIKV within 1-2 y after CHIKV was introduced to the region [31] .", "Of note is that Ae. aegypti has most likely been established in North America for over 300 y, while Ae. albopictus has been in many areas of the US, since 1985, primarily in Florida [32] and since then has expanded its range in the country. Reiskind et al. set out to determine if Ae. aegypti and Ae. albopictus mosquitoes captured in Florida were susceptible to CHIKV infection by a La Reunion isolate [32] . Each mosquito tested was highly susceptible to infection by a full-length infectious clone of the La Réunion Island isolate, CHIKV LR2006 OPY1 strain. Even though the Ae. albopictus strains were more susceptible to infection, overall ecology and differences in human biting patterns need to be studied further Characteristically, there are two rounds of translation: (+) sense genomic RNA (49S9 = 11.7 kb) acts directly as mRNA and is partially translated (59 end) to produce non-structural proteins (nsp's). These proteins are responsible for replication and formation of a complementary", "(2) strand, the template for further (+) strand synthesis. Subgenomic mRNA (26 S = 4.1 kb) replication occurs through the synthesis of full-length (2) intermediate RNA, which is regulated by nsp4 and p123 precursor in early infection and later by mature nsp's. Translation of the newly synthesized sub-genomic RNA results in production of structural proteins such as Capsid and protein E2-6k-E1 (from 39 end of genome). Assembly occurs at the cell surface, and the envelope is acquired as the virus buds from the cell and release and maturation almost simultaneous occurred. Replication occurs in the cytoplasm and is very rapid (,4 h) [28, 29] . doi:10.1371/journal.pntd.0000623.g002 www.plosntds.org to gain a more accurate understanding of a potential CHIKV epidemic in the US [32] .", "During the 7 d preceding birth, no human mother has been reported to transmit the disease vertically. However, about 50% of newborns delivered while the mother was infected with CHIKV contracted the disease from their mother, despite the method of delivery. Furthermore, there have been instances of CHIKV transmission from mother to fetus causing congenital illness and fetal death [33] .", "During the 2005-2006 La Reunion Island outbreaks, Ramful et al. discovered that mothers could transmit CHIKV to their progeny during the perinatal period (Day 24 to Day +1) [33, 34] , and it is associated with a high degree of morbidity. By mean Day 4 of life, all of the neonates were symptomatic for CHIKV, exhibiting common CHIKF symptoms. Six neonates were confirmed to have contracted CHIKV and developed mengoencephalitis. Of those mothers who, during the La Reunion Island epidemic, were infected long before delivery, only three fetal deaths were reported [12, 33] . Ramful et al. theorized that motherto-child transmission most likely happens transplacentally shortly before delivery [33] . A similar study by Gerardin et al. reported nineteen cases of neonatal infection associated with intrapartum maternal viremia that progressed to develop encephalitis owing to vertical transmission from infected mothers [34] .", "Clinical and epidemiological similarities with dengue fever make CHIKV diagnosis difficult, which may lead physicians to misdiagnose CHIKV as dengue fever; therefore, the incidence of CHIKV may actually be higher than currently believed (Table 1 ) [6, 12, 35] .", "The amount of time elapsed since disease onset is the most critical parameter when choosing a diagnostic test. CHIKV can be detected and isolated by culturing with mosquito cells (C6/36), Vero cells (mammalian), or in mice [26] . However, this method can take at least a week and only achieves a high sensitivity during the viremic phase, which usually only lasts up to 48 h after the bite. Five days post-infection, the viral isolation approach has a low sensitivity but is still the preferred method for detecting the CHIKV strain [12, 26, 31, 35] . RT-PCR on the other hand is a faster and more sensitive method that can be used within the first week of disease onset [26] , and it is currently the most sensitive method for detecting and quantifying viral mRNA [4, 36] .", "Classic serological detection, by assays such as ELISA [37] , immunofluorescence [5, 38] , complement binding, and haemagglutination inhibition [39] , constitutes the second diagnostic tool used for biological diagnosis of CHIKV infection. These proven techniques are useful for detection of Antigen in mosquitoes during epidemiological studies. These assays detect virus-specific IgM and IgG, however the sensitivity and specificity of these assays has been poorly characterized. Viral competence, or the potential of viral infection and transmission, is an important parameter that can be quantified by ELISA, viral culture, and PCR.", "A study by Ng et al. showed biomarkers indicative of severe CHIKV infection [40] . They found decreased levels of RANTES and increased levels of Interleukin-6 (IL-6) and Interleukin-1b (IL-1b) that could be sued for CHIKV detection in patients as indicators of CHIKV-driven cytokine storm. Couderc et al. demonstrate another cytokine, type-I IFN, as a key player in the progression to CHIKV infection [26] . Using an IFN-a/b null mouse model, they demonstrated evidence of muscles, joints, and skin as privileged CHIKV targets, which is consistent with human pathology. Although Ng et al. concluded that RANTES levels were significantly suppressed in severe CHIKF patients [40] , interestingly, an increase in levels of RANTES has been observed in dengue infection [41] . Since the symptoms of CHIKF mimic those of dengue fever, results obtained from this study strongly suggest that RANTES could be a potential distinctive biomarker that differentiates between these two clinically similar", "diseases.", "There are no approved antiviral treatments currently available for CHIKV [1, 3, 12, 42] . Currently, CHIKF is treated symptomatically, usually with non-steroidal anti-inflammatory drugs or steroids, bed rest, and fluids. Movement and mild exercise are thought to decrease stiffness and morning arthralgia, but heavy exercise may exacerbate rheumatic symptoms. Corticosteroids may be used in cases of debilitating chronic CHIKV infection. There is a debate about the appropriateness of chloroquine as treatment for unresolved, non-steroidal anti-inflammatory drugresistant arthritis [43] . A study showed that viral production was www.plosntds.org drastically reduced at 16 h post-infection after treatment with 100 mM dec-RVKR-cmk (Decanoyl-Arg-Val-Lys-Arg-chloromethylketone), a furine inhibitor [42, 44] . Chloroquine acted by raising the pH, blocking low pH-dependent entry of virus into the cell. It is important to note that dec-RVKR-cmk or chloroquine only inhibited viral spreading from cell", "to cell, not CHIKV replication once it had entered the cell [43] . However, most would agree that the best weapon against CHIKV is prevention. A live CHIKV vaccine developed by the United States reached phase II clinical trial encompassing 59 healthy volunteers [45] . Eight percent of the volunteers experienced transient arthralgia, while 98% of the volunteers had seroconversion [45] . However, live CHIKV vaccines are still questionable. One cannot discount the risk of a live vaccine possibly inducing chronic rheumatism. Also, there is the question as to whether widespread use among the public could trigger mosquito transmission or lead to chronic infection or viral reversion [1] .", "An alternative approach would be to produce a chimeric vaccine against CHIKV. Wang et al. developed a chimeric alphavirus vaccine that is uniformly attenuated and does not cause reactogenicity in mice [3] . Three different versions of this vaccine were made using three different backbone vectors: Venezuelan equine encephalitis virus (VEEV) attenuated vaccine strain T-83, naturally attenuated eastern equine encephalitis virus (EEEV), and attenuated Sindbis virus (SINV). In short, CHIKV structural proteins were engineered into the backbones of the aforementioned vaccines to produce the chimeras [3] . These chimeras were found to stimulate a strong humoral immunity, and even at doses of 5.3-5.8 log 10 PFU, they did not trigger reactogenicity. When vaccinated mice were challenged with CHIKV, neither adult nor neonatal mice gained weight, had fever, or displayed signs of neurological illness. Upon comparison of the chimeras with the Army181/25 vaccine, the Army vaccine resulted in higher", "levels of viremia and replication in the joints of neonatal mice. Because the joints are known targets of CHIKV, Wang et al. noted their vaccine might avoid the negative reactogenic side effects of the Army vaccine. After being subcutaneously vaccinated with 5.3-5.8 log 10 PFU of the chimeric vaccines, mice produced strong neutralizing antibody titers. The VEEV and EEEV chimeras yielded higher neutralizing antibody titers than the SINV chimera without being more virulent. On top of this, the VEEV and EEEV CHIKV chimeras seemed to be more immunogenic than the Army vaccine despite the chimeras' lower viremia and replication in the joints of neonatal mice [3] .", "Tiwari et al. [46] adopted a different strategy using formalin inactivated CHIKV in combination with alhydrogel (Aluminum Hydroxide) as an adjuvant. This study clearly suggests that this vaccine elicits both humoral and cell-mediated immune responses in mice, providing its immunogenic potential. A recent study by Couderc et al. [47] showed passive immunization as a potential treatment for CHIKV infection. Using purified immunoglobulin extracted from convalescent CHIKV patients, they demonstrated effective neutralizing activity against CHIKV infection both in vitro and in vivo. This thereby establishes a potential preventive and therapeutic approach to combat CHIKV infection. Pathogenesis studies conducted with related alpha virus, like RRV, have shown the role of macrophages in persistence on infection [48] . They also demonstrated the role of RRV-specific CD8 T cells in clearing viral load in infected patients, thereby warranting similar investigations with CHIKV and the importance", "of investigating a cell-mediated immune response-based vaccine against CHIKV [49] .", "There are always certain risks associated with live attenuated or inactivated viral vaccines [50] . One way to avoid these potential problems is to construct a consensus-based DNA vaccine. DNA based vaccines have an improved safety profile as compared to live or attenuated vaccines [51, 52] . A consequence of CHIKV's rapid evolution is difficulty in constructing a vaccine that will be able to Figure 3 . Levels of CHIKV-specific IgG in mice immunized with CHIKV vaccines. Each group of C57BL/6 mice (n = 5) was immunized with 12.5 mg of pVax1 control vector or CHIKV vaccine plasmids as indicated at 0 and 2 wk. Mice were bled 2 wk after each immunization, and each group's serum pool was diluted to 1:100 and 1:500 for reaction with specific vaccine constructs. Serum was incubated for 1 h at 37uC on 96-well plates coated with 2 mg/ml of respective CHIKV peptides, and antibody was detected using anti-mouse IgG-HRP and OD was measured at 405 nm. doi:10.1371/journal.pntd.0000623.g003", "www.plosntds.org effectively protect large populations from multiple strains of the virus. One of the strengths of DNA consensus vaccines is its ability to induce cross-reactive immune responses against the three distinct phylogenetic groups of CHIKV. Also DNA-based vaccines can be produced more rapidly than protein-based vaccines.", "Recently, Muthumani et al. constructed a vaccine that was shown to induce both humoral and cellular immunity in vivo in 3-4-wk-old female C57/BL6 mice [49] . These mice were immunized using an in vivo electroporation method to deliver the vaccine into the quadriceps muscle. The consensus construct was designed against E1, E2, and the core protein capsid. To design the construct, they aligned 21 sequences of CHIKV isolated between 1952 and 2006, using strains from differing countries, including La Reunion Island. The most common nucleotide among the sequences was chosen at each position to be used in the consensus construct, taking care not to alter the reading frame. They conducted codon and RNA optimization, added a strong Kozak sequence, and substituted signal peptide with an immunoglobulin E leader sequence to improve vaccine efficacy.", "After immunizing the mice, spleens were harvested along with serum and tested to determine antibody titer. After three immunizations, consensus E1, E2, and C vaccines were shown to induce T-cell immune responses leading to strong IFN-c responses and proliferation in C57/BL6 mice. Furthermore, when compared with control mice, immunized mice had higher total IgG levels as well as higher anti-E1 specific, anti-E2 specific, and anti-C specific IgG antibodies, suggesting a strong humoral immune response ( Figure 3 ) and also specificity for the antigens encoded in the vaccine constructs ( Figure 4 ). Because of its promising results and the need for a safer vaccine, this consensus DNA vaccine deserves further investigation. Determining longevity of protective effects of the vaccine and persistence of antibody and IFN-c responses could be the next step of investigation. Challenged studies of immunized mice must also be carried out.", "CHIKV mosquito-borne disease has caused massive outbreaks for at least half a century but is no longer confined to the www.plosntds.org developing nations. It began to encroach into the boundaries of the developing world. As a result, the NIAID has designated CHIKV as a Category C pathogen alongside the influenza and SARS-CoV viruses [3] . Realization of the potential severity of this disease is exigent; for instance, if used as a biological weapon, the world economy could be severely crippled; if enough members of the armed forces were to become infected during a military deployment, military operations could be significantly affected. Efforts to monitor the disease will only provide minimal warning in a global society, and steps to prevent the morbidity and mortality associated with pandemic are imperative [21, 31] . Despite the gravity of its infectious potency and the fear of it being a potential biological weapon, there is currently no vaccine for CHIKV infections. Live", "attenuated vaccine trials were carried out in 2000, but funding for the project was discontinued. Newer approaches such as DNA vaccines appear promising over conventional strategies like live attenuated or inactivated virus and thus call for further investigation. Recent advances such electroporation delivery and incorporation of adjuvants has boosted DNA vaccine efficacy [51, 53] . Despite the low antibody response to DNA vaccines, other numerous advantages have overshadowed these minor drawbacks (Table 2) , the most important one being the ability to induce both humoral and cellular immune responses [51, 54] .", "Judging by recent success, such as the immunogenic construct developed by Muthumani et al., DNA vaccines could play a major role in combating CHIKV [49] . Vaccines are literally a critical component of CHIKV disease control and therefore research in this area is highly encouraged. The dramatic spread of dengue viruses (DENV) throughout tropical America since 1980 via the same vectors and human hosts underscores the risk to public health in the Americas. The adverse events associated with the current live vaccine are well documented [55] . Realizing these drawbacks, earnest efforts should be taken to develop new strategies to forestall further spread and complications." ]	[ 3 ]	3,829	5,688
1,689	What spurred the discovery of the new vector Ae. albopictus?	2,484	[ "The 2005-2006 epidemic of CHIKV in La Reunion islands in the Indian Ocean," ]	[ "Chikungunya: A Potentially Emerging Epidemic?\n\nhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC2860491/\n\nSHA: f7c3160bef4169d29e2a8bdd79dd6e9056d4774c\n\nAuthors: Thiboutot, Michelle M.; Kannan, Senthil; Kawalekar, Omkar U.; Shedlock, Devon J.; Khan, Amir S.; Sarangan, Gopalsamy; Srikanth, Padma; Weiner, David B.; Muthumani, Karuppiah\nDate: 2010-04-27\nDOI: 10.1371/journal.pntd.0000623\nLicense: cc-by", "Abstract: Chikungunya virus is a mosquito-borne emerging pathogen that has a major health impact in humans and causes fever disease, headache, rash, nausea, vomiting, myalgia, and arthralgia. Indigenous to tropical Africa, recent large outbreaks have been reported in parts of South East Asia and several of its neighboring islands in 2005–07 and in Europe in 2007. Furthermore, positive cases have been confirmed in the United States in travelers returning from known outbreak areas. Currently, there is no vaccine or antiviral treatment. With the threat of an emerging global pandemic, the peculiar problems associated with the more immediate and seasonal epidemics warrant the development of an effective vaccine. In this review, we summarize the evidence supporting these concepts.", "Text: Chikungunya virus (CHIKV), a mosquito-borne pathogen listed by National Institute of Allergy and Infectious Diseases (NIAID) as a Category C Priority Pathogen that causes Chikungunya fever (CHIKF), has been spreading throughout Asia, Africa, and parts of Europe in recent times [1, 2, 3] . CHIKV is an arthropod-borne virus (arbovirus) and is transmitted to humans primarily by Aedes aegypti, the infamous yellow fever propagator [4, 5] . CHIKV infection is marked by severe joint pain, contorting its victims into unusual postures [6] . The disease gets its name from the Kimakonde vernacular language of Tanzania and Mozambique, and the word chikungunya means ''that which contorts or bends up'' and translates in Swahili to ''the illness of the bended walker'' [7, 8, 9] . In Africa, CHIKV is maintained in a sylvatic cycle among forest-dwelling Aedes spp. mosquitoes, wild primates, squirrels, birds, and rodents ( Figure 1 ) [10] . In Asia, the disease is vectored by Ae. aegypti and Ae.", "albopictus [11] . Transmission in Asia occurs in an urban cycle whereby the mosquito spreads the disease from an infected human to an uninfected human, following an epidemiological pattern similar to dengue fever [12] .", "The 2005-2006 epidemic of CHIKV in La Reunion islands in the Indian Ocean, spurred the discovery of a new vector species, Ae. albopictus [5] . Wrecking over one-third of the island's population, this epidemic peaked its devastation between January and February 2006, when over 46,000 cases came into light every week, including 284 deaths [5, 13] . Ae. albopictus is common in urban areas of the United States and is already flourishing in 36 states, raising grave concerns to the immunologically naive populace of the United States [14] .\n\nAccordingly, this review elaborately details the epidemiology and global expansion of CHIKV, describes its clinical features and pathogenesis and its symptoms and complications, and finally nominates a possible vaccine approach against CHIKV infection.", "CHIKV has been isolated into three genotypes based on phylogenetic studies. These genotypes, based on the gene sequences of an Envelope protein (E1), are Asian, East/Central/ South African, and West African [4, 11, 15] . Using phylogenetic models, Cherian et al. estimate that the Asian genotype of CHIKV emerged between 50 and 310 y ago, and the West and East African genotypes diverged between 100 and 840 y ago [15] . Since then, CHIKV has come a long way, with several mutations incorporated, and has continued to wreak epidemics in several regions. Recent activities of CHIKV include the Indian epidemic in 2005-2006, which was followed by a sudden explosion of cases in 2007. An estimated 1.3 million people across 13 states were reported to be infected in India [12, 16] , and CHIKV was also widespread in Malaysia, Sri Lanka, and Indonesia [17] . In July-August of 2007, CHIKV was reported in Italy, probably brought in by travelers from CHIKV-prone regions of India, Africa, and Indian", "Ocean islands such as Mauritius, Madagascar, and Seychelles. Few of the Italian isolates were found to have evolved from the Kerala isolate, which was associated with a A226V shift in E1 gene that represents a successful evolutionary adaptation in the mosquito vector similar to the ones observed in Reunion Island [2, 18, 19] .", "In recent times, with an increase in global travel, the risk for spreading CHIKV to non-endemic regions has heightened [1] . Several travelers have brought CHIKV home with them after visiting areas with actively infected populations [12, 20] . Such cases have been documented in European countries, Australia, Asia, and the United States [8, 21] . The United States has already reported at least twelve cases of travel-associated CHIKV, while France has reported 850 cases, and the United Kingdom 93 [8, 14] . Beyond this, CHIKV-infected travelers have also been diagnosed in Australia, Belgium, Canada, Czech Republic, French Guiana, Germany, Hong Kong, Italy, Japan, Kenya, Malaysia, Martinique, Norway, Switzerland, and Sri Lanka [21] . Some travelers were viremic, worrying public health officials about the spread of CHIKV to new areas [1, 8] .", "The incubation time for CHIKV is relatively short, requiring only 2-6 d with symptoms usually appearing 4-7 d post-infection [22] . Vazeille et al. detected CHIKV in the salivary glands of Ae. albopictus only 2 d after infection [5] . Upon infection, CHIKF tends to present itself in two phases. The first stage is acute, while the second stage, experienced by most but not all, is persistent, causing disabling polyarthritis. Characteristics of the acute phase include an abrupt onset of fever, arthralgia, and in some cases, maculopapular rash [6, 23] . The acute phase causes such intense joint and muscular pain that makes movement very difficult and prostrates its victims [6, 20] .", "Ninety-five percent of infected adults are symptomatic after infection, and of these, most become disabled for weeks to months as a result of decreased dexterity, loss of mobility, and delayed reaction. Eighteen months after disease onset, 40% of patients are found to still have anti-CHIKV IgM [6, 18, 23, 24] . The chronic stage of CHIKF is characterized by polyarthralgia that can last from weeks to years beyond the acute stage [6] . CHIKV has been shown to attack fibroblasts, explaining the involvement of muscles, joints, and skin connective tissues. The high number of nociceptive nerve endings found within the joints and muscle connective tissues can explain pain associated with CHIKF [25, 26] .", "More than 50% of patients who suffer from severe CHIKF are over 65 y old, and more than 33% of them die. Most adults who suffer from severe CHIKF have underlying medical conditions [6, 24, 27] . The other group that is disproportionately affected by severe CHIKV is children. Other complications associated with CHIKV, from most common to least common, include respiratory failure, cardiovascular decompensation, meningoencephalitis, severe acute hepatitis, severe cutaneous effects, other central nervous system problems, and kidney failure [6, 18, 20, 23, 24, 26, 27] .", "CHIKV undertakes a complex replication cycle upon host infection (Figure 2 ), which makes its genome susceptible to mutations [28, 29] . For instance, Ae. aegypti, responsible for epidemics in Kenya, Comoros, and Seychelles, carried CHIKV with an alanine in the 226 position of the E1 gene (E1-A226) [4, 18] . However, when the virus struck La Reunion Islands, a decline in population of Ae. aegypti, due to massive dichlorodiphenyltrichloroethane usage and dearth of Ae. albopictus species' www.plosntds.org population, resulted in an ecological pressure, favoring replacement of alanine at position 226 with valine (E1-A226V) [5] . This mutation allowed CHIKV's secondary vector species, Ae. albopictus, to supplement Ae. aegypti as its primary vector [5] .", "Within a year, the E1-A226V mutation was present in La Reunion Island, and Ae. albopictus apparently vectored the large epidemic infecting 34% of La Reunion Island's population [5] . All of the CHIKV strains isolated from Mayotte carried the E1-A226V mutation, and the mutation was also found in Madagascar in 2007 [5] . The E1-A226V mutation was not present at the beginning of the Indian Ocean Islands outbreak (before September 2005). However, more than 90% of later viral strains found there had incorporated the mutation (December-March 2006), indicating a genotype switch during the winter season [5, 18, 20] .", "The E1-A226V mutation also enabled an increase in infectivity of Ae. albopictus when compared to its infectivity of Ae. aegypti [4, 11, 18, 30] , and with several factors taken together, Ae. albopictus has become the new preferred and more lethal vector for CHIKV [4, 5, 11] . In fact, Tsetsarkin et al. found that a Green Fluorescent Protein tagged E1-A226V virus was 100 times more infective to Ae. albopictus than it was to Ae. aegypti [4] . In all the Indian Ocean Islands, Ae. albopictus became the main vector for CHIKV within 1-2 y after CHIKV was introduced to the region [31] .", "Of note is that Ae. aegypti has most likely been established in North America for over 300 y, while Ae. albopictus has been in many areas of the US, since 1985, primarily in Florida [32] and since then has expanded its range in the country. Reiskind et al. set out to determine if Ae. aegypti and Ae. albopictus mosquitoes captured in Florida were susceptible to CHIKV infection by a La Reunion isolate [32] . Each mosquito tested was highly susceptible to infection by a full-length infectious clone of the La Réunion Island isolate, CHIKV LR2006 OPY1 strain. Even though the Ae. albopictus strains were more susceptible to infection, overall ecology and differences in human biting patterns need to be studied further Characteristically, there are two rounds of translation: (+) sense genomic RNA (49S9 = 11.7 kb) acts directly as mRNA and is partially translated (59 end) to produce non-structural proteins (nsp's). These proteins are responsible for replication and formation of a complementary", "(2) strand, the template for further (+) strand synthesis. Subgenomic mRNA (26 S = 4.1 kb) replication occurs through the synthesis of full-length (2) intermediate RNA, which is regulated by nsp4 and p123 precursor in early infection and later by mature nsp's. Translation of the newly synthesized sub-genomic RNA results in production of structural proteins such as Capsid and protein E2-6k-E1 (from 39 end of genome). Assembly occurs at the cell surface, and the envelope is acquired as the virus buds from the cell and release and maturation almost simultaneous occurred. Replication occurs in the cytoplasm and is very rapid (,4 h) [28, 29] . doi:10.1371/journal.pntd.0000623.g002 www.plosntds.org to gain a more accurate understanding of a potential CHIKV epidemic in the US [32] .", "During the 7 d preceding birth, no human mother has been reported to transmit the disease vertically. However, about 50% of newborns delivered while the mother was infected with CHIKV contracted the disease from their mother, despite the method of delivery. Furthermore, there have been instances of CHIKV transmission from mother to fetus causing congenital illness and fetal death [33] .", "During the 2005-2006 La Reunion Island outbreaks, Ramful et al. discovered that mothers could transmit CHIKV to their progeny during the perinatal period (Day 24 to Day +1) [33, 34] , and it is associated with a high degree of morbidity. By mean Day 4 of life, all of the neonates were symptomatic for CHIKV, exhibiting common CHIKF symptoms. Six neonates were confirmed to have contracted CHIKV and developed mengoencephalitis. Of those mothers who, during the La Reunion Island epidemic, were infected long before delivery, only three fetal deaths were reported [12, 33] . Ramful et al. theorized that motherto-child transmission most likely happens transplacentally shortly before delivery [33] . A similar study by Gerardin et al. reported nineteen cases of neonatal infection associated with intrapartum maternal viremia that progressed to develop encephalitis owing to vertical transmission from infected mothers [34] .", "Clinical and epidemiological similarities with dengue fever make CHIKV diagnosis difficult, which may lead physicians to misdiagnose CHIKV as dengue fever; therefore, the incidence of CHIKV may actually be higher than currently believed (Table 1 ) [6, 12, 35] .", "The amount of time elapsed since disease onset is the most critical parameter when choosing a diagnostic test. CHIKV can be detected and isolated by culturing with mosquito cells (C6/36), Vero cells (mammalian), or in mice [26] . However, this method can take at least a week and only achieves a high sensitivity during the viremic phase, which usually only lasts up to 48 h after the bite. Five days post-infection, the viral isolation approach has a low sensitivity but is still the preferred method for detecting the CHIKV strain [12, 26, 31, 35] . RT-PCR on the other hand is a faster and more sensitive method that can be used within the first week of disease onset [26] , and it is currently the most sensitive method for detecting and quantifying viral mRNA [4, 36] .", "Classic serological detection, by assays such as ELISA [37] , immunofluorescence [5, 38] , complement binding, and haemagglutination inhibition [39] , constitutes the second diagnostic tool used for biological diagnosis of CHIKV infection. These proven techniques are useful for detection of Antigen in mosquitoes during epidemiological studies. These assays detect virus-specific IgM and IgG, however the sensitivity and specificity of these assays has been poorly characterized. Viral competence, or the potential of viral infection and transmission, is an important parameter that can be quantified by ELISA, viral culture, and PCR.", "A study by Ng et al. showed biomarkers indicative of severe CHIKV infection [40] . They found decreased levels of RANTES and increased levels of Interleukin-6 (IL-6) and Interleukin-1b (IL-1b) that could be sued for CHIKV detection in patients as indicators of CHIKV-driven cytokine storm. Couderc et al. demonstrate another cytokine, type-I IFN, as a key player in the progression to CHIKV infection [26] . Using an IFN-a/b null mouse model, they demonstrated evidence of muscles, joints, and skin as privileged CHIKV targets, which is consistent with human pathology. Although Ng et al. concluded that RANTES levels were significantly suppressed in severe CHIKF patients [40] , interestingly, an increase in levels of RANTES has been observed in dengue infection [41] . Since the symptoms of CHIKF mimic those of dengue fever, results obtained from this study strongly suggest that RANTES could be a potential distinctive biomarker that differentiates between these two clinically similar", "diseases.", "There are no approved antiviral treatments currently available for CHIKV [1, 3, 12, 42] . Currently, CHIKF is treated symptomatically, usually with non-steroidal anti-inflammatory drugs or steroids, bed rest, and fluids. Movement and mild exercise are thought to decrease stiffness and morning arthralgia, but heavy exercise may exacerbate rheumatic symptoms. Corticosteroids may be used in cases of debilitating chronic CHIKV infection. There is a debate about the appropriateness of chloroquine as treatment for unresolved, non-steroidal anti-inflammatory drugresistant arthritis [43] . A study showed that viral production was www.plosntds.org drastically reduced at 16 h post-infection after treatment with 100 mM dec-RVKR-cmk (Decanoyl-Arg-Val-Lys-Arg-chloromethylketone), a furine inhibitor [42, 44] . Chloroquine acted by raising the pH, blocking low pH-dependent entry of virus into the cell. It is important to note that dec-RVKR-cmk or chloroquine only inhibited viral spreading from cell", "to cell, not CHIKV replication once it had entered the cell [43] . However, most would agree that the best weapon against CHIKV is prevention. A live CHIKV vaccine developed by the United States reached phase II clinical trial encompassing 59 healthy volunteers [45] . Eight percent of the volunteers experienced transient arthralgia, while 98% of the volunteers had seroconversion [45] . However, live CHIKV vaccines are still questionable. One cannot discount the risk of a live vaccine possibly inducing chronic rheumatism. Also, there is the question as to whether widespread use among the public could trigger mosquito transmission or lead to chronic infection or viral reversion [1] .", "An alternative approach would be to produce a chimeric vaccine against CHIKV. Wang et al. developed a chimeric alphavirus vaccine that is uniformly attenuated and does not cause reactogenicity in mice [3] . Three different versions of this vaccine were made using three different backbone vectors: Venezuelan equine encephalitis virus (VEEV) attenuated vaccine strain T-83, naturally attenuated eastern equine encephalitis virus (EEEV), and attenuated Sindbis virus (SINV). In short, CHIKV structural proteins were engineered into the backbones of the aforementioned vaccines to produce the chimeras [3] . These chimeras were found to stimulate a strong humoral immunity, and even at doses of 5.3-5.8 log 10 PFU, they did not trigger reactogenicity. When vaccinated mice were challenged with CHIKV, neither adult nor neonatal mice gained weight, had fever, or displayed signs of neurological illness. Upon comparison of the chimeras with the Army181/25 vaccine, the Army vaccine resulted in higher", "levels of viremia and replication in the joints of neonatal mice. Because the joints are known targets of CHIKV, Wang et al. noted their vaccine might avoid the negative reactogenic side effects of the Army vaccine. After being subcutaneously vaccinated with 5.3-5.8 log 10 PFU of the chimeric vaccines, mice produced strong neutralizing antibody titers. The VEEV and EEEV chimeras yielded higher neutralizing antibody titers than the SINV chimera without being more virulent. On top of this, the VEEV and EEEV CHIKV chimeras seemed to be more immunogenic than the Army vaccine despite the chimeras' lower viremia and replication in the joints of neonatal mice [3] .", "Tiwari et al. [46] adopted a different strategy using formalin inactivated CHIKV in combination with alhydrogel (Aluminum Hydroxide) as an adjuvant. This study clearly suggests that this vaccine elicits both humoral and cell-mediated immune responses in mice, providing its immunogenic potential. A recent study by Couderc et al. [47] showed passive immunization as a potential treatment for CHIKV infection. Using purified immunoglobulin extracted from convalescent CHIKV patients, they demonstrated effective neutralizing activity against CHIKV infection both in vitro and in vivo. This thereby establishes a potential preventive and therapeutic approach to combat CHIKV infection. Pathogenesis studies conducted with related alpha virus, like RRV, have shown the role of macrophages in persistence on infection [48] . They also demonstrated the role of RRV-specific CD8 T cells in clearing viral load in infected patients, thereby warranting similar investigations with CHIKV and the importance", "of investigating a cell-mediated immune response-based vaccine against CHIKV [49] .", "There are always certain risks associated with live attenuated or inactivated viral vaccines [50] . One way to avoid these potential problems is to construct a consensus-based DNA vaccine. DNA based vaccines have an improved safety profile as compared to live or attenuated vaccines [51, 52] . A consequence of CHIKV's rapid evolution is difficulty in constructing a vaccine that will be able to Figure 3 . Levels of CHIKV-specific IgG in mice immunized with CHIKV vaccines. Each group of C57BL/6 mice (n = 5) was immunized with 12.5 mg of pVax1 control vector or CHIKV vaccine plasmids as indicated at 0 and 2 wk. Mice were bled 2 wk after each immunization, and each group's serum pool was diluted to 1:100 and 1:500 for reaction with specific vaccine constructs. Serum was incubated for 1 h at 37uC on 96-well plates coated with 2 mg/ml of respective CHIKV peptides, and antibody was detected using anti-mouse IgG-HRP and OD was measured at 405 nm. doi:10.1371/journal.pntd.0000623.g003", "www.plosntds.org effectively protect large populations from multiple strains of the virus. One of the strengths of DNA consensus vaccines is its ability to induce cross-reactive immune responses against the three distinct phylogenetic groups of CHIKV. Also DNA-based vaccines can be produced more rapidly than protein-based vaccines.", "Recently, Muthumani et al. constructed a vaccine that was shown to induce both humoral and cellular immunity in vivo in 3-4-wk-old female C57/BL6 mice [49] . These mice were immunized using an in vivo electroporation method to deliver the vaccine into the quadriceps muscle. The consensus construct was designed against E1, E2, and the core protein capsid. To design the construct, they aligned 21 sequences of CHIKV isolated between 1952 and 2006, using strains from differing countries, including La Reunion Island. The most common nucleotide among the sequences was chosen at each position to be used in the consensus construct, taking care not to alter the reading frame. They conducted codon and RNA optimization, added a strong Kozak sequence, and substituted signal peptide with an immunoglobulin E leader sequence to improve vaccine efficacy.", "After immunizing the mice, spleens were harvested along with serum and tested to determine antibody titer. After three immunizations, consensus E1, E2, and C vaccines were shown to induce T-cell immune responses leading to strong IFN-c responses and proliferation in C57/BL6 mice. Furthermore, when compared with control mice, immunized mice had higher total IgG levels as well as higher anti-E1 specific, anti-E2 specific, and anti-C specific IgG antibodies, suggesting a strong humoral immune response ( Figure 3 ) and also specificity for the antigens encoded in the vaccine constructs ( Figure 4 ). Because of its promising results and the need for a safer vaccine, this consensus DNA vaccine deserves further investigation. Determining longevity of protective effects of the vaccine and persistence of antibody and IFN-c responses could be the next step of investigation. Challenged studies of immunized mice must also be carried out.", "CHIKV mosquito-borne disease has caused massive outbreaks for at least half a century but is no longer confined to the www.plosntds.org developing nations. It began to encroach into the boundaries of the developing world. As a result, the NIAID has designated CHIKV as a Category C pathogen alongside the influenza and SARS-CoV viruses [3] . Realization of the potential severity of this disease is exigent; for instance, if used as a biological weapon, the world economy could be severely crippled; if enough members of the armed forces were to become infected during a military deployment, military operations could be significantly affected. Efforts to monitor the disease will only provide minimal warning in a global society, and steps to prevent the morbidity and mortality associated with pandemic are imperative [21, 31] . Despite the gravity of its infectious potency and the fear of it being a potential biological weapon, there is currently no vaccine for CHIKV infections. Live", "attenuated vaccine trials were carried out in 2000, but funding for the project was discontinued. Newer approaches such as DNA vaccines appear promising over conventional strategies like live attenuated or inactivated virus and thus call for further investigation. Recent advances such electroporation delivery and incorporation of adjuvants has boosted DNA vaccine efficacy [51, 53] . Despite the low antibody response to DNA vaccines, other numerous advantages have overshadowed these minor drawbacks (Table 2) , the most important one being the ability to induce both humoral and cellular immune responses [51, 54] .", "Judging by recent success, such as the immunogenic construct developed by Muthumani et al., DNA vaccines could play a major role in combating CHIKV [49] . Vaccines are literally a critical component of CHIKV disease control and therefore research in this area is highly encouraged. The dramatic spread of dengue viruses (DENV) throughout tropical America since 1980 via the same vectors and human hosts underscores the risk to public health in the Americas. The adverse events associated with the current live vaccine are well documented [55] . Realizing these drawbacks, earnest efforts should be taken to develop new strategies to forestall further spread and complications." ]	[ 4 ]	3,829	5,688
1,689	In the epidemic peak how many cases per week were there on the island?	2,485	[ "46,000" ]	[ "Chikungunya: A Potentially Emerging Epidemic?\n\nhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC2860491/\n\nSHA: f7c3160bef4169d29e2a8bdd79dd6e9056d4774c\n\nAuthors: Thiboutot, Michelle M.; Kannan, Senthil; Kawalekar, Omkar U.; Shedlock, Devon J.; Khan, Amir S.; Sarangan, Gopalsamy; Srikanth, Padma; Weiner, David B.; Muthumani, Karuppiah\nDate: 2010-04-27\nDOI: 10.1371/journal.pntd.0000623\nLicense: cc-by", "Abstract: Chikungunya virus is a mosquito-borne emerging pathogen that has a major health impact in humans and causes fever disease, headache, rash, nausea, vomiting, myalgia, and arthralgia. Indigenous to tropical Africa, recent large outbreaks have been reported in parts of South East Asia and several of its neighboring islands in 2005–07 and in Europe in 2007. Furthermore, positive cases have been confirmed in the United States in travelers returning from known outbreak areas. Currently, there is no vaccine or antiviral treatment. With the threat of an emerging global pandemic, the peculiar problems associated with the more immediate and seasonal epidemics warrant the development of an effective vaccine. In this review, we summarize the evidence supporting these concepts.", "Text: Chikungunya virus (CHIKV), a mosquito-borne pathogen listed by National Institute of Allergy and Infectious Diseases (NIAID) as a Category C Priority Pathogen that causes Chikungunya fever (CHIKF), has been spreading throughout Asia, Africa, and parts of Europe in recent times [1, 2, 3] . CHIKV is an arthropod-borne virus (arbovirus) and is transmitted to humans primarily by Aedes aegypti, the infamous yellow fever propagator [4, 5] . CHIKV infection is marked by severe joint pain, contorting its victims into unusual postures [6] . The disease gets its name from the Kimakonde vernacular language of Tanzania and Mozambique, and the word chikungunya means ''that which contorts or bends up'' and translates in Swahili to ''the illness of the bended walker'' [7, 8, 9] . In Africa, CHIKV is maintained in a sylvatic cycle among forest-dwelling Aedes spp. mosquitoes, wild primates, squirrels, birds, and rodents ( Figure 1 ) [10] . In Asia, the disease is vectored by Ae. aegypti and Ae.", "albopictus [11] . Transmission in Asia occurs in an urban cycle whereby the mosquito spreads the disease from an infected human to an uninfected human, following an epidemiological pattern similar to dengue fever [12] .", "The 2005-2006 epidemic of CHIKV in La Reunion islands in the Indian Ocean, spurred the discovery of a new vector species, Ae. albopictus [5] . Wrecking over one-third of the island's population, this epidemic peaked its devastation between January and February 2006, when over 46,000 cases came into light every week, including 284 deaths [5, 13] . Ae. albopictus is common in urban areas of the United States and is already flourishing in 36 states, raising grave concerns to the immunologically naive populace of the United States [14] .\n\nAccordingly, this review elaborately details the epidemiology and global expansion of CHIKV, describes its clinical features and pathogenesis and its symptoms and complications, and finally nominates a possible vaccine approach against CHIKV infection.", "CHIKV has been isolated into three genotypes based on phylogenetic studies. These genotypes, based on the gene sequences of an Envelope protein (E1), are Asian, East/Central/ South African, and West African [4, 11, 15] . Using phylogenetic models, Cherian et al. estimate that the Asian genotype of CHIKV emerged between 50 and 310 y ago, and the West and East African genotypes diverged between 100 and 840 y ago [15] . Since then, CHIKV has come a long way, with several mutations incorporated, and has continued to wreak epidemics in several regions. Recent activities of CHIKV include the Indian epidemic in 2005-2006, which was followed by a sudden explosion of cases in 2007. An estimated 1.3 million people across 13 states were reported to be infected in India [12, 16] , and CHIKV was also widespread in Malaysia, Sri Lanka, and Indonesia [17] . In July-August of 2007, CHIKV was reported in Italy, probably brought in by travelers from CHIKV-prone regions of India, Africa, and Indian", "Ocean islands such as Mauritius, Madagascar, and Seychelles. Few of the Italian isolates were found to have evolved from the Kerala isolate, which was associated with a A226V shift in E1 gene that represents a successful evolutionary adaptation in the mosquito vector similar to the ones observed in Reunion Island [2, 18, 19] .", "In recent times, with an increase in global travel, the risk for spreading CHIKV to non-endemic regions has heightened [1] . Several travelers have brought CHIKV home with them after visiting areas with actively infected populations [12, 20] . Such cases have been documented in European countries, Australia, Asia, and the United States [8, 21] . The United States has already reported at least twelve cases of travel-associated CHIKV, while France has reported 850 cases, and the United Kingdom 93 [8, 14] . Beyond this, CHIKV-infected travelers have also been diagnosed in Australia, Belgium, Canada, Czech Republic, French Guiana, Germany, Hong Kong, Italy, Japan, Kenya, Malaysia, Martinique, Norway, Switzerland, and Sri Lanka [21] . Some travelers were viremic, worrying public health officials about the spread of CHIKV to new areas [1, 8] .", "The incubation time for CHIKV is relatively short, requiring only 2-6 d with symptoms usually appearing 4-7 d post-infection [22] . Vazeille et al. detected CHIKV in the salivary glands of Ae. albopictus only 2 d after infection [5] . Upon infection, CHIKF tends to present itself in two phases. The first stage is acute, while the second stage, experienced by most but not all, is persistent, causing disabling polyarthritis. Characteristics of the acute phase include an abrupt onset of fever, arthralgia, and in some cases, maculopapular rash [6, 23] . The acute phase causes such intense joint and muscular pain that makes movement very difficult and prostrates its victims [6, 20] .", "Ninety-five percent of infected adults are symptomatic after infection, and of these, most become disabled for weeks to months as a result of decreased dexterity, loss of mobility, and delayed reaction. Eighteen months after disease onset, 40% of patients are found to still have anti-CHIKV IgM [6, 18, 23, 24] . The chronic stage of CHIKF is characterized by polyarthralgia that can last from weeks to years beyond the acute stage [6] . CHIKV has been shown to attack fibroblasts, explaining the involvement of muscles, joints, and skin connective tissues. The high number of nociceptive nerve endings found within the joints and muscle connective tissues can explain pain associated with CHIKF [25, 26] .", "More than 50% of patients who suffer from severe CHIKF are over 65 y old, and more than 33% of them die. Most adults who suffer from severe CHIKF have underlying medical conditions [6, 24, 27] . The other group that is disproportionately affected by severe CHIKV is children. Other complications associated with CHIKV, from most common to least common, include respiratory failure, cardiovascular decompensation, meningoencephalitis, severe acute hepatitis, severe cutaneous effects, other central nervous system problems, and kidney failure [6, 18, 20, 23, 24, 26, 27] .", "CHIKV undertakes a complex replication cycle upon host infection (Figure 2 ), which makes its genome susceptible to mutations [28, 29] . For instance, Ae. aegypti, responsible for epidemics in Kenya, Comoros, and Seychelles, carried CHIKV with an alanine in the 226 position of the E1 gene (E1-A226) [4, 18] . However, when the virus struck La Reunion Islands, a decline in population of Ae. aegypti, due to massive dichlorodiphenyltrichloroethane usage and dearth of Ae. albopictus species' www.plosntds.org population, resulted in an ecological pressure, favoring replacement of alanine at position 226 with valine (E1-A226V) [5] . This mutation allowed CHIKV's secondary vector species, Ae. albopictus, to supplement Ae. aegypti as its primary vector [5] .", "Within a year, the E1-A226V mutation was present in La Reunion Island, and Ae. albopictus apparently vectored the large epidemic infecting 34% of La Reunion Island's population [5] . All of the CHIKV strains isolated from Mayotte carried the E1-A226V mutation, and the mutation was also found in Madagascar in 2007 [5] . The E1-A226V mutation was not present at the beginning of the Indian Ocean Islands outbreak (before September 2005). However, more than 90% of later viral strains found there had incorporated the mutation (December-March 2006), indicating a genotype switch during the winter season [5, 18, 20] .", "The E1-A226V mutation also enabled an increase in infectivity of Ae. albopictus when compared to its infectivity of Ae. aegypti [4, 11, 18, 30] , and with several factors taken together, Ae. albopictus has become the new preferred and more lethal vector for CHIKV [4, 5, 11] . In fact, Tsetsarkin et al. found that a Green Fluorescent Protein tagged E1-A226V virus was 100 times more infective to Ae. albopictus than it was to Ae. aegypti [4] . In all the Indian Ocean Islands, Ae. albopictus became the main vector for CHIKV within 1-2 y after CHIKV was introduced to the region [31] .", "Of note is that Ae. aegypti has most likely been established in North America for over 300 y, while Ae. albopictus has been in many areas of the US, since 1985, primarily in Florida [32] and since then has expanded its range in the country. Reiskind et al. set out to determine if Ae. aegypti and Ae. albopictus mosquitoes captured in Florida were susceptible to CHIKV infection by a La Reunion isolate [32] . Each mosquito tested was highly susceptible to infection by a full-length infectious clone of the La Réunion Island isolate, CHIKV LR2006 OPY1 strain. Even though the Ae. albopictus strains were more susceptible to infection, overall ecology and differences in human biting patterns need to be studied further Characteristically, there are two rounds of translation: (+) sense genomic RNA (49S9 = 11.7 kb) acts directly as mRNA and is partially translated (59 end) to produce non-structural proteins (nsp's). These proteins are responsible for replication and formation of a complementary", "(2) strand, the template for further (+) strand synthesis. Subgenomic mRNA (26 S = 4.1 kb) replication occurs through the synthesis of full-length (2) intermediate RNA, which is regulated by nsp4 and p123 precursor in early infection and later by mature nsp's. Translation of the newly synthesized sub-genomic RNA results in production of structural proteins such as Capsid and protein E2-6k-E1 (from 39 end of genome). Assembly occurs at the cell surface, and the envelope is acquired as the virus buds from the cell and release and maturation almost simultaneous occurred. Replication occurs in the cytoplasm and is very rapid (,4 h) [28, 29] . doi:10.1371/journal.pntd.0000623.g002 www.plosntds.org to gain a more accurate understanding of a potential CHIKV epidemic in the US [32] .", "During the 7 d preceding birth, no human mother has been reported to transmit the disease vertically. However, about 50% of newborns delivered while the mother was infected with CHIKV contracted the disease from their mother, despite the method of delivery. Furthermore, there have been instances of CHIKV transmission from mother to fetus causing congenital illness and fetal death [33] .", "During the 2005-2006 La Reunion Island outbreaks, Ramful et al. discovered that mothers could transmit CHIKV to their progeny during the perinatal period (Day 24 to Day +1) [33, 34] , and it is associated with a high degree of morbidity. By mean Day 4 of life, all of the neonates were symptomatic for CHIKV, exhibiting common CHIKF symptoms. Six neonates were confirmed to have contracted CHIKV and developed mengoencephalitis. Of those mothers who, during the La Reunion Island epidemic, were infected long before delivery, only three fetal deaths were reported [12, 33] . Ramful et al. theorized that motherto-child transmission most likely happens transplacentally shortly before delivery [33] . A similar study by Gerardin et al. reported nineteen cases of neonatal infection associated with intrapartum maternal viremia that progressed to develop encephalitis owing to vertical transmission from infected mothers [34] .", "Clinical and epidemiological similarities with dengue fever make CHIKV diagnosis difficult, which may lead physicians to misdiagnose CHIKV as dengue fever; therefore, the incidence of CHIKV may actually be higher than currently believed (Table 1 ) [6, 12, 35] .", "The amount of time elapsed since disease onset is the most critical parameter when choosing a diagnostic test. CHIKV can be detected and isolated by culturing with mosquito cells (C6/36), Vero cells (mammalian), or in mice [26] . However, this method can take at least a week and only achieves a high sensitivity during the viremic phase, which usually only lasts up to 48 h after the bite. Five days post-infection, the viral isolation approach has a low sensitivity but is still the preferred method for detecting the CHIKV strain [12, 26, 31, 35] . RT-PCR on the other hand is a faster and more sensitive method that can be used within the first week of disease onset [26] , and it is currently the most sensitive method for detecting and quantifying viral mRNA [4, 36] .", "Classic serological detection, by assays such as ELISA [37] , immunofluorescence [5, 38] , complement binding, and haemagglutination inhibition [39] , constitutes the second diagnostic tool used for biological diagnosis of CHIKV infection. These proven techniques are useful for detection of Antigen in mosquitoes during epidemiological studies. These assays detect virus-specific IgM and IgG, however the sensitivity and specificity of these assays has been poorly characterized. Viral competence, or the potential of viral infection and transmission, is an important parameter that can be quantified by ELISA, viral culture, and PCR.", "A study by Ng et al. showed biomarkers indicative of severe CHIKV infection [40] . They found decreased levels of RANTES and increased levels of Interleukin-6 (IL-6) and Interleukin-1b (IL-1b) that could be sued for CHIKV detection in patients as indicators of CHIKV-driven cytokine storm. Couderc et al. demonstrate another cytokine, type-I IFN, as a key player in the progression to CHIKV infection [26] . Using an IFN-a/b null mouse model, they demonstrated evidence of muscles, joints, and skin as privileged CHIKV targets, which is consistent with human pathology. Although Ng et al. concluded that RANTES levels were significantly suppressed in severe CHIKF patients [40] , interestingly, an increase in levels of RANTES has been observed in dengue infection [41] . Since the symptoms of CHIKF mimic those of dengue fever, results obtained from this study strongly suggest that RANTES could be a potential distinctive biomarker that differentiates between these two clinically similar", "diseases.", "There are no approved antiviral treatments currently available for CHIKV [1, 3, 12, 42] . Currently, CHIKF is treated symptomatically, usually with non-steroidal anti-inflammatory drugs or steroids, bed rest, and fluids. Movement and mild exercise are thought to decrease stiffness and morning arthralgia, but heavy exercise may exacerbate rheumatic symptoms. Corticosteroids may be used in cases of debilitating chronic CHIKV infection. There is a debate about the appropriateness of chloroquine as treatment for unresolved, non-steroidal anti-inflammatory drugresistant arthritis [43] . A study showed that viral production was www.plosntds.org drastically reduced at 16 h post-infection after treatment with 100 mM dec-RVKR-cmk (Decanoyl-Arg-Val-Lys-Arg-chloromethylketone), a furine inhibitor [42, 44] . Chloroquine acted by raising the pH, blocking low pH-dependent entry of virus into the cell. It is important to note that dec-RVKR-cmk or chloroquine only inhibited viral spreading from cell", "to cell, not CHIKV replication once it had entered the cell [43] . However, most would agree that the best weapon against CHIKV is prevention. A live CHIKV vaccine developed by the United States reached phase II clinical trial encompassing 59 healthy volunteers [45] . Eight percent of the volunteers experienced transient arthralgia, while 98% of the volunteers had seroconversion [45] . However, live CHIKV vaccines are still questionable. One cannot discount the risk of a live vaccine possibly inducing chronic rheumatism. Also, there is the question as to whether widespread use among the public could trigger mosquito transmission or lead to chronic infection or viral reversion [1] .", "An alternative approach would be to produce a chimeric vaccine against CHIKV. Wang et al. developed a chimeric alphavirus vaccine that is uniformly attenuated and does not cause reactogenicity in mice [3] . Three different versions of this vaccine were made using three different backbone vectors: Venezuelan equine encephalitis virus (VEEV) attenuated vaccine strain T-83, naturally attenuated eastern equine encephalitis virus (EEEV), and attenuated Sindbis virus (SINV). In short, CHIKV structural proteins were engineered into the backbones of the aforementioned vaccines to produce the chimeras [3] . These chimeras were found to stimulate a strong humoral immunity, and even at doses of 5.3-5.8 log 10 PFU, they did not trigger reactogenicity. When vaccinated mice were challenged with CHIKV, neither adult nor neonatal mice gained weight, had fever, or displayed signs of neurological illness. Upon comparison of the chimeras with the Army181/25 vaccine, the Army vaccine resulted in higher", "levels of viremia and replication in the joints of neonatal mice. Because the joints are known targets of CHIKV, Wang et al. noted their vaccine might avoid the negative reactogenic side effects of the Army vaccine. After being subcutaneously vaccinated with 5.3-5.8 log 10 PFU of the chimeric vaccines, mice produced strong neutralizing antibody titers. The VEEV and EEEV chimeras yielded higher neutralizing antibody titers than the SINV chimera without being more virulent. On top of this, the VEEV and EEEV CHIKV chimeras seemed to be more immunogenic than the Army vaccine despite the chimeras' lower viremia and replication in the joints of neonatal mice [3] .", "Tiwari et al. [46] adopted a different strategy using formalin inactivated CHIKV in combination with alhydrogel (Aluminum Hydroxide) as an adjuvant. This study clearly suggests that this vaccine elicits both humoral and cell-mediated immune responses in mice, providing its immunogenic potential. A recent study by Couderc et al. [47] showed passive immunization as a potential treatment for CHIKV infection. Using purified immunoglobulin extracted from convalescent CHIKV patients, they demonstrated effective neutralizing activity against CHIKV infection both in vitro and in vivo. This thereby establishes a potential preventive and therapeutic approach to combat CHIKV infection. Pathogenesis studies conducted with related alpha virus, like RRV, have shown the role of macrophages in persistence on infection [48] . They also demonstrated the role of RRV-specific CD8 T cells in clearing viral load in infected patients, thereby warranting similar investigations with CHIKV and the importance", "of investigating a cell-mediated immune response-based vaccine against CHIKV [49] .", "There are always certain risks associated with live attenuated or inactivated viral vaccines [50] . One way to avoid these potential problems is to construct a consensus-based DNA vaccine. DNA based vaccines have an improved safety profile as compared to live or attenuated vaccines [51, 52] . A consequence of CHIKV's rapid evolution is difficulty in constructing a vaccine that will be able to Figure 3 . Levels of CHIKV-specific IgG in mice immunized with CHIKV vaccines. Each group of C57BL/6 mice (n = 5) was immunized with 12.5 mg of pVax1 control vector or CHIKV vaccine plasmids as indicated at 0 and 2 wk. Mice were bled 2 wk after each immunization, and each group's serum pool was diluted to 1:100 and 1:500 for reaction with specific vaccine constructs. Serum was incubated for 1 h at 37uC on 96-well plates coated with 2 mg/ml of respective CHIKV peptides, and antibody was detected using anti-mouse IgG-HRP and OD was measured at 405 nm. doi:10.1371/journal.pntd.0000623.g003", "www.plosntds.org effectively protect large populations from multiple strains of the virus. One of the strengths of DNA consensus vaccines is its ability to induce cross-reactive immune responses against the three distinct phylogenetic groups of CHIKV. Also DNA-based vaccines can be produced more rapidly than protein-based vaccines.", "Recently, Muthumani et al. constructed a vaccine that was shown to induce both humoral and cellular immunity in vivo in 3-4-wk-old female C57/BL6 mice [49] . These mice were immunized using an in vivo electroporation method to deliver the vaccine into the quadriceps muscle. The consensus construct was designed against E1, E2, and the core protein capsid. To design the construct, they aligned 21 sequences of CHIKV isolated between 1952 and 2006, using strains from differing countries, including La Reunion Island. The most common nucleotide among the sequences was chosen at each position to be used in the consensus construct, taking care not to alter the reading frame. They conducted codon and RNA optimization, added a strong Kozak sequence, and substituted signal peptide with an immunoglobulin E leader sequence to improve vaccine efficacy.", "After immunizing the mice, spleens were harvested along with serum and tested to determine antibody titer. After three immunizations, consensus E1, E2, and C vaccines were shown to induce T-cell immune responses leading to strong IFN-c responses and proliferation in C57/BL6 mice. Furthermore, when compared with control mice, immunized mice had higher total IgG levels as well as higher anti-E1 specific, anti-E2 specific, and anti-C specific IgG antibodies, suggesting a strong humoral immune response ( Figure 3 ) and also specificity for the antigens encoded in the vaccine constructs ( Figure 4 ). Because of its promising results and the need for a safer vaccine, this consensus DNA vaccine deserves further investigation. Determining longevity of protective effects of the vaccine and persistence of antibody and IFN-c responses could be the next step of investigation. Challenged studies of immunized mice must also be carried out.", "CHIKV mosquito-borne disease has caused massive outbreaks for at least half a century but is no longer confined to the www.plosntds.org developing nations. It began to encroach into the boundaries of the developing world. As a result, the NIAID has designated CHIKV as a Category C pathogen alongside the influenza and SARS-CoV viruses [3] . Realization of the potential severity of this disease is exigent; for instance, if used as a biological weapon, the world economy could be severely crippled; if enough members of the armed forces were to become infected during a military deployment, military operations could be significantly affected. Efforts to monitor the disease will only provide minimal warning in a global society, and steps to prevent the morbidity and mortality associated with pandemic are imperative [21, 31] . Despite the gravity of its infectious potency and the fear of it being a potential biological weapon, there is currently no vaccine for CHIKV infections. Live", "attenuated vaccine trials were carried out in 2000, but funding for the project was discontinued. Newer approaches such as DNA vaccines appear promising over conventional strategies like live attenuated or inactivated virus and thus call for further investigation. Recent advances such electroporation delivery and incorporation of adjuvants has boosted DNA vaccine efficacy [51, 53] . Despite the low antibody response to DNA vaccines, other numerous advantages have overshadowed these minor drawbacks (Table 2) , the most important one being the ability to induce both humoral and cellular immune responses [51, 54] .", "Judging by recent success, such as the immunogenic construct developed by Muthumani et al., DNA vaccines could play a major role in combating CHIKV [49] . Vaccines are literally a critical component of CHIKV disease control and therefore research in this area is highly encouraged. The dramatic spread of dengue viruses (DENV) throughout tropical America since 1980 via the same vectors and human hosts underscores the risk to public health in the Americas. The adverse events associated with the current live vaccine are well documented [55] . Realizing these drawbacks, earnest efforts should be taken to develop new strategies to forestall further spread and complications." ]	[ 4 ]	3,829	5,688
1,689	What does this review detail?	2,486	[ "the epidemiology and global expansion of CHIKV" ]	[ "Chikungunya: A Potentially Emerging Epidemic?\n\nhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC2860491/\n\nSHA: f7c3160bef4169d29e2a8bdd79dd6e9056d4774c\n\nAuthors: Thiboutot, Michelle M.; Kannan, Senthil; Kawalekar, Omkar U.; Shedlock, Devon J.; Khan, Amir S.; Sarangan, Gopalsamy; Srikanth, Padma; Weiner, David B.; Muthumani, Karuppiah\nDate: 2010-04-27\nDOI: 10.1371/journal.pntd.0000623\nLicense: cc-by", "Abstract: Chikungunya virus is a mosquito-borne emerging pathogen that has a major health impact in humans and causes fever disease, headache, rash, nausea, vomiting, myalgia, and arthralgia. Indigenous to tropical Africa, recent large outbreaks have been reported in parts of South East Asia and several of its neighboring islands in 2005–07 and in Europe in 2007. Furthermore, positive cases have been confirmed in the United States in travelers returning from known outbreak areas. Currently, there is no vaccine or antiviral treatment. With the threat of an emerging global pandemic, the peculiar problems associated with the more immediate and seasonal epidemics warrant the development of an effective vaccine. In this review, we summarize the evidence supporting these concepts.", "Text: Chikungunya virus (CHIKV), a mosquito-borne pathogen listed by National Institute of Allergy and Infectious Diseases (NIAID) as a Category C Priority Pathogen that causes Chikungunya fever (CHIKF), has been spreading throughout Asia, Africa, and parts of Europe in recent times [1, 2, 3] . CHIKV is an arthropod-borne virus (arbovirus) and is transmitted to humans primarily by Aedes aegypti, the infamous yellow fever propagator [4, 5] . CHIKV infection is marked by severe joint pain, contorting its victims into unusual postures [6] . The disease gets its name from the Kimakonde vernacular language of Tanzania and Mozambique, and the word chikungunya means ''that which contorts or bends up'' and translates in Swahili to ''the illness of the bended walker'' [7, 8, 9] . In Africa, CHIKV is maintained in a sylvatic cycle among forest-dwelling Aedes spp. mosquitoes, wild primates, squirrels, birds, and rodents ( Figure 1 ) [10] . In Asia, the disease is vectored by Ae. aegypti and Ae.", "albopictus [11] . Transmission in Asia occurs in an urban cycle whereby the mosquito spreads the disease from an infected human to an uninfected human, following an epidemiological pattern similar to dengue fever [12] .", "The 2005-2006 epidemic of CHIKV in La Reunion islands in the Indian Ocean, spurred the discovery of a new vector species, Ae. albopictus [5] . Wrecking over one-third of the island's population, this epidemic peaked its devastation between January and February 2006, when over 46,000 cases came into light every week, including 284 deaths [5, 13] . Ae. albopictus is common in urban areas of the United States and is already flourishing in 36 states, raising grave concerns to the immunologically naive populace of the United States [14] .\n\nAccordingly, this review elaborately details the epidemiology and global expansion of CHIKV, describes its clinical features and pathogenesis and its symptoms and complications, and finally nominates a possible vaccine approach against CHIKV infection.", "CHIKV has been isolated into three genotypes based on phylogenetic studies. These genotypes, based on the gene sequences of an Envelope protein (E1), are Asian, East/Central/ South African, and West African [4, 11, 15] . Using phylogenetic models, Cherian et al. estimate that the Asian genotype of CHIKV emerged between 50 and 310 y ago, and the West and East African genotypes diverged between 100 and 840 y ago [15] . Since then, CHIKV has come a long way, with several mutations incorporated, and has continued to wreak epidemics in several regions. Recent activities of CHIKV include the Indian epidemic in 2005-2006, which was followed by a sudden explosion of cases in 2007. An estimated 1.3 million people across 13 states were reported to be infected in India [12, 16] , and CHIKV was also widespread in Malaysia, Sri Lanka, and Indonesia [17] . In July-August of 2007, CHIKV was reported in Italy, probably brought in by travelers from CHIKV-prone regions of India, Africa, and Indian", "Ocean islands such as Mauritius, Madagascar, and Seychelles. Few of the Italian isolates were found to have evolved from the Kerala isolate, which was associated with a A226V shift in E1 gene that represents a successful evolutionary adaptation in the mosquito vector similar to the ones observed in Reunion Island [2, 18, 19] .", "In recent times, with an increase in global travel, the risk for spreading CHIKV to non-endemic regions has heightened [1] . Several travelers have brought CHIKV home with them after visiting areas with actively infected populations [12, 20] . Such cases have been documented in European countries, Australia, Asia, and the United States [8, 21] . The United States has already reported at least twelve cases of travel-associated CHIKV, while France has reported 850 cases, and the United Kingdom 93 [8, 14] . Beyond this, CHIKV-infected travelers have also been diagnosed in Australia, Belgium, Canada, Czech Republic, French Guiana, Germany, Hong Kong, Italy, Japan, Kenya, Malaysia, Martinique, Norway, Switzerland, and Sri Lanka [21] . Some travelers were viremic, worrying public health officials about the spread of CHIKV to new areas [1, 8] .", "The incubation time for CHIKV is relatively short, requiring only 2-6 d with symptoms usually appearing 4-7 d post-infection [22] . Vazeille et al. detected CHIKV in the salivary glands of Ae. albopictus only 2 d after infection [5] . Upon infection, CHIKF tends to present itself in two phases. The first stage is acute, while the second stage, experienced by most but not all, is persistent, causing disabling polyarthritis. Characteristics of the acute phase include an abrupt onset of fever, arthralgia, and in some cases, maculopapular rash [6, 23] . The acute phase causes such intense joint and muscular pain that makes movement very difficult and prostrates its victims [6, 20] .", "Ninety-five percent of infected adults are symptomatic after infection, and of these, most become disabled for weeks to months as a result of decreased dexterity, loss of mobility, and delayed reaction. Eighteen months after disease onset, 40% of patients are found to still have anti-CHIKV IgM [6, 18, 23, 24] . The chronic stage of CHIKF is characterized by polyarthralgia that can last from weeks to years beyond the acute stage [6] . CHIKV has been shown to attack fibroblasts, explaining the involvement of muscles, joints, and skin connective tissues. The high number of nociceptive nerve endings found within the joints and muscle connective tissues can explain pain associated with CHIKF [25, 26] .", "More than 50% of patients who suffer from severe CHIKF are over 65 y old, and more than 33% of them die. Most adults who suffer from severe CHIKF have underlying medical conditions [6, 24, 27] . The other group that is disproportionately affected by severe CHIKV is children. Other complications associated with CHIKV, from most common to least common, include respiratory failure, cardiovascular decompensation, meningoencephalitis, severe acute hepatitis, severe cutaneous effects, other central nervous system problems, and kidney failure [6, 18, 20, 23, 24, 26, 27] .", "CHIKV undertakes a complex replication cycle upon host infection (Figure 2 ), which makes its genome susceptible to mutations [28, 29] . For instance, Ae. aegypti, responsible for epidemics in Kenya, Comoros, and Seychelles, carried CHIKV with an alanine in the 226 position of the E1 gene (E1-A226) [4, 18] . However, when the virus struck La Reunion Islands, a decline in population of Ae. aegypti, due to massive dichlorodiphenyltrichloroethane usage and dearth of Ae. albopictus species' www.plosntds.org population, resulted in an ecological pressure, favoring replacement of alanine at position 226 with valine (E1-A226V) [5] . This mutation allowed CHIKV's secondary vector species, Ae. albopictus, to supplement Ae. aegypti as its primary vector [5] .", "Within a year, the E1-A226V mutation was present in La Reunion Island, and Ae. albopictus apparently vectored the large epidemic infecting 34% of La Reunion Island's population [5] . All of the CHIKV strains isolated from Mayotte carried the E1-A226V mutation, and the mutation was also found in Madagascar in 2007 [5] . The E1-A226V mutation was not present at the beginning of the Indian Ocean Islands outbreak (before September 2005). However, more than 90% of later viral strains found there had incorporated the mutation (December-March 2006), indicating a genotype switch during the winter season [5, 18, 20] .", "The E1-A226V mutation also enabled an increase in infectivity of Ae. albopictus when compared to its infectivity of Ae. aegypti [4, 11, 18, 30] , and with several factors taken together, Ae. albopictus has become the new preferred and more lethal vector for CHIKV [4, 5, 11] . In fact, Tsetsarkin et al. found that a Green Fluorescent Protein tagged E1-A226V virus was 100 times more infective to Ae. albopictus than it was to Ae. aegypti [4] . In all the Indian Ocean Islands, Ae. albopictus became the main vector for CHIKV within 1-2 y after CHIKV was introduced to the region [31] .", "Of note is that Ae. aegypti has most likely been established in North America for over 300 y, while Ae. albopictus has been in many areas of the US, since 1985, primarily in Florida [32] and since then has expanded its range in the country. Reiskind et al. set out to determine if Ae. aegypti and Ae. albopictus mosquitoes captured in Florida were susceptible to CHIKV infection by a La Reunion isolate [32] . Each mosquito tested was highly susceptible to infection by a full-length infectious clone of the La Réunion Island isolate, CHIKV LR2006 OPY1 strain. Even though the Ae. albopictus strains were more susceptible to infection, overall ecology and differences in human biting patterns need to be studied further Characteristically, there are two rounds of translation: (+) sense genomic RNA (49S9 = 11.7 kb) acts directly as mRNA and is partially translated (59 end) to produce non-structural proteins (nsp's). These proteins are responsible for replication and formation of a complementary", "(2) strand, the template for further (+) strand synthesis. Subgenomic mRNA (26 S = 4.1 kb) replication occurs through the synthesis of full-length (2) intermediate RNA, which is regulated by nsp4 and p123 precursor in early infection and later by mature nsp's. Translation of the newly synthesized sub-genomic RNA results in production of structural proteins such as Capsid and protein E2-6k-E1 (from 39 end of genome). Assembly occurs at the cell surface, and the envelope is acquired as the virus buds from the cell and release and maturation almost simultaneous occurred. Replication occurs in the cytoplasm and is very rapid (,4 h) [28, 29] . doi:10.1371/journal.pntd.0000623.g002 www.plosntds.org to gain a more accurate understanding of a potential CHIKV epidemic in the US [32] .", "During the 7 d preceding birth, no human mother has been reported to transmit the disease vertically. However, about 50% of newborns delivered while the mother was infected with CHIKV contracted the disease from their mother, despite the method of delivery. Furthermore, there have been instances of CHIKV transmission from mother to fetus causing congenital illness and fetal death [33] .", "During the 2005-2006 La Reunion Island outbreaks, Ramful et al. discovered that mothers could transmit CHIKV to their progeny during the perinatal period (Day 24 to Day +1) [33, 34] , and it is associated with a high degree of morbidity. By mean Day 4 of life, all of the neonates were symptomatic for CHIKV, exhibiting common CHIKF symptoms. Six neonates were confirmed to have contracted CHIKV and developed mengoencephalitis. Of those mothers who, during the La Reunion Island epidemic, were infected long before delivery, only three fetal deaths were reported [12, 33] . Ramful et al. theorized that motherto-child transmission most likely happens transplacentally shortly before delivery [33] . A similar study by Gerardin et al. reported nineteen cases of neonatal infection associated with intrapartum maternal viremia that progressed to develop encephalitis owing to vertical transmission from infected mothers [34] .", "Clinical and epidemiological similarities with dengue fever make CHIKV diagnosis difficult, which may lead physicians to misdiagnose CHIKV as dengue fever; therefore, the incidence of CHIKV may actually be higher than currently believed (Table 1 ) [6, 12, 35] .", "The amount of time elapsed since disease onset is the most critical parameter when choosing a diagnostic test. CHIKV can be detected and isolated by culturing with mosquito cells (C6/36), Vero cells (mammalian), or in mice [26] . However, this method can take at least a week and only achieves a high sensitivity during the viremic phase, which usually only lasts up to 48 h after the bite. Five days post-infection, the viral isolation approach has a low sensitivity but is still the preferred method for detecting the CHIKV strain [12, 26, 31, 35] . RT-PCR on the other hand is a faster and more sensitive method that can be used within the first week of disease onset [26] , and it is currently the most sensitive method for detecting and quantifying viral mRNA [4, 36] .", "Classic serological detection, by assays such as ELISA [37] , immunofluorescence [5, 38] , complement binding, and haemagglutination inhibition [39] , constitutes the second diagnostic tool used for biological diagnosis of CHIKV infection. These proven techniques are useful for detection of Antigen in mosquitoes during epidemiological studies. These assays detect virus-specific IgM and IgG, however the sensitivity and specificity of these assays has been poorly characterized. Viral competence, or the potential of viral infection and transmission, is an important parameter that can be quantified by ELISA, viral culture, and PCR.", "A study by Ng et al. showed biomarkers indicative of severe CHIKV infection [40] . They found decreased levels of RANTES and increased levels of Interleukin-6 (IL-6) and Interleukin-1b (IL-1b) that could be sued for CHIKV detection in patients as indicators of CHIKV-driven cytokine storm. Couderc et al. demonstrate another cytokine, type-I IFN, as a key player in the progression to CHIKV infection [26] . Using an IFN-a/b null mouse model, they demonstrated evidence of muscles, joints, and skin as privileged CHIKV targets, which is consistent with human pathology. Although Ng et al. concluded that RANTES levels were significantly suppressed in severe CHIKF patients [40] , interestingly, an increase in levels of RANTES has been observed in dengue infection [41] . Since the symptoms of CHIKF mimic those of dengue fever, results obtained from this study strongly suggest that RANTES could be a potential distinctive biomarker that differentiates between these two clinically similar", "diseases.", "There are no approved antiviral treatments currently available for CHIKV [1, 3, 12, 42] . Currently, CHIKF is treated symptomatically, usually with non-steroidal anti-inflammatory drugs or steroids, bed rest, and fluids. Movement and mild exercise are thought to decrease stiffness and morning arthralgia, but heavy exercise may exacerbate rheumatic symptoms. Corticosteroids may be used in cases of debilitating chronic CHIKV infection. There is a debate about the appropriateness of chloroquine as treatment for unresolved, non-steroidal anti-inflammatory drugresistant arthritis [43] . A study showed that viral production was www.plosntds.org drastically reduced at 16 h post-infection after treatment with 100 mM dec-RVKR-cmk (Decanoyl-Arg-Val-Lys-Arg-chloromethylketone), a furine inhibitor [42, 44] . Chloroquine acted by raising the pH, blocking low pH-dependent entry of virus into the cell. It is important to note that dec-RVKR-cmk or chloroquine only inhibited viral spreading from cell", "to cell, not CHIKV replication once it had entered the cell [43] . However, most would agree that the best weapon against CHIKV is prevention. A live CHIKV vaccine developed by the United States reached phase II clinical trial encompassing 59 healthy volunteers [45] . Eight percent of the volunteers experienced transient arthralgia, while 98% of the volunteers had seroconversion [45] . However, live CHIKV vaccines are still questionable. One cannot discount the risk of a live vaccine possibly inducing chronic rheumatism. Also, there is the question as to whether widespread use among the public could trigger mosquito transmission or lead to chronic infection or viral reversion [1] .", "An alternative approach would be to produce a chimeric vaccine against CHIKV. Wang et al. developed a chimeric alphavirus vaccine that is uniformly attenuated and does not cause reactogenicity in mice [3] . Three different versions of this vaccine were made using three different backbone vectors: Venezuelan equine encephalitis virus (VEEV) attenuated vaccine strain T-83, naturally attenuated eastern equine encephalitis virus (EEEV), and attenuated Sindbis virus (SINV). In short, CHIKV structural proteins were engineered into the backbones of the aforementioned vaccines to produce the chimeras [3] . These chimeras were found to stimulate a strong humoral immunity, and even at doses of 5.3-5.8 log 10 PFU, they did not trigger reactogenicity. When vaccinated mice were challenged with CHIKV, neither adult nor neonatal mice gained weight, had fever, or displayed signs of neurological illness. Upon comparison of the chimeras with the Army181/25 vaccine, the Army vaccine resulted in higher", "levels of viremia and replication in the joints of neonatal mice. Because the joints are known targets of CHIKV, Wang et al. noted their vaccine might avoid the negative reactogenic side effects of the Army vaccine. After being subcutaneously vaccinated with 5.3-5.8 log 10 PFU of the chimeric vaccines, mice produced strong neutralizing antibody titers. The VEEV and EEEV chimeras yielded higher neutralizing antibody titers than the SINV chimera without being more virulent. On top of this, the VEEV and EEEV CHIKV chimeras seemed to be more immunogenic than the Army vaccine despite the chimeras' lower viremia and replication in the joints of neonatal mice [3] .", "Tiwari et al. [46] adopted a different strategy using formalin inactivated CHIKV in combination with alhydrogel (Aluminum Hydroxide) as an adjuvant. This study clearly suggests that this vaccine elicits both humoral and cell-mediated immune responses in mice, providing its immunogenic potential. A recent study by Couderc et al. [47] showed passive immunization as a potential treatment for CHIKV infection. Using purified immunoglobulin extracted from convalescent CHIKV patients, they demonstrated effective neutralizing activity against CHIKV infection both in vitro and in vivo. This thereby establishes a potential preventive and therapeutic approach to combat CHIKV infection. Pathogenesis studies conducted with related alpha virus, like RRV, have shown the role of macrophages in persistence on infection [48] . They also demonstrated the role of RRV-specific CD8 T cells in clearing viral load in infected patients, thereby warranting similar investigations with CHIKV and the importance", "of investigating a cell-mediated immune response-based vaccine against CHIKV [49] .", "There are always certain risks associated with live attenuated or inactivated viral vaccines [50] . One way to avoid these potential problems is to construct a consensus-based DNA vaccine. DNA based vaccines have an improved safety profile as compared to live or attenuated vaccines [51, 52] . A consequence of CHIKV's rapid evolution is difficulty in constructing a vaccine that will be able to Figure 3 . Levels of CHIKV-specific IgG in mice immunized with CHIKV vaccines. Each group of C57BL/6 mice (n = 5) was immunized with 12.5 mg of pVax1 control vector or CHIKV vaccine plasmids as indicated at 0 and 2 wk. Mice were bled 2 wk after each immunization, and each group's serum pool was diluted to 1:100 and 1:500 for reaction with specific vaccine constructs. Serum was incubated for 1 h at 37uC on 96-well plates coated with 2 mg/ml of respective CHIKV peptides, and antibody was detected using anti-mouse IgG-HRP and OD was measured at 405 nm. doi:10.1371/journal.pntd.0000623.g003", "www.plosntds.org effectively protect large populations from multiple strains of the virus. One of the strengths of DNA consensus vaccines is its ability to induce cross-reactive immune responses against the three distinct phylogenetic groups of CHIKV. Also DNA-based vaccines can be produced more rapidly than protein-based vaccines.", "Recently, Muthumani et al. constructed a vaccine that was shown to induce both humoral and cellular immunity in vivo in 3-4-wk-old female C57/BL6 mice [49] . These mice were immunized using an in vivo electroporation method to deliver the vaccine into the quadriceps muscle. The consensus construct was designed against E1, E2, and the core protein capsid. To design the construct, they aligned 21 sequences of CHIKV isolated between 1952 and 2006, using strains from differing countries, including La Reunion Island. The most common nucleotide among the sequences was chosen at each position to be used in the consensus construct, taking care not to alter the reading frame. They conducted codon and RNA optimization, added a strong Kozak sequence, and substituted signal peptide with an immunoglobulin E leader sequence to improve vaccine efficacy.", "After immunizing the mice, spleens were harvested along with serum and tested to determine antibody titer. After three immunizations, consensus E1, E2, and C vaccines were shown to induce T-cell immune responses leading to strong IFN-c responses and proliferation in C57/BL6 mice. Furthermore, when compared with control mice, immunized mice had higher total IgG levels as well as higher anti-E1 specific, anti-E2 specific, and anti-C specific IgG antibodies, suggesting a strong humoral immune response ( Figure 3 ) and also specificity for the antigens encoded in the vaccine constructs ( Figure 4 ). Because of its promising results and the need for a safer vaccine, this consensus DNA vaccine deserves further investigation. Determining longevity of protective effects of the vaccine and persistence of antibody and IFN-c responses could be the next step of investigation. Challenged studies of immunized mice must also be carried out.", "CHIKV mosquito-borne disease has caused massive outbreaks for at least half a century but is no longer confined to the www.plosntds.org developing nations. It began to encroach into the boundaries of the developing world. As a result, the NIAID has designated CHIKV as a Category C pathogen alongside the influenza and SARS-CoV viruses [3] . Realization of the potential severity of this disease is exigent; for instance, if used as a biological weapon, the world economy could be severely crippled; if enough members of the armed forces were to become infected during a military deployment, military operations could be significantly affected. Efforts to monitor the disease will only provide minimal warning in a global society, and steps to prevent the morbidity and mortality associated with pandemic are imperative [21, 31] . Despite the gravity of its infectious potency and the fear of it being a potential biological weapon, there is currently no vaccine for CHIKV infections. Live", "attenuated vaccine trials were carried out in 2000, but funding for the project was discontinued. Newer approaches such as DNA vaccines appear promising over conventional strategies like live attenuated or inactivated virus and thus call for further investigation. Recent advances such electroporation delivery and incorporation of adjuvants has boosted DNA vaccine efficacy [51, 53] . Despite the low antibody response to DNA vaccines, other numerous advantages have overshadowed these minor drawbacks (Table 2) , the most important one being the ability to induce both humoral and cellular immune responses [51, 54] .", "Judging by recent success, such as the immunogenic construct developed by Muthumani et al., DNA vaccines could play a major role in combating CHIKV [49] . Vaccines are literally a critical component of CHIKV disease control and therefore research in this area is highly encouraged. The dramatic spread of dengue viruses (DENV) throughout tropical America since 1980 via the same vectors and human hosts underscores the risk to public health in the Americas. The adverse events associated with the current live vaccine are well documented [55] . Realizing these drawbacks, earnest efforts should be taken to develop new strategies to forestall further spread and complications." ]	[ 4 ]	3,829	5,688
1,689	What dose this review describe?	2,487	[ "its clinical features and pathogenesis and its symptoms and complications, and finally nominates a possible vaccine approach against CHIKV infection." ]	[ "Chikungunya: A Potentially Emerging Epidemic?\n\nhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC2860491/\n\nSHA: f7c3160bef4169d29e2a8bdd79dd6e9056d4774c\n\nAuthors: Thiboutot, Michelle M.; Kannan, Senthil; Kawalekar, Omkar U.; Shedlock, Devon J.; Khan, Amir S.; Sarangan, Gopalsamy; Srikanth, Padma; Weiner, David B.; Muthumani, Karuppiah\nDate: 2010-04-27\nDOI: 10.1371/journal.pntd.0000623\nLicense: cc-by", "Abstract: Chikungunya virus is a mosquito-borne emerging pathogen that has a major health impact in humans and causes fever disease, headache, rash, nausea, vomiting, myalgia, and arthralgia. Indigenous to tropical Africa, recent large outbreaks have been reported in parts of South East Asia and several of its neighboring islands in 2005–07 and in Europe in 2007. Furthermore, positive cases have been confirmed in the United States in travelers returning from known outbreak areas. Currently, there is no vaccine or antiviral treatment. With the threat of an emerging global pandemic, the peculiar problems associated with the more immediate and seasonal epidemics warrant the development of an effective vaccine. In this review, we summarize the evidence supporting these concepts.", "Text: Chikungunya virus (CHIKV), a mosquito-borne pathogen listed by National Institute of Allergy and Infectious Diseases (NIAID) as a Category C Priority Pathogen that causes Chikungunya fever (CHIKF), has been spreading throughout Asia, Africa, and parts of Europe in recent times [1, 2, 3] . CHIKV is an arthropod-borne virus (arbovirus) and is transmitted to humans primarily by Aedes aegypti, the infamous yellow fever propagator [4, 5] . CHIKV infection is marked by severe joint pain, contorting its victims into unusual postures [6] . The disease gets its name from the Kimakonde vernacular language of Tanzania and Mozambique, and the word chikungunya means ''that which contorts or bends up'' and translates in Swahili to ''the illness of the bended walker'' [7, 8, 9] . In Africa, CHIKV is maintained in a sylvatic cycle among forest-dwelling Aedes spp. mosquitoes, wild primates, squirrels, birds, and rodents ( Figure 1 ) [10] . In Asia, the disease is vectored by Ae. aegypti and Ae.", "albopictus [11] . Transmission in Asia occurs in an urban cycle whereby the mosquito spreads the disease from an infected human to an uninfected human, following an epidemiological pattern similar to dengue fever [12] .", "The 2005-2006 epidemic of CHIKV in La Reunion islands in the Indian Ocean, spurred the discovery of a new vector species, Ae. albopictus [5] . Wrecking over one-third of the island's population, this epidemic peaked its devastation between January and February 2006, when over 46,000 cases came into light every week, including 284 deaths [5, 13] . Ae. albopictus is common in urban areas of the United States and is already flourishing in 36 states, raising grave concerns to the immunologically naive populace of the United States [14] .\n\nAccordingly, this review elaborately details the epidemiology and global expansion of CHIKV, describes its clinical features and pathogenesis and its symptoms and complications, and finally nominates a possible vaccine approach against CHIKV infection.", "CHIKV has been isolated into three genotypes based on phylogenetic studies. These genotypes, based on the gene sequences of an Envelope protein (E1), are Asian, East/Central/ South African, and West African [4, 11, 15] . Using phylogenetic models, Cherian et al. estimate that the Asian genotype of CHIKV emerged between 50 and 310 y ago, and the West and East African genotypes diverged between 100 and 840 y ago [15] . Since then, CHIKV has come a long way, with several mutations incorporated, and has continued to wreak epidemics in several regions. Recent activities of CHIKV include the Indian epidemic in 2005-2006, which was followed by a sudden explosion of cases in 2007. An estimated 1.3 million people across 13 states were reported to be infected in India [12, 16] , and CHIKV was also widespread in Malaysia, Sri Lanka, and Indonesia [17] . In July-August of 2007, CHIKV was reported in Italy, probably brought in by travelers from CHIKV-prone regions of India, Africa, and Indian", "Ocean islands such as Mauritius, Madagascar, and Seychelles. Few of the Italian isolates were found to have evolved from the Kerala isolate, which was associated with a A226V shift in E1 gene that represents a successful evolutionary adaptation in the mosquito vector similar to the ones observed in Reunion Island [2, 18, 19] .", "In recent times, with an increase in global travel, the risk for spreading CHIKV to non-endemic regions has heightened [1] . Several travelers have brought CHIKV home with them after visiting areas with actively infected populations [12, 20] . Such cases have been documented in European countries, Australia, Asia, and the United States [8, 21] . The United States has already reported at least twelve cases of travel-associated CHIKV, while France has reported 850 cases, and the United Kingdom 93 [8, 14] . Beyond this, CHIKV-infected travelers have also been diagnosed in Australia, Belgium, Canada, Czech Republic, French Guiana, Germany, Hong Kong, Italy, Japan, Kenya, Malaysia, Martinique, Norway, Switzerland, and Sri Lanka [21] . Some travelers were viremic, worrying public health officials about the spread of CHIKV to new areas [1, 8] .", "The incubation time for CHIKV is relatively short, requiring only 2-6 d with symptoms usually appearing 4-7 d post-infection [22] . Vazeille et al. detected CHIKV in the salivary glands of Ae. albopictus only 2 d after infection [5] . Upon infection, CHIKF tends to present itself in two phases. The first stage is acute, while the second stage, experienced by most but not all, is persistent, causing disabling polyarthritis. Characteristics of the acute phase include an abrupt onset of fever, arthralgia, and in some cases, maculopapular rash [6, 23] . The acute phase causes such intense joint and muscular pain that makes movement very difficult and prostrates its victims [6, 20] .", "Ninety-five percent of infected adults are symptomatic after infection, and of these, most become disabled for weeks to months as a result of decreased dexterity, loss of mobility, and delayed reaction. Eighteen months after disease onset, 40% of patients are found to still have anti-CHIKV IgM [6, 18, 23, 24] . The chronic stage of CHIKF is characterized by polyarthralgia that can last from weeks to years beyond the acute stage [6] . CHIKV has been shown to attack fibroblasts, explaining the involvement of muscles, joints, and skin connective tissues. The high number of nociceptive nerve endings found within the joints and muscle connective tissues can explain pain associated with CHIKF [25, 26] .", "More than 50% of patients who suffer from severe CHIKF are over 65 y old, and more than 33% of them die. Most adults who suffer from severe CHIKF have underlying medical conditions [6, 24, 27] . The other group that is disproportionately affected by severe CHIKV is children. Other complications associated with CHIKV, from most common to least common, include respiratory failure, cardiovascular decompensation, meningoencephalitis, severe acute hepatitis, severe cutaneous effects, other central nervous system problems, and kidney failure [6, 18, 20, 23, 24, 26, 27] .", "CHIKV undertakes a complex replication cycle upon host infection (Figure 2 ), which makes its genome susceptible to mutations [28, 29] . For instance, Ae. aegypti, responsible for epidemics in Kenya, Comoros, and Seychelles, carried CHIKV with an alanine in the 226 position of the E1 gene (E1-A226) [4, 18] . However, when the virus struck La Reunion Islands, a decline in population of Ae. aegypti, due to massive dichlorodiphenyltrichloroethane usage and dearth of Ae. albopictus species' www.plosntds.org population, resulted in an ecological pressure, favoring replacement of alanine at position 226 with valine (E1-A226V) [5] . This mutation allowed CHIKV's secondary vector species, Ae. albopictus, to supplement Ae. aegypti as its primary vector [5] .", "Within a year, the E1-A226V mutation was present in La Reunion Island, and Ae. albopictus apparently vectored the large epidemic infecting 34% of La Reunion Island's population [5] . All of the CHIKV strains isolated from Mayotte carried the E1-A226V mutation, and the mutation was also found in Madagascar in 2007 [5] . The E1-A226V mutation was not present at the beginning of the Indian Ocean Islands outbreak (before September 2005). However, more than 90% of later viral strains found there had incorporated the mutation (December-March 2006), indicating a genotype switch during the winter season [5, 18, 20] .", "The E1-A226V mutation also enabled an increase in infectivity of Ae. albopictus when compared to its infectivity of Ae. aegypti [4, 11, 18, 30] , and with several factors taken together, Ae. albopictus has become the new preferred and more lethal vector for CHIKV [4, 5, 11] . In fact, Tsetsarkin et al. found that a Green Fluorescent Protein tagged E1-A226V virus was 100 times more infective to Ae. albopictus than it was to Ae. aegypti [4] . In all the Indian Ocean Islands, Ae. albopictus became the main vector for CHIKV within 1-2 y after CHIKV was introduced to the region [31] .", "Of note is that Ae. aegypti has most likely been established in North America for over 300 y, while Ae. albopictus has been in many areas of the US, since 1985, primarily in Florida [32] and since then has expanded its range in the country. Reiskind et al. set out to determine if Ae. aegypti and Ae. albopictus mosquitoes captured in Florida were susceptible to CHIKV infection by a La Reunion isolate [32] . Each mosquito tested was highly susceptible to infection by a full-length infectious clone of the La Réunion Island isolate, CHIKV LR2006 OPY1 strain. Even though the Ae. albopictus strains were more susceptible to infection, overall ecology and differences in human biting patterns need to be studied further Characteristically, there are two rounds of translation: (+) sense genomic RNA (49S9 = 11.7 kb) acts directly as mRNA and is partially translated (59 end) to produce non-structural proteins (nsp's). These proteins are responsible for replication and formation of a complementary", "(2) strand, the template for further (+) strand synthesis. Subgenomic mRNA (26 S = 4.1 kb) replication occurs through the synthesis of full-length (2) intermediate RNA, which is regulated by nsp4 and p123 precursor in early infection and later by mature nsp's. Translation of the newly synthesized sub-genomic RNA results in production of structural proteins such as Capsid and protein E2-6k-E1 (from 39 end of genome). Assembly occurs at the cell surface, and the envelope is acquired as the virus buds from the cell and release and maturation almost simultaneous occurred. Replication occurs in the cytoplasm and is very rapid (,4 h) [28, 29] . doi:10.1371/journal.pntd.0000623.g002 www.plosntds.org to gain a more accurate understanding of a potential CHIKV epidemic in the US [32] .", "During the 7 d preceding birth, no human mother has been reported to transmit the disease vertically. However, about 50% of newborns delivered while the mother was infected with CHIKV contracted the disease from their mother, despite the method of delivery. Furthermore, there have been instances of CHIKV transmission from mother to fetus causing congenital illness and fetal death [33] .", "During the 2005-2006 La Reunion Island outbreaks, Ramful et al. discovered that mothers could transmit CHIKV to their progeny during the perinatal period (Day 24 to Day +1) [33, 34] , and it is associated with a high degree of morbidity. By mean Day 4 of life, all of the neonates were symptomatic for CHIKV, exhibiting common CHIKF symptoms. Six neonates were confirmed to have contracted CHIKV and developed mengoencephalitis. Of those mothers who, during the La Reunion Island epidemic, were infected long before delivery, only three fetal deaths were reported [12, 33] . Ramful et al. theorized that motherto-child transmission most likely happens transplacentally shortly before delivery [33] . A similar study by Gerardin et al. reported nineteen cases of neonatal infection associated with intrapartum maternal viremia that progressed to develop encephalitis owing to vertical transmission from infected mothers [34] .", "Clinical and epidemiological similarities with dengue fever make CHIKV diagnosis difficult, which may lead physicians to misdiagnose CHIKV as dengue fever; therefore, the incidence of CHIKV may actually be higher than currently believed (Table 1 ) [6, 12, 35] .", "The amount of time elapsed since disease onset is the most critical parameter when choosing a diagnostic test. CHIKV can be detected and isolated by culturing with mosquito cells (C6/36), Vero cells (mammalian), or in mice [26] . However, this method can take at least a week and only achieves a high sensitivity during the viremic phase, which usually only lasts up to 48 h after the bite. Five days post-infection, the viral isolation approach has a low sensitivity but is still the preferred method for detecting the CHIKV strain [12, 26, 31, 35] . RT-PCR on the other hand is a faster and more sensitive method that can be used within the first week of disease onset [26] , and it is currently the most sensitive method for detecting and quantifying viral mRNA [4, 36] .", "Classic serological detection, by assays such as ELISA [37] , immunofluorescence [5, 38] , complement binding, and haemagglutination inhibition [39] , constitutes the second diagnostic tool used for biological diagnosis of CHIKV infection. These proven techniques are useful for detection of Antigen in mosquitoes during epidemiological studies. These assays detect virus-specific IgM and IgG, however the sensitivity and specificity of these assays has been poorly characterized. Viral competence, or the potential of viral infection and transmission, is an important parameter that can be quantified by ELISA, viral culture, and PCR.", "A study by Ng et al. showed biomarkers indicative of severe CHIKV infection [40] . They found decreased levels of RANTES and increased levels of Interleukin-6 (IL-6) and Interleukin-1b (IL-1b) that could be sued for CHIKV detection in patients as indicators of CHIKV-driven cytokine storm. Couderc et al. demonstrate another cytokine, type-I IFN, as a key player in the progression to CHIKV infection [26] . Using an IFN-a/b null mouse model, they demonstrated evidence of muscles, joints, and skin as privileged CHIKV targets, which is consistent with human pathology. Although Ng et al. concluded that RANTES levels were significantly suppressed in severe CHIKF patients [40] , interestingly, an increase in levels of RANTES has been observed in dengue infection [41] . Since the symptoms of CHIKF mimic those of dengue fever, results obtained from this study strongly suggest that RANTES could be a potential distinctive biomarker that differentiates between these two clinically similar", "diseases.", "There are no approved antiviral treatments currently available for CHIKV [1, 3, 12, 42] . Currently, CHIKF is treated symptomatically, usually with non-steroidal anti-inflammatory drugs or steroids, bed rest, and fluids. Movement and mild exercise are thought to decrease stiffness and morning arthralgia, but heavy exercise may exacerbate rheumatic symptoms. Corticosteroids may be used in cases of debilitating chronic CHIKV infection. There is a debate about the appropriateness of chloroquine as treatment for unresolved, non-steroidal anti-inflammatory drugresistant arthritis [43] . A study showed that viral production was www.plosntds.org drastically reduced at 16 h post-infection after treatment with 100 mM dec-RVKR-cmk (Decanoyl-Arg-Val-Lys-Arg-chloromethylketone), a furine inhibitor [42, 44] . Chloroquine acted by raising the pH, blocking low pH-dependent entry of virus into the cell. It is important to note that dec-RVKR-cmk or chloroquine only inhibited viral spreading from cell", "to cell, not CHIKV replication once it had entered the cell [43] . However, most would agree that the best weapon against CHIKV is prevention. A live CHIKV vaccine developed by the United States reached phase II clinical trial encompassing 59 healthy volunteers [45] . Eight percent of the volunteers experienced transient arthralgia, while 98% of the volunteers had seroconversion [45] . However, live CHIKV vaccines are still questionable. One cannot discount the risk of a live vaccine possibly inducing chronic rheumatism. Also, there is the question as to whether widespread use among the public could trigger mosquito transmission or lead to chronic infection or viral reversion [1] .", "An alternative approach would be to produce a chimeric vaccine against CHIKV. Wang et al. developed a chimeric alphavirus vaccine that is uniformly attenuated and does not cause reactogenicity in mice [3] . Three different versions of this vaccine were made using three different backbone vectors: Venezuelan equine encephalitis virus (VEEV) attenuated vaccine strain T-83, naturally attenuated eastern equine encephalitis virus (EEEV), and attenuated Sindbis virus (SINV). In short, CHIKV structural proteins were engineered into the backbones of the aforementioned vaccines to produce the chimeras [3] . These chimeras were found to stimulate a strong humoral immunity, and even at doses of 5.3-5.8 log 10 PFU, they did not trigger reactogenicity. When vaccinated mice were challenged with CHIKV, neither adult nor neonatal mice gained weight, had fever, or displayed signs of neurological illness. Upon comparison of the chimeras with the Army181/25 vaccine, the Army vaccine resulted in higher", "levels of viremia and replication in the joints of neonatal mice. Because the joints are known targets of CHIKV, Wang et al. noted their vaccine might avoid the negative reactogenic side effects of the Army vaccine. After being subcutaneously vaccinated with 5.3-5.8 log 10 PFU of the chimeric vaccines, mice produced strong neutralizing antibody titers. The VEEV and EEEV chimeras yielded higher neutralizing antibody titers than the SINV chimera without being more virulent. On top of this, the VEEV and EEEV CHIKV chimeras seemed to be more immunogenic than the Army vaccine despite the chimeras' lower viremia and replication in the joints of neonatal mice [3] .", "Tiwari et al. [46] adopted a different strategy using formalin inactivated CHIKV in combination with alhydrogel (Aluminum Hydroxide) as an adjuvant. This study clearly suggests that this vaccine elicits both humoral and cell-mediated immune responses in mice, providing its immunogenic potential. A recent study by Couderc et al. [47] showed passive immunization as a potential treatment for CHIKV infection. Using purified immunoglobulin extracted from convalescent CHIKV patients, they demonstrated effective neutralizing activity against CHIKV infection both in vitro and in vivo. This thereby establishes a potential preventive and therapeutic approach to combat CHIKV infection. Pathogenesis studies conducted with related alpha virus, like RRV, have shown the role of macrophages in persistence on infection [48] . They also demonstrated the role of RRV-specific CD8 T cells in clearing viral load in infected patients, thereby warranting similar investigations with CHIKV and the importance", "of investigating a cell-mediated immune response-based vaccine against CHIKV [49] .", "There are always certain risks associated with live attenuated or inactivated viral vaccines [50] . One way to avoid these potential problems is to construct a consensus-based DNA vaccine. DNA based vaccines have an improved safety profile as compared to live or attenuated vaccines [51, 52] . A consequence of CHIKV's rapid evolution is difficulty in constructing a vaccine that will be able to Figure 3 . Levels of CHIKV-specific IgG in mice immunized with CHIKV vaccines. Each group of C57BL/6 mice (n = 5) was immunized with 12.5 mg of pVax1 control vector or CHIKV vaccine plasmids as indicated at 0 and 2 wk. Mice were bled 2 wk after each immunization, and each group's serum pool was diluted to 1:100 and 1:500 for reaction with specific vaccine constructs. Serum was incubated for 1 h at 37uC on 96-well plates coated with 2 mg/ml of respective CHIKV peptides, and antibody was detected using anti-mouse IgG-HRP and OD was measured at 405 nm. doi:10.1371/journal.pntd.0000623.g003", "www.plosntds.org effectively protect large populations from multiple strains of the virus. One of the strengths of DNA consensus vaccines is its ability to induce cross-reactive immune responses against the three distinct phylogenetic groups of CHIKV. Also DNA-based vaccines can be produced more rapidly than protein-based vaccines.", "Recently, Muthumani et al. constructed a vaccine that was shown to induce both humoral and cellular immunity in vivo in 3-4-wk-old female C57/BL6 mice [49] . These mice were immunized using an in vivo electroporation method to deliver the vaccine into the quadriceps muscle. The consensus construct was designed against E1, E2, and the core protein capsid. To design the construct, they aligned 21 sequences of CHIKV isolated between 1952 and 2006, using strains from differing countries, including La Reunion Island. The most common nucleotide among the sequences was chosen at each position to be used in the consensus construct, taking care not to alter the reading frame. They conducted codon and RNA optimization, added a strong Kozak sequence, and substituted signal peptide with an immunoglobulin E leader sequence to improve vaccine efficacy.", "After immunizing the mice, spleens were harvested along with serum and tested to determine antibody titer. After three immunizations, consensus E1, E2, and C vaccines were shown to induce T-cell immune responses leading to strong IFN-c responses and proliferation in C57/BL6 mice. Furthermore, when compared with control mice, immunized mice had higher total IgG levels as well as higher anti-E1 specific, anti-E2 specific, and anti-C specific IgG antibodies, suggesting a strong humoral immune response ( Figure 3 ) and also specificity for the antigens encoded in the vaccine constructs ( Figure 4 ). Because of its promising results and the need for a safer vaccine, this consensus DNA vaccine deserves further investigation. Determining longevity of protective effects of the vaccine and persistence of antibody and IFN-c responses could be the next step of investigation. Challenged studies of immunized mice must also be carried out.", "CHIKV mosquito-borne disease has caused massive outbreaks for at least half a century but is no longer confined to the www.plosntds.org developing nations. It began to encroach into the boundaries of the developing world. As a result, the NIAID has designated CHIKV as a Category C pathogen alongside the influenza and SARS-CoV viruses [3] . Realization of the potential severity of this disease is exigent; for instance, if used as a biological weapon, the world economy could be severely crippled; if enough members of the armed forces were to become infected during a military deployment, military operations could be significantly affected. Efforts to monitor the disease will only provide minimal warning in a global society, and steps to prevent the morbidity and mortality associated with pandemic are imperative [21, 31] . Despite the gravity of its infectious potency and the fear of it being a potential biological weapon, there is currently no vaccine for CHIKV infections. Live", "attenuated vaccine trials were carried out in 2000, but funding for the project was discontinued. Newer approaches such as DNA vaccines appear promising over conventional strategies like live attenuated or inactivated virus and thus call for further investigation. Recent advances such electroporation delivery and incorporation of adjuvants has boosted DNA vaccine efficacy [51, 53] . Despite the low antibody response to DNA vaccines, other numerous advantages have overshadowed these minor drawbacks (Table 2) , the most important one being the ability to induce both humoral and cellular immune responses [51, 54] .", "Judging by recent success, such as the immunogenic construct developed by Muthumani et al., DNA vaccines could play a major role in combating CHIKV [49] . Vaccines are literally a critical component of CHIKV disease control and therefore research in this area is highly encouraged. The dramatic spread of dengue viruses (DENV) throughout tropical America since 1980 via the same vectors and human hosts underscores the risk to public health in the Americas. The adverse events associated with the current live vaccine are well documented [55] . Realizing these drawbacks, earnest efforts should be taken to develop new strategies to forestall further spread and complications." ]	[ 4 ]	3,829	5,688
1,689	How many genotypes of CHIKV have been isilated?	2,488	[ "three genotypes based on phylogenetic studies." ]	[ "Chikungunya: A Potentially Emerging Epidemic?\n\nhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC2860491/\n\nSHA: f7c3160bef4169d29e2a8bdd79dd6e9056d4774c\n\nAuthors: Thiboutot, Michelle M.; Kannan, Senthil; Kawalekar, Omkar U.; Shedlock, Devon J.; Khan, Amir S.; Sarangan, Gopalsamy; Srikanth, Padma; Weiner, David B.; Muthumani, Karuppiah\nDate: 2010-04-27\nDOI: 10.1371/journal.pntd.0000623\nLicense: cc-by", "Abstract: Chikungunya virus is a mosquito-borne emerging pathogen that has a major health impact in humans and causes fever disease, headache, rash, nausea, vomiting, myalgia, and arthralgia. Indigenous to tropical Africa, recent large outbreaks have been reported in parts of South East Asia and several of its neighboring islands in 2005–07 and in Europe in 2007. Furthermore, positive cases have been confirmed in the United States in travelers returning from known outbreak areas. Currently, there is no vaccine or antiviral treatment. With the threat of an emerging global pandemic, the peculiar problems associated with the more immediate and seasonal epidemics warrant the development of an effective vaccine. In this review, we summarize the evidence supporting these concepts.", "Text: Chikungunya virus (CHIKV), a mosquito-borne pathogen listed by National Institute of Allergy and Infectious Diseases (NIAID) as a Category C Priority Pathogen that causes Chikungunya fever (CHIKF), has been spreading throughout Asia, Africa, and parts of Europe in recent times [1, 2, 3] . CHIKV is an arthropod-borne virus (arbovirus) and is transmitted to humans primarily by Aedes aegypti, the infamous yellow fever propagator [4, 5] . CHIKV infection is marked by severe joint pain, contorting its victims into unusual postures [6] . The disease gets its name from the Kimakonde vernacular language of Tanzania and Mozambique, and the word chikungunya means ''that which contorts or bends up'' and translates in Swahili to ''the illness of the bended walker'' [7, 8, 9] . In Africa, CHIKV is maintained in a sylvatic cycle among forest-dwelling Aedes spp. mosquitoes, wild primates, squirrels, birds, and rodents ( Figure 1 ) [10] . In Asia, the disease is vectored by Ae. aegypti and Ae.", "albopictus [11] . Transmission in Asia occurs in an urban cycle whereby the mosquito spreads the disease from an infected human to an uninfected human, following an epidemiological pattern similar to dengue fever [12] .", "The 2005-2006 epidemic of CHIKV in La Reunion islands in the Indian Ocean, spurred the discovery of a new vector species, Ae. albopictus [5] . Wrecking over one-third of the island's population, this epidemic peaked its devastation between January and February 2006, when over 46,000 cases came into light every week, including 284 deaths [5, 13] . Ae. albopictus is common in urban areas of the United States and is already flourishing in 36 states, raising grave concerns to the immunologically naive populace of the United States [14] .\n\nAccordingly, this review elaborately details the epidemiology and global expansion of CHIKV, describes its clinical features and pathogenesis and its symptoms and complications, and finally nominates a possible vaccine approach against CHIKV infection.", "CHIKV has been isolated into three genotypes based on phylogenetic studies. These genotypes, based on the gene sequences of an Envelope protein (E1), are Asian, East/Central/ South African, and West African [4, 11, 15] . Using phylogenetic models, Cherian et al. estimate that the Asian genotype of CHIKV emerged between 50 and 310 y ago, and the West and East African genotypes diverged between 100 and 840 y ago [15] . Since then, CHIKV has come a long way, with several mutations incorporated, and has continued to wreak epidemics in several regions. Recent activities of CHIKV include the Indian epidemic in 2005-2006, which was followed by a sudden explosion of cases in 2007. An estimated 1.3 million people across 13 states were reported to be infected in India [12, 16] , and CHIKV was also widespread in Malaysia, Sri Lanka, and Indonesia [17] . In July-August of 2007, CHIKV was reported in Italy, probably brought in by travelers from CHIKV-prone regions of India, Africa, and Indian", "Ocean islands such as Mauritius, Madagascar, and Seychelles. Few of the Italian isolates were found to have evolved from the Kerala isolate, which was associated with a A226V shift in E1 gene that represents a successful evolutionary adaptation in the mosquito vector similar to the ones observed in Reunion Island [2, 18, 19] .", "In recent times, with an increase in global travel, the risk for spreading CHIKV to non-endemic regions has heightened [1] . Several travelers have brought CHIKV home with them after visiting areas with actively infected populations [12, 20] . Such cases have been documented in European countries, Australia, Asia, and the United States [8, 21] . The United States has already reported at least twelve cases of travel-associated CHIKV, while France has reported 850 cases, and the United Kingdom 93 [8, 14] . Beyond this, CHIKV-infected travelers have also been diagnosed in Australia, Belgium, Canada, Czech Republic, French Guiana, Germany, Hong Kong, Italy, Japan, Kenya, Malaysia, Martinique, Norway, Switzerland, and Sri Lanka [21] . Some travelers were viremic, worrying public health officials about the spread of CHIKV to new areas [1, 8] .", "The incubation time for CHIKV is relatively short, requiring only 2-6 d with symptoms usually appearing 4-7 d post-infection [22] . Vazeille et al. detected CHIKV in the salivary glands of Ae. albopictus only 2 d after infection [5] . Upon infection, CHIKF tends to present itself in two phases. The first stage is acute, while the second stage, experienced by most but not all, is persistent, causing disabling polyarthritis. Characteristics of the acute phase include an abrupt onset of fever, arthralgia, and in some cases, maculopapular rash [6, 23] . The acute phase causes such intense joint and muscular pain that makes movement very difficult and prostrates its victims [6, 20] .", "Ninety-five percent of infected adults are symptomatic after infection, and of these, most become disabled for weeks to months as a result of decreased dexterity, loss of mobility, and delayed reaction. Eighteen months after disease onset, 40% of patients are found to still have anti-CHIKV IgM [6, 18, 23, 24] . The chronic stage of CHIKF is characterized by polyarthralgia that can last from weeks to years beyond the acute stage [6] . CHIKV has been shown to attack fibroblasts, explaining the involvement of muscles, joints, and skin connective tissues. The high number of nociceptive nerve endings found within the joints and muscle connective tissues can explain pain associated with CHIKF [25, 26] .", "More than 50% of patients who suffer from severe CHIKF are over 65 y old, and more than 33% of them die. Most adults who suffer from severe CHIKF have underlying medical conditions [6, 24, 27] . The other group that is disproportionately affected by severe CHIKV is children. Other complications associated with CHIKV, from most common to least common, include respiratory failure, cardiovascular decompensation, meningoencephalitis, severe acute hepatitis, severe cutaneous effects, other central nervous system problems, and kidney failure [6, 18, 20, 23, 24, 26, 27] .", "CHIKV undertakes a complex replication cycle upon host infection (Figure 2 ), which makes its genome susceptible to mutations [28, 29] . For instance, Ae. aegypti, responsible for epidemics in Kenya, Comoros, and Seychelles, carried CHIKV with an alanine in the 226 position of the E1 gene (E1-A226) [4, 18] . However, when the virus struck La Reunion Islands, a decline in population of Ae. aegypti, due to massive dichlorodiphenyltrichloroethane usage and dearth of Ae. albopictus species' www.plosntds.org population, resulted in an ecological pressure, favoring replacement of alanine at position 226 with valine (E1-A226V) [5] . This mutation allowed CHIKV's secondary vector species, Ae. albopictus, to supplement Ae. aegypti as its primary vector [5] .", "Within a year, the E1-A226V mutation was present in La Reunion Island, and Ae. albopictus apparently vectored the large epidemic infecting 34% of La Reunion Island's population [5] . All of the CHIKV strains isolated from Mayotte carried the E1-A226V mutation, and the mutation was also found in Madagascar in 2007 [5] . The E1-A226V mutation was not present at the beginning of the Indian Ocean Islands outbreak (before September 2005). However, more than 90% of later viral strains found there had incorporated the mutation (December-March 2006), indicating a genotype switch during the winter season [5, 18, 20] .", "The E1-A226V mutation also enabled an increase in infectivity of Ae. albopictus when compared to its infectivity of Ae. aegypti [4, 11, 18, 30] , and with several factors taken together, Ae. albopictus has become the new preferred and more lethal vector for CHIKV [4, 5, 11] . In fact, Tsetsarkin et al. found that a Green Fluorescent Protein tagged E1-A226V virus was 100 times more infective to Ae. albopictus than it was to Ae. aegypti [4] . In all the Indian Ocean Islands, Ae. albopictus became the main vector for CHIKV within 1-2 y after CHIKV was introduced to the region [31] .", "Of note is that Ae. aegypti has most likely been established in North America for over 300 y, while Ae. albopictus has been in many areas of the US, since 1985, primarily in Florida [32] and since then has expanded its range in the country. Reiskind et al. set out to determine if Ae. aegypti and Ae. albopictus mosquitoes captured in Florida were susceptible to CHIKV infection by a La Reunion isolate [32] . Each mosquito tested was highly susceptible to infection by a full-length infectious clone of the La Réunion Island isolate, CHIKV LR2006 OPY1 strain. Even though the Ae. albopictus strains were more susceptible to infection, overall ecology and differences in human biting patterns need to be studied further Characteristically, there are two rounds of translation: (+) sense genomic RNA (49S9 = 11.7 kb) acts directly as mRNA and is partially translated (59 end) to produce non-structural proteins (nsp's). These proteins are responsible for replication and formation of a complementary", "(2) strand, the template for further (+) strand synthesis. Subgenomic mRNA (26 S = 4.1 kb) replication occurs through the synthesis of full-length (2) intermediate RNA, which is regulated by nsp4 and p123 precursor in early infection and later by mature nsp's. Translation of the newly synthesized sub-genomic RNA results in production of structural proteins such as Capsid and protein E2-6k-E1 (from 39 end of genome). Assembly occurs at the cell surface, and the envelope is acquired as the virus buds from the cell and release and maturation almost simultaneous occurred. Replication occurs in the cytoplasm and is very rapid (,4 h) [28, 29] . doi:10.1371/journal.pntd.0000623.g002 www.plosntds.org to gain a more accurate understanding of a potential CHIKV epidemic in the US [32] .", "During the 7 d preceding birth, no human mother has been reported to transmit the disease vertically. However, about 50% of newborns delivered while the mother was infected with CHIKV contracted the disease from their mother, despite the method of delivery. Furthermore, there have been instances of CHIKV transmission from mother to fetus causing congenital illness and fetal death [33] .", "During the 2005-2006 La Reunion Island outbreaks, Ramful et al. discovered that mothers could transmit CHIKV to their progeny during the perinatal period (Day 24 to Day +1) [33, 34] , and it is associated with a high degree of morbidity. By mean Day 4 of life, all of the neonates were symptomatic for CHIKV, exhibiting common CHIKF symptoms. Six neonates were confirmed to have contracted CHIKV and developed mengoencephalitis. Of those mothers who, during the La Reunion Island epidemic, were infected long before delivery, only three fetal deaths were reported [12, 33] . Ramful et al. theorized that motherto-child transmission most likely happens transplacentally shortly before delivery [33] . A similar study by Gerardin et al. reported nineteen cases of neonatal infection associated with intrapartum maternal viremia that progressed to develop encephalitis owing to vertical transmission from infected mothers [34] .", "Clinical and epidemiological similarities with dengue fever make CHIKV diagnosis difficult, which may lead physicians to misdiagnose CHIKV as dengue fever; therefore, the incidence of CHIKV may actually be higher than currently believed (Table 1 ) [6, 12, 35] .", "The amount of time elapsed since disease onset is the most critical parameter when choosing a diagnostic test. CHIKV can be detected and isolated by culturing with mosquito cells (C6/36), Vero cells (mammalian), or in mice [26] . However, this method can take at least a week and only achieves a high sensitivity during the viremic phase, which usually only lasts up to 48 h after the bite. Five days post-infection, the viral isolation approach has a low sensitivity but is still the preferred method for detecting the CHIKV strain [12, 26, 31, 35] . RT-PCR on the other hand is a faster and more sensitive method that can be used within the first week of disease onset [26] , and it is currently the most sensitive method for detecting and quantifying viral mRNA [4, 36] .", "Classic serological detection, by assays such as ELISA [37] , immunofluorescence [5, 38] , complement binding, and haemagglutination inhibition [39] , constitutes the second diagnostic tool used for biological diagnosis of CHIKV infection. These proven techniques are useful for detection of Antigen in mosquitoes during epidemiological studies. These assays detect virus-specific IgM and IgG, however the sensitivity and specificity of these assays has been poorly characterized. Viral competence, or the potential of viral infection and transmission, is an important parameter that can be quantified by ELISA, viral culture, and PCR.", "A study by Ng et al. showed biomarkers indicative of severe CHIKV infection [40] . They found decreased levels of RANTES and increased levels of Interleukin-6 (IL-6) and Interleukin-1b (IL-1b) that could be sued for CHIKV detection in patients as indicators of CHIKV-driven cytokine storm. Couderc et al. demonstrate another cytokine, type-I IFN, as a key player in the progression to CHIKV infection [26] . Using an IFN-a/b null mouse model, they demonstrated evidence of muscles, joints, and skin as privileged CHIKV targets, which is consistent with human pathology. Although Ng et al. concluded that RANTES levels were significantly suppressed in severe CHIKF patients [40] , interestingly, an increase in levels of RANTES has been observed in dengue infection [41] . Since the symptoms of CHIKF mimic those of dengue fever, results obtained from this study strongly suggest that RANTES could be a potential distinctive biomarker that differentiates between these two clinically similar", "diseases.", "There are no approved antiviral treatments currently available for CHIKV [1, 3, 12, 42] . Currently, CHIKF is treated symptomatically, usually with non-steroidal anti-inflammatory drugs or steroids, bed rest, and fluids. Movement and mild exercise are thought to decrease stiffness and morning arthralgia, but heavy exercise may exacerbate rheumatic symptoms. Corticosteroids may be used in cases of debilitating chronic CHIKV infection. There is a debate about the appropriateness of chloroquine as treatment for unresolved, non-steroidal anti-inflammatory drugresistant arthritis [43] . A study showed that viral production was www.plosntds.org drastically reduced at 16 h post-infection after treatment with 100 mM dec-RVKR-cmk (Decanoyl-Arg-Val-Lys-Arg-chloromethylketone), a furine inhibitor [42, 44] . Chloroquine acted by raising the pH, blocking low pH-dependent entry of virus into the cell. It is important to note that dec-RVKR-cmk or chloroquine only inhibited viral spreading from cell", "to cell, not CHIKV replication once it had entered the cell [43] . However, most would agree that the best weapon against CHIKV is prevention. A live CHIKV vaccine developed by the United States reached phase II clinical trial encompassing 59 healthy volunteers [45] . Eight percent of the volunteers experienced transient arthralgia, while 98% of the volunteers had seroconversion [45] . However, live CHIKV vaccines are still questionable. One cannot discount the risk of a live vaccine possibly inducing chronic rheumatism. Also, there is the question as to whether widespread use among the public could trigger mosquito transmission or lead to chronic infection or viral reversion [1] .", "An alternative approach would be to produce a chimeric vaccine against CHIKV. Wang et al. developed a chimeric alphavirus vaccine that is uniformly attenuated and does not cause reactogenicity in mice [3] . Three different versions of this vaccine were made using three different backbone vectors: Venezuelan equine encephalitis virus (VEEV) attenuated vaccine strain T-83, naturally attenuated eastern equine encephalitis virus (EEEV), and attenuated Sindbis virus (SINV). In short, CHIKV structural proteins were engineered into the backbones of the aforementioned vaccines to produce the chimeras [3] . These chimeras were found to stimulate a strong humoral immunity, and even at doses of 5.3-5.8 log 10 PFU, they did not trigger reactogenicity. When vaccinated mice were challenged with CHIKV, neither adult nor neonatal mice gained weight, had fever, or displayed signs of neurological illness. Upon comparison of the chimeras with the Army181/25 vaccine, the Army vaccine resulted in higher", "levels of viremia and replication in the joints of neonatal mice. Because the joints are known targets of CHIKV, Wang et al. noted their vaccine might avoid the negative reactogenic side effects of the Army vaccine. After being subcutaneously vaccinated with 5.3-5.8 log 10 PFU of the chimeric vaccines, mice produced strong neutralizing antibody titers. The VEEV and EEEV chimeras yielded higher neutralizing antibody titers than the SINV chimera without being more virulent. On top of this, the VEEV and EEEV CHIKV chimeras seemed to be more immunogenic than the Army vaccine despite the chimeras' lower viremia and replication in the joints of neonatal mice [3] .", "Tiwari et al. [46] adopted a different strategy using formalin inactivated CHIKV in combination with alhydrogel (Aluminum Hydroxide) as an adjuvant. This study clearly suggests that this vaccine elicits both humoral and cell-mediated immune responses in mice, providing its immunogenic potential. A recent study by Couderc et al. [47] showed passive immunization as a potential treatment for CHIKV infection. Using purified immunoglobulin extracted from convalescent CHIKV patients, they demonstrated effective neutralizing activity against CHIKV infection both in vitro and in vivo. This thereby establishes a potential preventive and therapeutic approach to combat CHIKV infection. Pathogenesis studies conducted with related alpha virus, like RRV, have shown the role of macrophages in persistence on infection [48] . They also demonstrated the role of RRV-specific CD8 T cells in clearing viral load in infected patients, thereby warranting similar investigations with CHIKV and the importance", "of investigating a cell-mediated immune response-based vaccine against CHIKV [49] .", "There are always certain risks associated with live attenuated or inactivated viral vaccines [50] . One way to avoid these potential problems is to construct a consensus-based DNA vaccine. DNA based vaccines have an improved safety profile as compared to live or attenuated vaccines [51, 52] . A consequence of CHIKV's rapid evolution is difficulty in constructing a vaccine that will be able to Figure 3 . Levels of CHIKV-specific IgG in mice immunized with CHIKV vaccines. Each group of C57BL/6 mice (n = 5) was immunized with 12.5 mg of pVax1 control vector or CHIKV vaccine plasmids as indicated at 0 and 2 wk. Mice were bled 2 wk after each immunization, and each group's serum pool was diluted to 1:100 and 1:500 for reaction with specific vaccine constructs. Serum was incubated for 1 h at 37uC on 96-well plates coated with 2 mg/ml of respective CHIKV peptides, and antibody was detected using anti-mouse IgG-HRP and OD was measured at 405 nm. doi:10.1371/journal.pntd.0000623.g003", "www.plosntds.org effectively protect large populations from multiple strains of the virus. One of the strengths of DNA consensus vaccines is its ability to induce cross-reactive immune responses against the three distinct phylogenetic groups of CHIKV. Also DNA-based vaccines can be produced more rapidly than protein-based vaccines.", "Recently, Muthumani et al. constructed a vaccine that was shown to induce both humoral and cellular immunity in vivo in 3-4-wk-old female C57/BL6 mice [49] . These mice were immunized using an in vivo electroporation method to deliver the vaccine into the quadriceps muscle. The consensus construct was designed against E1, E2, and the core protein capsid. To design the construct, they aligned 21 sequences of CHIKV isolated between 1952 and 2006, using strains from differing countries, including La Reunion Island. The most common nucleotide among the sequences was chosen at each position to be used in the consensus construct, taking care not to alter the reading frame. They conducted codon and RNA optimization, added a strong Kozak sequence, and substituted signal peptide with an immunoglobulin E leader sequence to improve vaccine efficacy.", "After immunizing the mice, spleens were harvested along with serum and tested to determine antibody titer. After three immunizations, consensus E1, E2, and C vaccines were shown to induce T-cell immune responses leading to strong IFN-c responses and proliferation in C57/BL6 mice. Furthermore, when compared with control mice, immunized mice had higher total IgG levels as well as higher anti-E1 specific, anti-E2 specific, and anti-C specific IgG antibodies, suggesting a strong humoral immune response ( Figure 3 ) and also specificity for the antigens encoded in the vaccine constructs ( Figure 4 ). Because of its promising results and the need for a safer vaccine, this consensus DNA vaccine deserves further investigation. Determining longevity of protective effects of the vaccine and persistence of antibody and IFN-c responses could be the next step of investigation. Challenged studies of immunized mice must also be carried out.", "CHIKV mosquito-borne disease has caused massive outbreaks for at least half a century but is no longer confined to the www.plosntds.org developing nations. It began to encroach into the boundaries of the developing world. As a result, the NIAID has designated CHIKV as a Category C pathogen alongside the influenza and SARS-CoV viruses [3] . Realization of the potential severity of this disease is exigent; for instance, if used as a biological weapon, the world economy could be severely crippled; if enough members of the armed forces were to become infected during a military deployment, military operations could be significantly affected. Efforts to monitor the disease will only provide minimal warning in a global society, and steps to prevent the morbidity and mortality associated with pandemic are imperative [21, 31] . Despite the gravity of its infectious potency and the fear of it being a potential biological weapon, there is currently no vaccine for CHIKV infections. Live", "attenuated vaccine trials were carried out in 2000, but funding for the project was discontinued. Newer approaches such as DNA vaccines appear promising over conventional strategies like live attenuated or inactivated virus and thus call for further investigation. Recent advances such electroporation delivery and incorporation of adjuvants has boosted DNA vaccine efficacy [51, 53] . Despite the low antibody response to DNA vaccines, other numerous advantages have overshadowed these minor drawbacks (Table 2) , the most important one being the ability to induce both humoral and cellular immune responses [51, 54] .", "Judging by recent success, such as the immunogenic construct developed by Muthumani et al., DNA vaccines could play a major role in combating CHIKV [49] . Vaccines are literally a critical component of CHIKV disease control and therefore research in this area is highly encouraged. The dramatic spread of dengue viruses (DENV) throughout tropical America since 1980 via the same vectors and human hosts underscores the risk to public health in the Americas. The adverse events associated with the current live vaccine are well documented [55] . Realizing these drawbacks, earnest efforts should be taken to develop new strategies to forestall further spread and complications." ]	[ 5 ]	3,829	5,688
1,689	What are the genotypes based on?	2,489	[ "the gene sequences of an Envelope protein (E1), are Asian, East/Central/ South African, and West African" ]	[ "Chikungunya: A Potentially Emerging Epidemic?\n\nhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC2860491/\n\nSHA: f7c3160bef4169d29e2a8bdd79dd6e9056d4774c\n\nAuthors: Thiboutot, Michelle M.; Kannan, Senthil; Kawalekar, Omkar U.; Shedlock, Devon J.; Khan, Amir S.; Sarangan, Gopalsamy; Srikanth, Padma; Weiner, David B.; Muthumani, Karuppiah\nDate: 2010-04-27\nDOI: 10.1371/journal.pntd.0000623\nLicense: cc-by", "Abstract: Chikungunya virus is a mosquito-borne emerging pathogen that has a major health impact in humans and causes fever disease, headache, rash, nausea, vomiting, myalgia, and arthralgia. Indigenous to tropical Africa, recent large outbreaks have been reported in parts of South East Asia and several of its neighboring islands in 2005–07 and in Europe in 2007. Furthermore, positive cases have been confirmed in the United States in travelers returning from known outbreak areas. Currently, there is no vaccine or antiviral treatment. With the threat of an emerging global pandemic, the peculiar problems associated with the more immediate and seasonal epidemics warrant the development of an effective vaccine. In this review, we summarize the evidence supporting these concepts.", "Text: Chikungunya virus (CHIKV), a mosquito-borne pathogen listed by National Institute of Allergy and Infectious Diseases (NIAID) as a Category C Priority Pathogen that causes Chikungunya fever (CHIKF), has been spreading throughout Asia, Africa, and parts of Europe in recent times [1, 2, 3] . CHIKV is an arthropod-borne virus (arbovirus) and is transmitted to humans primarily by Aedes aegypti, the infamous yellow fever propagator [4, 5] . CHIKV infection is marked by severe joint pain, contorting its victims into unusual postures [6] . The disease gets its name from the Kimakonde vernacular language of Tanzania and Mozambique, and the word chikungunya means ''that which contorts or bends up'' and translates in Swahili to ''the illness of the bended walker'' [7, 8, 9] . In Africa, CHIKV is maintained in a sylvatic cycle among forest-dwelling Aedes spp. mosquitoes, wild primates, squirrels, birds, and rodents ( Figure 1 ) [10] . In Asia, the disease is vectored by Ae. aegypti and Ae.", "albopictus [11] . Transmission in Asia occurs in an urban cycle whereby the mosquito spreads the disease from an infected human to an uninfected human, following an epidemiological pattern similar to dengue fever [12] .", "The 2005-2006 epidemic of CHIKV in La Reunion islands in the Indian Ocean, spurred the discovery of a new vector species, Ae. albopictus [5] . Wrecking over one-third of the island's population, this epidemic peaked its devastation between January and February 2006, when over 46,000 cases came into light every week, including 284 deaths [5, 13] . Ae. albopictus is common in urban areas of the United States and is already flourishing in 36 states, raising grave concerns to the immunologically naive populace of the United States [14] .\n\nAccordingly, this review elaborately details the epidemiology and global expansion of CHIKV, describes its clinical features and pathogenesis and its symptoms and complications, and finally nominates a possible vaccine approach against CHIKV infection.", "CHIKV has been isolated into three genotypes based on phylogenetic studies. These genotypes, based on the gene sequences of an Envelope protein (E1), are Asian, East/Central/ South African, and West African [4, 11, 15] . Using phylogenetic models, Cherian et al. estimate that the Asian genotype of CHIKV emerged between 50 and 310 y ago, and the West and East African genotypes diverged between 100 and 840 y ago [15] . Since then, CHIKV has come a long way, with several mutations incorporated, and has continued to wreak epidemics in several regions. Recent activities of CHIKV include the Indian epidemic in 2005-2006, which was followed by a sudden explosion of cases in 2007. An estimated 1.3 million people across 13 states were reported to be infected in India [12, 16] , and CHIKV was also widespread in Malaysia, Sri Lanka, and Indonesia [17] . In July-August of 2007, CHIKV was reported in Italy, probably brought in by travelers from CHIKV-prone regions of India, Africa, and Indian", "Ocean islands such as Mauritius, Madagascar, and Seychelles. Few of the Italian isolates were found to have evolved from the Kerala isolate, which was associated with a A226V shift in E1 gene that represents a successful evolutionary adaptation in the mosquito vector similar to the ones observed in Reunion Island [2, 18, 19] .", "In recent times, with an increase in global travel, the risk for spreading CHIKV to non-endemic regions has heightened [1] . Several travelers have brought CHIKV home with them after visiting areas with actively infected populations [12, 20] . Such cases have been documented in European countries, Australia, Asia, and the United States [8, 21] . The United States has already reported at least twelve cases of travel-associated CHIKV, while France has reported 850 cases, and the United Kingdom 93 [8, 14] . Beyond this, CHIKV-infected travelers have also been diagnosed in Australia, Belgium, Canada, Czech Republic, French Guiana, Germany, Hong Kong, Italy, Japan, Kenya, Malaysia, Martinique, Norway, Switzerland, and Sri Lanka [21] . Some travelers were viremic, worrying public health officials about the spread of CHIKV to new areas [1, 8] .", "The incubation time for CHIKV is relatively short, requiring only 2-6 d with symptoms usually appearing 4-7 d post-infection [22] . Vazeille et al. detected CHIKV in the salivary glands of Ae. albopictus only 2 d after infection [5] . Upon infection, CHIKF tends to present itself in two phases. The first stage is acute, while the second stage, experienced by most but not all, is persistent, causing disabling polyarthritis. Characteristics of the acute phase include an abrupt onset of fever, arthralgia, and in some cases, maculopapular rash [6, 23] . The acute phase causes such intense joint and muscular pain that makes movement very difficult and prostrates its victims [6, 20] .", "Ninety-five percent of infected adults are symptomatic after infection, and of these, most become disabled for weeks to months as a result of decreased dexterity, loss of mobility, and delayed reaction. Eighteen months after disease onset, 40% of patients are found to still have anti-CHIKV IgM [6, 18, 23, 24] . The chronic stage of CHIKF is characterized by polyarthralgia that can last from weeks to years beyond the acute stage [6] . CHIKV has been shown to attack fibroblasts, explaining the involvement of muscles, joints, and skin connective tissues. The high number of nociceptive nerve endings found within the joints and muscle connective tissues can explain pain associated with CHIKF [25, 26] .", "More than 50% of patients who suffer from severe CHIKF are over 65 y old, and more than 33% of them die. Most adults who suffer from severe CHIKF have underlying medical conditions [6, 24, 27] . The other group that is disproportionately affected by severe CHIKV is children. Other complications associated with CHIKV, from most common to least common, include respiratory failure, cardiovascular decompensation, meningoencephalitis, severe acute hepatitis, severe cutaneous effects, other central nervous system problems, and kidney failure [6, 18, 20, 23, 24, 26, 27] .", "CHIKV undertakes a complex replication cycle upon host infection (Figure 2 ), which makes its genome susceptible to mutations [28, 29] . For instance, Ae. aegypti, responsible for epidemics in Kenya, Comoros, and Seychelles, carried CHIKV with an alanine in the 226 position of the E1 gene (E1-A226) [4, 18] . However, when the virus struck La Reunion Islands, a decline in population of Ae. aegypti, due to massive dichlorodiphenyltrichloroethane usage and dearth of Ae. albopictus species' www.plosntds.org population, resulted in an ecological pressure, favoring replacement of alanine at position 226 with valine (E1-A226V) [5] . This mutation allowed CHIKV's secondary vector species, Ae. albopictus, to supplement Ae. aegypti as its primary vector [5] .", "Within a year, the E1-A226V mutation was present in La Reunion Island, and Ae. albopictus apparently vectored the large epidemic infecting 34% of La Reunion Island's population [5] . All of the CHIKV strains isolated from Mayotte carried the E1-A226V mutation, and the mutation was also found in Madagascar in 2007 [5] . The E1-A226V mutation was not present at the beginning of the Indian Ocean Islands outbreak (before September 2005). However, more than 90% of later viral strains found there had incorporated the mutation (December-March 2006), indicating a genotype switch during the winter season [5, 18, 20] .", "The E1-A226V mutation also enabled an increase in infectivity of Ae. albopictus when compared to its infectivity of Ae. aegypti [4, 11, 18, 30] , and with several factors taken together, Ae. albopictus has become the new preferred and more lethal vector for CHIKV [4, 5, 11] . In fact, Tsetsarkin et al. found that a Green Fluorescent Protein tagged E1-A226V virus was 100 times more infective to Ae. albopictus than it was to Ae. aegypti [4] . In all the Indian Ocean Islands, Ae. albopictus became the main vector for CHIKV within 1-2 y after CHIKV was introduced to the region [31] .", "Of note is that Ae. aegypti has most likely been established in North America for over 300 y, while Ae. albopictus has been in many areas of the US, since 1985, primarily in Florida [32] and since then has expanded its range in the country. Reiskind et al. set out to determine if Ae. aegypti and Ae. albopictus mosquitoes captured in Florida were susceptible to CHIKV infection by a La Reunion isolate [32] . Each mosquito tested was highly susceptible to infection by a full-length infectious clone of the La Réunion Island isolate, CHIKV LR2006 OPY1 strain. Even though the Ae. albopictus strains were more susceptible to infection, overall ecology and differences in human biting patterns need to be studied further Characteristically, there are two rounds of translation: (+) sense genomic RNA (49S9 = 11.7 kb) acts directly as mRNA and is partially translated (59 end) to produce non-structural proteins (nsp's). These proteins are responsible for replication and formation of a complementary", "(2) strand, the template for further (+) strand synthesis. Subgenomic mRNA (26 S = 4.1 kb) replication occurs through the synthesis of full-length (2) intermediate RNA, which is regulated by nsp4 and p123 precursor in early infection and later by mature nsp's. Translation of the newly synthesized sub-genomic RNA results in production of structural proteins such as Capsid and protein E2-6k-E1 (from 39 end of genome). Assembly occurs at the cell surface, and the envelope is acquired as the virus buds from the cell and release and maturation almost simultaneous occurred. Replication occurs in the cytoplasm and is very rapid (,4 h) [28, 29] . doi:10.1371/journal.pntd.0000623.g002 www.plosntds.org to gain a more accurate understanding of a potential CHIKV epidemic in the US [32] .", "During the 7 d preceding birth, no human mother has been reported to transmit the disease vertically. However, about 50% of newborns delivered while the mother was infected with CHIKV contracted the disease from their mother, despite the method of delivery. Furthermore, there have been instances of CHIKV transmission from mother to fetus causing congenital illness and fetal death [33] .", "During the 2005-2006 La Reunion Island outbreaks, Ramful et al. discovered that mothers could transmit CHIKV to their progeny during the perinatal period (Day 24 to Day +1) [33, 34] , and it is associated with a high degree of morbidity. By mean Day 4 of life, all of the neonates were symptomatic for CHIKV, exhibiting common CHIKF symptoms. Six neonates were confirmed to have contracted CHIKV and developed mengoencephalitis. Of those mothers who, during the La Reunion Island epidemic, were infected long before delivery, only three fetal deaths were reported [12, 33] . Ramful et al. theorized that motherto-child transmission most likely happens transplacentally shortly before delivery [33] . A similar study by Gerardin et al. reported nineteen cases of neonatal infection associated with intrapartum maternal viremia that progressed to develop encephalitis owing to vertical transmission from infected mothers [34] .", "Clinical and epidemiological similarities with dengue fever make CHIKV diagnosis difficult, which may lead physicians to misdiagnose CHIKV as dengue fever; therefore, the incidence of CHIKV may actually be higher than currently believed (Table 1 ) [6, 12, 35] .", "The amount of time elapsed since disease onset is the most critical parameter when choosing a diagnostic test. CHIKV can be detected and isolated by culturing with mosquito cells (C6/36), Vero cells (mammalian), or in mice [26] . However, this method can take at least a week and only achieves a high sensitivity during the viremic phase, which usually only lasts up to 48 h after the bite. Five days post-infection, the viral isolation approach has a low sensitivity but is still the preferred method for detecting the CHIKV strain [12, 26, 31, 35] . RT-PCR on the other hand is a faster and more sensitive method that can be used within the first week of disease onset [26] , and it is currently the most sensitive method for detecting and quantifying viral mRNA [4, 36] .", "Classic serological detection, by assays such as ELISA [37] , immunofluorescence [5, 38] , complement binding, and haemagglutination inhibition [39] , constitutes the second diagnostic tool used for biological diagnosis of CHIKV infection. These proven techniques are useful for detection of Antigen in mosquitoes during epidemiological studies. These assays detect virus-specific IgM and IgG, however the sensitivity and specificity of these assays has been poorly characterized. Viral competence, or the potential of viral infection and transmission, is an important parameter that can be quantified by ELISA, viral culture, and PCR.", "A study by Ng et al. showed biomarkers indicative of severe CHIKV infection [40] . They found decreased levels of RANTES and increased levels of Interleukin-6 (IL-6) and Interleukin-1b (IL-1b) that could be sued for CHIKV detection in patients as indicators of CHIKV-driven cytokine storm. Couderc et al. demonstrate another cytokine, type-I IFN, as a key player in the progression to CHIKV infection [26] . Using an IFN-a/b null mouse model, they demonstrated evidence of muscles, joints, and skin as privileged CHIKV targets, which is consistent with human pathology. Although Ng et al. concluded that RANTES levels were significantly suppressed in severe CHIKF patients [40] , interestingly, an increase in levels of RANTES has been observed in dengue infection [41] . Since the symptoms of CHIKF mimic those of dengue fever, results obtained from this study strongly suggest that RANTES could be a potential distinctive biomarker that differentiates between these two clinically similar", "diseases.", "There are no approved antiviral treatments currently available for CHIKV [1, 3, 12, 42] . Currently, CHIKF is treated symptomatically, usually with non-steroidal anti-inflammatory drugs or steroids, bed rest, and fluids. Movement and mild exercise are thought to decrease stiffness and morning arthralgia, but heavy exercise may exacerbate rheumatic symptoms. Corticosteroids may be used in cases of debilitating chronic CHIKV infection. There is a debate about the appropriateness of chloroquine as treatment for unresolved, non-steroidal anti-inflammatory drugresistant arthritis [43] . A study showed that viral production was www.plosntds.org drastically reduced at 16 h post-infection after treatment with 100 mM dec-RVKR-cmk (Decanoyl-Arg-Val-Lys-Arg-chloromethylketone), a furine inhibitor [42, 44] . Chloroquine acted by raising the pH, blocking low pH-dependent entry of virus into the cell. It is important to note that dec-RVKR-cmk or chloroquine only inhibited viral spreading from cell", "to cell, not CHIKV replication once it had entered the cell [43] . However, most would agree that the best weapon against CHIKV is prevention. A live CHIKV vaccine developed by the United States reached phase II clinical trial encompassing 59 healthy volunteers [45] . Eight percent of the volunteers experienced transient arthralgia, while 98% of the volunteers had seroconversion [45] . However, live CHIKV vaccines are still questionable. One cannot discount the risk of a live vaccine possibly inducing chronic rheumatism. Also, there is the question as to whether widespread use among the public could trigger mosquito transmission or lead to chronic infection or viral reversion [1] .", "An alternative approach would be to produce a chimeric vaccine against CHIKV. Wang et al. developed a chimeric alphavirus vaccine that is uniformly attenuated and does not cause reactogenicity in mice [3] . Three different versions of this vaccine were made using three different backbone vectors: Venezuelan equine encephalitis virus (VEEV) attenuated vaccine strain T-83, naturally attenuated eastern equine encephalitis virus (EEEV), and attenuated Sindbis virus (SINV). In short, CHIKV structural proteins were engineered into the backbones of the aforementioned vaccines to produce the chimeras [3] . These chimeras were found to stimulate a strong humoral immunity, and even at doses of 5.3-5.8 log 10 PFU, they did not trigger reactogenicity. When vaccinated mice were challenged with CHIKV, neither adult nor neonatal mice gained weight, had fever, or displayed signs of neurological illness. Upon comparison of the chimeras with the Army181/25 vaccine, the Army vaccine resulted in higher", "levels of viremia and replication in the joints of neonatal mice. Because the joints are known targets of CHIKV, Wang et al. noted their vaccine might avoid the negative reactogenic side effects of the Army vaccine. After being subcutaneously vaccinated with 5.3-5.8 log 10 PFU of the chimeric vaccines, mice produced strong neutralizing antibody titers. The VEEV and EEEV chimeras yielded higher neutralizing antibody titers than the SINV chimera without being more virulent. On top of this, the VEEV and EEEV CHIKV chimeras seemed to be more immunogenic than the Army vaccine despite the chimeras' lower viremia and replication in the joints of neonatal mice [3] .", "Tiwari et al. [46] adopted a different strategy using formalin inactivated CHIKV in combination with alhydrogel (Aluminum Hydroxide) as an adjuvant. This study clearly suggests that this vaccine elicits both humoral and cell-mediated immune responses in mice, providing its immunogenic potential. A recent study by Couderc et al. [47] showed passive immunization as a potential treatment for CHIKV infection. Using purified immunoglobulin extracted from convalescent CHIKV patients, they demonstrated effective neutralizing activity against CHIKV infection both in vitro and in vivo. This thereby establishes a potential preventive and therapeutic approach to combat CHIKV infection. Pathogenesis studies conducted with related alpha virus, like RRV, have shown the role of macrophages in persistence on infection [48] . They also demonstrated the role of RRV-specific CD8 T cells in clearing viral load in infected patients, thereby warranting similar investigations with CHIKV and the importance", "of investigating a cell-mediated immune response-based vaccine against CHIKV [49] .", "There are always certain risks associated with live attenuated or inactivated viral vaccines [50] . One way to avoid these potential problems is to construct a consensus-based DNA vaccine. DNA based vaccines have an improved safety profile as compared to live or attenuated vaccines [51, 52] . A consequence of CHIKV's rapid evolution is difficulty in constructing a vaccine that will be able to Figure 3 . Levels of CHIKV-specific IgG in mice immunized with CHIKV vaccines. Each group of C57BL/6 mice (n = 5) was immunized with 12.5 mg of pVax1 control vector or CHIKV vaccine plasmids as indicated at 0 and 2 wk. Mice were bled 2 wk after each immunization, and each group's serum pool was diluted to 1:100 and 1:500 for reaction with specific vaccine constructs. Serum was incubated for 1 h at 37uC on 96-well plates coated with 2 mg/ml of respective CHIKV peptides, and antibody was detected using anti-mouse IgG-HRP and OD was measured at 405 nm. doi:10.1371/journal.pntd.0000623.g003", "www.plosntds.org effectively protect large populations from multiple strains of the virus. One of the strengths of DNA consensus vaccines is its ability to induce cross-reactive immune responses against the three distinct phylogenetic groups of CHIKV. Also DNA-based vaccines can be produced more rapidly than protein-based vaccines.", "Recently, Muthumani et al. constructed a vaccine that was shown to induce both humoral and cellular immunity in vivo in 3-4-wk-old female C57/BL6 mice [49] . These mice were immunized using an in vivo electroporation method to deliver the vaccine into the quadriceps muscle. The consensus construct was designed against E1, E2, and the core protein capsid. To design the construct, they aligned 21 sequences of CHIKV isolated between 1952 and 2006, using strains from differing countries, including La Reunion Island. The most common nucleotide among the sequences was chosen at each position to be used in the consensus construct, taking care not to alter the reading frame. They conducted codon and RNA optimization, added a strong Kozak sequence, and substituted signal peptide with an immunoglobulin E leader sequence to improve vaccine efficacy.", "After immunizing the mice, spleens were harvested along with serum and tested to determine antibody titer. After three immunizations, consensus E1, E2, and C vaccines were shown to induce T-cell immune responses leading to strong IFN-c responses and proliferation in C57/BL6 mice. Furthermore, when compared with control mice, immunized mice had higher total IgG levels as well as higher anti-E1 specific, anti-E2 specific, and anti-C specific IgG antibodies, suggesting a strong humoral immune response ( Figure 3 ) and also specificity for the antigens encoded in the vaccine constructs ( Figure 4 ). Because of its promising results and the need for a safer vaccine, this consensus DNA vaccine deserves further investigation. Determining longevity of protective effects of the vaccine and persistence of antibody and IFN-c responses could be the next step of investigation. Challenged studies of immunized mice must also be carried out.", "CHIKV mosquito-borne disease has caused massive outbreaks for at least half a century but is no longer confined to the www.plosntds.org developing nations. It began to encroach into the boundaries of the developing world. As a result, the NIAID has designated CHIKV as a Category C pathogen alongside the influenza and SARS-CoV viruses [3] . Realization of the potential severity of this disease is exigent; for instance, if used as a biological weapon, the world economy could be severely crippled; if enough members of the armed forces were to become infected during a military deployment, military operations could be significantly affected. Efforts to monitor the disease will only provide minimal warning in a global society, and steps to prevent the morbidity and mortality associated with pandemic are imperative [21, 31] . Despite the gravity of its infectious potency and the fear of it being a potential biological weapon, there is currently no vaccine for CHIKV infections. Live", "attenuated vaccine trials were carried out in 2000, but funding for the project was discontinued. Newer approaches such as DNA vaccines appear promising over conventional strategies like live attenuated or inactivated virus and thus call for further investigation. Recent advances such electroporation delivery and incorporation of adjuvants has boosted DNA vaccine efficacy [51, 53] . Despite the low antibody response to DNA vaccines, other numerous advantages have overshadowed these minor drawbacks (Table 2) , the most important one being the ability to induce both humoral and cellular immune responses [51, 54] .", "Judging by recent success, such as the immunogenic construct developed by Muthumani et al., DNA vaccines could play a major role in combating CHIKV [49] . Vaccines are literally a critical component of CHIKV disease control and therefore research in this area is highly encouraged. The dramatic spread of dengue viruses (DENV) throughout tropical America since 1980 via the same vectors and human hosts underscores the risk to public health in the Americas. The adverse events associated with the current live vaccine are well documented [55] . Realizing these drawbacks, earnest efforts should be taken to develop new strategies to forestall further spread and complications." ]	[ 5 ]	3,829	5,688
1,689	hen did Asian genotype emerge?	2,490	[ "between 50 and 310 y ago," ]	[ "Chikungunya: A Potentially Emerging Epidemic?\n\nhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC2860491/\n\nSHA: f7c3160bef4169d29e2a8bdd79dd6e9056d4774c\n\nAuthors: Thiboutot, Michelle M.; Kannan, Senthil; Kawalekar, Omkar U.; Shedlock, Devon J.; Khan, Amir S.; Sarangan, Gopalsamy; Srikanth, Padma; Weiner, David B.; Muthumani, Karuppiah\nDate: 2010-04-27\nDOI: 10.1371/journal.pntd.0000623\nLicense: cc-by", "Abstract: Chikungunya virus is a mosquito-borne emerging pathogen that has a major health impact in humans and causes fever disease, headache, rash, nausea, vomiting, myalgia, and arthralgia. Indigenous to tropical Africa, recent large outbreaks have been reported in parts of South East Asia and several of its neighboring islands in 2005–07 and in Europe in 2007. Furthermore, positive cases have been confirmed in the United States in travelers returning from known outbreak areas. Currently, there is no vaccine or antiviral treatment. With the threat of an emerging global pandemic, the peculiar problems associated with the more immediate and seasonal epidemics warrant the development of an effective vaccine. In this review, we summarize the evidence supporting these concepts.", "Text: Chikungunya virus (CHIKV), a mosquito-borne pathogen listed by National Institute of Allergy and Infectious Diseases (NIAID) as a Category C Priority Pathogen that causes Chikungunya fever (CHIKF), has been spreading throughout Asia, Africa, and parts of Europe in recent times [1, 2, 3] . CHIKV is an arthropod-borne virus (arbovirus) and is transmitted to humans primarily by Aedes aegypti, the infamous yellow fever propagator [4, 5] . CHIKV infection is marked by severe joint pain, contorting its victims into unusual postures [6] . The disease gets its name from the Kimakonde vernacular language of Tanzania and Mozambique, and the word chikungunya means ''that which contorts or bends up'' and translates in Swahili to ''the illness of the bended walker'' [7, 8, 9] . In Africa, CHIKV is maintained in a sylvatic cycle among forest-dwelling Aedes spp. mosquitoes, wild primates, squirrels, birds, and rodents ( Figure 1 ) [10] . In Asia, the disease is vectored by Ae. aegypti and Ae.", "albopictus [11] . Transmission in Asia occurs in an urban cycle whereby the mosquito spreads the disease from an infected human to an uninfected human, following an epidemiological pattern similar to dengue fever [12] .", "The 2005-2006 epidemic of CHIKV in La Reunion islands in the Indian Ocean, spurred the discovery of a new vector species, Ae. albopictus [5] . Wrecking over one-third of the island's population, this epidemic peaked its devastation between January and February 2006, when over 46,000 cases came into light every week, including 284 deaths [5, 13] . Ae. albopictus is common in urban areas of the United States and is already flourishing in 36 states, raising grave concerns to the immunologically naive populace of the United States [14] .\n\nAccordingly, this review elaborately details the epidemiology and global expansion of CHIKV, describes its clinical features and pathogenesis and its symptoms and complications, and finally nominates a possible vaccine approach against CHIKV infection.", "CHIKV has been isolated into three genotypes based on phylogenetic studies. These genotypes, based on the gene sequences of an Envelope protein (E1), are Asian, East/Central/ South African, and West African [4, 11, 15] . Using phylogenetic models, Cherian et al. estimate that the Asian genotype of CHIKV emerged between 50 and 310 y ago, and the West and East African genotypes diverged between 100 and 840 y ago [15] . Since then, CHIKV has come a long way, with several mutations incorporated, and has continued to wreak epidemics in several regions. Recent activities of CHIKV include the Indian epidemic in 2005-2006, which was followed by a sudden explosion of cases in 2007. An estimated 1.3 million people across 13 states were reported to be infected in India [12, 16] , and CHIKV was also widespread in Malaysia, Sri Lanka, and Indonesia [17] . In July-August of 2007, CHIKV was reported in Italy, probably brought in by travelers from CHIKV-prone regions of India, Africa, and Indian", "Ocean islands such as Mauritius, Madagascar, and Seychelles. Few of the Italian isolates were found to have evolved from the Kerala isolate, which was associated with a A226V shift in E1 gene that represents a successful evolutionary adaptation in the mosquito vector similar to the ones observed in Reunion Island [2, 18, 19] .", "In recent times, with an increase in global travel, the risk for spreading CHIKV to non-endemic regions has heightened [1] . Several travelers have brought CHIKV home with them after visiting areas with actively infected populations [12, 20] . Such cases have been documented in European countries, Australia, Asia, and the United States [8, 21] . The United States has already reported at least twelve cases of travel-associated CHIKV, while France has reported 850 cases, and the United Kingdom 93 [8, 14] . Beyond this, CHIKV-infected travelers have also been diagnosed in Australia, Belgium, Canada, Czech Republic, French Guiana, Germany, Hong Kong, Italy, Japan, Kenya, Malaysia, Martinique, Norway, Switzerland, and Sri Lanka [21] . Some travelers were viremic, worrying public health officials about the spread of CHIKV to new areas [1, 8] .", "The incubation time for CHIKV is relatively short, requiring only 2-6 d with symptoms usually appearing 4-7 d post-infection [22] . Vazeille et al. detected CHIKV in the salivary glands of Ae. albopictus only 2 d after infection [5] . Upon infection, CHIKF tends to present itself in two phases. The first stage is acute, while the second stage, experienced by most but not all, is persistent, causing disabling polyarthritis. Characteristics of the acute phase include an abrupt onset of fever, arthralgia, and in some cases, maculopapular rash [6, 23] . The acute phase causes such intense joint and muscular pain that makes movement very difficult and prostrates its victims [6, 20] .", "Ninety-five percent of infected adults are symptomatic after infection, and of these, most become disabled for weeks to months as a result of decreased dexterity, loss of mobility, and delayed reaction. Eighteen months after disease onset, 40% of patients are found to still have anti-CHIKV IgM [6, 18, 23, 24] . The chronic stage of CHIKF is characterized by polyarthralgia that can last from weeks to years beyond the acute stage [6] . CHIKV has been shown to attack fibroblasts, explaining the involvement of muscles, joints, and skin connective tissues. The high number of nociceptive nerve endings found within the joints and muscle connective tissues can explain pain associated with CHIKF [25, 26] .", "More than 50% of patients who suffer from severe CHIKF are over 65 y old, and more than 33% of them die. Most adults who suffer from severe CHIKF have underlying medical conditions [6, 24, 27] . The other group that is disproportionately affected by severe CHIKV is children. Other complications associated with CHIKV, from most common to least common, include respiratory failure, cardiovascular decompensation, meningoencephalitis, severe acute hepatitis, severe cutaneous effects, other central nervous system problems, and kidney failure [6, 18, 20, 23, 24, 26, 27] .", "CHIKV undertakes a complex replication cycle upon host infection (Figure 2 ), which makes its genome susceptible to mutations [28, 29] . For instance, Ae. aegypti, responsible for epidemics in Kenya, Comoros, and Seychelles, carried CHIKV with an alanine in the 226 position of the E1 gene (E1-A226) [4, 18] . However, when the virus struck La Reunion Islands, a decline in population of Ae. aegypti, due to massive dichlorodiphenyltrichloroethane usage and dearth of Ae. albopictus species' www.plosntds.org population, resulted in an ecological pressure, favoring replacement of alanine at position 226 with valine (E1-A226V) [5] . This mutation allowed CHIKV's secondary vector species, Ae. albopictus, to supplement Ae. aegypti as its primary vector [5] .", "Within a year, the E1-A226V mutation was present in La Reunion Island, and Ae. albopictus apparently vectored the large epidemic infecting 34% of La Reunion Island's population [5] . All of the CHIKV strains isolated from Mayotte carried the E1-A226V mutation, and the mutation was also found in Madagascar in 2007 [5] . The E1-A226V mutation was not present at the beginning of the Indian Ocean Islands outbreak (before September 2005). However, more than 90% of later viral strains found there had incorporated the mutation (December-March 2006), indicating a genotype switch during the winter season [5, 18, 20] .", "The E1-A226V mutation also enabled an increase in infectivity of Ae. albopictus when compared to its infectivity of Ae. aegypti [4, 11, 18, 30] , and with several factors taken together, Ae. albopictus has become the new preferred and more lethal vector for CHIKV [4, 5, 11] . In fact, Tsetsarkin et al. found that a Green Fluorescent Protein tagged E1-A226V virus was 100 times more infective to Ae. albopictus than it was to Ae. aegypti [4] . In all the Indian Ocean Islands, Ae. albopictus became the main vector for CHIKV within 1-2 y after CHIKV was introduced to the region [31] .", "Of note is that Ae. aegypti has most likely been established in North America for over 300 y, while Ae. albopictus has been in many areas of the US, since 1985, primarily in Florida [32] and since then has expanded its range in the country. Reiskind et al. set out to determine if Ae. aegypti and Ae. albopictus mosquitoes captured in Florida were susceptible to CHIKV infection by a La Reunion isolate [32] . Each mosquito tested was highly susceptible to infection by a full-length infectious clone of the La Réunion Island isolate, CHIKV LR2006 OPY1 strain. Even though the Ae. albopictus strains were more susceptible to infection, overall ecology and differences in human biting patterns need to be studied further Characteristically, there are two rounds of translation: (+) sense genomic RNA (49S9 = 11.7 kb) acts directly as mRNA and is partially translated (59 end) to produce non-structural proteins (nsp's). These proteins are responsible for replication and formation of a complementary", "(2) strand, the template for further (+) strand synthesis. Subgenomic mRNA (26 S = 4.1 kb) replication occurs through the synthesis of full-length (2) intermediate RNA, which is regulated by nsp4 and p123 precursor in early infection and later by mature nsp's. Translation of the newly synthesized sub-genomic RNA results in production of structural proteins such as Capsid and protein E2-6k-E1 (from 39 end of genome). Assembly occurs at the cell surface, and the envelope is acquired as the virus buds from the cell and release and maturation almost simultaneous occurred. Replication occurs in the cytoplasm and is very rapid (,4 h) [28, 29] . doi:10.1371/journal.pntd.0000623.g002 www.plosntds.org to gain a more accurate understanding of a potential CHIKV epidemic in the US [32] .", "During the 7 d preceding birth, no human mother has been reported to transmit the disease vertically. However, about 50% of newborns delivered while the mother was infected with CHIKV contracted the disease from their mother, despite the method of delivery. Furthermore, there have been instances of CHIKV transmission from mother to fetus causing congenital illness and fetal death [33] .", "During the 2005-2006 La Reunion Island outbreaks, Ramful et al. discovered that mothers could transmit CHIKV to their progeny during the perinatal period (Day 24 to Day +1) [33, 34] , and it is associated with a high degree of morbidity. By mean Day 4 of life, all of the neonates were symptomatic for CHIKV, exhibiting common CHIKF symptoms. Six neonates were confirmed to have contracted CHIKV and developed mengoencephalitis. Of those mothers who, during the La Reunion Island epidemic, were infected long before delivery, only three fetal deaths were reported [12, 33] . Ramful et al. theorized that motherto-child transmission most likely happens transplacentally shortly before delivery [33] . A similar study by Gerardin et al. reported nineteen cases of neonatal infection associated with intrapartum maternal viremia that progressed to develop encephalitis owing to vertical transmission from infected mothers [34] .", "Clinical and epidemiological similarities with dengue fever make CHIKV diagnosis difficult, which may lead physicians to misdiagnose CHIKV as dengue fever; therefore, the incidence of CHIKV may actually be higher than currently believed (Table 1 ) [6, 12, 35] .", "The amount of time elapsed since disease onset is the most critical parameter when choosing a diagnostic test. CHIKV can be detected and isolated by culturing with mosquito cells (C6/36), Vero cells (mammalian), or in mice [26] . However, this method can take at least a week and only achieves a high sensitivity during the viremic phase, which usually only lasts up to 48 h after the bite. Five days post-infection, the viral isolation approach has a low sensitivity but is still the preferred method for detecting the CHIKV strain [12, 26, 31, 35] . RT-PCR on the other hand is a faster and more sensitive method that can be used within the first week of disease onset [26] , and it is currently the most sensitive method for detecting and quantifying viral mRNA [4, 36] .", "Classic serological detection, by assays such as ELISA [37] , immunofluorescence [5, 38] , complement binding, and haemagglutination inhibition [39] , constitutes the second diagnostic tool used for biological diagnosis of CHIKV infection. These proven techniques are useful for detection of Antigen in mosquitoes during epidemiological studies. These assays detect virus-specific IgM and IgG, however the sensitivity and specificity of these assays has been poorly characterized. Viral competence, or the potential of viral infection and transmission, is an important parameter that can be quantified by ELISA, viral culture, and PCR.", "A study by Ng et al. showed biomarkers indicative of severe CHIKV infection [40] . They found decreased levels of RANTES and increased levels of Interleukin-6 (IL-6) and Interleukin-1b (IL-1b) that could be sued for CHIKV detection in patients as indicators of CHIKV-driven cytokine storm. Couderc et al. demonstrate another cytokine, type-I IFN, as a key player in the progression to CHIKV infection [26] . Using an IFN-a/b null mouse model, they demonstrated evidence of muscles, joints, and skin as privileged CHIKV targets, which is consistent with human pathology. Although Ng et al. concluded that RANTES levels were significantly suppressed in severe CHIKF patients [40] , interestingly, an increase in levels of RANTES has been observed in dengue infection [41] . Since the symptoms of CHIKF mimic those of dengue fever, results obtained from this study strongly suggest that RANTES could be a potential distinctive biomarker that differentiates between these two clinically similar", "diseases.", "There are no approved antiviral treatments currently available for CHIKV [1, 3, 12, 42] . Currently, CHIKF is treated symptomatically, usually with non-steroidal anti-inflammatory drugs or steroids, bed rest, and fluids. Movement and mild exercise are thought to decrease stiffness and morning arthralgia, but heavy exercise may exacerbate rheumatic symptoms. Corticosteroids may be used in cases of debilitating chronic CHIKV infection. There is a debate about the appropriateness of chloroquine as treatment for unresolved, non-steroidal anti-inflammatory drugresistant arthritis [43] . A study showed that viral production was www.plosntds.org drastically reduced at 16 h post-infection after treatment with 100 mM dec-RVKR-cmk (Decanoyl-Arg-Val-Lys-Arg-chloromethylketone), a furine inhibitor [42, 44] . Chloroquine acted by raising the pH, blocking low pH-dependent entry of virus into the cell. It is important to note that dec-RVKR-cmk or chloroquine only inhibited viral spreading from cell", "to cell, not CHIKV replication once it had entered the cell [43] . However, most would agree that the best weapon against CHIKV is prevention. A live CHIKV vaccine developed by the United States reached phase II clinical trial encompassing 59 healthy volunteers [45] . Eight percent of the volunteers experienced transient arthralgia, while 98% of the volunteers had seroconversion [45] . However, live CHIKV vaccines are still questionable. One cannot discount the risk of a live vaccine possibly inducing chronic rheumatism. Also, there is the question as to whether widespread use among the public could trigger mosquito transmission or lead to chronic infection or viral reversion [1] .", "An alternative approach would be to produce a chimeric vaccine against CHIKV. Wang et al. developed a chimeric alphavirus vaccine that is uniformly attenuated and does not cause reactogenicity in mice [3] . Three different versions of this vaccine were made using three different backbone vectors: Venezuelan equine encephalitis virus (VEEV) attenuated vaccine strain T-83, naturally attenuated eastern equine encephalitis virus (EEEV), and attenuated Sindbis virus (SINV). In short, CHIKV structural proteins were engineered into the backbones of the aforementioned vaccines to produce the chimeras [3] . These chimeras were found to stimulate a strong humoral immunity, and even at doses of 5.3-5.8 log 10 PFU, they did not trigger reactogenicity. When vaccinated mice were challenged with CHIKV, neither adult nor neonatal mice gained weight, had fever, or displayed signs of neurological illness. Upon comparison of the chimeras with the Army181/25 vaccine, the Army vaccine resulted in higher", "levels of viremia and replication in the joints of neonatal mice. Because the joints are known targets of CHIKV, Wang et al. noted their vaccine might avoid the negative reactogenic side effects of the Army vaccine. After being subcutaneously vaccinated with 5.3-5.8 log 10 PFU of the chimeric vaccines, mice produced strong neutralizing antibody titers. The VEEV and EEEV chimeras yielded higher neutralizing antibody titers than the SINV chimera without being more virulent. On top of this, the VEEV and EEEV CHIKV chimeras seemed to be more immunogenic than the Army vaccine despite the chimeras' lower viremia and replication in the joints of neonatal mice [3] .", "Tiwari et al. [46] adopted a different strategy using formalin inactivated CHIKV in combination with alhydrogel (Aluminum Hydroxide) as an adjuvant. This study clearly suggests that this vaccine elicits both humoral and cell-mediated immune responses in mice, providing its immunogenic potential. A recent study by Couderc et al. [47] showed passive immunization as a potential treatment for CHIKV infection. Using purified immunoglobulin extracted from convalescent CHIKV patients, they demonstrated effective neutralizing activity against CHIKV infection both in vitro and in vivo. This thereby establishes a potential preventive and therapeutic approach to combat CHIKV infection. Pathogenesis studies conducted with related alpha virus, like RRV, have shown the role of macrophages in persistence on infection [48] . They also demonstrated the role of RRV-specific CD8 T cells in clearing viral load in infected patients, thereby warranting similar investigations with CHIKV and the importance", "of investigating a cell-mediated immune response-based vaccine against CHIKV [49] .", "There are always certain risks associated with live attenuated or inactivated viral vaccines [50] . One way to avoid these potential problems is to construct a consensus-based DNA vaccine. DNA based vaccines have an improved safety profile as compared to live or attenuated vaccines [51, 52] . A consequence of CHIKV's rapid evolution is difficulty in constructing a vaccine that will be able to Figure 3 . Levels of CHIKV-specific IgG in mice immunized with CHIKV vaccines. Each group of C57BL/6 mice (n = 5) was immunized with 12.5 mg of pVax1 control vector or CHIKV vaccine plasmids as indicated at 0 and 2 wk. Mice were bled 2 wk after each immunization, and each group's serum pool was diluted to 1:100 and 1:500 for reaction with specific vaccine constructs. Serum was incubated for 1 h at 37uC on 96-well plates coated with 2 mg/ml of respective CHIKV peptides, and antibody was detected using anti-mouse IgG-HRP and OD was measured at 405 nm. doi:10.1371/journal.pntd.0000623.g003", "www.plosntds.org effectively protect large populations from multiple strains of the virus. One of the strengths of DNA consensus vaccines is its ability to induce cross-reactive immune responses against the three distinct phylogenetic groups of CHIKV. Also DNA-based vaccines can be produced more rapidly than protein-based vaccines.", "Recently, Muthumani et al. constructed a vaccine that was shown to induce both humoral and cellular immunity in vivo in 3-4-wk-old female C57/BL6 mice [49] . These mice were immunized using an in vivo electroporation method to deliver the vaccine into the quadriceps muscle. The consensus construct was designed against E1, E2, and the core protein capsid. To design the construct, they aligned 21 sequences of CHIKV isolated between 1952 and 2006, using strains from differing countries, including La Reunion Island. The most common nucleotide among the sequences was chosen at each position to be used in the consensus construct, taking care not to alter the reading frame. They conducted codon and RNA optimization, added a strong Kozak sequence, and substituted signal peptide with an immunoglobulin E leader sequence to improve vaccine efficacy.", "After immunizing the mice, spleens were harvested along with serum and tested to determine antibody titer. After three immunizations, consensus E1, E2, and C vaccines were shown to induce T-cell immune responses leading to strong IFN-c responses and proliferation in C57/BL6 mice. Furthermore, when compared with control mice, immunized mice had higher total IgG levels as well as higher anti-E1 specific, anti-E2 specific, and anti-C specific IgG antibodies, suggesting a strong humoral immune response ( Figure 3 ) and also specificity for the antigens encoded in the vaccine constructs ( Figure 4 ). Because of its promising results and the need for a safer vaccine, this consensus DNA vaccine deserves further investigation. Determining longevity of protective effects of the vaccine and persistence of antibody and IFN-c responses could be the next step of investigation. Challenged studies of immunized mice must also be carried out.", "CHIKV mosquito-borne disease has caused massive outbreaks for at least half a century but is no longer confined to the www.plosntds.org developing nations. It began to encroach into the boundaries of the developing world. As a result, the NIAID has designated CHIKV as a Category C pathogen alongside the influenza and SARS-CoV viruses [3] . Realization of the potential severity of this disease is exigent; for instance, if used as a biological weapon, the world economy could be severely crippled; if enough members of the armed forces were to become infected during a military deployment, military operations could be significantly affected. Efforts to monitor the disease will only provide minimal warning in a global society, and steps to prevent the morbidity and mortality associated with pandemic are imperative [21, 31] . Despite the gravity of its infectious potency and the fear of it being a potential biological weapon, there is currently no vaccine for CHIKV infections. Live", "attenuated vaccine trials were carried out in 2000, but funding for the project was discontinued. Newer approaches such as DNA vaccines appear promising over conventional strategies like live attenuated or inactivated virus and thus call for further investigation. Recent advances such electroporation delivery and incorporation of adjuvants has boosted DNA vaccine efficacy [51, 53] . Despite the low antibody response to DNA vaccines, other numerous advantages have overshadowed these minor drawbacks (Table 2) , the most important one being the ability to induce both humoral and cellular immune responses [51, 54] .", "Judging by recent success, such as the immunogenic construct developed by Muthumani et al., DNA vaccines could play a major role in combating CHIKV [49] . Vaccines are literally a critical component of CHIKV disease control and therefore research in this area is highly encouraged. The dramatic spread of dengue viruses (DENV) throughout tropical America since 1980 via the same vectors and human hosts underscores the risk to public health in the Americas. The adverse events associated with the current live vaccine are well documented [55] . Realizing these drawbacks, earnest efforts should be taken to develop new strategies to forestall further spread and complications." ]	[ 5 ]	3,829	5,688
1,689	When didthe Asian genotype diverge from African genotype?	2,491	[ "between 100 and 840 y ago" ]	[ "Chikungunya: A Potentially Emerging Epidemic?\n\nhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC2860491/\n\nSHA: f7c3160bef4169d29e2a8bdd79dd6e9056d4774c\n\nAuthors: Thiboutot, Michelle M.; Kannan, Senthil; Kawalekar, Omkar U.; Shedlock, Devon J.; Khan, Amir S.; Sarangan, Gopalsamy; Srikanth, Padma; Weiner, David B.; Muthumani, Karuppiah\nDate: 2010-04-27\nDOI: 10.1371/journal.pntd.0000623\nLicense: cc-by", "Abstract: Chikungunya virus is a mosquito-borne emerging pathogen that has a major health impact in humans and causes fever disease, headache, rash, nausea, vomiting, myalgia, and arthralgia. Indigenous to tropical Africa, recent large outbreaks have been reported in parts of South East Asia and several of its neighboring islands in 2005–07 and in Europe in 2007. Furthermore, positive cases have been confirmed in the United States in travelers returning from known outbreak areas. Currently, there is no vaccine or antiviral treatment. With the threat of an emerging global pandemic, the peculiar problems associated with the more immediate and seasonal epidemics warrant the development of an effective vaccine. In this review, we summarize the evidence supporting these concepts.", "Text: Chikungunya virus (CHIKV), a mosquito-borne pathogen listed by National Institute of Allergy and Infectious Diseases (NIAID) as a Category C Priority Pathogen that causes Chikungunya fever (CHIKF), has been spreading throughout Asia, Africa, and parts of Europe in recent times [1, 2, 3] . CHIKV is an arthropod-borne virus (arbovirus) and is transmitted to humans primarily by Aedes aegypti, the infamous yellow fever propagator [4, 5] . CHIKV infection is marked by severe joint pain, contorting its victims into unusual postures [6] . The disease gets its name from the Kimakonde vernacular language of Tanzania and Mozambique, and the word chikungunya means ''that which contorts or bends up'' and translates in Swahili to ''the illness of the bended walker'' [7, 8, 9] . In Africa, CHIKV is maintained in a sylvatic cycle among forest-dwelling Aedes spp. mosquitoes, wild primates, squirrels, birds, and rodents ( Figure 1 ) [10] . In Asia, the disease is vectored by Ae. aegypti and Ae.", "albopictus [11] . Transmission in Asia occurs in an urban cycle whereby the mosquito spreads the disease from an infected human to an uninfected human, following an epidemiological pattern similar to dengue fever [12] .", "The 2005-2006 epidemic of CHIKV in La Reunion islands in the Indian Ocean, spurred the discovery of a new vector species, Ae. albopictus [5] . Wrecking over one-third of the island's population, this epidemic peaked its devastation between January and February 2006, when over 46,000 cases came into light every week, including 284 deaths [5, 13] . Ae. albopictus is common in urban areas of the United States and is already flourishing in 36 states, raising grave concerns to the immunologically naive populace of the United States [14] .\n\nAccordingly, this review elaborately details the epidemiology and global expansion of CHIKV, describes its clinical features and pathogenesis and its symptoms and complications, and finally nominates a possible vaccine approach against CHIKV infection.", "CHIKV has been isolated into three genotypes based on phylogenetic studies. These genotypes, based on the gene sequences of an Envelope protein (E1), are Asian, East/Central/ South African, and West African [4, 11, 15] . Using phylogenetic models, Cherian et al. estimate that the Asian genotype of CHIKV emerged between 50 and 310 y ago, and the West and East African genotypes diverged between 100 and 840 y ago [15] . Since then, CHIKV has come a long way, with several mutations incorporated, and has continued to wreak epidemics in several regions. Recent activities of CHIKV include the Indian epidemic in 2005-2006, which was followed by a sudden explosion of cases in 2007. An estimated 1.3 million people across 13 states were reported to be infected in India [12, 16] , and CHIKV was also widespread in Malaysia, Sri Lanka, and Indonesia [17] . In July-August of 2007, CHIKV was reported in Italy, probably brought in by travelers from CHIKV-prone regions of India, Africa, and Indian", "Ocean islands such as Mauritius, Madagascar, and Seychelles. Few of the Italian isolates were found to have evolved from the Kerala isolate, which was associated with a A226V shift in E1 gene that represents a successful evolutionary adaptation in the mosquito vector similar to the ones observed in Reunion Island [2, 18, 19] .", "In recent times, with an increase in global travel, the risk for spreading CHIKV to non-endemic regions has heightened [1] . Several travelers have brought CHIKV home with them after visiting areas with actively infected populations [12, 20] . Such cases have been documented in European countries, Australia, Asia, and the United States [8, 21] . The United States has already reported at least twelve cases of travel-associated CHIKV, while France has reported 850 cases, and the United Kingdom 93 [8, 14] . Beyond this, CHIKV-infected travelers have also been diagnosed in Australia, Belgium, Canada, Czech Republic, French Guiana, Germany, Hong Kong, Italy, Japan, Kenya, Malaysia, Martinique, Norway, Switzerland, and Sri Lanka [21] . Some travelers were viremic, worrying public health officials about the spread of CHIKV to new areas [1, 8] .", "The incubation time for CHIKV is relatively short, requiring only 2-6 d with symptoms usually appearing 4-7 d post-infection [22] . Vazeille et al. detected CHIKV in the salivary glands of Ae. albopictus only 2 d after infection [5] . Upon infection, CHIKF tends to present itself in two phases. The first stage is acute, while the second stage, experienced by most but not all, is persistent, causing disabling polyarthritis. Characteristics of the acute phase include an abrupt onset of fever, arthralgia, and in some cases, maculopapular rash [6, 23] . The acute phase causes such intense joint and muscular pain that makes movement very difficult and prostrates its victims [6, 20] .", "Ninety-five percent of infected adults are symptomatic after infection, and of these, most become disabled for weeks to months as a result of decreased dexterity, loss of mobility, and delayed reaction. Eighteen months after disease onset, 40% of patients are found to still have anti-CHIKV IgM [6, 18, 23, 24] . The chronic stage of CHIKF is characterized by polyarthralgia that can last from weeks to years beyond the acute stage [6] . CHIKV has been shown to attack fibroblasts, explaining the involvement of muscles, joints, and skin connective tissues. The high number of nociceptive nerve endings found within the joints and muscle connective tissues can explain pain associated with CHIKF [25, 26] .", "More than 50% of patients who suffer from severe CHIKF are over 65 y old, and more than 33% of them die. Most adults who suffer from severe CHIKF have underlying medical conditions [6, 24, 27] . The other group that is disproportionately affected by severe CHIKV is children. Other complications associated with CHIKV, from most common to least common, include respiratory failure, cardiovascular decompensation, meningoencephalitis, severe acute hepatitis, severe cutaneous effects, other central nervous system problems, and kidney failure [6, 18, 20, 23, 24, 26, 27] .", "CHIKV undertakes a complex replication cycle upon host infection (Figure 2 ), which makes its genome susceptible to mutations [28, 29] . For instance, Ae. aegypti, responsible for epidemics in Kenya, Comoros, and Seychelles, carried CHIKV with an alanine in the 226 position of the E1 gene (E1-A226) [4, 18] . However, when the virus struck La Reunion Islands, a decline in population of Ae. aegypti, due to massive dichlorodiphenyltrichloroethane usage and dearth of Ae. albopictus species' www.plosntds.org population, resulted in an ecological pressure, favoring replacement of alanine at position 226 with valine (E1-A226V) [5] . This mutation allowed CHIKV's secondary vector species, Ae. albopictus, to supplement Ae. aegypti as its primary vector [5] .", "Within a year, the E1-A226V mutation was present in La Reunion Island, and Ae. albopictus apparently vectored the large epidemic infecting 34% of La Reunion Island's population [5] . All of the CHIKV strains isolated from Mayotte carried the E1-A226V mutation, and the mutation was also found in Madagascar in 2007 [5] . The E1-A226V mutation was not present at the beginning of the Indian Ocean Islands outbreak (before September 2005). However, more than 90% of later viral strains found there had incorporated the mutation (December-March 2006), indicating a genotype switch during the winter season [5, 18, 20] .", "The E1-A226V mutation also enabled an increase in infectivity of Ae. albopictus when compared to its infectivity of Ae. aegypti [4, 11, 18, 30] , and with several factors taken together, Ae. albopictus has become the new preferred and more lethal vector for CHIKV [4, 5, 11] . In fact, Tsetsarkin et al. found that a Green Fluorescent Protein tagged E1-A226V virus was 100 times more infective to Ae. albopictus than it was to Ae. aegypti [4] . In all the Indian Ocean Islands, Ae. albopictus became the main vector for CHIKV within 1-2 y after CHIKV was introduced to the region [31] .", "Of note is that Ae. aegypti has most likely been established in North America for over 300 y, while Ae. albopictus has been in many areas of the US, since 1985, primarily in Florida [32] and since then has expanded its range in the country. Reiskind et al. set out to determine if Ae. aegypti and Ae. albopictus mosquitoes captured in Florida were susceptible to CHIKV infection by a La Reunion isolate [32] . Each mosquito tested was highly susceptible to infection by a full-length infectious clone of the La Réunion Island isolate, CHIKV LR2006 OPY1 strain. Even though the Ae. albopictus strains were more susceptible to infection, overall ecology and differences in human biting patterns need to be studied further Characteristically, there are two rounds of translation: (+) sense genomic RNA (49S9 = 11.7 kb) acts directly as mRNA and is partially translated (59 end) to produce non-structural proteins (nsp's). These proteins are responsible for replication and formation of a complementary", "(2) strand, the template for further (+) strand synthesis. Subgenomic mRNA (26 S = 4.1 kb) replication occurs through the synthesis of full-length (2) intermediate RNA, which is regulated by nsp4 and p123 precursor in early infection and later by mature nsp's. Translation of the newly synthesized sub-genomic RNA results in production of structural proteins such as Capsid and protein E2-6k-E1 (from 39 end of genome). Assembly occurs at the cell surface, and the envelope is acquired as the virus buds from the cell and release and maturation almost simultaneous occurred. Replication occurs in the cytoplasm and is very rapid (,4 h) [28, 29] . doi:10.1371/journal.pntd.0000623.g002 www.plosntds.org to gain a more accurate understanding of a potential CHIKV epidemic in the US [32] .", "During the 7 d preceding birth, no human mother has been reported to transmit the disease vertically. However, about 50% of newborns delivered while the mother was infected with CHIKV contracted the disease from their mother, despite the method of delivery. Furthermore, there have been instances of CHIKV transmission from mother to fetus causing congenital illness and fetal death [33] .", "During the 2005-2006 La Reunion Island outbreaks, Ramful et al. discovered that mothers could transmit CHIKV to their progeny during the perinatal period (Day 24 to Day +1) [33, 34] , and it is associated with a high degree of morbidity. By mean Day 4 of life, all of the neonates were symptomatic for CHIKV, exhibiting common CHIKF symptoms. Six neonates were confirmed to have contracted CHIKV and developed mengoencephalitis. Of those mothers who, during the La Reunion Island epidemic, were infected long before delivery, only three fetal deaths were reported [12, 33] . Ramful et al. theorized that motherto-child transmission most likely happens transplacentally shortly before delivery [33] . A similar study by Gerardin et al. reported nineteen cases of neonatal infection associated with intrapartum maternal viremia that progressed to develop encephalitis owing to vertical transmission from infected mothers [34] .", "Clinical and epidemiological similarities with dengue fever make CHIKV diagnosis difficult, which may lead physicians to misdiagnose CHIKV as dengue fever; therefore, the incidence of CHIKV may actually be higher than currently believed (Table 1 ) [6, 12, 35] .", "The amount of time elapsed since disease onset is the most critical parameter when choosing a diagnostic test. CHIKV can be detected and isolated by culturing with mosquito cells (C6/36), Vero cells (mammalian), or in mice [26] . However, this method can take at least a week and only achieves a high sensitivity during the viremic phase, which usually only lasts up to 48 h after the bite. Five days post-infection, the viral isolation approach has a low sensitivity but is still the preferred method for detecting the CHIKV strain [12, 26, 31, 35] . RT-PCR on the other hand is a faster and more sensitive method that can be used within the first week of disease onset [26] , and it is currently the most sensitive method for detecting and quantifying viral mRNA [4, 36] .", "Classic serological detection, by assays such as ELISA [37] , immunofluorescence [5, 38] , complement binding, and haemagglutination inhibition [39] , constitutes the second diagnostic tool used for biological diagnosis of CHIKV infection. These proven techniques are useful for detection of Antigen in mosquitoes during epidemiological studies. These assays detect virus-specific IgM and IgG, however the sensitivity and specificity of these assays has been poorly characterized. Viral competence, or the potential of viral infection and transmission, is an important parameter that can be quantified by ELISA, viral culture, and PCR.", "A study by Ng et al. showed biomarkers indicative of severe CHIKV infection [40] . They found decreased levels of RANTES and increased levels of Interleukin-6 (IL-6) and Interleukin-1b (IL-1b) that could be sued for CHIKV detection in patients as indicators of CHIKV-driven cytokine storm. Couderc et al. demonstrate another cytokine, type-I IFN, as a key player in the progression to CHIKV infection [26] . Using an IFN-a/b null mouse model, they demonstrated evidence of muscles, joints, and skin as privileged CHIKV targets, which is consistent with human pathology. Although Ng et al. concluded that RANTES levels were significantly suppressed in severe CHIKF patients [40] , interestingly, an increase in levels of RANTES has been observed in dengue infection [41] . Since the symptoms of CHIKF mimic those of dengue fever, results obtained from this study strongly suggest that RANTES could be a potential distinctive biomarker that differentiates between these two clinically similar", "diseases.", "There are no approved antiviral treatments currently available for CHIKV [1, 3, 12, 42] . Currently, CHIKF is treated symptomatically, usually with non-steroidal anti-inflammatory drugs or steroids, bed rest, and fluids. Movement and mild exercise are thought to decrease stiffness and morning arthralgia, but heavy exercise may exacerbate rheumatic symptoms. Corticosteroids may be used in cases of debilitating chronic CHIKV infection. There is a debate about the appropriateness of chloroquine as treatment for unresolved, non-steroidal anti-inflammatory drugresistant arthritis [43] . A study showed that viral production was www.plosntds.org drastically reduced at 16 h post-infection after treatment with 100 mM dec-RVKR-cmk (Decanoyl-Arg-Val-Lys-Arg-chloromethylketone), a furine inhibitor [42, 44] . Chloroquine acted by raising the pH, blocking low pH-dependent entry of virus into the cell. It is important to note that dec-RVKR-cmk or chloroquine only inhibited viral spreading from cell", "to cell, not CHIKV replication once it had entered the cell [43] . However, most would agree that the best weapon against CHIKV is prevention. A live CHIKV vaccine developed by the United States reached phase II clinical trial encompassing 59 healthy volunteers [45] . Eight percent of the volunteers experienced transient arthralgia, while 98% of the volunteers had seroconversion [45] . However, live CHIKV vaccines are still questionable. One cannot discount the risk of a live vaccine possibly inducing chronic rheumatism. Also, there is the question as to whether widespread use among the public could trigger mosquito transmission or lead to chronic infection or viral reversion [1] .", "An alternative approach would be to produce a chimeric vaccine against CHIKV. Wang et al. developed a chimeric alphavirus vaccine that is uniformly attenuated and does not cause reactogenicity in mice [3] . Three different versions of this vaccine were made using three different backbone vectors: Venezuelan equine encephalitis virus (VEEV) attenuated vaccine strain T-83, naturally attenuated eastern equine encephalitis virus (EEEV), and attenuated Sindbis virus (SINV). In short, CHIKV structural proteins were engineered into the backbones of the aforementioned vaccines to produce the chimeras [3] . These chimeras were found to stimulate a strong humoral immunity, and even at doses of 5.3-5.8 log 10 PFU, they did not trigger reactogenicity. When vaccinated mice were challenged with CHIKV, neither adult nor neonatal mice gained weight, had fever, or displayed signs of neurological illness. Upon comparison of the chimeras with the Army181/25 vaccine, the Army vaccine resulted in higher", "levels of viremia and replication in the joints of neonatal mice. Because the joints are known targets of CHIKV, Wang et al. noted their vaccine might avoid the negative reactogenic side effects of the Army vaccine. After being subcutaneously vaccinated with 5.3-5.8 log 10 PFU of the chimeric vaccines, mice produced strong neutralizing antibody titers. The VEEV and EEEV chimeras yielded higher neutralizing antibody titers than the SINV chimera without being more virulent. On top of this, the VEEV and EEEV CHIKV chimeras seemed to be more immunogenic than the Army vaccine despite the chimeras' lower viremia and replication in the joints of neonatal mice [3] .", "Tiwari et al. [46] adopted a different strategy using formalin inactivated CHIKV in combination with alhydrogel (Aluminum Hydroxide) as an adjuvant. This study clearly suggests that this vaccine elicits both humoral and cell-mediated immune responses in mice, providing its immunogenic potential. A recent study by Couderc et al. [47] showed passive immunization as a potential treatment for CHIKV infection. Using purified immunoglobulin extracted from convalescent CHIKV patients, they demonstrated effective neutralizing activity against CHIKV infection both in vitro and in vivo. This thereby establishes a potential preventive and therapeutic approach to combat CHIKV infection. Pathogenesis studies conducted with related alpha virus, like RRV, have shown the role of macrophages in persistence on infection [48] . They also demonstrated the role of RRV-specific CD8 T cells in clearing viral load in infected patients, thereby warranting similar investigations with CHIKV and the importance", "of investigating a cell-mediated immune response-based vaccine against CHIKV [49] .", "There are always certain risks associated with live attenuated or inactivated viral vaccines [50] . One way to avoid these potential problems is to construct a consensus-based DNA vaccine. DNA based vaccines have an improved safety profile as compared to live or attenuated vaccines [51, 52] . A consequence of CHIKV's rapid evolution is difficulty in constructing a vaccine that will be able to Figure 3 . Levels of CHIKV-specific IgG in mice immunized with CHIKV vaccines. Each group of C57BL/6 mice (n = 5) was immunized with 12.5 mg of pVax1 control vector or CHIKV vaccine plasmids as indicated at 0 and 2 wk. Mice were bled 2 wk after each immunization, and each group's serum pool was diluted to 1:100 and 1:500 for reaction with specific vaccine constructs. Serum was incubated for 1 h at 37uC on 96-well plates coated with 2 mg/ml of respective CHIKV peptides, and antibody was detected using anti-mouse IgG-HRP and OD was measured at 405 nm. doi:10.1371/journal.pntd.0000623.g003", "www.plosntds.org effectively protect large populations from multiple strains of the virus. One of the strengths of DNA consensus vaccines is its ability to induce cross-reactive immune responses against the three distinct phylogenetic groups of CHIKV. Also DNA-based vaccines can be produced more rapidly than protein-based vaccines.", "Recently, Muthumani et al. constructed a vaccine that was shown to induce both humoral and cellular immunity in vivo in 3-4-wk-old female C57/BL6 mice [49] . These mice were immunized using an in vivo electroporation method to deliver the vaccine into the quadriceps muscle. The consensus construct was designed against E1, E2, and the core protein capsid. To design the construct, they aligned 21 sequences of CHIKV isolated between 1952 and 2006, using strains from differing countries, including La Reunion Island. The most common nucleotide among the sequences was chosen at each position to be used in the consensus construct, taking care not to alter the reading frame. They conducted codon and RNA optimization, added a strong Kozak sequence, and substituted signal peptide with an immunoglobulin E leader sequence to improve vaccine efficacy.", "After immunizing the mice, spleens were harvested along with serum and tested to determine antibody titer. After three immunizations, consensus E1, E2, and C vaccines were shown to induce T-cell immune responses leading to strong IFN-c responses and proliferation in C57/BL6 mice. Furthermore, when compared with control mice, immunized mice had higher total IgG levels as well as higher anti-E1 specific, anti-E2 specific, and anti-C specific IgG antibodies, suggesting a strong humoral immune response ( Figure 3 ) and also specificity for the antigens encoded in the vaccine constructs ( Figure 4 ). Because of its promising results and the need for a safer vaccine, this consensus DNA vaccine deserves further investigation. Determining longevity of protective effects of the vaccine and persistence of antibody and IFN-c responses could be the next step of investigation. Challenged studies of immunized mice must also be carried out.", "CHIKV mosquito-borne disease has caused massive outbreaks for at least half a century but is no longer confined to the www.plosntds.org developing nations. It began to encroach into the boundaries of the developing world. As a result, the NIAID has designated CHIKV as a Category C pathogen alongside the influenza and SARS-CoV viruses [3] . Realization of the potential severity of this disease is exigent; for instance, if used as a biological weapon, the world economy could be severely crippled; if enough members of the armed forces were to become infected during a military deployment, military operations could be significantly affected. Efforts to monitor the disease will only provide minimal warning in a global society, and steps to prevent the morbidity and mortality associated with pandemic are imperative [21, 31] . Despite the gravity of its infectious potency and the fear of it being a potential biological weapon, there is currently no vaccine for CHIKV infections. Live", "attenuated vaccine trials were carried out in 2000, but funding for the project was discontinued. Newer approaches such as DNA vaccines appear promising over conventional strategies like live attenuated or inactivated virus and thus call for further investigation. Recent advances such electroporation delivery and incorporation of adjuvants has boosted DNA vaccine efficacy [51, 53] . Despite the low antibody response to DNA vaccines, other numerous advantages have overshadowed these minor drawbacks (Table 2) , the most important one being the ability to induce both humoral and cellular immune responses [51, 54] .", "Judging by recent success, such as the immunogenic construct developed by Muthumani et al., DNA vaccines could play a major role in combating CHIKV [49] . Vaccines are literally a critical component of CHIKV disease control and therefore research in this area is highly encouraged. The dramatic spread of dengue viruses (DENV) throughout tropical America since 1980 via the same vectors and human hosts underscores the risk to public health in the Americas. The adverse events associated with the current live vaccine are well documented [55] . Realizing these drawbacks, earnest efforts should be taken to develop new strategies to forestall further spread and complications." ]	[ 5 ]	3,829	5,688
1,689	What is the status of Asian CHIKV since its emergence?	2,492	[ "has come a long way, with several mutations incorporated, and has continued to wreak epidemics in several regions" ]	[ "Chikungunya: A Potentially Emerging Epidemic?\n\nhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC2860491/\n\nSHA: f7c3160bef4169d29e2a8bdd79dd6e9056d4774c\n\nAuthors: Thiboutot, Michelle M.; Kannan, Senthil; Kawalekar, Omkar U.; Shedlock, Devon J.; Khan, Amir S.; Sarangan, Gopalsamy; Srikanth, Padma; Weiner, David B.; Muthumani, Karuppiah\nDate: 2010-04-27\nDOI: 10.1371/journal.pntd.0000623\nLicense: cc-by", "Abstract: Chikungunya virus is a mosquito-borne emerging pathogen that has a major health impact in humans and causes fever disease, headache, rash, nausea, vomiting, myalgia, and arthralgia. Indigenous to tropical Africa, recent large outbreaks have been reported in parts of South East Asia and several of its neighboring islands in 2005–07 and in Europe in 2007. Furthermore, positive cases have been confirmed in the United States in travelers returning from known outbreak areas. Currently, there is no vaccine or antiviral treatment. With the threat of an emerging global pandemic, the peculiar problems associated with the more immediate and seasonal epidemics warrant the development of an effective vaccine. In this review, we summarize the evidence supporting these concepts.", "Text: Chikungunya virus (CHIKV), a mosquito-borne pathogen listed by National Institute of Allergy and Infectious Diseases (NIAID) as a Category C Priority Pathogen that causes Chikungunya fever (CHIKF), has been spreading throughout Asia, Africa, and parts of Europe in recent times [1, 2, 3] . CHIKV is an arthropod-borne virus (arbovirus) and is transmitted to humans primarily by Aedes aegypti, the infamous yellow fever propagator [4, 5] . CHIKV infection is marked by severe joint pain, contorting its victims into unusual postures [6] . The disease gets its name from the Kimakonde vernacular language of Tanzania and Mozambique, and the word chikungunya means ''that which contorts or bends up'' and translates in Swahili to ''the illness of the bended walker'' [7, 8, 9] . In Africa, CHIKV is maintained in a sylvatic cycle among forest-dwelling Aedes spp. mosquitoes, wild primates, squirrels, birds, and rodents ( Figure 1 ) [10] . In Asia, the disease is vectored by Ae. aegypti and Ae.", "albopictus [11] . Transmission in Asia occurs in an urban cycle whereby the mosquito spreads the disease from an infected human to an uninfected human, following an epidemiological pattern similar to dengue fever [12] .", "The 2005-2006 epidemic of CHIKV in La Reunion islands in the Indian Ocean, spurred the discovery of a new vector species, Ae. albopictus [5] . Wrecking over one-third of the island's population, this epidemic peaked its devastation between January and February 2006, when over 46,000 cases came into light every week, including 284 deaths [5, 13] . Ae. albopictus is common in urban areas of the United States and is already flourishing in 36 states, raising grave concerns to the immunologically naive populace of the United States [14] .\n\nAccordingly, this review elaborately details the epidemiology and global expansion of CHIKV, describes its clinical features and pathogenesis and its symptoms and complications, and finally nominates a possible vaccine approach against CHIKV infection.", "CHIKV has been isolated into three genotypes based on phylogenetic studies. These genotypes, based on the gene sequences of an Envelope protein (E1), are Asian, East/Central/ South African, and West African [4, 11, 15] . Using phylogenetic models, Cherian et al. estimate that the Asian genotype of CHIKV emerged between 50 and 310 y ago, and the West and East African genotypes diverged between 100 and 840 y ago [15] . Since then, CHIKV has come a long way, with several mutations incorporated, and has continued to wreak epidemics in several regions. Recent activities of CHIKV include the Indian epidemic in 2005-2006, which was followed by a sudden explosion of cases in 2007. An estimated 1.3 million people across 13 states were reported to be infected in India [12, 16] , and CHIKV was also widespread in Malaysia, Sri Lanka, and Indonesia [17] . In July-August of 2007, CHIKV was reported in Italy, probably brought in by travelers from CHIKV-prone regions of India, Africa, and Indian", "Ocean islands such as Mauritius, Madagascar, and Seychelles. Few of the Italian isolates were found to have evolved from the Kerala isolate, which was associated with a A226V shift in E1 gene that represents a successful evolutionary adaptation in the mosquito vector similar to the ones observed in Reunion Island [2, 18, 19] .", "In recent times, with an increase in global travel, the risk for spreading CHIKV to non-endemic regions has heightened [1] . Several travelers have brought CHIKV home with them after visiting areas with actively infected populations [12, 20] . Such cases have been documented in European countries, Australia, Asia, and the United States [8, 21] . The United States has already reported at least twelve cases of travel-associated CHIKV, while France has reported 850 cases, and the United Kingdom 93 [8, 14] . Beyond this, CHIKV-infected travelers have also been diagnosed in Australia, Belgium, Canada, Czech Republic, French Guiana, Germany, Hong Kong, Italy, Japan, Kenya, Malaysia, Martinique, Norway, Switzerland, and Sri Lanka [21] . Some travelers were viremic, worrying public health officials about the spread of CHIKV to new areas [1, 8] .", "The incubation time for CHIKV is relatively short, requiring only 2-6 d with symptoms usually appearing 4-7 d post-infection [22] . Vazeille et al. detected CHIKV in the salivary glands of Ae. albopictus only 2 d after infection [5] . Upon infection, CHIKF tends to present itself in two phases. The first stage is acute, while the second stage, experienced by most but not all, is persistent, causing disabling polyarthritis. Characteristics of the acute phase include an abrupt onset of fever, arthralgia, and in some cases, maculopapular rash [6, 23] . The acute phase causes such intense joint and muscular pain that makes movement very difficult and prostrates its victims [6, 20] .", "Ninety-five percent of infected adults are symptomatic after infection, and of these, most become disabled for weeks to months as a result of decreased dexterity, loss of mobility, and delayed reaction. Eighteen months after disease onset, 40% of patients are found to still have anti-CHIKV IgM [6, 18, 23, 24] . The chronic stage of CHIKF is characterized by polyarthralgia that can last from weeks to years beyond the acute stage [6] . CHIKV has been shown to attack fibroblasts, explaining the involvement of muscles, joints, and skin connective tissues. The high number of nociceptive nerve endings found within the joints and muscle connective tissues can explain pain associated with CHIKF [25, 26] .", "More than 50% of patients who suffer from severe CHIKF are over 65 y old, and more than 33% of them die. Most adults who suffer from severe CHIKF have underlying medical conditions [6, 24, 27] . The other group that is disproportionately affected by severe CHIKV is children. Other complications associated with CHIKV, from most common to least common, include respiratory failure, cardiovascular decompensation, meningoencephalitis, severe acute hepatitis, severe cutaneous effects, other central nervous system problems, and kidney failure [6, 18, 20, 23, 24, 26, 27] .", "CHIKV undertakes a complex replication cycle upon host infection (Figure 2 ), which makes its genome susceptible to mutations [28, 29] . For instance, Ae. aegypti, responsible for epidemics in Kenya, Comoros, and Seychelles, carried CHIKV with an alanine in the 226 position of the E1 gene (E1-A226) [4, 18] . However, when the virus struck La Reunion Islands, a decline in population of Ae. aegypti, due to massive dichlorodiphenyltrichloroethane usage and dearth of Ae. albopictus species' www.plosntds.org population, resulted in an ecological pressure, favoring replacement of alanine at position 226 with valine (E1-A226V) [5] . This mutation allowed CHIKV's secondary vector species, Ae. albopictus, to supplement Ae. aegypti as its primary vector [5] .", "Within a year, the E1-A226V mutation was present in La Reunion Island, and Ae. albopictus apparently vectored the large epidemic infecting 34% of La Reunion Island's population [5] . All of the CHIKV strains isolated from Mayotte carried the E1-A226V mutation, and the mutation was also found in Madagascar in 2007 [5] . The E1-A226V mutation was not present at the beginning of the Indian Ocean Islands outbreak (before September 2005). However, more than 90% of later viral strains found there had incorporated the mutation (December-March 2006), indicating a genotype switch during the winter season [5, 18, 20] .", "The E1-A226V mutation also enabled an increase in infectivity of Ae. albopictus when compared to its infectivity of Ae. aegypti [4, 11, 18, 30] , and with several factors taken together, Ae. albopictus has become the new preferred and more lethal vector for CHIKV [4, 5, 11] . In fact, Tsetsarkin et al. found that a Green Fluorescent Protein tagged E1-A226V virus was 100 times more infective to Ae. albopictus than it was to Ae. aegypti [4] . In all the Indian Ocean Islands, Ae. albopictus became the main vector for CHIKV within 1-2 y after CHIKV was introduced to the region [31] .", "Of note is that Ae. aegypti has most likely been established in North America for over 300 y, while Ae. albopictus has been in many areas of the US, since 1985, primarily in Florida [32] and since then has expanded its range in the country. Reiskind et al. set out to determine if Ae. aegypti and Ae. albopictus mosquitoes captured in Florida were susceptible to CHIKV infection by a La Reunion isolate [32] . Each mosquito tested was highly susceptible to infection by a full-length infectious clone of the La Réunion Island isolate, CHIKV LR2006 OPY1 strain. Even though the Ae. albopictus strains were more susceptible to infection, overall ecology and differences in human biting patterns need to be studied further Characteristically, there are two rounds of translation: (+) sense genomic RNA (49S9 = 11.7 kb) acts directly as mRNA and is partially translated (59 end) to produce non-structural proteins (nsp's). These proteins are responsible for replication and formation of a complementary", "(2) strand, the template for further (+) strand synthesis. Subgenomic mRNA (26 S = 4.1 kb) replication occurs through the synthesis of full-length (2) intermediate RNA, which is regulated by nsp4 and p123 precursor in early infection and later by mature nsp's. Translation of the newly synthesized sub-genomic RNA results in production of structural proteins such as Capsid and protein E2-6k-E1 (from 39 end of genome). Assembly occurs at the cell surface, and the envelope is acquired as the virus buds from the cell and release and maturation almost simultaneous occurred. Replication occurs in the cytoplasm and is very rapid (,4 h) [28, 29] . doi:10.1371/journal.pntd.0000623.g002 www.plosntds.org to gain a more accurate understanding of a potential CHIKV epidemic in the US [32] .", "During the 7 d preceding birth, no human mother has been reported to transmit the disease vertically. However, about 50% of newborns delivered while the mother was infected with CHIKV contracted the disease from their mother, despite the method of delivery. Furthermore, there have been instances of CHIKV transmission from mother to fetus causing congenital illness and fetal death [33] .", "During the 2005-2006 La Reunion Island outbreaks, Ramful et al. discovered that mothers could transmit CHIKV to their progeny during the perinatal period (Day 24 to Day +1) [33, 34] , and it is associated with a high degree of morbidity. By mean Day 4 of life, all of the neonates were symptomatic for CHIKV, exhibiting common CHIKF symptoms. Six neonates were confirmed to have contracted CHIKV and developed mengoencephalitis. Of those mothers who, during the La Reunion Island epidemic, were infected long before delivery, only three fetal deaths were reported [12, 33] . Ramful et al. theorized that motherto-child transmission most likely happens transplacentally shortly before delivery [33] . A similar study by Gerardin et al. reported nineteen cases of neonatal infection associated with intrapartum maternal viremia that progressed to develop encephalitis owing to vertical transmission from infected mothers [34] .", "Clinical and epidemiological similarities with dengue fever make CHIKV diagnosis difficult, which may lead physicians to misdiagnose CHIKV as dengue fever; therefore, the incidence of CHIKV may actually be higher than currently believed (Table 1 ) [6, 12, 35] .", "The amount of time elapsed since disease onset is the most critical parameter when choosing a diagnostic test. CHIKV can be detected and isolated by culturing with mosquito cells (C6/36), Vero cells (mammalian), or in mice [26] . However, this method can take at least a week and only achieves a high sensitivity during the viremic phase, which usually only lasts up to 48 h after the bite. Five days post-infection, the viral isolation approach has a low sensitivity but is still the preferred method for detecting the CHIKV strain [12, 26, 31, 35] . RT-PCR on the other hand is a faster and more sensitive method that can be used within the first week of disease onset [26] , and it is currently the most sensitive method for detecting and quantifying viral mRNA [4, 36] .", "Classic serological detection, by assays such as ELISA [37] , immunofluorescence [5, 38] , complement binding, and haemagglutination inhibition [39] , constitutes the second diagnostic tool used for biological diagnosis of CHIKV infection. These proven techniques are useful for detection of Antigen in mosquitoes during epidemiological studies. These assays detect virus-specific IgM and IgG, however the sensitivity and specificity of these assays has been poorly characterized. Viral competence, or the potential of viral infection and transmission, is an important parameter that can be quantified by ELISA, viral culture, and PCR.", "A study by Ng et al. showed biomarkers indicative of severe CHIKV infection [40] . They found decreased levels of RANTES and increased levels of Interleukin-6 (IL-6) and Interleukin-1b (IL-1b) that could be sued for CHIKV detection in patients as indicators of CHIKV-driven cytokine storm. Couderc et al. demonstrate another cytokine, type-I IFN, as a key player in the progression to CHIKV infection [26] . Using an IFN-a/b null mouse model, they demonstrated evidence of muscles, joints, and skin as privileged CHIKV targets, which is consistent with human pathology. Although Ng et al. concluded that RANTES levels were significantly suppressed in severe CHIKF patients [40] , interestingly, an increase in levels of RANTES has been observed in dengue infection [41] . Since the symptoms of CHIKF mimic those of dengue fever, results obtained from this study strongly suggest that RANTES could be a potential distinctive biomarker that differentiates between these two clinically similar", "diseases.", "There are no approved antiviral treatments currently available for CHIKV [1, 3, 12, 42] . Currently, CHIKF is treated symptomatically, usually with non-steroidal anti-inflammatory drugs or steroids, bed rest, and fluids. Movement and mild exercise are thought to decrease stiffness and morning arthralgia, but heavy exercise may exacerbate rheumatic symptoms. Corticosteroids may be used in cases of debilitating chronic CHIKV infection. There is a debate about the appropriateness of chloroquine as treatment for unresolved, non-steroidal anti-inflammatory drugresistant arthritis [43] . A study showed that viral production was www.plosntds.org drastically reduced at 16 h post-infection after treatment with 100 mM dec-RVKR-cmk (Decanoyl-Arg-Val-Lys-Arg-chloromethylketone), a furine inhibitor [42, 44] . Chloroquine acted by raising the pH, blocking low pH-dependent entry of virus into the cell. It is important to note that dec-RVKR-cmk or chloroquine only inhibited viral spreading from cell", "to cell, not CHIKV replication once it had entered the cell [43] . However, most would agree that the best weapon against CHIKV is prevention. A live CHIKV vaccine developed by the United States reached phase II clinical trial encompassing 59 healthy volunteers [45] . Eight percent of the volunteers experienced transient arthralgia, while 98% of the volunteers had seroconversion [45] . However, live CHIKV vaccines are still questionable. One cannot discount the risk of a live vaccine possibly inducing chronic rheumatism. Also, there is the question as to whether widespread use among the public could trigger mosquito transmission or lead to chronic infection or viral reversion [1] .", "An alternative approach would be to produce a chimeric vaccine against CHIKV. Wang et al. developed a chimeric alphavirus vaccine that is uniformly attenuated and does not cause reactogenicity in mice [3] . Three different versions of this vaccine were made using three different backbone vectors: Venezuelan equine encephalitis virus (VEEV) attenuated vaccine strain T-83, naturally attenuated eastern equine encephalitis virus (EEEV), and attenuated Sindbis virus (SINV). In short, CHIKV structural proteins were engineered into the backbones of the aforementioned vaccines to produce the chimeras [3] . These chimeras were found to stimulate a strong humoral immunity, and even at doses of 5.3-5.8 log 10 PFU, they did not trigger reactogenicity. When vaccinated mice were challenged with CHIKV, neither adult nor neonatal mice gained weight, had fever, or displayed signs of neurological illness. Upon comparison of the chimeras with the Army181/25 vaccine, the Army vaccine resulted in higher", "levels of viremia and replication in the joints of neonatal mice. Because the joints are known targets of CHIKV, Wang et al. noted their vaccine might avoid the negative reactogenic side effects of the Army vaccine. After being subcutaneously vaccinated with 5.3-5.8 log 10 PFU of the chimeric vaccines, mice produced strong neutralizing antibody titers. The VEEV and EEEV chimeras yielded higher neutralizing antibody titers than the SINV chimera without being more virulent. On top of this, the VEEV and EEEV CHIKV chimeras seemed to be more immunogenic than the Army vaccine despite the chimeras' lower viremia and replication in the joints of neonatal mice [3] .", "Tiwari et al. [46] adopted a different strategy using formalin inactivated CHIKV in combination with alhydrogel (Aluminum Hydroxide) as an adjuvant. This study clearly suggests that this vaccine elicits both humoral and cell-mediated immune responses in mice, providing its immunogenic potential. A recent study by Couderc et al. [47] showed passive immunization as a potential treatment for CHIKV infection. Using purified immunoglobulin extracted from convalescent CHIKV patients, they demonstrated effective neutralizing activity against CHIKV infection both in vitro and in vivo. This thereby establishes a potential preventive and therapeutic approach to combat CHIKV infection. Pathogenesis studies conducted with related alpha virus, like RRV, have shown the role of macrophages in persistence on infection [48] . They also demonstrated the role of RRV-specific CD8 T cells in clearing viral load in infected patients, thereby warranting similar investigations with CHIKV and the importance", "of investigating a cell-mediated immune response-based vaccine against CHIKV [49] .", "There are always certain risks associated with live attenuated or inactivated viral vaccines [50] . One way to avoid these potential problems is to construct a consensus-based DNA vaccine. DNA based vaccines have an improved safety profile as compared to live or attenuated vaccines [51, 52] . A consequence of CHIKV's rapid evolution is difficulty in constructing a vaccine that will be able to Figure 3 . Levels of CHIKV-specific IgG in mice immunized with CHIKV vaccines. Each group of C57BL/6 mice (n = 5) was immunized with 12.5 mg of pVax1 control vector or CHIKV vaccine plasmids as indicated at 0 and 2 wk. Mice were bled 2 wk after each immunization, and each group's serum pool was diluted to 1:100 and 1:500 for reaction with specific vaccine constructs. Serum was incubated for 1 h at 37uC on 96-well plates coated with 2 mg/ml of respective CHIKV peptides, and antibody was detected using anti-mouse IgG-HRP and OD was measured at 405 nm. doi:10.1371/journal.pntd.0000623.g003", "www.plosntds.org effectively protect large populations from multiple strains of the virus. One of the strengths of DNA consensus vaccines is its ability to induce cross-reactive immune responses against the three distinct phylogenetic groups of CHIKV. Also DNA-based vaccines can be produced more rapidly than protein-based vaccines.", "Recently, Muthumani et al. constructed a vaccine that was shown to induce both humoral and cellular immunity in vivo in 3-4-wk-old female C57/BL6 mice [49] . These mice were immunized using an in vivo electroporation method to deliver the vaccine into the quadriceps muscle. The consensus construct was designed against E1, E2, and the core protein capsid. To design the construct, they aligned 21 sequences of CHIKV isolated between 1952 and 2006, using strains from differing countries, including La Reunion Island. The most common nucleotide among the sequences was chosen at each position to be used in the consensus construct, taking care not to alter the reading frame. They conducted codon and RNA optimization, added a strong Kozak sequence, and substituted signal peptide with an immunoglobulin E leader sequence to improve vaccine efficacy.", "After immunizing the mice, spleens were harvested along with serum and tested to determine antibody titer. After three immunizations, consensus E1, E2, and C vaccines were shown to induce T-cell immune responses leading to strong IFN-c responses and proliferation in C57/BL6 mice. Furthermore, when compared with control mice, immunized mice had higher total IgG levels as well as higher anti-E1 specific, anti-E2 specific, and anti-C specific IgG antibodies, suggesting a strong humoral immune response ( Figure 3 ) and also specificity for the antigens encoded in the vaccine constructs ( Figure 4 ). Because of its promising results and the need for a safer vaccine, this consensus DNA vaccine deserves further investigation. Determining longevity of protective effects of the vaccine and persistence of antibody and IFN-c responses could be the next step of investigation. Challenged studies of immunized mice must also be carried out.", "CHIKV mosquito-borne disease has caused massive outbreaks for at least half a century but is no longer confined to the www.plosntds.org developing nations. It began to encroach into the boundaries of the developing world. As a result, the NIAID has designated CHIKV as a Category C pathogen alongside the influenza and SARS-CoV viruses [3] . Realization of the potential severity of this disease is exigent; for instance, if used as a biological weapon, the world economy could be severely crippled; if enough members of the armed forces were to become infected during a military deployment, military operations could be significantly affected. Efforts to monitor the disease will only provide minimal warning in a global society, and steps to prevent the morbidity and mortality associated with pandemic are imperative [21, 31] . Despite the gravity of its infectious potency and the fear of it being a potential biological weapon, there is currently no vaccine for CHIKV infections. Live", "attenuated vaccine trials were carried out in 2000, but funding for the project was discontinued. Newer approaches such as DNA vaccines appear promising over conventional strategies like live attenuated or inactivated virus and thus call for further investigation. Recent advances such electroporation delivery and incorporation of adjuvants has boosted DNA vaccine efficacy [51, 53] . Despite the low antibody response to DNA vaccines, other numerous advantages have overshadowed these minor drawbacks (Table 2) , the most important one being the ability to induce both humoral and cellular immune responses [51, 54] .", "Judging by recent success, such as the immunogenic construct developed by Muthumani et al., DNA vaccines could play a major role in combating CHIKV [49] . Vaccines are literally a critical component of CHIKV disease control and therefore research in this area is highly encouraged. The dramatic spread of dengue viruses (DENV) throughout tropical America since 1980 via the same vectors and human hosts underscores the risk to public health in the Americas. The adverse events associated with the current live vaccine are well documented [55] . Realizing these drawbacks, earnest efforts should be taken to develop new strategies to forestall further spread and complications." ]	[ 5 ]	3,829	5,688
1,689	What are the recent activities of CHIKV?	2,493	[ "the Indian epidemic in 2005-2006, which was followed by a sudden explosion of cases in 2007. An estimated 1.3 million people across 13 states were reported to be infected in India [12, 16] , and CHIKV was also widespread in Malaysia, Sri Lanka, and Indonesia [17] . In July-August of 2007, CHIKV was reported in Italy, probably brought in by travelers from CHIKV-prone regions of India, Africa, and Indian Ocean islands such as Mauritius, Madagascar, and Seychelles." ]	[ "Chikungunya: A Potentially Emerging Epidemic?\n\nhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC2860491/\n\nSHA: f7c3160bef4169d29e2a8bdd79dd6e9056d4774c\n\nAuthors: Thiboutot, Michelle M.; Kannan, Senthil; Kawalekar, Omkar U.; Shedlock, Devon J.; Khan, Amir S.; Sarangan, Gopalsamy; Srikanth, Padma; Weiner, David B.; Muthumani, Karuppiah\nDate: 2010-04-27\nDOI: 10.1371/journal.pntd.0000623\nLicense: cc-by", "Abstract: Chikungunya virus is a mosquito-borne emerging pathogen that has a major health impact in humans and causes fever disease, headache, rash, nausea, vomiting, myalgia, and arthralgia. Indigenous to tropical Africa, recent large outbreaks have been reported in parts of South East Asia and several of its neighboring islands in 2005–07 and in Europe in 2007. Furthermore, positive cases have been confirmed in the United States in travelers returning from known outbreak areas. Currently, there is no vaccine or antiviral treatment. With the threat of an emerging global pandemic, the peculiar problems associated with the more immediate and seasonal epidemics warrant the development of an effective vaccine. In this review, we summarize the evidence supporting these concepts.", "Text: Chikungunya virus (CHIKV), a mosquito-borne pathogen listed by National Institute of Allergy and Infectious Diseases (NIAID) as a Category C Priority Pathogen that causes Chikungunya fever (CHIKF), has been spreading throughout Asia, Africa, and parts of Europe in recent times [1, 2, 3] . CHIKV is an arthropod-borne virus (arbovirus) and is transmitted to humans primarily by Aedes aegypti, the infamous yellow fever propagator [4, 5] . CHIKV infection is marked by severe joint pain, contorting its victims into unusual postures [6] . The disease gets its name from the Kimakonde vernacular language of Tanzania and Mozambique, and the word chikungunya means ''that which contorts or bends up'' and translates in Swahili to ''the illness of the bended walker'' [7, 8, 9] . In Africa, CHIKV is maintained in a sylvatic cycle among forest-dwelling Aedes spp. mosquitoes, wild primates, squirrels, birds, and rodents ( Figure 1 ) [10] . In Asia, the disease is vectored by Ae. aegypti and Ae.", "albopictus [11] . Transmission in Asia occurs in an urban cycle whereby the mosquito spreads the disease from an infected human to an uninfected human, following an epidemiological pattern similar to dengue fever [12] .", "The 2005-2006 epidemic of CHIKV in La Reunion islands in the Indian Ocean, spurred the discovery of a new vector species, Ae. albopictus [5] . Wrecking over one-third of the island's population, this epidemic peaked its devastation between January and February 2006, when over 46,000 cases came into light every week, including 284 deaths [5, 13] . Ae. albopictus is common in urban areas of the United States and is already flourishing in 36 states, raising grave concerns to the immunologically naive populace of the United States [14] .\n\nAccordingly, this review elaborately details the epidemiology and global expansion of CHIKV, describes its clinical features and pathogenesis and its symptoms and complications, and finally nominates a possible vaccine approach against CHIKV infection.", "CHIKV has been isolated into three genotypes based on phylogenetic studies. These genotypes, based on the gene sequences of an Envelope protein (E1), are Asian, East/Central/ South African, and West African [4, 11, 15] . Using phylogenetic models, Cherian et al. estimate that the Asian genotype of CHIKV emerged between 50 and 310 y ago, and the West and East African genotypes diverged between 100 and 840 y ago [15] . Since then, CHIKV has come a long way, with several mutations incorporated, and has continued to wreak epidemics in several regions. Recent activities of CHIKV include the Indian epidemic in 2005-2006, which was followed by a sudden explosion of cases in 2007. An estimated 1.3 million people across 13 states were reported to be infected in India [12, 16] , and CHIKV was also widespread in Malaysia, Sri Lanka, and Indonesia [17] . In July-August of 2007, CHIKV was reported in Italy, probably brought in by travelers from CHIKV-prone regions of India, Africa, and Indian", "Ocean islands such as Mauritius, Madagascar, and Seychelles. Few of the Italian isolates were found to have evolved from the Kerala isolate, which was associated with a A226V shift in E1 gene that represents a successful evolutionary adaptation in the mosquito vector similar to the ones observed in Reunion Island [2, 18, 19] .", "In recent times, with an increase in global travel, the risk for spreading CHIKV to non-endemic regions has heightened [1] . Several travelers have brought CHIKV home with them after visiting areas with actively infected populations [12, 20] . Such cases have been documented in European countries, Australia, Asia, and the United States [8, 21] . The United States has already reported at least twelve cases of travel-associated CHIKV, while France has reported 850 cases, and the United Kingdom 93 [8, 14] . Beyond this, CHIKV-infected travelers have also been diagnosed in Australia, Belgium, Canada, Czech Republic, French Guiana, Germany, Hong Kong, Italy, Japan, Kenya, Malaysia, Martinique, Norway, Switzerland, and Sri Lanka [21] . Some travelers were viremic, worrying public health officials about the spread of CHIKV to new areas [1, 8] .", "The incubation time for CHIKV is relatively short, requiring only 2-6 d with symptoms usually appearing 4-7 d post-infection [22] . Vazeille et al. detected CHIKV in the salivary glands of Ae. albopictus only 2 d after infection [5] . Upon infection, CHIKF tends to present itself in two phases. The first stage is acute, while the second stage, experienced by most but not all, is persistent, causing disabling polyarthritis. Characteristics of the acute phase include an abrupt onset of fever, arthralgia, and in some cases, maculopapular rash [6, 23] . The acute phase causes such intense joint and muscular pain that makes movement very difficult and prostrates its victims [6, 20] .", "Ninety-five percent of infected adults are symptomatic after infection, and of these, most become disabled for weeks to months as a result of decreased dexterity, loss of mobility, and delayed reaction. Eighteen months after disease onset, 40% of patients are found to still have anti-CHIKV IgM [6, 18, 23, 24] . The chronic stage of CHIKF is characterized by polyarthralgia that can last from weeks to years beyond the acute stage [6] . CHIKV has been shown to attack fibroblasts, explaining the involvement of muscles, joints, and skin connective tissues. The high number of nociceptive nerve endings found within the joints and muscle connective tissues can explain pain associated with CHIKF [25, 26] .", "More than 50% of patients who suffer from severe CHIKF are over 65 y old, and more than 33% of them die. Most adults who suffer from severe CHIKF have underlying medical conditions [6, 24, 27] . The other group that is disproportionately affected by severe CHIKV is children. Other complications associated with CHIKV, from most common to least common, include respiratory failure, cardiovascular decompensation, meningoencephalitis, severe acute hepatitis, severe cutaneous effects, other central nervous system problems, and kidney failure [6, 18, 20, 23, 24, 26, 27] .", "CHIKV undertakes a complex replication cycle upon host infection (Figure 2 ), which makes its genome susceptible to mutations [28, 29] . For instance, Ae. aegypti, responsible for epidemics in Kenya, Comoros, and Seychelles, carried CHIKV with an alanine in the 226 position of the E1 gene (E1-A226) [4, 18] . However, when the virus struck La Reunion Islands, a decline in population of Ae. aegypti, due to massive dichlorodiphenyltrichloroethane usage and dearth of Ae. albopictus species' www.plosntds.org population, resulted in an ecological pressure, favoring replacement of alanine at position 226 with valine (E1-A226V) [5] . This mutation allowed CHIKV's secondary vector species, Ae. albopictus, to supplement Ae. aegypti as its primary vector [5] .", "Within a year, the E1-A226V mutation was present in La Reunion Island, and Ae. albopictus apparently vectored the large epidemic infecting 34% of La Reunion Island's population [5] . All of the CHIKV strains isolated from Mayotte carried the E1-A226V mutation, and the mutation was also found in Madagascar in 2007 [5] . The E1-A226V mutation was not present at the beginning of the Indian Ocean Islands outbreak (before September 2005). However, more than 90% of later viral strains found there had incorporated the mutation (December-March 2006), indicating a genotype switch during the winter season [5, 18, 20] .", "The E1-A226V mutation also enabled an increase in infectivity of Ae. albopictus when compared to its infectivity of Ae. aegypti [4, 11, 18, 30] , and with several factors taken together, Ae. albopictus has become the new preferred and more lethal vector for CHIKV [4, 5, 11] . In fact, Tsetsarkin et al. found that a Green Fluorescent Protein tagged E1-A226V virus was 100 times more infective to Ae. albopictus than it was to Ae. aegypti [4] . In all the Indian Ocean Islands, Ae. albopictus became the main vector for CHIKV within 1-2 y after CHIKV was introduced to the region [31] .", "Of note is that Ae. aegypti has most likely been established in North America for over 300 y, while Ae. albopictus has been in many areas of the US, since 1985, primarily in Florida [32] and since then has expanded its range in the country. Reiskind et al. set out to determine if Ae. aegypti and Ae. albopictus mosquitoes captured in Florida were susceptible to CHIKV infection by a La Reunion isolate [32] . Each mosquito tested was highly susceptible to infection by a full-length infectious clone of the La Réunion Island isolate, CHIKV LR2006 OPY1 strain. Even though the Ae. albopictus strains were more susceptible to infection, overall ecology and differences in human biting patterns need to be studied further Characteristically, there are two rounds of translation: (+) sense genomic RNA (49S9 = 11.7 kb) acts directly as mRNA and is partially translated (59 end) to produce non-structural proteins (nsp's). These proteins are responsible for replication and formation of a complementary", "(2) strand, the template for further (+) strand synthesis. Subgenomic mRNA (26 S = 4.1 kb) replication occurs through the synthesis of full-length (2) intermediate RNA, which is regulated by nsp4 and p123 precursor in early infection and later by mature nsp's. Translation of the newly synthesized sub-genomic RNA results in production of structural proteins such as Capsid and protein E2-6k-E1 (from 39 end of genome). Assembly occurs at the cell surface, and the envelope is acquired as the virus buds from the cell and release and maturation almost simultaneous occurred. Replication occurs in the cytoplasm and is very rapid (,4 h) [28, 29] . doi:10.1371/journal.pntd.0000623.g002 www.plosntds.org to gain a more accurate understanding of a potential CHIKV epidemic in the US [32] .", "During the 7 d preceding birth, no human mother has been reported to transmit the disease vertically. However, about 50% of newborns delivered while the mother was infected with CHIKV contracted the disease from their mother, despite the method of delivery. Furthermore, there have been instances of CHIKV transmission from mother to fetus causing congenital illness and fetal death [33] .", "During the 2005-2006 La Reunion Island outbreaks, Ramful et al. discovered that mothers could transmit CHIKV to their progeny during the perinatal period (Day 24 to Day +1) [33, 34] , and it is associated with a high degree of morbidity. By mean Day 4 of life, all of the neonates were symptomatic for CHIKV, exhibiting common CHIKF symptoms. Six neonates were confirmed to have contracted CHIKV and developed mengoencephalitis. Of those mothers who, during the La Reunion Island epidemic, were infected long before delivery, only three fetal deaths were reported [12, 33] . Ramful et al. theorized that motherto-child transmission most likely happens transplacentally shortly before delivery [33] . A similar study by Gerardin et al. reported nineteen cases of neonatal infection associated with intrapartum maternal viremia that progressed to develop encephalitis owing to vertical transmission from infected mothers [34] .", "Clinical and epidemiological similarities with dengue fever make CHIKV diagnosis difficult, which may lead physicians to misdiagnose CHIKV as dengue fever; therefore, the incidence of CHIKV may actually be higher than currently believed (Table 1 ) [6, 12, 35] .", "The amount of time elapsed since disease onset is the most critical parameter when choosing a diagnostic test. CHIKV can be detected and isolated by culturing with mosquito cells (C6/36), Vero cells (mammalian), or in mice [26] . However, this method can take at least a week and only achieves a high sensitivity during the viremic phase, which usually only lasts up to 48 h after the bite. Five days post-infection, the viral isolation approach has a low sensitivity but is still the preferred method for detecting the CHIKV strain [12, 26, 31, 35] . RT-PCR on the other hand is a faster and more sensitive method that can be used within the first week of disease onset [26] , and it is currently the most sensitive method for detecting and quantifying viral mRNA [4, 36] .", "Classic serological detection, by assays such as ELISA [37] , immunofluorescence [5, 38] , complement binding, and haemagglutination inhibition [39] , constitutes the second diagnostic tool used for biological diagnosis of CHIKV infection. These proven techniques are useful for detection of Antigen in mosquitoes during epidemiological studies. These assays detect virus-specific IgM and IgG, however the sensitivity and specificity of these assays has been poorly characterized. Viral competence, or the potential of viral infection and transmission, is an important parameter that can be quantified by ELISA, viral culture, and PCR.", "A study by Ng et al. showed biomarkers indicative of severe CHIKV infection [40] . They found decreased levels of RANTES and increased levels of Interleukin-6 (IL-6) and Interleukin-1b (IL-1b) that could be sued for CHIKV detection in patients as indicators of CHIKV-driven cytokine storm. Couderc et al. demonstrate another cytokine, type-I IFN, as a key player in the progression to CHIKV infection [26] . Using an IFN-a/b null mouse model, they demonstrated evidence of muscles, joints, and skin as privileged CHIKV targets, which is consistent with human pathology. Although Ng et al. concluded that RANTES levels were significantly suppressed in severe CHIKF patients [40] , interestingly, an increase in levels of RANTES has been observed in dengue infection [41] . Since the symptoms of CHIKF mimic those of dengue fever, results obtained from this study strongly suggest that RANTES could be a potential distinctive biomarker that differentiates between these two clinically similar", "diseases.", "There are no approved antiviral treatments currently available for CHIKV [1, 3, 12, 42] . Currently, CHIKF is treated symptomatically, usually with non-steroidal anti-inflammatory drugs or steroids, bed rest, and fluids. Movement and mild exercise are thought to decrease stiffness and morning arthralgia, but heavy exercise may exacerbate rheumatic symptoms. Corticosteroids may be used in cases of debilitating chronic CHIKV infection. There is a debate about the appropriateness of chloroquine as treatment for unresolved, non-steroidal anti-inflammatory drugresistant arthritis [43] . A study showed that viral production was www.plosntds.org drastically reduced at 16 h post-infection after treatment with 100 mM dec-RVKR-cmk (Decanoyl-Arg-Val-Lys-Arg-chloromethylketone), a furine inhibitor [42, 44] . Chloroquine acted by raising the pH, blocking low pH-dependent entry of virus into the cell. It is important to note that dec-RVKR-cmk or chloroquine only inhibited viral spreading from cell", "to cell, not CHIKV replication once it had entered the cell [43] . However, most would agree that the best weapon against CHIKV is prevention. A live CHIKV vaccine developed by the United States reached phase II clinical trial encompassing 59 healthy volunteers [45] . Eight percent of the volunteers experienced transient arthralgia, while 98% of the volunteers had seroconversion [45] . However, live CHIKV vaccines are still questionable. One cannot discount the risk of a live vaccine possibly inducing chronic rheumatism. Also, there is the question as to whether widespread use among the public could trigger mosquito transmission or lead to chronic infection or viral reversion [1] .", "An alternative approach would be to produce a chimeric vaccine against CHIKV. Wang et al. developed a chimeric alphavirus vaccine that is uniformly attenuated and does not cause reactogenicity in mice [3] . Three different versions of this vaccine were made using three different backbone vectors: Venezuelan equine encephalitis virus (VEEV) attenuated vaccine strain T-83, naturally attenuated eastern equine encephalitis virus (EEEV), and attenuated Sindbis virus (SINV). In short, CHIKV structural proteins were engineered into the backbones of the aforementioned vaccines to produce the chimeras [3] . These chimeras were found to stimulate a strong humoral immunity, and even at doses of 5.3-5.8 log 10 PFU, they did not trigger reactogenicity. When vaccinated mice were challenged with CHIKV, neither adult nor neonatal mice gained weight, had fever, or displayed signs of neurological illness. Upon comparison of the chimeras with the Army181/25 vaccine, the Army vaccine resulted in higher", "levels of viremia and replication in the joints of neonatal mice. Because the joints are known targets of CHIKV, Wang et al. noted their vaccine might avoid the negative reactogenic side effects of the Army vaccine. After being subcutaneously vaccinated with 5.3-5.8 log 10 PFU of the chimeric vaccines, mice produced strong neutralizing antibody titers. The VEEV and EEEV chimeras yielded higher neutralizing antibody titers than the SINV chimera without being more virulent. On top of this, the VEEV and EEEV CHIKV chimeras seemed to be more immunogenic than the Army vaccine despite the chimeras' lower viremia and replication in the joints of neonatal mice [3] .", "Tiwari et al. [46] adopted a different strategy using formalin inactivated CHIKV in combination with alhydrogel (Aluminum Hydroxide) as an adjuvant. This study clearly suggests that this vaccine elicits both humoral and cell-mediated immune responses in mice, providing its immunogenic potential. A recent study by Couderc et al. [47] showed passive immunization as a potential treatment for CHIKV infection. Using purified immunoglobulin extracted from convalescent CHIKV patients, they demonstrated effective neutralizing activity against CHIKV infection both in vitro and in vivo. This thereby establishes a potential preventive and therapeutic approach to combat CHIKV infection. Pathogenesis studies conducted with related alpha virus, like RRV, have shown the role of macrophages in persistence on infection [48] . They also demonstrated the role of RRV-specific CD8 T cells in clearing viral load in infected patients, thereby warranting similar investigations with CHIKV and the importance", "of investigating a cell-mediated immune response-based vaccine against CHIKV [49] .", "There are always certain risks associated with live attenuated or inactivated viral vaccines [50] . One way to avoid these potential problems is to construct a consensus-based DNA vaccine. DNA based vaccines have an improved safety profile as compared to live or attenuated vaccines [51, 52] . A consequence of CHIKV's rapid evolution is difficulty in constructing a vaccine that will be able to Figure 3 . Levels of CHIKV-specific IgG in mice immunized with CHIKV vaccines. Each group of C57BL/6 mice (n = 5) was immunized with 12.5 mg of pVax1 control vector or CHIKV vaccine plasmids as indicated at 0 and 2 wk. Mice were bled 2 wk after each immunization, and each group's serum pool was diluted to 1:100 and 1:500 for reaction with specific vaccine constructs. Serum was incubated for 1 h at 37uC on 96-well plates coated with 2 mg/ml of respective CHIKV peptides, and antibody was detected using anti-mouse IgG-HRP and OD was measured at 405 nm. doi:10.1371/journal.pntd.0000623.g003", "www.plosntds.org effectively protect large populations from multiple strains of the virus. One of the strengths of DNA consensus vaccines is its ability to induce cross-reactive immune responses against the three distinct phylogenetic groups of CHIKV. Also DNA-based vaccines can be produced more rapidly than protein-based vaccines.", "Recently, Muthumani et al. constructed a vaccine that was shown to induce both humoral and cellular immunity in vivo in 3-4-wk-old female C57/BL6 mice [49] . These mice were immunized using an in vivo electroporation method to deliver the vaccine into the quadriceps muscle. The consensus construct was designed against E1, E2, and the core protein capsid. To design the construct, they aligned 21 sequences of CHIKV isolated between 1952 and 2006, using strains from differing countries, including La Reunion Island. The most common nucleotide among the sequences was chosen at each position to be used in the consensus construct, taking care not to alter the reading frame. They conducted codon and RNA optimization, added a strong Kozak sequence, and substituted signal peptide with an immunoglobulin E leader sequence to improve vaccine efficacy.", "After immunizing the mice, spleens were harvested along with serum and tested to determine antibody titer. After three immunizations, consensus E1, E2, and C vaccines were shown to induce T-cell immune responses leading to strong IFN-c responses and proliferation in C57/BL6 mice. Furthermore, when compared with control mice, immunized mice had higher total IgG levels as well as higher anti-E1 specific, anti-E2 specific, and anti-C specific IgG antibodies, suggesting a strong humoral immune response ( Figure 3 ) and also specificity for the antigens encoded in the vaccine constructs ( Figure 4 ). Because of its promising results and the need for a safer vaccine, this consensus DNA vaccine deserves further investigation. Determining longevity of protective effects of the vaccine and persistence of antibody and IFN-c responses could be the next step of investigation. Challenged studies of immunized mice must also be carried out.", "CHIKV mosquito-borne disease has caused massive outbreaks for at least half a century but is no longer confined to the www.plosntds.org developing nations. It began to encroach into the boundaries of the developing world. As a result, the NIAID has designated CHIKV as a Category C pathogen alongside the influenza and SARS-CoV viruses [3] . Realization of the potential severity of this disease is exigent; for instance, if used as a biological weapon, the world economy could be severely crippled; if enough members of the armed forces were to become infected during a military deployment, military operations could be significantly affected. Efforts to monitor the disease will only provide minimal warning in a global society, and steps to prevent the morbidity and mortality associated with pandemic are imperative [21, 31] . Despite the gravity of its infectious potency and the fear of it being a potential biological weapon, there is currently no vaccine for CHIKV infections. Live", "attenuated vaccine trials were carried out in 2000, but funding for the project was discontinued. Newer approaches such as DNA vaccines appear promising over conventional strategies like live attenuated or inactivated virus and thus call for further investigation. Recent advances such electroporation delivery and incorporation of adjuvants has boosted DNA vaccine efficacy [51, 53] . Despite the low antibody response to DNA vaccines, other numerous advantages have overshadowed these minor drawbacks (Table 2) , the most important one being the ability to induce both humoral and cellular immune responses [51, 54] .", "Judging by recent success, such as the immunogenic construct developed by Muthumani et al., DNA vaccines could play a major role in combating CHIKV [49] . Vaccines are literally a critical component of CHIKV disease control and therefore research in this area is highly encouraged. The dramatic spread of dengue viruses (DENV) throughout tropical America since 1980 via the same vectors and human hosts underscores the risk to public health in the Americas. The adverse events associated with the current live vaccine are well documented [55] . Realizing these drawbacks, earnest efforts should be taken to develop new strategies to forestall further spread and complications." ]	[]	3,829	5,688
1,689	How was the Italian isolation found to have evolved from?	2,494	[ "from the Kerala isolate, which was associated with a A226V shift in E1 gene that represents a successful evolutionary adaptation in the mosquito vector similar to the ones observed in Reunion Island [" ]	[ "Chikungunya: A Potentially Emerging Epidemic?\n\nhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC2860491/\n\nSHA: f7c3160bef4169d29e2a8bdd79dd6e9056d4774c\n\nAuthors: Thiboutot, Michelle M.; Kannan, Senthil; Kawalekar, Omkar U.; Shedlock, Devon J.; Khan, Amir S.; Sarangan, Gopalsamy; Srikanth, Padma; Weiner, David B.; Muthumani, Karuppiah\nDate: 2010-04-27\nDOI: 10.1371/journal.pntd.0000623\nLicense: cc-by", "Abstract: Chikungunya virus is a mosquito-borne emerging pathogen that has a major health impact in humans and causes fever disease, headache, rash, nausea, vomiting, myalgia, and arthralgia. Indigenous to tropical Africa, recent large outbreaks have been reported in parts of South East Asia and several of its neighboring islands in 2005–07 and in Europe in 2007. Furthermore, positive cases have been confirmed in the United States in travelers returning from known outbreak areas. Currently, there is no vaccine or antiviral treatment. With the threat of an emerging global pandemic, the peculiar problems associated with the more immediate and seasonal epidemics warrant the development of an effective vaccine. In this review, we summarize the evidence supporting these concepts.", "Text: Chikungunya virus (CHIKV), a mosquito-borne pathogen listed by National Institute of Allergy and Infectious Diseases (NIAID) as a Category C Priority Pathogen that causes Chikungunya fever (CHIKF), has been spreading throughout Asia, Africa, and parts of Europe in recent times [1, 2, 3] . CHIKV is an arthropod-borne virus (arbovirus) and is transmitted to humans primarily by Aedes aegypti, the infamous yellow fever propagator [4, 5] . CHIKV infection is marked by severe joint pain, contorting its victims into unusual postures [6] . The disease gets its name from the Kimakonde vernacular language of Tanzania and Mozambique, and the word chikungunya means ''that which contorts or bends up'' and translates in Swahili to ''the illness of the bended walker'' [7, 8, 9] . In Africa, CHIKV is maintained in a sylvatic cycle among forest-dwelling Aedes spp. mosquitoes, wild primates, squirrels, birds, and rodents ( Figure 1 ) [10] . In Asia, the disease is vectored by Ae. aegypti and Ae.", "albopictus [11] . Transmission in Asia occurs in an urban cycle whereby the mosquito spreads the disease from an infected human to an uninfected human, following an epidemiological pattern similar to dengue fever [12] .", "The 2005-2006 epidemic of CHIKV in La Reunion islands in the Indian Ocean, spurred the discovery of a new vector species, Ae. albopictus [5] . Wrecking over one-third of the island's population, this epidemic peaked its devastation between January and February 2006, when over 46,000 cases came into light every week, including 284 deaths [5, 13] . Ae. albopictus is common in urban areas of the United States and is already flourishing in 36 states, raising grave concerns to the immunologically naive populace of the United States [14] .\n\nAccordingly, this review elaborately details the epidemiology and global expansion of CHIKV, describes its clinical features and pathogenesis and its symptoms and complications, and finally nominates a possible vaccine approach against CHIKV infection.", "CHIKV has been isolated into three genotypes based on phylogenetic studies. These genotypes, based on the gene sequences of an Envelope protein (E1), are Asian, East/Central/ South African, and West African [4, 11, 15] . Using phylogenetic models, Cherian et al. estimate that the Asian genotype of CHIKV emerged between 50 and 310 y ago, and the West and East African genotypes diverged between 100 and 840 y ago [15] . Since then, CHIKV has come a long way, with several mutations incorporated, and has continued to wreak epidemics in several regions. Recent activities of CHIKV include the Indian epidemic in 2005-2006, which was followed by a sudden explosion of cases in 2007. An estimated 1.3 million people across 13 states were reported to be infected in India [12, 16] , and CHIKV was also widespread in Malaysia, Sri Lanka, and Indonesia [17] . In July-August of 2007, CHIKV was reported in Italy, probably brought in by travelers from CHIKV-prone regions of India, Africa, and Indian", "Ocean islands such as Mauritius, Madagascar, and Seychelles. Few of the Italian isolates were found to have evolved from the Kerala isolate, which was associated with a A226V shift in E1 gene that represents a successful evolutionary adaptation in the mosquito vector similar to the ones observed in Reunion Island [2, 18, 19] .", "In recent times, with an increase in global travel, the risk for spreading CHIKV to non-endemic regions has heightened [1] . Several travelers have brought CHIKV home with them after visiting areas with actively infected populations [12, 20] . Such cases have been documented in European countries, Australia, Asia, and the United States [8, 21] . The United States has already reported at least twelve cases of travel-associated CHIKV, while France has reported 850 cases, and the United Kingdom 93 [8, 14] . Beyond this, CHIKV-infected travelers have also been diagnosed in Australia, Belgium, Canada, Czech Republic, French Guiana, Germany, Hong Kong, Italy, Japan, Kenya, Malaysia, Martinique, Norway, Switzerland, and Sri Lanka [21] . Some travelers were viremic, worrying public health officials about the spread of CHIKV to new areas [1, 8] .", "The incubation time for CHIKV is relatively short, requiring only 2-6 d with symptoms usually appearing 4-7 d post-infection [22] . Vazeille et al. detected CHIKV in the salivary glands of Ae. albopictus only 2 d after infection [5] . Upon infection, CHIKF tends to present itself in two phases. The first stage is acute, while the second stage, experienced by most but not all, is persistent, causing disabling polyarthritis. Characteristics of the acute phase include an abrupt onset of fever, arthralgia, and in some cases, maculopapular rash [6, 23] . The acute phase causes such intense joint and muscular pain that makes movement very difficult and prostrates its victims [6, 20] .", "Ninety-five percent of infected adults are symptomatic after infection, and of these, most become disabled for weeks to months as a result of decreased dexterity, loss of mobility, and delayed reaction. Eighteen months after disease onset, 40% of patients are found to still have anti-CHIKV IgM [6, 18, 23, 24] . The chronic stage of CHIKF is characterized by polyarthralgia that can last from weeks to years beyond the acute stage [6] . CHIKV has been shown to attack fibroblasts, explaining the involvement of muscles, joints, and skin connective tissues. The high number of nociceptive nerve endings found within the joints and muscle connective tissues can explain pain associated with CHIKF [25, 26] .", "More than 50% of patients who suffer from severe CHIKF are over 65 y old, and more than 33% of them die. Most adults who suffer from severe CHIKF have underlying medical conditions [6, 24, 27] . The other group that is disproportionately affected by severe CHIKV is children. Other complications associated with CHIKV, from most common to least common, include respiratory failure, cardiovascular decompensation, meningoencephalitis, severe acute hepatitis, severe cutaneous effects, other central nervous system problems, and kidney failure [6, 18, 20, 23, 24, 26, 27] .", "CHIKV undertakes a complex replication cycle upon host infection (Figure 2 ), which makes its genome susceptible to mutations [28, 29] . For instance, Ae. aegypti, responsible for epidemics in Kenya, Comoros, and Seychelles, carried CHIKV with an alanine in the 226 position of the E1 gene (E1-A226) [4, 18] . However, when the virus struck La Reunion Islands, a decline in population of Ae. aegypti, due to massive dichlorodiphenyltrichloroethane usage and dearth of Ae. albopictus species' www.plosntds.org population, resulted in an ecological pressure, favoring replacement of alanine at position 226 with valine (E1-A226V) [5] . This mutation allowed CHIKV's secondary vector species, Ae. albopictus, to supplement Ae. aegypti as its primary vector [5] .", "Within a year, the E1-A226V mutation was present in La Reunion Island, and Ae. albopictus apparently vectored the large epidemic infecting 34% of La Reunion Island's population [5] . All of the CHIKV strains isolated from Mayotte carried the E1-A226V mutation, and the mutation was also found in Madagascar in 2007 [5] . The E1-A226V mutation was not present at the beginning of the Indian Ocean Islands outbreak (before September 2005). However, more than 90% of later viral strains found there had incorporated the mutation (December-March 2006), indicating a genotype switch during the winter season [5, 18, 20] .", "The E1-A226V mutation also enabled an increase in infectivity of Ae. albopictus when compared to its infectivity of Ae. aegypti [4, 11, 18, 30] , and with several factors taken together, Ae. albopictus has become the new preferred and more lethal vector for CHIKV [4, 5, 11] . In fact, Tsetsarkin et al. found that a Green Fluorescent Protein tagged E1-A226V virus was 100 times more infective to Ae. albopictus than it was to Ae. aegypti [4] . In all the Indian Ocean Islands, Ae. albopictus became the main vector for CHIKV within 1-2 y after CHIKV was introduced to the region [31] .", "Of note is that Ae. aegypti has most likely been established in North America for over 300 y, while Ae. albopictus has been in many areas of the US, since 1985, primarily in Florida [32] and since then has expanded its range in the country. Reiskind et al. set out to determine if Ae. aegypti and Ae. albopictus mosquitoes captured in Florida were susceptible to CHIKV infection by a La Reunion isolate [32] . Each mosquito tested was highly susceptible to infection by a full-length infectious clone of the La Réunion Island isolate, CHIKV LR2006 OPY1 strain. Even though the Ae. albopictus strains were more susceptible to infection, overall ecology and differences in human biting patterns need to be studied further Characteristically, there are two rounds of translation: (+) sense genomic RNA (49S9 = 11.7 kb) acts directly as mRNA and is partially translated (59 end) to produce non-structural proteins (nsp's). These proteins are responsible for replication and formation of a complementary", "(2) strand, the template for further (+) strand synthesis. Subgenomic mRNA (26 S = 4.1 kb) replication occurs through the synthesis of full-length (2) intermediate RNA, which is regulated by nsp4 and p123 precursor in early infection and later by mature nsp's. Translation of the newly synthesized sub-genomic RNA results in production of structural proteins such as Capsid and protein E2-6k-E1 (from 39 end of genome). Assembly occurs at the cell surface, and the envelope is acquired as the virus buds from the cell and release and maturation almost simultaneous occurred. Replication occurs in the cytoplasm and is very rapid (,4 h) [28, 29] . doi:10.1371/journal.pntd.0000623.g002 www.plosntds.org to gain a more accurate understanding of a potential CHIKV epidemic in the US [32] .", "During the 7 d preceding birth, no human mother has been reported to transmit the disease vertically. However, about 50% of newborns delivered while the mother was infected with CHIKV contracted the disease from their mother, despite the method of delivery. Furthermore, there have been instances of CHIKV transmission from mother to fetus causing congenital illness and fetal death [33] .", "During the 2005-2006 La Reunion Island outbreaks, Ramful et al. discovered that mothers could transmit CHIKV to their progeny during the perinatal period (Day 24 to Day +1) [33, 34] , and it is associated with a high degree of morbidity. By mean Day 4 of life, all of the neonates were symptomatic for CHIKV, exhibiting common CHIKF symptoms. Six neonates were confirmed to have contracted CHIKV and developed mengoencephalitis. Of those mothers who, during the La Reunion Island epidemic, were infected long before delivery, only three fetal deaths were reported [12, 33] . Ramful et al. theorized that motherto-child transmission most likely happens transplacentally shortly before delivery [33] . A similar study by Gerardin et al. reported nineteen cases of neonatal infection associated with intrapartum maternal viremia that progressed to develop encephalitis owing to vertical transmission from infected mothers [34] .", "Clinical and epidemiological similarities with dengue fever make CHIKV diagnosis difficult, which may lead physicians to misdiagnose CHIKV as dengue fever; therefore, the incidence of CHIKV may actually be higher than currently believed (Table 1 ) [6, 12, 35] .", "The amount of time elapsed since disease onset is the most critical parameter when choosing a diagnostic test. CHIKV can be detected and isolated by culturing with mosquito cells (C6/36), Vero cells (mammalian), or in mice [26] . However, this method can take at least a week and only achieves a high sensitivity during the viremic phase, which usually only lasts up to 48 h after the bite. Five days post-infection, the viral isolation approach has a low sensitivity but is still the preferred method for detecting the CHIKV strain [12, 26, 31, 35] . RT-PCR on the other hand is a faster and more sensitive method that can be used within the first week of disease onset [26] , and it is currently the most sensitive method for detecting and quantifying viral mRNA [4, 36] .", "Classic serological detection, by assays such as ELISA [37] , immunofluorescence [5, 38] , complement binding, and haemagglutination inhibition [39] , constitutes the second diagnostic tool used for biological diagnosis of CHIKV infection. These proven techniques are useful for detection of Antigen in mosquitoes during epidemiological studies. These assays detect virus-specific IgM and IgG, however the sensitivity and specificity of these assays has been poorly characterized. Viral competence, or the potential of viral infection and transmission, is an important parameter that can be quantified by ELISA, viral culture, and PCR.", "A study by Ng et al. showed biomarkers indicative of severe CHIKV infection [40] . They found decreased levels of RANTES and increased levels of Interleukin-6 (IL-6) and Interleukin-1b (IL-1b) that could be sued for CHIKV detection in patients as indicators of CHIKV-driven cytokine storm. Couderc et al. demonstrate another cytokine, type-I IFN, as a key player in the progression to CHIKV infection [26] . Using an IFN-a/b null mouse model, they demonstrated evidence of muscles, joints, and skin as privileged CHIKV targets, which is consistent with human pathology. Although Ng et al. concluded that RANTES levels were significantly suppressed in severe CHIKF patients [40] , interestingly, an increase in levels of RANTES has been observed in dengue infection [41] . Since the symptoms of CHIKF mimic those of dengue fever, results obtained from this study strongly suggest that RANTES could be a potential distinctive biomarker that differentiates between these two clinically similar", "diseases.", "There are no approved antiviral treatments currently available for CHIKV [1, 3, 12, 42] . Currently, CHIKF is treated symptomatically, usually with non-steroidal anti-inflammatory drugs or steroids, bed rest, and fluids. Movement and mild exercise are thought to decrease stiffness and morning arthralgia, but heavy exercise may exacerbate rheumatic symptoms. Corticosteroids may be used in cases of debilitating chronic CHIKV infection. There is a debate about the appropriateness of chloroquine as treatment for unresolved, non-steroidal anti-inflammatory drugresistant arthritis [43] . A study showed that viral production was www.plosntds.org drastically reduced at 16 h post-infection after treatment with 100 mM dec-RVKR-cmk (Decanoyl-Arg-Val-Lys-Arg-chloromethylketone), a furine inhibitor [42, 44] . Chloroquine acted by raising the pH, blocking low pH-dependent entry of virus into the cell. It is important to note that dec-RVKR-cmk or chloroquine only inhibited viral spreading from cell", "to cell, not CHIKV replication once it had entered the cell [43] . However, most would agree that the best weapon against CHIKV is prevention. A live CHIKV vaccine developed by the United States reached phase II clinical trial encompassing 59 healthy volunteers [45] . Eight percent of the volunteers experienced transient arthralgia, while 98% of the volunteers had seroconversion [45] . However, live CHIKV vaccines are still questionable. One cannot discount the risk of a live vaccine possibly inducing chronic rheumatism. Also, there is the question as to whether widespread use among the public could trigger mosquito transmission or lead to chronic infection or viral reversion [1] .", "An alternative approach would be to produce a chimeric vaccine against CHIKV. Wang et al. developed a chimeric alphavirus vaccine that is uniformly attenuated and does not cause reactogenicity in mice [3] . Three different versions of this vaccine were made using three different backbone vectors: Venezuelan equine encephalitis virus (VEEV) attenuated vaccine strain T-83, naturally attenuated eastern equine encephalitis virus (EEEV), and attenuated Sindbis virus (SINV). In short, CHIKV structural proteins were engineered into the backbones of the aforementioned vaccines to produce the chimeras [3] . These chimeras were found to stimulate a strong humoral immunity, and even at doses of 5.3-5.8 log 10 PFU, they did not trigger reactogenicity. When vaccinated mice were challenged with CHIKV, neither adult nor neonatal mice gained weight, had fever, or displayed signs of neurological illness. Upon comparison of the chimeras with the Army181/25 vaccine, the Army vaccine resulted in higher", "levels of viremia and replication in the joints of neonatal mice. Because the joints are known targets of CHIKV, Wang et al. noted their vaccine might avoid the negative reactogenic side effects of the Army vaccine. After being subcutaneously vaccinated with 5.3-5.8 log 10 PFU of the chimeric vaccines, mice produced strong neutralizing antibody titers. The VEEV and EEEV chimeras yielded higher neutralizing antibody titers than the SINV chimera without being more virulent. On top of this, the VEEV and EEEV CHIKV chimeras seemed to be more immunogenic than the Army vaccine despite the chimeras' lower viremia and replication in the joints of neonatal mice [3] .", "Tiwari et al. [46] adopted a different strategy using formalin inactivated CHIKV in combination with alhydrogel (Aluminum Hydroxide) as an adjuvant. This study clearly suggests that this vaccine elicits both humoral and cell-mediated immune responses in mice, providing its immunogenic potential. A recent study by Couderc et al. [47] showed passive immunization as a potential treatment for CHIKV infection. Using purified immunoglobulin extracted from convalescent CHIKV patients, they demonstrated effective neutralizing activity against CHIKV infection both in vitro and in vivo. This thereby establishes a potential preventive and therapeutic approach to combat CHIKV infection. Pathogenesis studies conducted with related alpha virus, like RRV, have shown the role of macrophages in persistence on infection [48] . They also demonstrated the role of RRV-specific CD8 T cells in clearing viral load in infected patients, thereby warranting similar investigations with CHIKV and the importance", "of investigating a cell-mediated immune response-based vaccine against CHIKV [49] .", "There are always certain risks associated with live attenuated or inactivated viral vaccines [50] . One way to avoid these potential problems is to construct a consensus-based DNA vaccine. DNA based vaccines have an improved safety profile as compared to live or attenuated vaccines [51, 52] . A consequence of CHIKV's rapid evolution is difficulty in constructing a vaccine that will be able to Figure 3 . Levels of CHIKV-specific IgG in mice immunized with CHIKV vaccines. Each group of C57BL/6 mice (n = 5) was immunized with 12.5 mg of pVax1 control vector or CHIKV vaccine plasmids as indicated at 0 and 2 wk. Mice were bled 2 wk after each immunization, and each group's serum pool was diluted to 1:100 and 1:500 for reaction with specific vaccine constructs. Serum was incubated for 1 h at 37uC on 96-well plates coated with 2 mg/ml of respective CHIKV peptides, and antibody was detected using anti-mouse IgG-HRP and OD was measured at 405 nm. doi:10.1371/journal.pntd.0000623.g003", "www.plosntds.org effectively protect large populations from multiple strains of the virus. One of the strengths of DNA consensus vaccines is its ability to induce cross-reactive immune responses against the three distinct phylogenetic groups of CHIKV. Also DNA-based vaccines can be produced more rapidly than protein-based vaccines.", "Recently, Muthumani et al. constructed a vaccine that was shown to induce both humoral and cellular immunity in vivo in 3-4-wk-old female C57/BL6 mice [49] . These mice were immunized using an in vivo electroporation method to deliver the vaccine into the quadriceps muscle. The consensus construct was designed against E1, E2, and the core protein capsid. To design the construct, they aligned 21 sequences of CHIKV isolated between 1952 and 2006, using strains from differing countries, including La Reunion Island. The most common nucleotide among the sequences was chosen at each position to be used in the consensus construct, taking care not to alter the reading frame. They conducted codon and RNA optimization, added a strong Kozak sequence, and substituted signal peptide with an immunoglobulin E leader sequence to improve vaccine efficacy.", "After immunizing the mice, spleens were harvested along with serum and tested to determine antibody titer. After three immunizations, consensus E1, E2, and C vaccines were shown to induce T-cell immune responses leading to strong IFN-c responses and proliferation in C57/BL6 mice. Furthermore, when compared with control mice, immunized mice had higher total IgG levels as well as higher anti-E1 specific, anti-E2 specific, and anti-C specific IgG antibodies, suggesting a strong humoral immune response ( Figure 3 ) and also specificity for the antigens encoded in the vaccine constructs ( Figure 4 ). Because of its promising results and the need for a safer vaccine, this consensus DNA vaccine deserves further investigation. Determining longevity of protective effects of the vaccine and persistence of antibody and IFN-c responses could be the next step of investigation. Challenged studies of immunized mice must also be carried out.", "CHIKV mosquito-borne disease has caused massive outbreaks for at least half a century but is no longer confined to the www.plosntds.org developing nations. It began to encroach into the boundaries of the developing world. As a result, the NIAID has designated CHIKV as a Category C pathogen alongside the influenza and SARS-CoV viruses [3] . Realization of the potential severity of this disease is exigent; for instance, if used as a biological weapon, the world economy could be severely crippled; if enough members of the armed forces were to become infected during a military deployment, military operations could be significantly affected. Efforts to monitor the disease will only provide minimal warning in a global society, and steps to prevent the morbidity and mortality associated with pandemic are imperative [21, 31] . Despite the gravity of its infectious potency and the fear of it being a potential biological weapon, there is currently no vaccine for CHIKV infections. Live", "attenuated vaccine trials were carried out in 2000, but funding for the project was discontinued. Newer approaches such as DNA vaccines appear promising over conventional strategies like live attenuated or inactivated virus and thus call for further investigation. Recent advances such electroporation delivery and incorporation of adjuvants has boosted DNA vaccine efficacy [51, 53] . Despite the low antibody response to DNA vaccines, other numerous advantages have overshadowed these minor drawbacks (Table 2) , the most important one being the ability to induce both humoral and cellular immune responses [51, 54] .", "Judging by recent success, such as the immunogenic construct developed by Muthumani et al., DNA vaccines could play a major role in combating CHIKV [49] . Vaccines are literally a critical component of CHIKV disease control and therefore research in this area is highly encouraged. The dramatic spread of dengue viruses (DENV) throughout tropical America since 1980 via the same vectors and human hosts underscores the risk to public health in the Americas. The adverse events associated with the current live vaccine are well documented [55] . Realizing these drawbacks, earnest efforts should be taken to develop new strategies to forestall further spread and complications." ]	[ 6 ]	3,829	5,688
1,689	How many days is the incubation period?	2,495	[ "2-6 d" ]	[ "Chikungunya: A Potentially Emerging Epidemic?\n\nhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC2860491/\n\nSHA: f7c3160bef4169d29e2a8bdd79dd6e9056d4774c\n\nAuthors: Thiboutot, Michelle M.; Kannan, Senthil; Kawalekar, Omkar U.; Shedlock, Devon J.; Khan, Amir S.; Sarangan, Gopalsamy; Srikanth, Padma; Weiner, David B.; Muthumani, Karuppiah\nDate: 2010-04-27\nDOI: 10.1371/journal.pntd.0000623\nLicense: cc-by", "Abstract: Chikungunya virus is a mosquito-borne emerging pathogen that has a major health impact in humans and causes fever disease, headache, rash, nausea, vomiting, myalgia, and arthralgia. Indigenous to tropical Africa, recent large outbreaks have been reported in parts of South East Asia and several of its neighboring islands in 2005–07 and in Europe in 2007. Furthermore, positive cases have been confirmed in the United States in travelers returning from known outbreak areas. Currently, there is no vaccine or antiviral treatment. With the threat of an emerging global pandemic, the peculiar problems associated with the more immediate and seasonal epidemics warrant the development of an effective vaccine. In this review, we summarize the evidence supporting these concepts.", "Text: Chikungunya virus (CHIKV), a mosquito-borne pathogen listed by National Institute of Allergy and Infectious Diseases (NIAID) as a Category C Priority Pathogen that causes Chikungunya fever (CHIKF), has been spreading throughout Asia, Africa, and parts of Europe in recent times [1, 2, 3] . CHIKV is an arthropod-borne virus (arbovirus) and is transmitted to humans primarily by Aedes aegypti, the infamous yellow fever propagator [4, 5] . CHIKV infection is marked by severe joint pain, contorting its victims into unusual postures [6] . The disease gets its name from the Kimakonde vernacular language of Tanzania and Mozambique, and the word chikungunya means ''that which contorts or bends up'' and translates in Swahili to ''the illness of the bended walker'' [7, 8, 9] . In Africa, CHIKV is maintained in a sylvatic cycle among forest-dwelling Aedes spp. mosquitoes, wild primates, squirrels, birds, and rodents ( Figure 1 ) [10] . In Asia, the disease is vectored by Ae. aegypti and Ae.", "albopictus [11] . Transmission in Asia occurs in an urban cycle whereby the mosquito spreads the disease from an infected human to an uninfected human, following an epidemiological pattern similar to dengue fever [12] .", "The 2005-2006 epidemic of CHIKV in La Reunion islands in the Indian Ocean, spurred the discovery of a new vector species, Ae. albopictus [5] . Wrecking over one-third of the island's population, this epidemic peaked its devastation between January and February 2006, when over 46,000 cases came into light every week, including 284 deaths [5, 13] . Ae. albopictus is common in urban areas of the United States and is already flourishing in 36 states, raising grave concerns to the immunologically naive populace of the United States [14] .\n\nAccordingly, this review elaborately details the epidemiology and global expansion of CHIKV, describes its clinical features and pathogenesis and its symptoms and complications, and finally nominates a possible vaccine approach against CHIKV infection.", "CHIKV has been isolated into three genotypes based on phylogenetic studies. These genotypes, based on the gene sequences of an Envelope protein (E1), are Asian, East/Central/ South African, and West African [4, 11, 15] . Using phylogenetic models, Cherian et al. estimate that the Asian genotype of CHIKV emerged between 50 and 310 y ago, and the West and East African genotypes diverged between 100 and 840 y ago [15] . Since then, CHIKV has come a long way, with several mutations incorporated, and has continued to wreak epidemics in several regions. Recent activities of CHIKV include the Indian epidemic in 2005-2006, which was followed by a sudden explosion of cases in 2007. An estimated 1.3 million people across 13 states were reported to be infected in India [12, 16] , and CHIKV was also widespread in Malaysia, Sri Lanka, and Indonesia [17] . In July-August of 2007, CHIKV was reported in Italy, probably brought in by travelers from CHIKV-prone regions of India, Africa, and Indian", "Ocean islands such as Mauritius, Madagascar, and Seychelles. Few of the Italian isolates were found to have evolved from the Kerala isolate, which was associated with a A226V shift in E1 gene that represents a successful evolutionary adaptation in the mosquito vector similar to the ones observed in Reunion Island [2, 18, 19] .", "In recent times, with an increase in global travel, the risk for spreading CHIKV to non-endemic regions has heightened [1] . Several travelers have brought CHIKV home with them after visiting areas with actively infected populations [12, 20] . Such cases have been documented in European countries, Australia, Asia, and the United States [8, 21] . The United States has already reported at least twelve cases of travel-associated CHIKV, while France has reported 850 cases, and the United Kingdom 93 [8, 14] . Beyond this, CHIKV-infected travelers have also been diagnosed in Australia, Belgium, Canada, Czech Republic, French Guiana, Germany, Hong Kong, Italy, Japan, Kenya, Malaysia, Martinique, Norway, Switzerland, and Sri Lanka [21] . Some travelers were viremic, worrying public health officials about the spread of CHIKV to new areas [1, 8] .", "The incubation time for CHIKV is relatively short, requiring only 2-6 d with symptoms usually appearing 4-7 d post-infection [22] . Vazeille et al. detected CHIKV in the salivary glands of Ae. albopictus only 2 d after infection [5] . Upon infection, CHIKF tends to present itself in two phases. The first stage is acute, while the second stage, experienced by most but not all, is persistent, causing disabling polyarthritis. Characteristics of the acute phase include an abrupt onset of fever, arthralgia, and in some cases, maculopapular rash [6, 23] . The acute phase causes such intense joint and muscular pain that makes movement very difficult and prostrates its victims [6, 20] .", "Ninety-five percent of infected adults are symptomatic after infection, and of these, most become disabled for weeks to months as a result of decreased dexterity, loss of mobility, and delayed reaction. Eighteen months after disease onset, 40% of patients are found to still have anti-CHIKV IgM [6, 18, 23, 24] . The chronic stage of CHIKF is characterized by polyarthralgia that can last from weeks to years beyond the acute stage [6] . CHIKV has been shown to attack fibroblasts, explaining the involvement of muscles, joints, and skin connective tissues. The high number of nociceptive nerve endings found within the joints and muscle connective tissues can explain pain associated with CHIKF [25, 26] .", "More than 50% of patients who suffer from severe CHIKF are over 65 y old, and more than 33% of them die. Most adults who suffer from severe CHIKF have underlying medical conditions [6, 24, 27] . The other group that is disproportionately affected by severe CHIKV is children. Other complications associated with CHIKV, from most common to least common, include respiratory failure, cardiovascular decompensation, meningoencephalitis, severe acute hepatitis, severe cutaneous effects, other central nervous system problems, and kidney failure [6, 18, 20, 23, 24, 26, 27] .", "CHIKV undertakes a complex replication cycle upon host infection (Figure 2 ), which makes its genome susceptible to mutations [28, 29] . For instance, Ae. aegypti, responsible for epidemics in Kenya, Comoros, and Seychelles, carried CHIKV with an alanine in the 226 position of the E1 gene (E1-A226) [4, 18] . However, when the virus struck La Reunion Islands, a decline in population of Ae. aegypti, due to massive dichlorodiphenyltrichloroethane usage and dearth of Ae. albopictus species' www.plosntds.org population, resulted in an ecological pressure, favoring replacement of alanine at position 226 with valine (E1-A226V) [5] . This mutation allowed CHIKV's secondary vector species, Ae. albopictus, to supplement Ae. aegypti as its primary vector [5] .", "Within a year, the E1-A226V mutation was present in La Reunion Island, and Ae. albopictus apparently vectored the large epidemic infecting 34% of La Reunion Island's population [5] . All of the CHIKV strains isolated from Mayotte carried the E1-A226V mutation, and the mutation was also found in Madagascar in 2007 [5] . The E1-A226V mutation was not present at the beginning of the Indian Ocean Islands outbreak (before September 2005). However, more than 90% of later viral strains found there had incorporated the mutation (December-March 2006), indicating a genotype switch during the winter season [5, 18, 20] .", "The E1-A226V mutation also enabled an increase in infectivity of Ae. albopictus when compared to its infectivity of Ae. aegypti [4, 11, 18, 30] , and with several factors taken together, Ae. albopictus has become the new preferred and more lethal vector for CHIKV [4, 5, 11] . In fact, Tsetsarkin et al. found that a Green Fluorescent Protein tagged E1-A226V virus was 100 times more infective to Ae. albopictus than it was to Ae. aegypti [4] . In all the Indian Ocean Islands, Ae. albopictus became the main vector for CHIKV within 1-2 y after CHIKV was introduced to the region [31] .", "Of note is that Ae. aegypti has most likely been established in North America for over 300 y, while Ae. albopictus has been in many areas of the US, since 1985, primarily in Florida [32] and since then has expanded its range in the country. Reiskind et al. set out to determine if Ae. aegypti and Ae. albopictus mosquitoes captured in Florida were susceptible to CHIKV infection by a La Reunion isolate [32] . Each mosquito tested was highly susceptible to infection by a full-length infectious clone of the La Réunion Island isolate, CHIKV LR2006 OPY1 strain. Even though the Ae. albopictus strains were more susceptible to infection, overall ecology and differences in human biting patterns need to be studied further Characteristically, there are two rounds of translation: (+) sense genomic RNA (49S9 = 11.7 kb) acts directly as mRNA and is partially translated (59 end) to produce non-structural proteins (nsp's). These proteins are responsible for replication and formation of a complementary", "(2) strand, the template for further (+) strand synthesis. Subgenomic mRNA (26 S = 4.1 kb) replication occurs through the synthesis of full-length (2) intermediate RNA, which is regulated by nsp4 and p123 precursor in early infection and later by mature nsp's. Translation of the newly synthesized sub-genomic RNA results in production of structural proteins such as Capsid and protein E2-6k-E1 (from 39 end of genome). Assembly occurs at the cell surface, and the envelope is acquired as the virus buds from the cell and release and maturation almost simultaneous occurred. Replication occurs in the cytoplasm and is very rapid (,4 h) [28, 29] . doi:10.1371/journal.pntd.0000623.g002 www.plosntds.org to gain a more accurate understanding of a potential CHIKV epidemic in the US [32] .", "During the 7 d preceding birth, no human mother has been reported to transmit the disease vertically. However, about 50% of newborns delivered while the mother was infected with CHIKV contracted the disease from their mother, despite the method of delivery. Furthermore, there have been instances of CHIKV transmission from mother to fetus causing congenital illness and fetal death [33] .", "During the 2005-2006 La Reunion Island outbreaks, Ramful et al. discovered that mothers could transmit CHIKV to their progeny during the perinatal period (Day 24 to Day +1) [33, 34] , and it is associated with a high degree of morbidity. By mean Day 4 of life, all of the neonates were symptomatic for CHIKV, exhibiting common CHIKF symptoms. Six neonates were confirmed to have contracted CHIKV and developed mengoencephalitis. Of those mothers who, during the La Reunion Island epidemic, were infected long before delivery, only three fetal deaths were reported [12, 33] . Ramful et al. theorized that motherto-child transmission most likely happens transplacentally shortly before delivery [33] . A similar study by Gerardin et al. reported nineteen cases of neonatal infection associated with intrapartum maternal viremia that progressed to develop encephalitis owing to vertical transmission from infected mothers [34] .", "Clinical and epidemiological similarities with dengue fever make CHIKV diagnosis difficult, which may lead physicians to misdiagnose CHIKV as dengue fever; therefore, the incidence of CHIKV may actually be higher than currently believed (Table 1 ) [6, 12, 35] .", "The amount of time elapsed since disease onset is the most critical parameter when choosing a diagnostic test. CHIKV can be detected and isolated by culturing with mosquito cells (C6/36), Vero cells (mammalian), or in mice [26] . However, this method can take at least a week and only achieves a high sensitivity during the viremic phase, which usually only lasts up to 48 h after the bite. Five days post-infection, the viral isolation approach has a low sensitivity but is still the preferred method for detecting the CHIKV strain [12, 26, 31, 35] . RT-PCR on the other hand is a faster and more sensitive method that can be used within the first week of disease onset [26] , and it is currently the most sensitive method for detecting and quantifying viral mRNA [4, 36] .", "Classic serological detection, by assays such as ELISA [37] , immunofluorescence [5, 38] , complement binding, and haemagglutination inhibition [39] , constitutes the second diagnostic tool used for biological diagnosis of CHIKV infection. These proven techniques are useful for detection of Antigen in mosquitoes during epidemiological studies. These assays detect virus-specific IgM and IgG, however the sensitivity and specificity of these assays has been poorly characterized. Viral competence, or the potential of viral infection and transmission, is an important parameter that can be quantified by ELISA, viral culture, and PCR.", "A study by Ng et al. showed biomarkers indicative of severe CHIKV infection [40] . They found decreased levels of RANTES and increased levels of Interleukin-6 (IL-6) and Interleukin-1b (IL-1b) that could be sued for CHIKV detection in patients as indicators of CHIKV-driven cytokine storm. Couderc et al. demonstrate another cytokine, type-I IFN, as a key player in the progression to CHIKV infection [26] . Using an IFN-a/b null mouse model, they demonstrated evidence of muscles, joints, and skin as privileged CHIKV targets, which is consistent with human pathology. Although Ng et al. concluded that RANTES levels were significantly suppressed in severe CHIKF patients [40] , interestingly, an increase in levels of RANTES has been observed in dengue infection [41] . Since the symptoms of CHIKF mimic those of dengue fever, results obtained from this study strongly suggest that RANTES could be a potential distinctive biomarker that differentiates between these two clinically similar", "diseases.", "There are no approved antiviral treatments currently available for CHIKV [1, 3, 12, 42] . Currently, CHIKF is treated symptomatically, usually with non-steroidal anti-inflammatory drugs or steroids, bed rest, and fluids. Movement and mild exercise are thought to decrease stiffness and morning arthralgia, but heavy exercise may exacerbate rheumatic symptoms. Corticosteroids may be used in cases of debilitating chronic CHIKV infection. There is a debate about the appropriateness of chloroquine as treatment for unresolved, non-steroidal anti-inflammatory drugresistant arthritis [43] . A study showed that viral production was www.plosntds.org drastically reduced at 16 h post-infection after treatment with 100 mM dec-RVKR-cmk (Decanoyl-Arg-Val-Lys-Arg-chloromethylketone), a furine inhibitor [42, 44] . Chloroquine acted by raising the pH, blocking low pH-dependent entry of virus into the cell. It is important to note that dec-RVKR-cmk or chloroquine only inhibited viral spreading from cell", "to cell, not CHIKV replication once it had entered the cell [43] . However, most would agree that the best weapon against CHIKV is prevention. A live CHIKV vaccine developed by the United States reached phase II clinical trial encompassing 59 healthy volunteers [45] . Eight percent of the volunteers experienced transient arthralgia, while 98% of the volunteers had seroconversion [45] . However, live CHIKV vaccines are still questionable. One cannot discount the risk of a live vaccine possibly inducing chronic rheumatism. Also, there is the question as to whether widespread use among the public could trigger mosquito transmission or lead to chronic infection or viral reversion [1] .", "An alternative approach would be to produce a chimeric vaccine against CHIKV. Wang et al. developed a chimeric alphavirus vaccine that is uniformly attenuated and does not cause reactogenicity in mice [3] . Three different versions of this vaccine were made using three different backbone vectors: Venezuelan equine encephalitis virus (VEEV) attenuated vaccine strain T-83, naturally attenuated eastern equine encephalitis virus (EEEV), and attenuated Sindbis virus (SINV). In short, CHIKV structural proteins were engineered into the backbones of the aforementioned vaccines to produce the chimeras [3] . These chimeras were found to stimulate a strong humoral immunity, and even at doses of 5.3-5.8 log 10 PFU, they did not trigger reactogenicity. When vaccinated mice were challenged with CHIKV, neither adult nor neonatal mice gained weight, had fever, or displayed signs of neurological illness. Upon comparison of the chimeras with the Army181/25 vaccine, the Army vaccine resulted in higher", "levels of viremia and replication in the joints of neonatal mice. Because the joints are known targets of CHIKV, Wang et al. noted their vaccine might avoid the negative reactogenic side effects of the Army vaccine. After being subcutaneously vaccinated with 5.3-5.8 log 10 PFU of the chimeric vaccines, mice produced strong neutralizing antibody titers. The VEEV and EEEV chimeras yielded higher neutralizing antibody titers than the SINV chimera without being more virulent. On top of this, the VEEV and EEEV CHIKV chimeras seemed to be more immunogenic than the Army vaccine despite the chimeras' lower viremia and replication in the joints of neonatal mice [3] .", "Tiwari et al. [46] adopted a different strategy using formalin inactivated CHIKV in combination with alhydrogel (Aluminum Hydroxide) as an adjuvant. This study clearly suggests that this vaccine elicits both humoral and cell-mediated immune responses in mice, providing its immunogenic potential. A recent study by Couderc et al. [47] showed passive immunization as a potential treatment for CHIKV infection. Using purified immunoglobulin extracted from convalescent CHIKV patients, they demonstrated effective neutralizing activity against CHIKV infection both in vitro and in vivo. This thereby establishes a potential preventive and therapeutic approach to combat CHIKV infection. Pathogenesis studies conducted with related alpha virus, like RRV, have shown the role of macrophages in persistence on infection [48] . They also demonstrated the role of RRV-specific CD8 T cells in clearing viral load in infected patients, thereby warranting similar investigations with CHIKV and the importance", "of investigating a cell-mediated immune response-based vaccine against CHIKV [49] .", "There are always certain risks associated with live attenuated or inactivated viral vaccines [50] . One way to avoid these potential problems is to construct a consensus-based DNA vaccine. DNA based vaccines have an improved safety profile as compared to live or attenuated vaccines [51, 52] . A consequence of CHIKV's rapid evolution is difficulty in constructing a vaccine that will be able to Figure 3 . Levels of CHIKV-specific IgG in mice immunized with CHIKV vaccines. Each group of C57BL/6 mice (n = 5) was immunized with 12.5 mg of pVax1 control vector or CHIKV vaccine plasmids as indicated at 0 and 2 wk. Mice were bled 2 wk after each immunization, and each group's serum pool was diluted to 1:100 and 1:500 for reaction with specific vaccine constructs. Serum was incubated for 1 h at 37uC on 96-well plates coated with 2 mg/ml of respective CHIKV peptides, and antibody was detected using anti-mouse IgG-HRP and OD was measured at 405 nm. doi:10.1371/journal.pntd.0000623.g003", "www.plosntds.org effectively protect large populations from multiple strains of the virus. One of the strengths of DNA consensus vaccines is its ability to induce cross-reactive immune responses against the three distinct phylogenetic groups of CHIKV. Also DNA-based vaccines can be produced more rapidly than protein-based vaccines.", "Recently, Muthumani et al. constructed a vaccine that was shown to induce both humoral and cellular immunity in vivo in 3-4-wk-old female C57/BL6 mice [49] . These mice were immunized using an in vivo electroporation method to deliver the vaccine into the quadriceps muscle. The consensus construct was designed against E1, E2, and the core protein capsid. To design the construct, they aligned 21 sequences of CHIKV isolated between 1952 and 2006, using strains from differing countries, including La Reunion Island. The most common nucleotide among the sequences was chosen at each position to be used in the consensus construct, taking care not to alter the reading frame. They conducted codon and RNA optimization, added a strong Kozak sequence, and substituted signal peptide with an immunoglobulin E leader sequence to improve vaccine efficacy.", "After immunizing the mice, spleens were harvested along with serum and tested to determine antibody titer. After three immunizations, consensus E1, E2, and C vaccines were shown to induce T-cell immune responses leading to strong IFN-c responses and proliferation in C57/BL6 mice. Furthermore, when compared with control mice, immunized mice had higher total IgG levels as well as higher anti-E1 specific, anti-E2 specific, and anti-C specific IgG antibodies, suggesting a strong humoral immune response ( Figure 3 ) and also specificity for the antigens encoded in the vaccine constructs ( Figure 4 ). Because of its promising results and the need for a safer vaccine, this consensus DNA vaccine deserves further investigation. Determining longevity of protective effects of the vaccine and persistence of antibody and IFN-c responses could be the next step of investigation. Challenged studies of immunized mice must also be carried out.", "CHIKV mosquito-borne disease has caused massive outbreaks for at least half a century but is no longer confined to the www.plosntds.org developing nations. It began to encroach into the boundaries of the developing world. As a result, the NIAID has designated CHIKV as a Category C pathogen alongside the influenza and SARS-CoV viruses [3] . Realization of the potential severity of this disease is exigent; for instance, if used as a biological weapon, the world economy could be severely crippled; if enough members of the armed forces were to become infected during a military deployment, military operations could be significantly affected. Efforts to monitor the disease will only provide minimal warning in a global society, and steps to prevent the morbidity and mortality associated with pandemic are imperative [21, 31] . Despite the gravity of its infectious potency and the fear of it being a potential biological weapon, there is currently no vaccine for CHIKV infections. Live", "attenuated vaccine trials were carried out in 2000, but funding for the project was discontinued. Newer approaches such as DNA vaccines appear promising over conventional strategies like live attenuated or inactivated virus and thus call for further investigation. Recent advances such electroporation delivery and incorporation of adjuvants has boosted DNA vaccine efficacy [51, 53] . Despite the low antibody response to DNA vaccines, other numerous advantages have overshadowed these minor drawbacks (Table 2) , the most important one being the ability to induce both humoral and cellular immune responses [51, 54] .", "Judging by recent success, such as the immunogenic construct developed by Muthumani et al., DNA vaccines could play a major role in combating CHIKV [49] . Vaccines are literally a critical component of CHIKV disease control and therefore research in this area is highly encouraged. The dramatic spread of dengue viruses (DENV) throughout tropical America since 1980 via the same vectors and human hosts underscores the risk to public health in the Americas. The adverse events associated with the current live vaccine are well documented [55] . Realizing these drawbacks, earnest efforts should be taken to develop new strategies to forestall further spread and complications." ]	[ 8 ]	3,829	5,688
1,689	In how many days do the symptoms arise?	2,496	[ "4-7" ]	[ "Chikungunya: A Potentially Emerging Epidemic?\n\nhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC2860491/\n\nSHA: f7c3160bef4169d29e2a8bdd79dd6e9056d4774c\n\nAuthors: Thiboutot, Michelle M.; Kannan, Senthil; Kawalekar, Omkar U.; Shedlock, Devon J.; Khan, Amir S.; Sarangan, Gopalsamy; Srikanth, Padma; Weiner, David B.; Muthumani, Karuppiah\nDate: 2010-04-27\nDOI: 10.1371/journal.pntd.0000623\nLicense: cc-by", "Abstract: Chikungunya virus is a mosquito-borne emerging pathogen that has a major health impact in humans and causes fever disease, headache, rash, nausea, vomiting, myalgia, and arthralgia. Indigenous to tropical Africa, recent large outbreaks have been reported in parts of South East Asia and several of its neighboring islands in 2005–07 and in Europe in 2007. Furthermore, positive cases have been confirmed in the United States in travelers returning from known outbreak areas. Currently, there is no vaccine or antiviral treatment. With the threat of an emerging global pandemic, the peculiar problems associated with the more immediate and seasonal epidemics warrant the development of an effective vaccine. In this review, we summarize the evidence supporting these concepts.", "Text: Chikungunya virus (CHIKV), a mosquito-borne pathogen listed by National Institute of Allergy and Infectious Diseases (NIAID) as a Category C Priority Pathogen that causes Chikungunya fever (CHIKF), has been spreading throughout Asia, Africa, and parts of Europe in recent times [1, 2, 3] . CHIKV is an arthropod-borne virus (arbovirus) and is transmitted to humans primarily by Aedes aegypti, the infamous yellow fever propagator [4, 5] . CHIKV infection is marked by severe joint pain, contorting its victims into unusual postures [6] . The disease gets its name from the Kimakonde vernacular language of Tanzania and Mozambique, and the word chikungunya means ''that which contorts or bends up'' and translates in Swahili to ''the illness of the bended walker'' [7, 8, 9] . In Africa, CHIKV is maintained in a sylvatic cycle among forest-dwelling Aedes spp. mosquitoes, wild primates, squirrels, birds, and rodents ( Figure 1 ) [10] . In Asia, the disease is vectored by Ae. aegypti and Ae.", "albopictus [11] . Transmission in Asia occurs in an urban cycle whereby the mosquito spreads the disease from an infected human to an uninfected human, following an epidemiological pattern similar to dengue fever [12] .", "The 2005-2006 epidemic of CHIKV in La Reunion islands in the Indian Ocean, spurred the discovery of a new vector species, Ae. albopictus [5] . Wrecking over one-third of the island's population, this epidemic peaked its devastation between January and February 2006, when over 46,000 cases came into light every week, including 284 deaths [5, 13] . Ae. albopictus is common in urban areas of the United States and is already flourishing in 36 states, raising grave concerns to the immunologically naive populace of the United States [14] .\n\nAccordingly, this review elaborately details the epidemiology and global expansion of CHIKV, describes its clinical features and pathogenesis and its symptoms and complications, and finally nominates a possible vaccine approach against CHIKV infection.", "CHIKV has been isolated into three genotypes based on phylogenetic studies. These genotypes, based on the gene sequences of an Envelope protein (E1), are Asian, East/Central/ South African, and West African [4, 11, 15] . Using phylogenetic models, Cherian et al. estimate that the Asian genotype of CHIKV emerged between 50 and 310 y ago, and the West and East African genotypes diverged between 100 and 840 y ago [15] . Since then, CHIKV has come a long way, with several mutations incorporated, and has continued to wreak epidemics in several regions. Recent activities of CHIKV include the Indian epidemic in 2005-2006, which was followed by a sudden explosion of cases in 2007. An estimated 1.3 million people across 13 states were reported to be infected in India [12, 16] , and CHIKV was also widespread in Malaysia, Sri Lanka, and Indonesia [17] . In July-August of 2007, CHIKV was reported in Italy, probably brought in by travelers from CHIKV-prone regions of India, Africa, and Indian", "Ocean islands such as Mauritius, Madagascar, and Seychelles. Few of the Italian isolates were found to have evolved from the Kerala isolate, which was associated with a A226V shift in E1 gene that represents a successful evolutionary adaptation in the mosquito vector similar to the ones observed in Reunion Island [2, 18, 19] .", "In recent times, with an increase in global travel, the risk for spreading CHIKV to non-endemic regions has heightened [1] . Several travelers have brought CHIKV home with them after visiting areas with actively infected populations [12, 20] . Such cases have been documented in European countries, Australia, Asia, and the United States [8, 21] . The United States has already reported at least twelve cases of travel-associated CHIKV, while France has reported 850 cases, and the United Kingdom 93 [8, 14] . Beyond this, CHIKV-infected travelers have also been diagnosed in Australia, Belgium, Canada, Czech Republic, French Guiana, Germany, Hong Kong, Italy, Japan, Kenya, Malaysia, Martinique, Norway, Switzerland, and Sri Lanka [21] . Some travelers were viremic, worrying public health officials about the spread of CHIKV to new areas [1, 8] .", "The incubation time for CHIKV is relatively short, requiring only 2-6 d with symptoms usually appearing 4-7 d post-infection [22] . Vazeille et al. detected CHIKV in the salivary glands of Ae. albopictus only 2 d after infection [5] . Upon infection, CHIKF tends to present itself in two phases. The first stage is acute, while the second stage, experienced by most but not all, is persistent, causing disabling polyarthritis. Characteristics of the acute phase include an abrupt onset of fever, arthralgia, and in some cases, maculopapular rash [6, 23] . The acute phase causes such intense joint and muscular pain that makes movement very difficult and prostrates its victims [6, 20] .", "Ninety-five percent of infected adults are symptomatic after infection, and of these, most become disabled for weeks to months as a result of decreased dexterity, loss of mobility, and delayed reaction. Eighteen months after disease onset, 40% of patients are found to still have anti-CHIKV IgM [6, 18, 23, 24] . The chronic stage of CHIKF is characterized by polyarthralgia that can last from weeks to years beyond the acute stage [6] . CHIKV has been shown to attack fibroblasts, explaining the involvement of muscles, joints, and skin connective tissues. The high number of nociceptive nerve endings found within the joints and muscle connective tissues can explain pain associated with CHIKF [25, 26] .", "More than 50% of patients who suffer from severe CHIKF are over 65 y old, and more than 33% of them die. Most adults who suffer from severe CHIKF have underlying medical conditions [6, 24, 27] . The other group that is disproportionately affected by severe CHIKV is children. Other complications associated with CHIKV, from most common to least common, include respiratory failure, cardiovascular decompensation, meningoencephalitis, severe acute hepatitis, severe cutaneous effects, other central nervous system problems, and kidney failure [6, 18, 20, 23, 24, 26, 27] .", "CHIKV undertakes a complex replication cycle upon host infection (Figure 2 ), which makes its genome susceptible to mutations [28, 29] . For instance, Ae. aegypti, responsible for epidemics in Kenya, Comoros, and Seychelles, carried CHIKV with an alanine in the 226 position of the E1 gene (E1-A226) [4, 18] . However, when the virus struck La Reunion Islands, a decline in population of Ae. aegypti, due to massive dichlorodiphenyltrichloroethane usage and dearth of Ae. albopictus species' www.plosntds.org population, resulted in an ecological pressure, favoring replacement of alanine at position 226 with valine (E1-A226V) [5] . This mutation allowed CHIKV's secondary vector species, Ae. albopictus, to supplement Ae. aegypti as its primary vector [5] .", "Within a year, the E1-A226V mutation was present in La Reunion Island, and Ae. albopictus apparently vectored the large epidemic infecting 34% of La Reunion Island's population [5] . All of the CHIKV strains isolated from Mayotte carried the E1-A226V mutation, and the mutation was also found in Madagascar in 2007 [5] . The E1-A226V mutation was not present at the beginning of the Indian Ocean Islands outbreak (before September 2005). However, more than 90% of later viral strains found there had incorporated the mutation (December-March 2006), indicating a genotype switch during the winter season [5, 18, 20] .", "The E1-A226V mutation also enabled an increase in infectivity of Ae. albopictus when compared to its infectivity of Ae. aegypti [4, 11, 18, 30] , and with several factors taken together, Ae. albopictus has become the new preferred and more lethal vector for CHIKV [4, 5, 11] . In fact, Tsetsarkin et al. found that a Green Fluorescent Protein tagged E1-A226V virus was 100 times more infective to Ae. albopictus than it was to Ae. aegypti [4] . In all the Indian Ocean Islands, Ae. albopictus became the main vector for CHIKV within 1-2 y after CHIKV was introduced to the region [31] .", "Of note is that Ae. aegypti has most likely been established in North America for over 300 y, while Ae. albopictus has been in many areas of the US, since 1985, primarily in Florida [32] and since then has expanded its range in the country. Reiskind et al. set out to determine if Ae. aegypti and Ae. albopictus mosquitoes captured in Florida were susceptible to CHIKV infection by a La Reunion isolate [32] . Each mosquito tested was highly susceptible to infection by a full-length infectious clone of the La Réunion Island isolate, CHIKV LR2006 OPY1 strain. Even though the Ae. albopictus strains were more susceptible to infection, overall ecology and differences in human biting patterns need to be studied further Characteristically, there are two rounds of translation: (+) sense genomic RNA (49S9 = 11.7 kb) acts directly as mRNA and is partially translated (59 end) to produce non-structural proteins (nsp's). These proteins are responsible for replication and formation of a complementary", "(2) strand, the template for further (+) strand synthesis. Subgenomic mRNA (26 S = 4.1 kb) replication occurs through the synthesis of full-length (2) intermediate RNA, which is regulated by nsp4 and p123 precursor in early infection and later by mature nsp's. Translation of the newly synthesized sub-genomic RNA results in production of structural proteins such as Capsid and protein E2-6k-E1 (from 39 end of genome). Assembly occurs at the cell surface, and the envelope is acquired as the virus buds from the cell and release and maturation almost simultaneous occurred. Replication occurs in the cytoplasm and is very rapid (,4 h) [28, 29] . doi:10.1371/journal.pntd.0000623.g002 www.plosntds.org to gain a more accurate understanding of a potential CHIKV epidemic in the US [32] .", "During the 7 d preceding birth, no human mother has been reported to transmit the disease vertically. However, about 50% of newborns delivered while the mother was infected with CHIKV contracted the disease from their mother, despite the method of delivery. Furthermore, there have been instances of CHIKV transmission from mother to fetus causing congenital illness and fetal death [33] .", "During the 2005-2006 La Reunion Island outbreaks, Ramful et al. discovered that mothers could transmit CHIKV to their progeny during the perinatal period (Day 24 to Day +1) [33, 34] , and it is associated with a high degree of morbidity. By mean Day 4 of life, all of the neonates were symptomatic for CHIKV, exhibiting common CHIKF symptoms. Six neonates were confirmed to have contracted CHIKV and developed mengoencephalitis. Of those mothers who, during the La Reunion Island epidemic, were infected long before delivery, only three fetal deaths were reported [12, 33] . Ramful et al. theorized that motherto-child transmission most likely happens transplacentally shortly before delivery [33] . A similar study by Gerardin et al. reported nineteen cases of neonatal infection associated with intrapartum maternal viremia that progressed to develop encephalitis owing to vertical transmission from infected mothers [34] .", "Clinical and epidemiological similarities with dengue fever make CHIKV diagnosis difficult, which may lead physicians to misdiagnose CHIKV as dengue fever; therefore, the incidence of CHIKV may actually be higher than currently believed (Table 1 ) [6, 12, 35] .", "The amount of time elapsed since disease onset is the most critical parameter when choosing a diagnostic test. CHIKV can be detected and isolated by culturing with mosquito cells (C6/36), Vero cells (mammalian), or in mice [26] . However, this method can take at least a week and only achieves a high sensitivity during the viremic phase, which usually only lasts up to 48 h after the bite. Five days post-infection, the viral isolation approach has a low sensitivity but is still the preferred method for detecting the CHIKV strain [12, 26, 31, 35] . RT-PCR on the other hand is a faster and more sensitive method that can be used within the first week of disease onset [26] , and it is currently the most sensitive method for detecting and quantifying viral mRNA [4, 36] .", "Classic serological detection, by assays such as ELISA [37] , immunofluorescence [5, 38] , complement binding, and haemagglutination inhibition [39] , constitutes the second diagnostic tool used for biological diagnosis of CHIKV infection. These proven techniques are useful for detection of Antigen in mosquitoes during epidemiological studies. These assays detect virus-specific IgM and IgG, however the sensitivity and specificity of these assays has been poorly characterized. Viral competence, or the potential of viral infection and transmission, is an important parameter that can be quantified by ELISA, viral culture, and PCR.", "A study by Ng et al. showed biomarkers indicative of severe CHIKV infection [40] . They found decreased levels of RANTES and increased levels of Interleukin-6 (IL-6) and Interleukin-1b (IL-1b) that could be sued for CHIKV detection in patients as indicators of CHIKV-driven cytokine storm. Couderc et al. demonstrate another cytokine, type-I IFN, as a key player in the progression to CHIKV infection [26] . Using an IFN-a/b null mouse model, they demonstrated evidence of muscles, joints, and skin as privileged CHIKV targets, which is consistent with human pathology. Although Ng et al. concluded that RANTES levels were significantly suppressed in severe CHIKF patients [40] , interestingly, an increase in levels of RANTES has been observed in dengue infection [41] . Since the symptoms of CHIKF mimic those of dengue fever, results obtained from this study strongly suggest that RANTES could be a potential distinctive biomarker that differentiates between these two clinically similar", "diseases.", "There are no approved antiviral treatments currently available for CHIKV [1, 3, 12, 42] . Currently, CHIKF is treated symptomatically, usually with non-steroidal anti-inflammatory drugs or steroids, bed rest, and fluids. Movement and mild exercise are thought to decrease stiffness and morning arthralgia, but heavy exercise may exacerbate rheumatic symptoms. Corticosteroids may be used in cases of debilitating chronic CHIKV infection. There is a debate about the appropriateness of chloroquine as treatment for unresolved, non-steroidal anti-inflammatory drugresistant arthritis [43] . A study showed that viral production was www.plosntds.org drastically reduced at 16 h post-infection after treatment with 100 mM dec-RVKR-cmk (Decanoyl-Arg-Val-Lys-Arg-chloromethylketone), a furine inhibitor [42, 44] . Chloroquine acted by raising the pH, blocking low pH-dependent entry of virus into the cell. It is important to note that dec-RVKR-cmk or chloroquine only inhibited viral spreading from cell", "to cell, not CHIKV replication once it had entered the cell [43] . However, most would agree that the best weapon against CHIKV is prevention. A live CHIKV vaccine developed by the United States reached phase II clinical trial encompassing 59 healthy volunteers [45] . Eight percent of the volunteers experienced transient arthralgia, while 98% of the volunteers had seroconversion [45] . However, live CHIKV vaccines are still questionable. One cannot discount the risk of a live vaccine possibly inducing chronic rheumatism. Also, there is the question as to whether widespread use among the public could trigger mosquito transmission or lead to chronic infection or viral reversion [1] .", "An alternative approach would be to produce a chimeric vaccine against CHIKV. Wang et al. developed a chimeric alphavirus vaccine that is uniformly attenuated and does not cause reactogenicity in mice [3] . Three different versions of this vaccine were made using three different backbone vectors: Venezuelan equine encephalitis virus (VEEV) attenuated vaccine strain T-83, naturally attenuated eastern equine encephalitis virus (EEEV), and attenuated Sindbis virus (SINV). In short, CHIKV structural proteins were engineered into the backbones of the aforementioned vaccines to produce the chimeras [3] . These chimeras were found to stimulate a strong humoral immunity, and even at doses of 5.3-5.8 log 10 PFU, they did not trigger reactogenicity. When vaccinated mice were challenged with CHIKV, neither adult nor neonatal mice gained weight, had fever, or displayed signs of neurological illness. Upon comparison of the chimeras with the Army181/25 vaccine, the Army vaccine resulted in higher", "levels of viremia and replication in the joints of neonatal mice. Because the joints are known targets of CHIKV, Wang et al. noted their vaccine might avoid the negative reactogenic side effects of the Army vaccine. After being subcutaneously vaccinated with 5.3-5.8 log 10 PFU of the chimeric vaccines, mice produced strong neutralizing antibody titers. The VEEV and EEEV chimeras yielded higher neutralizing antibody titers than the SINV chimera without being more virulent. On top of this, the VEEV and EEEV CHIKV chimeras seemed to be more immunogenic than the Army vaccine despite the chimeras' lower viremia and replication in the joints of neonatal mice [3] .", "Tiwari et al. [46] adopted a different strategy using formalin inactivated CHIKV in combination with alhydrogel (Aluminum Hydroxide) as an adjuvant. This study clearly suggests that this vaccine elicits both humoral and cell-mediated immune responses in mice, providing its immunogenic potential. A recent study by Couderc et al. [47] showed passive immunization as a potential treatment for CHIKV infection. Using purified immunoglobulin extracted from convalescent CHIKV patients, they demonstrated effective neutralizing activity against CHIKV infection both in vitro and in vivo. This thereby establishes a potential preventive and therapeutic approach to combat CHIKV infection. Pathogenesis studies conducted with related alpha virus, like RRV, have shown the role of macrophages in persistence on infection [48] . They also demonstrated the role of RRV-specific CD8 T cells in clearing viral load in infected patients, thereby warranting similar investigations with CHIKV and the importance", "of investigating a cell-mediated immune response-based vaccine against CHIKV [49] .", "There are always certain risks associated with live attenuated or inactivated viral vaccines [50] . One way to avoid these potential problems is to construct a consensus-based DNA vaccine. DNA based vaccines have an improved safety profile as compared to live or attenuated vaccines [51, 52] . A consequence of CHIKV's rapid evolution is difficulty in constructing a vaccine that will be able to Figure 3 . Levels of CHIKV-specific IgG in mice immunized with CHIKV vaccines. Each group of C57BL/6 mice (n = 5) was immunized with 12.5 mg of pVax1 control vector or CHIKV vaccine plasmids as indicated at 0 and 2 wk. Mice were bled 2 wk after each immunization, and each group's serum pool was diluted to 1:100 and 1:500 for reaction with specific vaccine constructs. Serum was incubated for 1 h at 37uC on 96-well plates coated with 2 mg/ml of respective CHIKV peptides, and antibody was detected using anti-mouse IgG-HRP and OD was measured at 405 nm. doi:10.1371/journal.pntd.0000623.g003", "www.plosntds.org effectively protect large populations from multiple strains of the virus. One of the strengths of DNA consensus vaccines is its ability to induce cross-reactive immune responses against the three distinct phylogenetic groups of CHIKV. Also DNA-based vaccines can be produced more rapidly than protein-based vaccines.", "Recently, Muthumani et al. constructed a vaccine that was shown to induce both humoral and cellular immunity in vivo in 3-4-wk-old female C57/BL6 mice [49] . These mice were immunized using an in vivo electroporation method to deliver the vaccine into the quadriceps muscle. The consensus construct was designed against E1, E2, and the core protein capsid. To design the construct, they aligned 21 sequences of CHIKV isolated between 1952 and 2006, using strains from differing countries, including La Reunion Island. The most common nucleotide among the sequences was chosen at each position to be used in the consensus construct, taking care not to alter the reading frame. They conducted codon and RNA optimization, added a strong Kozak sequence, and substituted signal peptide with an immunoglobulin E leader sequence to improve vaccine efficacy.", "After immunizing the mice, spleens were harvested along with serum and tested to determine antibody titer. After three immunizations, consensus E1, E2, and C vaccines were shown to induce T-cell immune responses leading to strong IFN-c responses and proliferation in C57/BL6 mice. Furthermore, when compared with control mice, immunized mice had higher total IgG levels as well as higher anti-E1 specific, anti-E2 specific, and anti-C specific IgG antibodies, suggesting a strong humoral immune response ( Figure 3 ) and also specificity for the antigens encoded in the vaccine constructs ( Figure 4 ). Because of its promising results and the need for a safer vaccine, this consensus DNA vaccine deserves further investigation. Determining longevity of protective effects of the vaccine and persistence of antibody and IFN-c responses could be the next step of investigation. Challenged studies of immunized mice must also be carried out.", "CHIKV mosquito-borne disease has caused massive outbreaks for at least half a century but is no longer confined to the www.plosntds.org developing nations. It began to encroach into the boundaries of the developing world. As a result, the NIAID has designated CHIKV as a Category C pathogen alongside the influenza and SARS-CoV viruses [3] . Realization of the potential severity of this disease is exigent; for instance, if used as a biological weapon, the world economy could be severely crippled; if enough members of the armed forces were to become infected during a military deployment, military operations could be significantly affected. Efforts to monitor the disease will only provide minimal warning in a global society, and steps to prevent the morbidity and mortality associated with pandemic are imperative [21, 31] . Despite the gravity of its infectious potency and the fear of it being a potential biological weapon, there is currently no vaccine for CHIKV infections. Live", "attenuated vaccine trials were carried out in 2000, but funding for the project was discontinued. Newer approaches such as DNA vaccines appear promising over conventional strategies like live attenuated or inactivated virus and thus call for further investigation. Recent advances such electroporation delivery and incorporation of adjuvants has boosted DNA vaccine efficacy [51, 53] . Despite the low antibody response to DNA vaccines, other numerous advantages have overshadowed these minor drawbacks (Table 2) , the most important one being the ability to induce both humoral and cellular immune responses [51, 54] .", "Judging by recent success, such as the immunogenic construct developed by Muthumani et al., DNA vaccines could play a major role in combating CHIKV [49] . Vaccines are literally a critical component of CHIKV disease control and therefore research in this area is highly encouraged. The dramatic spread of dengue viruses (DENV) throughout tropical America since 1980 via the same vectors and human hosts underscores the risk to public health in the Americas. The adverse events associated with the current live vaccine are well documented [55] . Realizing these drawbacks, earnest efforts should be taken to develop new strategies to forestall further spread and complications." ]	[ 8 ]	3,829	5,688
1,689	What are exhibited in the two phases?	2,497	[ "The first stage is acute, while the second stage, experienced by most but not all, is persistent, causing disabling polyarthritis. Characteristics of the acute phase include an abrupt onset of fever, arthralgia, and in some cases, maculopapular rash [6, 23] . The acute phase causes such intense joint and muscular pain that makes movement very difficult and prostrates its victims [" ]	[ "Chikungunya: A Potentially Emerging Epidemic?\n\nhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC2860491/\n\nSHA: f7c3160bef4169d29e2a8bdd79dd6e9056d4774c\n\nAuthors: Thiboutot, Michelle M.; Kannan, Senthil; Kawalekar, Omkar U.; Shedlock, Devon J.; Khan, Amir S.; Sarangan, Gopalsamy; Srikanth, Padma; Weiner, David B.; Muthumani, Karuppiah\nDate: 2010-04-27\nDOI: 10.1371/journal.pntd.0000623\nLicense: cc-by", "Abstract: Chikungunya virus is a mosquito-borne emerging pathogen that has a major health impact in humans and causes fever disease, headache, rash, nausea, vomiting, myalgia, and arthralgia. Indigenous to tropical Africa, recent large outbreaks have been reported in parts of South East Asia and several of its neighboring islands in 2005–07 and in Europe in 2007. Furthermore, positive cases have been confirmed in the United States in travelers returning from known outbreak areas. Currently, there is no vaccine or antiviral treatment. With the threat of an emerging global pandemic, the peculiar problems associated with the more immediate and seasonal epidemics warrant the development of an effective vaccine. In this review, we summarize the evidence supporting these concepts.", "Text: Chikungunya virus (CHIKV), a mosquito-borne pathogen listed by National Institute of Allergy and Infectious Diseases (NIAID) as a Category C Priority Pathogen that causes Chikungunya fever (CHIKF), has been spreading throughout Asia, Africa, and parts of Europe in recent times [1, 2, 3] . CHIKV is an arthropod-borne virus (arbovirus) and is transmitted to humans primarily by Aedes aegypti, the infamous yellow fever propagator [4, 5] . CHIKV infection is marked by severe joint pain, contorting its victims into unusual postures [6] . The disease gets its name from the Kimakonde vernacular language of Tanzania and Mozambique, and the word chikungunya means ''that which contorts or bends up'' and translates in Swahili to ''the illness of the bended walker'' [7, 8, 9] . In Africa, CHIKV is maintained in a sylvatic cycle among forest-dwelling Aedes spp. mosquitoes, wild primates, squirrels, birds, and rodents ( Figure 1 ) [10] . In Asia, the disease is vectored by Ae. aegypti and Ae.", "albopictus [11] . Transmission in Asia occurs in an urban cycle whereby the mosquito spreads the disease from an infected human to an uninfected human, following an epidemiological pattern similar to dengue fever [12] .", "The 2005-2006 epidemic of CHIKV in La Reunion islands in the Indian Ocean, spurred the discovery of a new vector species, Ae. albopictus [5] . Wrecking over one-third of the island's population, this epidemic peaked its devastation between January and February 2006, when over 46,000 cases came into light every week, including 284 deaths [5, 13] . Ae. albopictus is common in urban areas of the United States and is already flourishing in 36 states, raising grave concerns to the immunologically naive populace of the United States [14] .\n\nAccordingly, this review elaborately details the epidemiology and global expansion of CHIKV, describes its clinical features and pathogenesis and its symptoms and complications, and finally nominates a possible vaccine approach against CHIKV infection.", "CHIKV has been isolated into three genotypes based on phylogenetic studies. These genotypes, based on the gene sequences of an Envelope protein (E1), are Asian, East/Central/ South African, and West African [4, 11, 15] . Using phylogenetic models, Cherian et al. estimate that the Asian genotype of CHIKV emerged between 50 and 310 y ago, and the West and East African genotypes diverged between 100 and 840 y ago [15] . Since then, CHIKV has come a long way, with several mutations incorporated, and has continued to wreak epidemics in several regions. Recent activities of CHIKV include the Indian epidemic in 2005-2006, which was followed by a sudden explosion of cases in 2007. An estimated 1.3 million people across 13 states were reported to be infected in India [12, 16] , and CHIKV was also widespread in Malaysia, Sri Lanka, and Indonesia [17] . In July-August of 2007, CHIKV was reported in Italy, probably brought in by travelers from CHIKV-prone regions of India, Africa, and Indian", "Ocean islands such as Mauritius, Madagascar, and Seychelles. Few of the Italian isolates were found to have evolved from the Kerala isolate, which was associated with a A226V shift in E1 gene that represents a successful evolutionary adaptation in the mosquito vector similar to the ones observed in Reunion Island [2, 18, 19] .", "In recent times, with an increase in global travel, the risk for spreading CHIKV to non-endemic regions has heightened [1] . Several travelers have brought CHIKV home with them after visiting areas with actively infected populations [12, 20] . Such cases have been documented in European countries, Australia, Asia, and the United States [8, 21] . The United States has already reported at least twelve cases of travel-associated CHIKV, while France has reported 850 cases, and the United Kingdom 93 [8, 14] . Beyond this, CHIKV-infected travelers have also been diagnosed in Australia, Belgium, Canada, Czech Republic, French Guiana, Germany, Hong Kong, Italy, Japan, Kenya, Malaysia, Martinique, Norway, Switzerland, and Sri Lanka [21] . Some travelers were viremic, worrying public health officials about the spread of CHIKV to new areas [1, 8] .", "The incubation time for CHIKV is relatively short, requiring only 2-6 d with symptoms usually appearing 4-7 d post-infection [22] . Vazeille et al. detected CHIKV in the salivary glands of Ae. albopictus only 2 d after infection [5] . Upon infection, CHIKF tends to present itself in two phases. The first stage is acute, while the second stage, experienced by most but not all, is persistent, causing disabling polyarthritis. Characteristics of the acute phase include an abrupt onset of fever, arthralgia, and in some cases, maculopapular rash [6, 23] . The acute phase causes such intense joint and muscular pain that makes movement very difficult and prostrates its victims [6, 20] .", "Ninety-five percent of infected adults are symptomatic after infection, and of these, most become disabled for weeks to months as a result of decreased dexterity, loss of mobility, and delayed reaction. Eighteen months after disease onset, 40% of patients are found to still have anti-CHIKV IgM [6, 18, 23, 24] . The chronic stage of CHIKF is characterized by polyarthralgia that can last from weeks to years beyond the acute stage [6] . CHIKV has been shown to attack fibroblasts, explaining the involvement of muscles, joints, and skin connective tissues. The high number of nociceptive nerve endings found within the joints and muscle connective tissues can explain pain associated with CHIKF [25, 26] .", "More than 50% of patients who suffer from severe CHIKF are over 65 y old, and more than 33% of them die. Most adults who suffer from severe CHIKF have underlying medical conditions [6, 24, 27] . The other group that is disproportionately affected by severe CHIKV is children. Other complications associated with CHIKV, from most common to least common, include respiratory failure, cardiovascular decompensation, meningoencephalitis, severe acute hepatitis, severe cutaneous effects, other central nervous system problems, and kidney failure [6, 18, 20, 23, 24, 26, 27] .", "CHIKV undertakes a complex replication cycle upon host infection (Figure 2 ), which makes its genome susceptible to mutations [28, 29] . For instance, Ae. aegypti, responsible for epidemics in Kenya, Comoros, and Seychelles, carried CHIKV with an alanine in the 226 position of the E1 gene (E1-A226) [4, 18] . However, when the virus struck La Reunion Islands, a decline in population of Ae. aegypti, due to massive dichlorodiphenyltrichloroethane usage and dearth of Ae. albopictus species' www.plosntds.org population, resulted in an ecological pressure, favoring replacement of alanine at position 226 with valine (E1-A226V) [5] . This mutation allowed CHIKV's secondary vector species, Ae. albopictus, to supplement Ae. aegypti as its primary vector [5] .", "Within a year, the E1-A226V mutation was present in La Reunion Island, and Ae. albopictus apparently vectored the large epidemic infecting 34% of La Reunion Island's population [5] . All of the CHIKV strains isolated from Mayotte carried the E1-A226V mutation, and the mutation was also found in Madagascar in 2007 [5] . The E1-A226V mutation was not present at the beginning of the Indian Ocean Islands outbreak (before September 2005). However, more than 90% of later viral strains found there had incorporated the mutation (December-March 2006), indicating a genotype switch during the winter season [5, 18, 20] .", "The E1-A226V mutation also enabled an increase in infectivity of Ae. albopictus when compared to its infectivity of Ae. aegypti [4, 11, 18, 30] , and with several factors taken together, Ae. albopictus has become the new preferred and more lethal vector for CHIKV [4, 5, 11] . In fact, Tsetsarkin et al. found that a Green Fluorescent Protein tagged E1-A226V virus was 100 times more infective to Ae. albopictus than it was to Ae. aegypti [4] . In all the Indian Ocean Islands, Ae. albopictus became the main vector for CHIKV within 1-2 y after CHIKV was introduced to the region [31] .", "Of note is that Ae. aegypti has most likely been established in North America for over 300 y, while Ae. albopictus has been in many areas of the US, since 1985, primarily in Florida [32] and since then has expanded its range in the country. Reiskind et al. set out to determine if Ae. aegypti and Ae. albopictus mosquitoes captured in Florida were susceptible to CHIKV infection by a La Reunion isolate [32] . Each mosquito tested was highly susceptible to infection by a full-length infectious clone of the La Réunion Island isolate, CHIKV LR2006 OPY1 strain. Even though the Ae. albopictus strains were more susceptible to infection, overall ecology and differences in human biting patterns need to be studied further Characteristically, there are two rounds of translation: (+) sense genomic RNA (49S9 = 11.7 kb) acts directly as mRNA and is partially translated (59 end) to produce non-structural proteins (nsp's). These proteins are responsible for replication and formation of a complementary", "(2) strand, the template for further (+) strand synthesis. Subgenomic mRNA (26 S = 4.1 kb) replication occurs through the synthesis of full-length (2) intermediate RNA, which is regulated by nsp4 and p123 precursor in early infection and later by mature nsp's. Translation of the newly synthesized sub-genomic RNA results in production of structural proteins such as Capsid and protein E2-6k-E1 (from 39 end of genome). Assembly occurs at the cell surface, and the envelope is acquired as the virus buds from the cell and release and maturation almost simultaneous occurred. Replication occurs in the cytoplasm and is very rapid (,4 h) [28, 29] . doi:10.1371/journal.pntd.0000623.g002 www.plosntds.org to gain a more accurate understanding of a potential CHIKV epidemic in the US [32] .", "During the 7 d preceding birth, no human mother has been reported to transmit the disease vertically. However, about 50% of newborns delivered while the mother was infected with CHIKV contracted the disease from their mother, despite the method of delivery. Furthermore, there have been instances of CHIKV transmission from mother to fetus causing congenital illness and fetal death [33] .", "During the 2005-2006 La Reunion Island outbreaks, Ramful et al. discovered that mothers could transmit CHIKV to their progeny during the perinatal period (Day 24 to Day +1) [33, 34] , and it is associated with a high degree of morbidity. By mean Day 4 of life, all of the neonates were symptomatic for CHIKV, exhibiting common CHIKF symptoms. Six neonates were confirmed to have contracted CHIKV and developed mengoencephalitis. Of those mothers who, during the La Reunion Island epidemic, were infected long before delivery, only three fetal deaths were reported [12, 33] . Ramful et al. theorized that motherto-child transmission most likely happens transplacentally shortly before delivery [33] . A similar study by Gerardin et al. reported nineteen cases of neonatal infection associated with intrapartum maternal viremia that progressed to develop encephalitis owing to vertical transmission from infected mothers [34] .", "Clinical and epidemiological similarities with dengue fever make CHIKV diagnosis difficult, which may lead physicians to misdiagnose CHIKV as dengue fever; therefore, the incidence of CHIKV may actually be higher than currently believed (Table 1 ) [6, 12, 35] .", "The amount of time elapsed since disease onset is the most critical parameter when choosing a diagnostic test. CHIKV can be detected and isolated by culturing with mosquito cells (C6/36), Vero cells (mammalian), or in mice [26] . However, this method can take at least a week and only achieves a high sensitivity during the viremic phase, which usually only lasts up to 48 h after the bite. Five days post-infection, the viral isolation approach has a low sensitivity but is still the preferred method for detecting the CHIKV strain [12, 26, 31, 35] . RT-PCR on the other hand is a faster and more sensitive method that can be used within the first week of disease onset [26] , and it is currently the most sensitive method for detecting and quantifying viral mRNA [4, 36] .", "Classic serological detection, by assays such as ELISA [37] , immunofluorescence [5, 38] , complement binding, and haemagglutination inhibition [39] , constitutes the second diagnostic tool used for biological diagnosis of CHIKV infection. These proven techniques are useful for detection of Antigen in mosquitoes during epidemiological studies. These assays detect virus-specific IgM and IgG, however the sensitivity and specificity of these assays has been poorly characterized. Viral competence, or the potential of viral infection and transmission, is an important parameter that can be quantified by ELISA, viral culture, and PCR.", "A study by Ng et al. showed biomarkers indicative of severe CHIKV infection [40] . They found decreased levels of RANTES and increased levels of Interleukin-6 (IL-6) and Interleukin-1b (IL-1b) that could be sued for CHIKV detection in patients as indicators of CHIKV-driven cytokine storm. Couderc et al. demonstrate another cytokine, type-I IFN, as a key player in the progression to CHIKV infection [26] . Using an IFN-a/b null mouse model, they demonstrated evidence of muscles, joints, and skin as privileged CHIKV targets, which is consistent with human pathology. Although Ng et al. concluded that RANTES levels were significantly suppressed in severe CHIKF patients [40] , interestingly, an increase in levels of RANTES has been observed in dengue infection [41] . Since the symptoms of CHIKF mimic those of dengue fever, results obtained from this study strongly suggest that RANTES could be a potential distinctive biomarker that differentiates between these two clinically similar", "diseases.", "There are no approved antiviral treatments currently available for CHIKV [1, 3, 12, 42] . Currently, CHIKF is treated symptomatically, usually with non-steroidal anti-inflammatory drugs or steroids, bed rest, and fluids. Movement and mild exercise are thought to decrease stiffness and morning arthralgia, but heavy exercise may exacerbate rheumatic symptoms. Corticosteroids may be used in cases of debilitating chronic CHIKV infection. There is a debate about the appropriateness of chloroquine as treatment for unresolved, non-steroidal anti-inflammatory drugresistant arthritis [43] . A study showed that viral production was www.plosntds.org drastically reduced at 16 h post-infection after treatment with 100 mM dec-RVKR-cmk (Decanoyl-Arg-Val-Lys-Arg-chloromethylketone), a furine inhibitor [42, 44] . Chloroquine acted by raising the pH, blocking low pH-dependent entry of virus into the cell. It is important to note that dec-RVKR-cmk or chloroquine only inhibited viral spreading from cell", "to cell, not CHIKV replication once it had entered the cell [43] . However, most would agree that the best weapon against CHIKV is prevention. A live CHIKV vaccine developed by the United States reached phase II clinical trial encompassing 59 healthy volunteers [45] . Eight percent of the volunteers experienced transient arthralgia, while 98% of the volunteers had seroconversion [45] . However, live CHIKV vaccines are still questionable. One cannot discount the risk of a live vaccine possibly inducing chronic rheumatism. Also, there is the question as to whether widespread use among the public could trigger mosquito transmission or lead to chronic infection or viral reversion [1] .", "An alternative approach would be to produce a chimeric vaccine against CHIKV. Wang et al. developed a chimeric alphavirus vaccine that is uniformly attenuated and does not cause reactogenicity in mice [3] . Three different versions of this vaccine were made using three different backbone vectors: Venezuelan equine encephalitis virus (VEEV) attenuated vaccine strain T-83, naturally attenuated eastern equine encephalitis virus (EEEV), and attenuated Sindbis virus (SINV). In short, CHIKV structural proteins were engineered into the backbones of the aforementioned vaccines to produce the chimeras [3] . These chimeras were found to stimulate a strong humoral immunity, and even at doses of 5.3-5.8 log 10 PFU, they did not trigger reactogenicity. When vaccinated mice were challenged with CHIKV, neither adult nor neonatal mice gained weight, had fever, or displayed signs of neurological illness. Upon comparison of the chimeras with the Army181/25 vaccine, the Army vaccine resulted in higher", "levels of viremia and replication in the joints of neonatal mice. Because the joints are known targets of CHIKV, Wang et al. noted their vaccine might avoid the negative reactogenic side effects of the Army vaccine. After being subcutaneously vaccinated with 5.3-5.8 log 10 PFU of the chimeric vaccines, mice produced strong neutralizing antibody titers. The VEEV and EEEV chimeras yielded higher neutralizing antibody titers than the SINV chimera without being more virulent. On top of this, the VEEV and EEEV CHIKV chimeras seemed to be more immunogenic than the Army vaccine despite the chimeras' lower viremia and replication in the joints of neonatal mice [3] .", "Tiwari et al. [46] adopted a different strategy using formalin inactivated CHIKV in combination with alhydrogel (Aluminum Hydroxide) as an adjuvant. This study clearly suggests that this vaccine elicits both humoral and cell-mediated immune responses in mice, providing its immunogenic potential. A recent study by Couderc et al. [47] showed passive immunization as a potential treatment for CHIKV infection. Using purified immunoglobulin extracted from convalescent CHIKV patients, they demonstrated effective neutralizing activity against CHIKV infection both in vitro and in vivo. This thereby establishes a potential preventive and therapeutic approach to combat CHIKV infection. Pathogenesis studies conducted with related alpha virus, like RRV, have shown the role of macrophages in persistence on infection [48] . They also demonstrated the role of RRV-specific CD8 T cells in clearing viral load in infected patients, thereby warranting similar investigations with CHIKV and the importance", "of investigating a cell-mediated immune response-based vaccine against CHIKV [49] .", "There are always certain risks associated with live attenuated or inactivated viral vaccines [50] . One way to avoid these potential problems is to construct a consensus-based DNA vaccine. DNA based vaccines have an improved safety profile as compared to live or attenuated vaccines [51, 52] . A consequence of CHIKV's rapid evolution is difficulty in constructing a vaccine that will be able to Figure 3 . Levels of CHIKV-specific IgG in mice immunized with CHIKV vaccines. Each group of C57BL/6 mice (n = 5) was immunized with 12.5 mg of pVax1 control vector or CHIKV vaccine plasmids as indicated at 0 and 2 wk. Mice were bled 2 wk after each immunization, and each group's serum pool was diluted to 1:100 and 1:500 for reaction with specific vaccine constructs. Serum was incubated for 1 h at 37uC on 96-well plates coated with 2 mg/ml of respective CHIKV peptides, and antibody was detected using anti-mouse IgG-HRP and OD was measured at 405 nm. doi:10.1371/journal.pntd.0000623.g003", "www.plosntds.org effectively protect large populations from multiple strains of the virus. One of the strengths of DNA consensus vaccines is its ability to induce cross-reactive immune responses against the three distinct phylogenetic groups of CHIKV. Also DNA-based vaccines can be produced more rapidly than protein-based vaccines.", "Recently, Muthumani et al. constructed a vaccine that was shown to induce both humoral and cellular immunity in vivo in 3-4-wk-old female C57/BL6 mice [49] . These mice were immunized using an in vivo electroporation method to deliver the vaccine into the quadriceps muscle. The consensus construct was designed against E1, E2, and the core protein capsid. To design the construct, they aligned 21 sequences of CHIKV isolated between 1952 and 2006, using strains from differing countries, including La Reunion Island. The most common nucleotide among the sequences was chosen at each position to be used in the consensus construct, taking care not to alter the reading frame. They conducted codon and RNA optimization, added a strong Kozak sequence, and substituted signal peptide with an immunoglobulin E leader sequence to improve vaccine efficacy.", "After immunizing the mice, spleens were harvested along with serum and tested to determine antibody titer. After three immunizations, consensus E1, E2, and C vaccines were shown to induce T-cell immune responses leading to strong IFN-c responses and proliferation in C57/BL6 mice. Furthermore, when compared with control mice, immunized mice had higher total IgG levels as well as higher anti-E1 specific, anti-E2 specific, and anti-C specific IgG antibodies, suggesting a strong humoral immune response ( Figure 3 ) and also specificity for the antigens encoded in the vaccine constructs ( Figure 4 ). Because of its promising results and the need for a safer vaccine, this consensus DNA vaccine deserves further investigation. Determining longevity of protective effects of the vaccine and persistence of antibody and IFN-c responses could be the next step of investigation. Challenged studies of immunized mice must also be carried out.", "CHIKV mosquito-borne disease has caused massive outbreaks for at least half a century but is no longer confined to the www.plosntds.org developing nations. It began to encroach into the boundaries of the developing world. As a result, the NIAID has designated CHIKV as a Category C pathogen alongside the influenza and SARS-CoV viruses [3] . Realization of the potential severity of this disease is exigent; for instance, if used as a biological weapon, the world economy could be severely crippled; if enough members of the armed forces were to become infected during a military deployment, military operations could be significantly affected. Efforts to monitor the disease will only provide minimal warning in a global society, and steps to prevent the morbidity and mortality associated with pandemic are imperative [21, 31] . Despite the gravity of its infectious potency and the fear of it being a potential biological weapon, there is currently no vaccine for CHIKV infections. Live", "attenuated vaccine trials were carried out in 2000, but funding for the project was discontinued. Newer approaches such as DNA vaccines appear promising over conventional strategies like live attenuated or inactivated virus and thus call for further investigation. Recent advances such electroporation delivery and incorporation of adjuvants has boosted DNA vaccine efficacy [51, 53] . Despite the low antibody response to DNA vaccines, other numerous advantages have overshadowed these minor drawbacks (Table 2) , the most important one being the ability to induce both humoral and cellular immune responses [51, 54] .", "Judging by recent success, such as the immunogenic construct developed by Muthumani et al., DNA vaccines could play a major role in combating CHIKV [49] . Vaccines are literally a critical component of CHIKV disease control and therefore research in this area is highly encouraged. The dramatic spread of dengue viruses (DENV) throughout tropical America since 1980 via the same vectors and human hosts underscores the risk to public health in the Americas. The adverse events associated with the current live vaccine are well documented [55] . Realizing these drawbacks, earnest efforts should be taken to develop new strategies to forestall further spread and complications." ]	[ 8 ]	3,829	5,688
1,689	What are consequences of infection?	2,498	[ "Ninety-five percent of infected adults are symptomatic after infection, and of these, most become disabled for weeks to months as a result of decreased dexterity, loss of mobility, and delayed reaction." ]	[ "Chikungunya: A Potentially Emerging Epidemic?\n\nhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC2860491/\n\nSHA: f7c3160bef4169d29e2a8bdd79dd6e9056d4774c\n\nAuthors: Thiboutot, Michelle M.; Kannan, Senthil; Kawalekar, Omkar U.; Shedlock, Devon J.; Khan, Amir S.; Sarangan, Gopalsamy; Srikanth, Padma; Weiner, David B.; Muthumani, Karuppiah\nDate: 2010-04-27\nDOI: 10.1371/journal.pntd.0000623\nLicense: cc-by", "Abstract: Chikungunya virus is a mosquito-borne emerging pathogen that has a major health impact in humans and causes fever disease, headache, rash, nausea, vomiting, myalgia, and arthralgia. Indigenous to tropical Africa, recent large outbreaks have been reported in parts of South East Asia and several of its neighboring islands in 2005–07 and in Europe in 2007. Furthermore, positive cases have been confirmed in the United States in travelers returning from known outbreak areas. Currently, there is no vaccine or antiviral treatment. With the threat of an emerging global pandemic, the peculiar problems associated with the more immediate and seasonal epidemics warrant the development of an effective vaccine. In this review, we summarize the evidence supporting these concepts.", "Text: Chikungunya virus (CHIKV), a mosquito-borne pathogen listed by National Institute of Allergy and Infectious Diseases (NIAID) as a Category C Priority Pathogen that causes Chikungunya fever (CHIKF), has been spreading throughout Asia, Africa, and parts of Europe in recent times [1, 2, 3] . CHIKV is an arthropod-borne virus (arbovirus) and is transmitted to humans primarily by Aedes aegypti, the infamous yellow fever propagator [4, 5] . CHIKV infection is marked by severe joint pain, contorting its victims into unusual postures [6] . The disease gets its name from the Kimakonde vernacular language of Tanzania and Mozambique, and the word chikungunya means ''that which contorts or bends up'' and translates in Swahili to ''the illness of the bended walker'' [7, 8, 9] . In Africa, CHIKV is maintained in a sylvatic cycle among forest-dwelling Aedes spp. mosquitoes, wild primates, squirrels, birds, and rodents ( Figure 1 ) [10] . In Asia, the disease is vectored by Ae. aegypti and Ae.", "albopictus [11] . Transmission in Asia occurs in an urban cycle whereby the mosquito spreads the disease from an infected human to an uninfected human, following an epidemiological pattern similar to dengue fever [12] .", "The 2005-2006 epidemic of CHIKV in La Reunion islands in the Indian Ocean, spurred the discovery of a new vector species, Ae. albopictus [5] . Wrecking over one-third of the island's population, this epidemic peaked its devastation between January and February 2006, when over 46,000 cases came into light every week, including 284 deaths [5, 13] . Ae. albopictus is common in urban areas of the United States and is already flourishing in 36 states, raising grave concerns to the immunologically naive populace of the United States [14] .\n\nAccordingly, this review elaborately details the epidemiology and global expansion of CHIKV, describes its clinical features and pathogenesis and its symptoms and complications, and finally nominates a possible vaccine approach against CHIKV infection.", "CHIKV has been isolated into three genotypes based on phylogenetic studies. These genotypes, based on the gene sequences of an Envelope protein (E1), are Asian, East/Central/ South African, and West African [4, 11, 15] . Using phylogenetic models, Cherian et al. estimate that the Asian genotype of CHIKV emerged between 50 and 310 y ago, and the West and East African genotypes diverged between 100 and 840 y ago [15] . Since then, CHIKV has come a long way, with several mutations incorporated, and has continued to wreak epidemics in several regions. Recent activities of CHIKV include the Indian epidemic in 2005-2006, which was followed by a sudden explosion of cases in 2007. An estimated 1.3 million people across 13 states were reported to be infected in India [12, 16] , and CHIKV was also widespread in Malaysia, Sri Lanka, and Indonesia [17] . In July-August of 2007, CHIKV was reported in Italy, probably brought in by travelers from CHIKV-prone regions of India, Africa, and Indian", "Ocean islands such as Mauritius, Madagascar, and Seychelles. Few of the Italian isolates were found to have evolved from the Kerala isolate, which was associated with a A226V shift in E1 gene that represents a successful evolutionary adaptation in the mosquito vector similar to the ones observed in Reunion Island [2, 18, 19] .", "In recent times, with an increase in global travel, the risk for spreading CHIKV to non-endemic regions has heightened [1] . Several travelers have brought CHIKV home with them after visiting areas with actively infected populations [12, 20] . Such cases have been documented in European countries, Australia, Asia, and the United States [8, 21] . The United States has already reported at least twelve cases of travel-associated CHIKV, while France has reported 850 cases, and the United Kingdom 93 [8, 14] . Beyond this, CHIKV-infected travelers have also been diagnosed in Australia, Belgium, Canada, Czech Republic, French Guiana, Germany, Hong Kong, Italy, Japan, Kenya, Malaysia, Martinique, Norway, Switzerland, and Sri Lanka [21] . Some travelers were viremic, worrying public health officials about the spread of CHIKV to new areas [1, 8] .", "The incubation time for CHIKV is relatively short, requiring only 2-6 d with symptoms usually appearing 4-7 d post-infection [22] . Vazeille et al. detected CHIKV in the salivary glands of Ae. albopictus only 2 d after infection [5] . Upon infection, CHIKF tends to present itself in two phases. The first stage is acute, while the second stage, experienced by most but not all, is persistent, causing disabling polyarthritis. Characteristics of the acute phase include an abrupt onset of fever, arthralgia, and in some cases, maculopapular rash [6, 23] . The acute phase causes such intense joint and muscular pain that makes movement very difficult and prostrates its victims [6, 20] .", "Ninety-five percent of infected adults are symptomatic after infection, and of these, most become disabled for weeks to months as a result of decreased dexterity, loss of mobility, and delayed reaction. Eighteen months after disease onset, 40% of patients are found to still have anti-CHIKV IgM [6, 18, 23, 24] . The chronic stage of CHIKF is characterized by polyarthralgia that can last from weeks to years beyond the acute stage [6] . CHIKV has been shown to attack fibroblasts, explaining the involvement of muscles, joints, and skin connective tissues. The high number of nociceptive nerve endings found within the joints and muscle connective tissues can explain pain associated with CHIKF [25, 26] .", "More than 50% of patients who suffer from severe CHIKF are over 65 y old, and more than 33% of them die. Most adults who suffer from severe CHIKF have underlying medical conditions [6, 24, 27] . The other group that is disproportionately affected by severe CHIKV is children. Other complications associated with CHIKV, from most common to least common, include respiratory failure, cardiovascular decompensation, meningoencephalitis, severe acute hepatitis, severe cutaneous effects, other central nervous system problems, and kidney failure [6, 18, 20, 23, 24, 26, 27] .", "CHIKV undertakes a complex replication cycle upon host infection (Figure 2 ), which makes its genome susceptible to mutations [28, 29] . For instance, Ae. aegypti, responsible for epidemics in Kenya, Comoros, and Seychelles, carried CHIKV with an alanine in the 226 position of the E1 gene (E1-A226) [4, 18] . However, when the virus struck La Reunion Islands, a decline in population of Ae. aegypti, due to massive dichlorodiphenyltrichloroethane usage and dearth of Ae. albopictus species' www.plosntds.org population, resulted in an ecological pressure, favoring replacement of alanine at position 226 with valine (E1-A226V) [5] . This mutation allowed CHIKV's secondary vector species, Ae. albopictus, to supplement Ae. aegypti as its primary vector [5] .", "Within a year, the E1-A226V mutation was present in La Reunion Island, and Ae. albopictus apparently vectored the large epidemic infecting 34% of La Reunion Island's population [5] . All of the CHIKV strains isolated from Mayotte carried the E1-A226V mutation, and the mutation was also found in Madagascar in 2007 [5] . The E1-A226V mutation was not present at the beginning of the Indian Ocean Islands outbreak (before September 2005). However, more than 90% of later viral strains found there had incorporated the mutation (December-March 2006), indicating a genotype switch during the winter season [5, 18, 20] .", "The E1-A226V mutation also enabled an increase in infectivity of Ae. albopictus when compared to its infectivity of Ae. aegypti [4, 11, 18, 30] , and with several factors taken together, Ae. albopictus has become the new preferred and more lethal vector for CHIKV [4, 5, 11] . In fact, Tsetsarkin et al. found that a Green Fluorescent Protein tagged E1-A226V virus was 100 times more infective to Ae. albopictus than it was to Ae. aegypti [4] . In all the Indian Ocean Islands, Ae. albopictus became the main vector for CHIKV within 1-2 y after CHIKV was introduced to the region [31] .", "Of note is that Ae. aegypti has most likely been established in North America for over 300 y, while Ae. albopictus has been in many areas of the US, since 1985, primarily in Florida [32] and since then has expanded its range in the country. Reiskind et al. set out to determine if Ae. aegypti and Ae. albopictus mosquitoes captured in Florida were susceptible to CHIKV infection by a La Reunion isolate [32] . Each mosquito tested was highly susceptible to infection by a full-length infectious clone of the La Réunion Island isolate, CHIKV LR2006 OPY1 strain. Even though the Ae. albopictus strains were more susceptible to infection, overall ecology and differences in human biting patterns need to be studied further Characteristically, there are two rounds of translation: (+) sense genomic RNA (49S9 = 11.7 kb) acts directly as mRNA and is partially translated (59 end) to produce non-structural proteins (nsp's). These proteins are responsible for replication and formation of a complementary", "(2) strand, the template for further (+) strand synthesis. Subgenomic mRNA (26 S = 4.1 kb) replication occurs through the synthesis of full-length (2) intermediate RNA, which is regulated by nsp4 and p123 precursor in early infection and later by mature nsp's. Translation of the newly synthesized sub-genomic RNA results in production of structural proteins such as Capsid and protein E2-6k-E1 (from 39 end of genome). Assembly occurs at the cell surface, and the envelope is acquired as the virus buds from the cell and release and maturation almost simultaneous occurred. Replication occurs in the cytoplasm and is very rapid (,4 h) [28, 29] . doi:10.1371/journal.pntd.0000623.g002 www.plosntds.org to gain a more accurate understanding of a potential CHIKV epidemic in the US [32] .", "During the 7 d preceding birth, no human mother has been reported to transmit the disease vertically. However, about 50% of newborns delivered while the mother was infected with CHIKV contracted the disease from their mother, despite the method of delivery. Furthermore, there have been instances of CHIKV transmission from mother to fetus causing congenital illness and fetal death [33] .", "During the 2005-2006 La Reunion Island outbreaks, Ramful et al. discovered that mothers could transmit CHIKV to their progeny during the perinatal period (Day 24 to Day +1) [33, 34] , and it is associated with a high degree of morbidity. By mean Day 4 of life, all of the neonates were symptomatic for CHIKV, exhibiting common CHIKF symptoms. Six neonates were confirmed to have contracted CHIKV and developed mengoencephalitis. Of those mothers who, during the La Reunion Island epidemic, were infected long before delivery, only three fetal deaths were reported [12, 33] . Ramful et al. theorized that motherto-child transmission most likely happens transplacentally shortly before delivery [33] . A similar study by Gerardin et al. reported nineteen cases of neonatal infection associated with intrapartum maternal viremia that progressed to develop encephalitis owing to vertical transmission from infected mothers [34] .", "Clinical and epidemiological similarities with dengue fever make CHIKV diagnosis difficult, which may lead physicians to misdiagnose CHIKV as dengue fever; therefore, the incidence of CHIKV may actually be higher than currently believed (Table 1 ) [6, 12, 35] .", "The amount of time elapsed since disease onset is the most critical parameter when choosing a diagnostic test. CHIKV can be detected and isolated by culturing with mosquito cells (C6/36), Vero cells (mammalian), or in mice [26] . However, this method can take at least a week and only achieves a high sensitivity during the viremic phase, which usually only lasts up to 48 h after the bite. Five days post-infection, the viral isolation approach has a low sensitivity but is still the preferred method for detecting the CHIKV strain [12, 26, 31, 35] . RT-PCR on the other hand is a faster and more sensitive method that can be used within the first week of disease onset [26] , and it is currently the most sensitive method for detecting and quantifying viral mRNA [4, 36] .", "Classic serological detection, by assays such as ELISA [37] , immunofluorescence [5, 38] , complement binding, and haemagglutination inhibition [39] , constitutes the second diagnostic tool used for biological diagnosis of CHIKV infection. These proven techniques are useful for detection of Antigen in mosquitoes during epidemiological studies. These assays detect virus-specific IgM and IgG, however the sensitivity and specificity of these assays has been poorly characterized. Viral competence, or the potential of viral infection and transmission, is an important parameter that can be quantified by ELISA, viral culture, and PCR.", "A study by Ng et al. showed biomarkers indicative of severe CHIKV infection [40] . They found decreased levels of RANTES and increased levels of Interleukin-6 (IL-6) and Interleukin-1b (IL-1b) that could be sued for CHIKV detection in patients as indicators of CHIKV-driven cytokine storm. Couderc et al. demonstrate another cytokine, type-I IFN, as a key player in the progression to CHIKV infection [26] . Using an IFN-a/b null mouse model, they demonstrated evidence of muscles, joints, and skin as privileged CHIKV targets, which is consistent with human pathology. Although Ng et al. concluded that RANTES levels were significantly suppressed in severe CHIKF patients [40] , interestingly, an increase in levels of RANTES has been observed in dengue infection [41] . Since the symptoms of CHIKF mimic those of dengue fever, results obtained from this study strongly suggest that RANTES could be a potential distinctive biomarker that differentiates between these two clinically similar", "diseases.", "There are no approved antiviral treatments currently available for CHIKV [1, 3, 12, 42] . Currently, CHIKF is treated symptomatically, usually with non-steroidal anti-inflammatory drugs or steroids, bed rest, and fluids. Movement and mild exercise are thought to decrease stiffness and morning arthralgia, but heavy exercise may exacerbate rheumatic symptoms. Corticosteroids may be used in cases of debilitating chronic CHIKV infection. There is a debate about the appropriateness of chloroquine as treatment for unresolved, non-steroidal anti-inflammatory drugresistant arthritis [43] . A study showed that viral production was www.plosntds.org drastically reduced at 16 h post-infection after treatment with 100 mM dec-RVKR-cmk (Decanoyl-Arg-Val-Lys-Arg-chloromethylketone), a furine inhibitor [42, 44] . Chloroquine acted by raising the pH, blocking low pH-dependent entry of virus into the cell. It is important to note that dec-RVKR-cmk or chloroquine only inhibited viral spreading from cell", "to cell, not CHIKV replication once it had entered the cell [43] . However, most would agree that the best weapon against CHIKV is prevention. A live CHIKV vaccine developed by the United States reached phase II clinical trial encompassing 59 healthy volunteers [45] . Eight percent of the volunteers experienced transient arthralgia, while 98% of the volunteers had seroconversion [45] . However, live CHIKV vaccines are still questionable. One cannot discount the risk of a live vaccine possibly inducing chronic rheumatism. Also, there is the question as to whether widespread use among the public could trigger mosquito transmission or lead to chronic infection or viral reversion [1] .", "An alternative approach would be to produce a chimeric vaccine against CHIKV. Wang et al. developed a chimeric alphavirus vaccine that is uniformly attenuated and does not cause reactogenicity in mice [3] . Three different versions of this vaccine were made using three different backbone vectors: Venezuelan equine encephalitis virus (VEEV) attenuated vaccine strain T-83, naturally attenuated eastern equine encephalitis virus (EEEV), and attenuated Sindbis virus (SINV). In short, CHIKV structural proteins were engineered into the backbones of the aforementioned vaccines to produce the chimeras [3] . These chimeras were found to stimulate a strong humoral immunity, and even at doses of 5.3-5.8 log 10 PFU, they did not trigger reactogenicity. When vaccinated mice were challenged with CHIKV, neither adult nor neonatal mice gained weight, had fever, or displayed signs of neurological illness. Upon comparison of the chimeras with the Army181/25 vaccine, the Army vaccine resulted in higher", "levels of viremia and replication in the joints of neonatal mice. Because the joints are known targets of CHIKV, Wang et al. noted their vaccine might avoid the negative reactogenic side effects of the Army vaccine. After being subcutaneously vaccinated with 5.3-5.8 log 10 PFU of the chimeric vaccines, mice produced strong neutralizing antibody titers. The VEEV and EEEV chimeras yielded higher neutralizing antibody titers than the SINV chimera without being more virulent. On top of this, the VEEV and EEEV CHIKV chimeras seemed to be more immunogenic than the Army vaccine despite the chimeras' lower viremia and replication in the joints of neonatal mice [3] .", "Tiwari et al. [46] adopted a different strategy using formalin inactivated CHIKV in combination with alhydrogel (Aluminum Hydroxide) as an adjuvant. This study clearly suggests that this vaccine elicits both humoral and cell-mediated immune responses in mice, providing its immunogenic potential. A recent study by Couderc et al. [47] showed passive immunization as a potential treatment for CHIKV infection. Using purified immunoglobulin extracted from convalescent CHIKV patients, they demonstrated effective neutralizing activity against CHIKV infection both in vitro and in vivo. This thereby establishes a potential preventive and therapeutic approach to combat CHIKV infection. Pathogenesis studies conducted with related alpha virus, like RRV, have shown the role of macrophages in persistence on infection [48] . They also demonstrated the role of RRV-specific CD8 T cells in clearing viral load in infected patients, thereby warranting similar investigations with CHIKV and the importance", "of investigating a cell-mediated immune response-based vaccine against CHIKV [49] .", "There are always certain risks associated with live attenuated or inactivated viral vaccines [50] . One way to avoid these potential problems is to construct a consensus-based DNA vaccine. DNA based vaccines have an improved safety profile as compared to live or attenuated vaccines [51, 52] . A consequence of CHIKV's rapid evolution is difficulty in constructing a vaccine that will be able to Figure 3 . Levels of CHIKV-specific IgG in mice immunized with CHIKV vaccines. Each group of C57BL/6 mice (n = 5) was immunized with 12.5 mg of pVax1 control vector or CHIKV vaccine plasmids as indicated at 0 and 2 wk. Mice were bled 2 wk after each immunization, and each group's serum pool was diluted to 1:100 and 1:500 for reaction with specific vaccine constructs. Serum was incubated for 1 h at 37uC on 96-well plates coated with 2 mg/ml of respective CHIKV peptides, and antibody was detected using anti-mouse IgG-HRP and OD was measured at 405 nm. doi:10.1371/journal.pntd.0000623.g003", "www.plosntds.org effectively protect large populations from multiple strains of the virus. One of the strengths of DNA consensus vaccines is its ability to induce cross-reactive immune responses against the three distinct phylogenetic groups of CHIKV. Also DNA-based vaccines can be produced more rapidly than protein-based vaccines.", "Recently, Muthumani et al. constructed a vaccine that was shown to induce both humoral and cellular immunity in vivo in 3-4-wk-old female C57/BL6 mice [49] . These mice were immunized using an in vivo electroporation method to deliver the vaccine into the quadriceps muscle. The consensus construct was designed against E1, E2, and the core protein capsid. To design the construct, they aligned 21 sequences of CHIKV isolated between 1952 and 2006, using strains from differing countries, including La Reunion Island. The most common nucleotide among the sequences was chosen at each position to be used in the consensus construct, taking care not to alter the reading frame. They conducted codon and RNA optimization, added a strong Kozak sequence, and substituted signal peptide with an immunoglobulin E leader sequence to improve vaccine efficacy.", "After immunizing the mice, spleens were harvested along with serum and tested to determine antibody titer. After three immunizations, consensus E1, E2, and C vaccines were shown to induce T-cell immune responses leading to strong IFN-c responses and proliferation in C57/BL6 mice. Furthermore, when compared with control mice, immunized mice had higher total IgG levels as well as higher anti-E1 specific, anti-E2 specific, and anti-C specific IgG antibodies, suggesting a strong humoral immune response ( Figure 3 ) and also specificity for the antigens encoded in the vaccine constructs ( Figure 4 ). Because of its promising results and the need for a safer vaccine, this consensus DNA vaccine deserves further investigation. Determining longevity of protective effects of the vaccine and persistence of antibody and IFN-c responses could be the next step of investigation. Challenged studies of immunized mice must also be carried out.", "CHIKV mosquito-borne disease has caused massive outbreaks for at least half a century but is no longer confined to the www.plosntds.org developing nations. It began to encroach into the boundaries of the developing world. As a result, the NIAID has designated CHIKV as a Category C pathogen alongside the influenza and SARS-CoV viruses [3] . Realization of the potential severity of this disease is exigent; for instance, if used as a biological weapon, the world economy could be severely crippled; if enough members of the armed forces were to become infected during a military deployment, military operations could be significantly affected. Efforts to monitor the disease will only provide minimal warning in a global society, and steps to prevent the morbidity and mortality associated with pandemic are imperative [21, 31] . Despite the gravity of its infectious potency and the fear of it being a potential biological weapon, there is currently no vaccine for CHIKV infections. Live", "attenuated vaccine trials were carried out in 2000, but funding for the project was discontinued. Newer approaches such as DNA vaccines appear promising over conventional strategies like live attenuated or inactivated virus and thus call for further investigation. Recent advances such electroporation delivery and incorporation of adjuvants has boosted DNA vaccine efficacy [51, 53] . Despite the low antibody response to DNA vaccines, other numerous advantages have overshadowed these minor drawbacks (Table 2) , the most important one being the ability to induce both humoral and cellular immune responses [51, 54] .", "Judging by recent success, such as the immunogenic construct developed by Muthumani et al., DNA vaccines could play a major role in combating CHIKV [49] . Vaccines are literally a critical component of CHIKV disease control and therefore research in this area is highly encouraged. The dramatic spread of dengue viruses (DENV) throughout tropical America since 1980 via the same vectors and human hosts underscores the risk to public health in the Americas. The adverse events associated with the current live vaccine are well documented [55] . Realizing these drawbacks, earnest efforts should be taken to develop new strategies to forestall further spread and complications." ]	[ 9 ]	3,829	5,688
1,689	What percentage of the patients still have the CHIKV IgM after eighteen months?	2,499	[ "The chronic stage of CHIKF is characterized by" ]	[ "Chikungunya: A Potentially Emerging Epidemic?\n\nhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC2860491/\n\nSHA: f7c3160bef4169d29e2a8bdd79dd6e9056d4774c\n\nAuthors: Thiboutot, Michelle M.; Kannan, Senthil; Kawalekar, Omkar U.; Shedlock, Devon J.; Khan, Amir S.; Sarangan, Gopalsamy; Srikanth, Padma; Weiner, David B.; Muthumani, Karuppiah\nDate: 2010-04-27\nDOI: 10.1371/journal.pntd.0000623\nLicense: cc-by", "Abstract: Chikungunya virus is a mosquito-borne emerging pathogen that has a major health impact in humans and causes fever disease, headache, rash, nausea, vomiting, myalgia, and arthralgia. Indigenous to tropical Africa, recent large outbreaks have been reported in parts of South East Asia and several of its neighboring islands in 2005–07 and in Europe in 2007. Furthermore, positive cases have been confirmed in the United States in travelers returning from known outbreak areas. Currently, there is no vaccine or antiviral treatment. With the threat of an emerging global pandemic, the peculiar problems associated with the more immediate and seasonal epidemics warrant the development of an effective vaccine. In this review, we summarize the evidence supporting these concepts.", "Text: Chikungunya virus (CHIKV), a mosquito-borne pathogen listed by National Institute of Allergy and Infectious Diseases (NIAID) as a Category C Priority Pathogen that causes Chikungunya fever (CHIKF), has been spreading throughout Asia, Africa, and parts of Europe in recent times [1, 2, 3] . CHIKV is an arthropod-borne virus (arbovirus) and is transmitted to humans primarily by Aedes aegypti, the infamous yellow fever propagator [4, 5] . CHIKV infection is marked by severe joint pain, contorting its victims into unusual postures [6] . The disease gets its name from the Kimakonde vernacular language of Tanzania and Mozambique, and the word chikungunya means ''that which contorts or bends up'' and translates in Swahili to ''the illness of the bended walker'' [7, 8, 9] . In Africa, CHIKV is maintained in a sylvatic cycle among forest-dwelling Aedes spp. mosquitoes, wild primates, squirrels, birds, and rodents ( Figure 1 ) [10] . In Asia, the disease is vectored by Ae. aegypti and Ae.", "albopictus [11] . Transmission in Asia occurs in an urban cycle whereby the mosquito spreads the disease from an infected human to an uninfected human, following an epidemiological pattern similar to dengue fever [12] .", "The 2005-2006 epidemic of CHIKV in La Reunion islands in the Indian Ocean, spurred the discovery of a new vector species, Ae. albopictus [5] . Wrecking over one-third of the island's population, this epidemic peaked its devastation between January and February 2006, when over 46,000 cases came into light every week, including 284 deaths [5, 13] . Ae. albopictus is common in urban areas of the United States and is already flourishing in 36 states, raising grave concerns to the immunologically naive populace of the United States [14] .\n\nAccordingly, this review elaborately details the epidemiology and global expansion of CHIKV, describes its clinical features and pathogenesis and its symptoms and complications, and finally nominates a possible vaccine approach against CHIKV infection.", "CHIKV has been isolated into three genotypes based on phylogenetic studies. These genotypes, based on the gene sequences of an Envelope protein (E1), are Asian, East/Central/ South African, and West African [4, 11, 15] . Using phylogenetic models, Cherian et al. estimate that the Asian genotype of CHIKV emerged between 50 and 310 y ago, and the West and East African genotypes diverged between 100 and 840 y ago [15] . Since then, CHIKV has come a long way, with several mutations incorporated, and has continued to wreak epidemics in several regions. Recent activities of CHIKV include the Indian epidemic in 2005-2006, which was followed by a sudden explosion of cases in 2007. An estimated 1.3 million people across 13 states were reported to be infected in India [12, 16] , and CHIKV was also widespread in Malaysia, Sri Lanka, and Indonesia [17] . In July-August of 2007, CHIKV was reported in Italy, probably brought in by travelers from CHIKV-prone regions of India, Africa, and Indian", "Ocean islands such as Mauritius, Madagascar, and Seychelles. Few of the Italian isolates were found to have evolved from the Kerala isolate, which was associated with a A226V shift in E1 gene that represents a successful evolutionary adaptation in the mosquito vector similar to the ones observed in Reunion Island [2, 18, 19] .", "In recent times, with an increase in global travel, the risk for spreading CHIKV to non-endemic regions has heightened [1] . Several travelers have brought CHIKV home with them after visiting areas with actively infected populations [12, 20] . Such cases have been documented in European countries, Australia, Asia, and the United States [8, 21] . The United States has already reported at least twelve cases of travel-associated CHIKV, while France has reported 850 cases, and the United Kingdom 93 [8, 14] . Beyond this, CHIKV-infected travelers have also been diagnosed in Australia, Belgium, Canada, Czech Republic, French Guiana, Germany, Hong Kong, Italy, Japan, Kenya, Malaysia, Martinique, Norway, Switzerland, and Sri Lanka [21] . Some travelers were viremic, worrying public health officials about the spread of CHIKV to new areas [1, 8] .", "The incubation time for CHIKV is relatively short, requiring only 2-6 d with symptoms usually appearing 4-7 d post-infection [22] . Vazeille et al. detected CHIKV in the salivary glands of Ae. albopictus only 2 d after infection [5] . Upon infection, CHIKF tends to present itself in two phases. The first stage is acute, while the second stage, experienced by most but not all, is persistent, causing disabling polyarthritis. Characteristics of the acute phase include an abrupt onset of fever, arthralgia, and in some cases, maculopapular rash [6, 23] . The acute phase causes such intense joint and muscular pain that makes movement very difficult and prostrates its victims [6, 20] .", "Ninety-five percent of infected adults are symptomatic after infection, and of these, most become disabled for weeks to months as a result of decreased dexterity, loss of mobility, and delayed reaction. Eighteen months after disease onset, 40% of patients are found to still have anti-CHIKV IgM [6, 18, 23, 24] . The chronic stage of CHIKF is characterized by polyarthralgia that can last from weeks to years beyond the acute stage [6] . CHIKV has been shown to attack fibroblasts, explaining the involvement of muscles, joints, and skin connective tissues. The high number of nociceptive nerve endings found within the joints and muscle connective tissues can explain pain associated with CHIKF [25, 26] .", "More than 50% of patients who suffer from severe CHIKF are over 65 y old, and more than 33% of them die. Most adults who suffer from severe CHIKF have underlying medical conditions [6, 24, 27] . The other group that is disproportionately affected by severe CHIKV is children. Other complications associated with CHIKV, from most common to least common, include respiratory failure, cardiovascular decompensation, meningoencephalitis, severe acute hepatitis, severe cutaneous effects, other central nervous system problems, and kidney failure [6, 18, 20, 23, 24, 26, 27] .", "CHIKV undertakes a complex replication cycle upon host infection (Figure 2 ), which makes its genome susceptible to mutations [28, 29] . For instance, Ae. aegypti, responsible for epidemics in Kenya, Comoros, and Seychelles, carried CHIKV with an alanine in the 226 position of the E1 gene (E1-A226) [4, 18] . However, when the virus struck La Reunion Islands, a decline in population of Ae. aegypti, due to massive dichlorodiphenyltrichloroethane usage and dearth of Ae. albopictus species' www.plosntds.org population, resulted in an ecological pressure, favoring replacement of alanine at position 226 with valine (E1-A226V) [5] . This mutation allowed CHIKV's secondary vector species, Ae. albopictus, to supplement Ae. aegypti as its primary vector [5] .", "Within a year, the E1-A226V mutation was present in La Reunion Island, and Ae. albopictus apparently vectored the large epidemic infecting 34% of La Reunion Island's population [5] . All of the CHIKV strains isolated from Mayotte carried the E1-A226V mutation, and the mutation was also found in Madagascar in 2007 [5] . The E1-A226V mutation was not present at the beginning of the Indian Ocean Islands outbreak (before September 2005). However, more than 90% of later viral strains found there had incorporated the mutation (December-March 2006), indicating a genotype switch during the winter season [5, 18, 20] .", "The E1-A226V mutation also enabled an increase in infectivity of Ae. albopictus when compared to its infectivity of Ae. aegypti [4, 11, 18, 30] , and with several factors taken together, Ae. albopictus has become the new preferred and more lethal vector for CHIKV [4, 5, 11] . In fact, Tsetsarkin et al. found that a Green Fluorescent Protein tagged E1-A226V virus was 100 times more infective to Ae. albopictus than it was to Ae. aegypti [4] . In all the Indian Ocean Islands, Ae. albopictus became the main vector for CHIKV within 1-2 y after CHIKV was introduced to the region [31] .", "Of note is that Ae. aegypti has most likely been established in North America for over 300 y, while Ae. albopictus has been in many areas of the US, since 1985, primarily in Florida [32] and since then has expanded its range in the country. Reiskind et al. set out to determine if Ae. aegypti and Ae. albopictus mosquitoes captured in Florida were susceptible to CHIKV infection by a La Reunion isolate [32] . Each mosquito tested was highly susceptible to infection by a full-length infectious clone of the La Réunion Island isolate, CHIKV LR2006 OPY1 strain. Even though the Ae. albopictus strains were more susceptible to infection, overall ecology and differences in human biting patterns need to be studied further Characteristically, there are two rounds of translation: (+) sense genomic RNA (49S9 = 11.7 kb) acts directly as mRNA and is partially translated (59 end) to produce non-structural proteins (nsp's). These proteins are responsible for replication and formation of a complementary", "(2) strand, the template for further (+) strand synthesis. Subgenomic mRNA (26 S = 4.1 kb) replication occurs through the synthesis of full-length (2) intermediate RNA, which is regulated by nsp4 and p123 precursor in early infection and later by mature nsp's. Translation of the newly synthesized sub-genomic RNA results in production of structural proteins such as Capsid and protein E2-6k-E1 (from 39 end of genome). Assembly occurs at the cell surface, and the envelope is acquired as the virus buds from the cell and release and maturation almost simultaneous occurred. Replication occurs in the cytoplasm and is very rapid (,4 h) [28, 29] . doi:10.1371/journal.pntd.0000623.g002 www.plosntds.org to gain a more accurate understanding of a potential CHIKV epidemic in the US [32] .", "During the 7 d preceding birth, no human mother has been reported to transmit the disease vertically. However, about 50% of newborns delivered while the mother was infected with CHIKV contracted the disease from their mother, despite the method of delivery. Furthermore, there have been instances of CHIKV transmission from mother to fetus causing congenital illness and fetal death [33] .", "During the 2005-2006 La Reunion Island outbreaks, Ramful et al. discovered that mothers could transmit CHIKV to their progeny during the perinatal period (Day 24 to Day +1) [33, 34] , and it is associated with a high degree of morbidity. By mean Day 4 of life, all of the neonates were symptomatic for CHIKV, exhibiting common CHIKF symptoms. Six neonates were confirmed to have contracted CHIKV and developed mengoencephalitis. Of those mothers who, during the La Reunion Island epidemic, were infected long before delivery, only three fetal deaths were reported [12, 33] . Ramful et al. theorized that motherto-child transmission most likely happens transplacentally shortly before delivery [33] . A similar study by Gerardin et al. reported nineteen cases of neonatal infection associated with intrapartum maternal viremia that progressed to develop encephalitis owing to vertical transmission from infected mothers [34] .", "Clinical and epidemiological similarities with dengue fever make CHIKV diagnosis difficult, which may lead physicians to misdiagnose CHIKV as dengue fever; therefore, the incidence of CHIKV may actually be higher than currently believed (Table 1 ) [6, 12, 35] .", "The amount of time elapsed since disease onset is the most critical parameter when choosing a diagnostic test. CHIKV can be detected and isolated by culturing with mosquito cells (C6/36), Vero cells (mammalian), or in mice [26] . However, this method can take at least a week and only achieves a high sensitivity during the viremic phase, which usually only lasts up to 48 h after the bite. Five days post-infection, the viral isolation approach has a low sensitivity but is still the preferred method for detecting the CHIKV strain [12, 26, 31, 35] . RT-PCR on the other hand is a faster and more sensitive method that can be used within the first week of disease onset [26] , and it is currently the most sensitive method for detecting and quantifying viral mRNA [4, 36] .", "Classic serological detection, by assays such as ELISA [37] , immunofluorescence [5, 38] , complement binding, and haemagglutination inhibition [39] , constitutes the second diagnostic tool used for biological diagnosis of CHIKV infection. These proven techniques are useful for detection of Antigen in mosquitoes during epidemiological studies. These assays detect virus-specific IgM and IgG, however the sensitivity and specificity of these assays has been poorly characterized. Viral competence, or the potential of viral infection and transmission, is an important parameter that can be quantified by ELISA, viral culture, and PCR.", "A study by Ng et al. showed biomarkers indicative of severe CHIKV infection [40] . They found decreased levels of RANTES and increased levels of Interleukin-6 (IL-6) and Interleukin-1b (IL-1b) that could be sued for CHIKV detection in patients as indicators of CHIKV-driven cytokine storm. Couderc et al. demonstrate another cytokine, type-I IFN, as a key player in the progression to CHIKV infection [26] . Using an IFN-a/b null mouse model, they demonstrated evidence of muscles, joints, and skin as privileged CHIKV targets, which is consistent with human pathology. Although Ng et al. concluded that RANTES levels were significantly suppressed in severe CHIKF patients [40] , interestingly, an increase in levels of RANTES has been observed in dengue infection [41] . Since the symptoms of CHIKF mimic those of dengue fever, results obtained from this study strongly suggest that RANTES could be a potential distinctive biomarker that differentiates between these two clinically similar", "diseases.", "There are no approved antiviral treatments currently available for CHIKV [1, 3, 12, 42] . Currently, CHIKF is treated symptomatically, usually with non-steroidal anti-inflammatory drugs or steroids, bed rest, and fluids. Movement and mild exercise are thought to decrease stiffness and morning arthralgia, but heavy exercise may exacerbate rheumatic symptoms. Corticosteroids may be used in cases of debilitating chronic CHIKV infection. There is a debate about the appropriateness of chloroquine as treatment for unresolved, non-steroidal anti-inflammatory drugresistant arthritis [43] . A study showed that viral production was www.plosntds.org drastically reduced at 16 h post-infection after treatment with 100 mM dec-RVKR-cmk (Decanoyl-Arg-Val-Lys-Arg-chloromethylketone), a furine inhibitor [42, 44] . Chloroquine acted by raising the pH, blocking low pH-dependent entry of virus into the cell. It is important to note that dec-RVKR-cmk or chloroquine only inhibited viral spreading from cell", "to cell, not CHIKV replication once it had entered the cell [43] . However, most would agree that the best weapon against CHIKV is prevention. A live CHIKV vaccine developed by the United States reached phase II clinical trial encompassing 59 healthy volunteers [45] . Eight percent of the volunteers experienced transient arthralgia, while 98% of the volunteers had seroconversion [45] . However, live CHIKV vaccines are still questionable. One cannot discount the risk of a live vaccine possibly inducing chronic rheumatism. Also, there is the question as to whether widespread use among the public could trigger mosquito transmission or lead to chronic infection or viral reversion [1] .", "An alternative approach would be to produce a chimeric vaccine against CHIKV. Wang et al. developed a chimeric alphavirus vaccine that is uniformly attenuated and does not cause reactogenicity in mice [3] . Three different versions of this vaccine were made using three different backbone vectors: Venezuelan equine encephalitis virus (VEEV) attenuated vaccine strain T-83, naturally attenuated eastern equine encephalitis virus (EEEV), and attenuated Sindbis virus (SINV). In short, CHIKV structural proteins were engineered into the backbones of the aforementioned vaccines to produce the chimeras [3] . These chimeras were found to stimulate a strong humoral immunity, and even at doses of 5.3-5.8 log 10 PFU, they did not trigger reactogenicity. When vaccinated mice were challenged with CHIKV, neither adult nor neonatal mice gained weight, had fever, or displayed signs of neurological illness. Upon comparison of the chimeras with the Army181/25 vaccine, the Army vaccine resulted in higher", "levels of viremia and replication in the joints of neonatal mice. Because the joints are known targets of CHIKV, Wang et al. noted their vaccine might avoid the negative reactogenic side effects of the Army vaccine. After being subcutaneously vaccinated with 5.3-5.8 log 10 PFU of the chimeric vaccines, mice produced strong neutralizing antibody titers. The VEEV and EEEV chimeras yielded higher neutralizing antibody titers than the SINV chimera without being more virulent. On top of this, the VEEV and EEEV CHIKV chimeras seemed to be more immunogenic than the Army vaccine despite the chimeras' lower viremia and replication in the joints of neonatal mice [3] .", "Tiwari et al. [46] adopted a different strategy using formalin inactivated CHIKV in combination with alhydrogel (Aluminum Hydroxide) as an adjuvant. This study clearly suggests that this vaccine elicits both humoral and cell-mediated immune responses in mice, providing its immunogenic potential. A recent study by Couderc et al. [47] showed passive immunization as a potential treatment for CHIKV infection. Using purified immunoglobulin extracted from convalescent CHIKV patients, they demonstrated effective neutralizing activity against CHIKV infection both in vitro and in vivo. This thereby establishes a potential preventive and therapeutic approach to combat CHIKV infection. Pathogenesis studies conducted with related alpha virus, like RRV, have shown the role of macrophages in persistence on infection [48] . They also demonstrated the role of RRV-specific CD8 T cells in clearing viral load in infected patients, thereby warranting similar investigations with CHIKV and the importance", "of investigating a cell-mediated immune response-based vaccine against CHIKV [49] .", "There are always certain risks associated with live attenuated or inactivated viral vaccines [50] . One way to avoid these potential problems is to construct a consensus-based DNA vaccine. DNA based vaccines have an improved safety profile as compared to live or attenuated vaccines [51, 52] . A consequence of CHIKV's rapid evolution is difficulty in constructing a vaccine that will be able to Figure 3 . Levels of CHIKV-specific IgG in mice immunized with CHIKV vaccines. Each group of C57BL/6 mice (n = 5) was immunized with 12.5 mg of pVax1 control vector or CHIKV vaccine plasmids as indicated at 0 and 2 wk. Mice were bled 2 wk after each immunization, and each group's serum pool was diluted to 1:100 and 1:500 for reaction with specific vaccine constructs. Serum was incubated for 1 h at 37uC on 96-well plates coated with 2 mg/ml of respective CHIKV peptides, and antibody was detected using anti-mouse IgG-HRP and OD was measured at 405 nm. doi:10.1371/journal.pntd.0000623.g003", "www.plosntds.org effectively protect large populations from multiple strains of the virus. One of the strengths of DNA consensus vaccines is its ability to induce cross-reactive immune responses against the three distinct phylogenetic groups of CHIKV. Also DNA-based vaccines can be produced more rapidly than protein-based vaccines.", "Recently, Muthumani et al. constructed a vaccine that was shown to induce both humoral and cellular immunity in vivo in 3-4-wk-old female C57/BL6 mice [49] . These mice were immunized using an in vivo electroporation method to deliver the vaccine into the quadriceps muscle. The consensus construct was designed against E1, E2, and the core protein capsid. To design the construct, they aligned 21 sequences of CHIKV isolated between 1952 and 2006, using strains from differing countries, including La Reunion Island. The most common nucleotide among the sequences was chosen at each position to be used in the consensus construct, taking care not to alter the reading frame. They conducted codon and RNA optimization, added a strong Kozak sequence, and substituted signal peptide with an immunoglobulin E leader sequence to improve vaccine efficacy.", "After immunizing the mice, spleens were harvested along with serum and tested to determine antibody titer. After three immunizations, consensus E1, E2, and C vaccines were shown to induce T-cell immune responses leading to strong IFN-c responses and proliferation in C57/BL6 mice. Furthermore, when compared with control mice, immunized mice had higher total IgG levels as well as higher anti-E1 specific, anti-E2 specific, and anti-C specific IgG antibodies, suggesting a strong humoral immune response ( Figure 3 ) and also specificity for the antigens encoded in the vaccine constructs ( Figure 4 ). Because of its promising results and the need for a safer vaccine, this consensus DNA vaccine deserves further investigation. Determining longevity of protective effects of the vaccine and persistence of antibody and IFN-c responses could be the next step of investigation. Challenged studies of immunized mice must also be carried out.", "CHIKV mosquito-borne disease has caused massive outbreaks for at least half a century but is no longer confined to the www.plosntds.org developing nations. It began to encroach into the boundaries of the developing world. As a result, the NIAID has designated CHIKV as a Category C pathogen alongside the influenza and SARS-CoV viruses [3] . Realization of the potential severity of this disease is exigent; for instance, if used as a biological weapon, the world economy could be severely crippled; if enough members of the armed forces were to become infected during a military deployment, military operations could be significantly affected. Efforts to monitor the disease will only provide minimal warning in a global society, and steps to prevent the morbidity and mortality associated with pandemic are imperative [21, 31] . Despite the gravity of its infectious potency and the fear of it being a potential biological weapon, there is currently no vaccine for CHIKV infections. Live", "attenuated vaccine trials were carried out in 2000, but funding for the project was discontinued. Newer approaches such as DNA vaccines appear promising over conventional strategies like live attenuated or inactivated virus and thus call for further investigation. Recent advances such electroporation delivery and incorporation of adjuvants has boosted DNA vaccine efficacy [51, 53] . Despite the low antibody response to DNA vaccines, other numerous advantages have overshadowed these minor drawbacks (Table 2) , the most important one being the ability to induce both humoral and cellular immune responses [51, 54] .", "Judging by recent success, such as the immunogenic construct developed by Muthumani et al., DNA vaccines could play a major role in combating CHIKV [49] . Vaccines are literally a critical component of CHIKV disease control and therefore research in this area is highly encouraged. The dramatic spread of dengue viruses (DENV) throughout tropical America since 1980 via the same vectors and human hosts underscores the risk to public health in the Americas. The adverse events associated with the current live vaccine are well documented [55] . Realizing these drawbacks, earnest efforts should be taken to develop new strategies to forestall further spread and complications." ]	[ 9 ]	3,829	5,688
1,689	What is te chronic stage characterized by?	2,500	[ "by polyarthralgia that can last from weeks to years beyond the acute stage" ]	[ "Chikungunya: A Potentially Emerging Epidemic?\n\nhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC2860491/\n\nSHA: f7c3160bef4169d29e2a8bdd79dd6e9056d4774c\n\nAuthors: Thiboutot, Michelle M.; Kannan, Senthil; Kawalekar, Omkar U.; Shedlock, Devon J.; Khan, Amir S.; Sarangan, Gopalsamy; Srikanth, Padma; Weiner, David B.; Muthumani, Karuppiah\nDate: 2010-04-27\nDOI: 10.1371/journal.pntd.0000623\nLicense: cc-by", "Abstract: Chikungunya virus is a mosquito-borne emerging pathogen that has a major health impact in humans and causes fever disease, headache, rash, nausea, vomiting, myalgia, and arthralgia. Indigenous to tropical Africa, recent large outbreaks have been reported in parts of South East Asia and several of its neighboring islands in 2005–07 and in Europe in 2007. Furthermore, positive cases have been confirmed in the United States in travelers returning from known outbreak areas. Currently, there is no vaccine or antiviral treatment. With the threat of an emerging global pandemic, the peculiar problems associated with the more immediate and seasonal epidemics warrant the development of an effective vaccine. In this review, we summarize the evidence supporting these concepts.", "Text: Chikungunya virus (CHIKV), a mosquito-borne pathogen listed by National Institute of Allergy and Infectious Diseases (NIAID) as a Category C Priority Pathogen that causes Chikungunya fever (CHIKF), has been spreading throughout Asia, Africa, and parts of Europe in recent times [1, 2, 3] . CHIKV is an arthropod-borne virus (arbovirus) and is transmitted to humans primarily by Aedes aegypti, the infamous yellow fever propagator [4, 5] . CHIKV infection is marked by severe joint pain, contorting its victims into unusual postures [6] . The disease gets its name from the Kimakonde vernacular language of Tanzania and Mozambique, and the word chikungunya means ''that which contorts or bends up'' and translates in Swahili to ''the illness of the bended walker'' [7, 8, 9] . In Africa, CHIKV is maintained in a sylvatic cycle among forest-dwelling Aedes spp. mosquitoes, wild primates, squirrels, birds, and rodents ( Figure 1 ) [10] . In Asia, the disease is vectored by Ae. aegypti and Ae.", "albopictus [11] . Transmission in Asia occurs in an urban cycle whereby the mosquito spreads the disease from an infected human to an uninfected human, following an epidemiological pattern similar to dengue fever [12] .", "The 2005-2006 epidemic of CHIKV in La Reunion islands in the Indian Ocean, spurred the discovery of a new vector species, Ae. albopictus [5] . Wrecking over one-third of the island's population, this epidemic peaked its devastation between January and February 2006, when over 46,000 cases came into light every week, including 284 deaths [5, 13] . Ae. albopictus is common in urban areas of the United States and is already flourishing in 36 states, raising grave concerns to the immunologically naive populace of the United States [14] .\n\nAccordingly, this review elaborately details the epidemiology and global expansion of CHIKV, describes its clinical features and pathogenesis and its symptoms and complications, and finally nominates a possible vaccine approach against CHIKV infection.", "CHIKV has been isolated into three genotypes based on phylogenetic studies. These genotypes, based on the gene sequences of an Envelope protein (E1), are Asian, East/Central/ South African, and West African [4, 11, 15] . Using phylogenetic models, Cherian et al. estimate that the Asian genotype of CHIKV emerged between 50 and 310 y ago, and the West and East African genotypes diverged between 100 and 840 y ago [15] . Since then, CHIKV has come a long way, with several mutations incorporated, and has continued to wreak epidemics in several regions. Recent activities of CHIKV include the Indian epidemic in 2005-2006, which was followed by a sudden explosion of cases in 2007. An estimated 1.3 million people across 13 states were reported to be infected in India [12, 16] , and CHIKV was also widespread in Malaysia, Sri Lanka, and Indonesia [17] . In July-August of 2007, CHIKV was reported in Italy, probably brought in by travelers from CHIKV-prone regions of India, Africa, and Indian", "Ocean islands such as Mauritius, Madagascar, and Seychelles. Few of the Italian isolates were found to have evolved from the Kerala isolate, which was associated with a A226V shift in E1 gene that represents a successful evolutionary adaptation in the mosquito vector similar to the ones observed in Reunion Island [2, 18, 19] .", "In recent times, with an increase in global travel, the risk for spreading CHIKV to non-endemic regions has heightened [1] . Several travelers have brought CHIKV home with them after visiting areas with actively infected populations [12, 20] . Such cases have been documented in European countries, Australia, Asia, and the United States [8, 21] . The United States has already reported at least twelve cases of travel-associated CHIKV, while France has reported 850 cases, and the United Kingdom 93 [8, 14] . Beyond this, CHIKV-infected travelers have also been diagnosed in Australia, Belgium, Canada, Czech Republic, French Guiana, Germany, Hong Kong, Italy, Japan, Kenya, Malaysia, Martinique, Norway, Switzerland, and Sri Lanka [21] . Some travelers were viremic, worrying public health officials about the spread of CHIKV to new areas [1, 8] .", "The incubation time for CHIKV is relatively short, requiring only 2-6 d with symptoms usually appearing 4-7 d post-infection [22] . Vazeille et al. detected CHIKV in the salivary glands of Ae. albopictus only 2 d after infection [5] . Upon infection, CHIKF tends to present itself in two phases. The first stage is acute, while the second stage, experienced by most but not all, is persistent, causing disabling polyarthritis. Characteristics of the acute phase include an abrupt onset of fever, arthralgia, and in some cases, maculopapular rash [6, 23] . The acute phase causes such intense joint and muscular pain that makes movement very difficult and prostrates its victims [6, 20] .", "Ninety-five percent of infected adults are symptomatic after infection, and of these, most become disabled for weeks to months as a result of decreased dexterity, loss of mobility, and delayed reaction. Eighteen months after disease onset, 40% of patients are found to still have anti-CHIKV IgM [6, 18, 23, 24] . The chronic stage of CHIKF is characterized by polyarthralgia that can last from weeks to years beyond the acute stage [6] . CHIKV has been shown to attack fibroblasts, explaining the involvement of muscles, joints, and skin connective tissues. The high number of nociceptive nerve endings found within the joints and muscle connective tissues can explain pain associated with CHIKF [25, 26] .", "More than 50% of patients who suffer from severe CHIKF are over 65 y old, and more than 33% of them die. Most adults who suffer from severe CHIKF have underlying medical conditions [6, 24, 27] . The other group that is disproportionately affected by severe CHIKV is children. Other complications associated with CHIKV, from most common to least common, include respiratory failure, cardiovascular decompensation, meningoencephalitis, severe acute hepatitis, severe cutaneous effects, other central nervous system problems, and kidney failure [6, 18, 20, 23, 24, 26, 27] .", "CHIKV undertakes a complex replication cycle upon host infection (Figure 2 ), which makes its genome susceptible to mutations [28, 29] . For instance, Ae. aegypti, responsible for epidemics in Kenya, Comoros, and Seychelles, carried CHIKV with an alanine in the 226 position of the E1 gene (E1-A226) [4, 18] . However, when the virus struck La Reunion Islands, a decline in population of Ae. aegypti, due to massive dichlorodiphenyltrichloroethane usage and dearth of Ae. albopictus species' www.plosntds.org population, resulted in an ecological pressure, favoring replacement of alanine at position 226 with valine (E1-A226V) [5] . This mutation allowed CHIKV's secondary vector species, Ae. albopictus, to supplement Ae. aegypti as its primary vector [5] .", "Within a year, the E1-A226V mutation was present in La Reunion Island, and Ae. albopictus apparently vectored the large epidemic infecting 34% of La Reunion Island's population [5] . All of the CHIKV strains isolated from Mayotte carried the E1-A226V mutation, and the mutation was also found in Madagascar in 2007 [5] . The E1-A226V mutation was not present at the beginning of the Indian Ocean Islands outbreak (before September 2005). However, more than 90% of later viral strains found there had incorporated the mutation (December-March 2006), indicating a genotype switch during the winter season [5, 18, 20] .", "The E1-A226V mutation also enabled an increase in infectivity of Ae. albopictus when compared to its infectivity of Ae. aegypti [4, 11, 18, 30] , and with several factors taken together, Ae. albopictus has become the new preferred and more lethal vector for CHIKV [4, 5, 11] . In fact, Tsetsarkin et al. found that a Green Fluorescent Protein tagged E1-A226V virus was 100 times more infective to Ae. albopictus than it was to Ae. aegypti [4] . In all the Indian Ocean Islands, Ae. albopictus became the main vector for CHIKV within 1-2 y after CHIKV was introduced to the region [31] .", "Of note is that Ae. aegypti has most likely been established in North America for over 300 y, while Ae. albopictus has been in many areas of the US, since 1985, primarily in Florida [32] and since then has expanded its range in the country. Reiskind et al. set out to determine if Ae. aegypti and Ae. albopictus mosquitoes captured in Florida were susceptible to CHIKV infection by a La Reunion isolate [32] . Each mosquito tested was highly susceptible to infection by a full-length infectious clone of the La Réunion Island isolate, CHIKV LR2006 OPY1 strain. Even though the Ae. albopictus strains were more susceptible to infection, overall ecology and differences in human biting patterns need to be studied further Characteristically, there are two rounds of translation: (+) sense genomic RNA (49S9 = 11.7 kb) acts directly as mRNA and is partially translated (59 end) to produce non-structural proteins (nsp's). These proteins are responsible for replication and formation of a complementary", "(2) strand, the template for further (+) strand synthesis. Subgenomic mRNA (26 S = 4.1 kb) replication occurs through the synthesis of full-length (2) intermediate RNA, which is regulated by nsp4 and p123 precursor in early infection and later by mature nsp's. Translation of the newly synthesized sub-genomic RNA results in production of structural proteins such as Capsid and protein E2-6k-E1 (from 39 end of genome). Assembly occurs at the cell surface, and the envelope is acquired as the virus buds from the cell and release and maturation almost simultaneous occurred. Replication occurs in the cytoplasm and is very rapid (,4 h) [28, 29] . doi:10.1371/journal.pntd.0000623.g002 www.plosntds.org to gain a more accurate understanding of a potential CHIKV epidemic in the US [32] .", "During the 7 d preceding birth, no human mother has been reported to transmit the disease vertically. However, about 50% of newborns delivered while the mother was infected with CHIKV contracted the disease from their mother, despite the method of delivery. Furthermore, there have been instances of CHIKV transmission from mother to fetus causing congenital illness and fetal death [33] .", "During the 2005-2006 La Reunion Island outbreaks, Ramful et al. discovered that mothers could transmit CHIKV to their progeny during the perinatal period (Day 24 to Day +1) [33, 34] , and it is associated with a high degree of morbidity. By mean Day 4 of life, all of the neonates were symptomatic for CHIKV, exhibiting common CHIKF symptoms. Six neonates were confirmed to have contracted CHIKV and developed mengoencephalitis. Of those mothers who, during the La Reunion Island epidemic, were infected long before delivery, only three fetal deaths were reported [12, 33] . Ramful et al. theorized that motherto-child transmission most likely happens transplacentally shortly before delivery [33] . A similar study by Gerardin et al. reported nineteen cases of neonatal infection associated with intrapartum maternal viremia that progressed to develop encephalitis owing to vertical transmission from infected mothers [34] .", "Clinical and epidemiological similarities with dengue fever make CHIKV diagnosis difficult, which may lead physicians to misdiagnose CHIKV as dengue fever; therefore, the incidence of CHIKV may actually be higher than currently believed (Table 1 ) [6, 12, 35] .", "The amount of time elapsed since disease onset is the most critical parameter when choosing a diagnostic test. CHIKV can be detected and isolated by culturing with mosquito cells (C6/36), Vero cells (mammalian), or in mice [26] . However, this method can take at least a week and only achieves a high sensitivity during the viremic phase, which usually only lasts up to 48 h after the bite. Five days post-infection, the viral isolation approach has a low sensitivity but is still the preferred method for detecting the CHIKV strain [12, 26, 31, 35] . RT-PCR on the other hand is a faster and more sensitive method that can be used within the first week of disease onset [26] , and it is currently the most sensitive method for detecting and quantifying viral mRNA [4, 36] .", "Classic serological detection, by assays such as ELISA [37] , immunofluorescence [5, 38] , complement binding, and haemagglutination inhibition [39] , constitutes the second diagnostic tool used for biological diagnosis of CHIKV infection. These proven techniques are useful for detection of Antigen in mosquitoes during epidemiological studies. These assays detect virus-specific IgM and IgG, however the sensitivity and specificity of these assays has been poorly characterized. Viral competence, or the potential of viral infection and transmission, is an important parameter that can be quantified by ELISA, viral culture, and PCR.", "A study by Ng et al. showed biomarkers indicative of severe CHIKV infection [40] . They found decreased levels of RANTES and increased levels of Interleukin-6 (IL-6) and Interleukin-1b (IL-1b) that could be sued for CHIKV detection in patients as indicators of CHIKV-driven cytokine storm. Couderc et al. demonstrate another cytokine, type-I IFN, as a key player in the progression to CHIKV infection [26] . Using an IFN-a/b null mouse model, they demonstrated evidence of muscles, joints, and skin as privileged CHIKV targets, which is consistent with human pathology. Although Ng et al. concluded that RANTES levels were significantly suppressed in severe CHIKF patients [40] , interestingly, an increase in levels of RANTES has been observed in dengue infection [41] . Since the symptoms of CHIKF mimic those of dengue fever, results obtained from this study strongly suggest that RANTES could be a potential distinctive biomarker that differentiates between these two clinically similar", "diseases.", "There are no approved antiviral treatments currently available for CHIKV [1, 3, 12, 42] . Currently, CHIKF is treated symptomatically, usually with non-steroidal anti-inflammatory drugs or steroids, bed rest, and fluids. Movement and mild exercise are thought to decrease stiffness and morning arthralgia, but heavy exercise may exacerbate rheumatic symptoms. Corticosteroids may be used in cases of debilitating chronic CHIKV infection. There is a debate about the appropriateness of chloroquine as treatment for unresolved, non-steroidal anti-inflammatory drugresistant arthritis [43] . A study showed that viral production was www.plosntds.org drastically reduced at 16 h post-infection after treatment with 100 mM dec-RVKR-cmk (Decanoyl-Arg-Val-Lys-Arg-chloromethylketone), a furine inhibitor [42, 44] . Chloroquine acted by raising the pH, blocking low pH-dependent entry of virus into the cell. It is important to note that dec-RVKR-cmk or chloroquine only inhibited viral spreading from cell", "to cell, not CHIKV replication once it had entered the cell [43] . However, most would agree that the best weapon against CHIKV is prevention. A live CHIKV vaccine developed by the United States reached phase II clinical trial encompassing 59 healthy volunteers [45] . Eight percent of the volunteers experienced transient arthralgia, while 98% of the volunteers had seroconversion [45] . However, live CHIKV vaccines are still questionable. One cannot discount the risk of a live vaccine possibly inducing chronic rheumatism. Also, there is the question as to whether widespread use among the public could trigger mosquito transmission or lead to chronic infection or viral reversion [1] .", "An alternative approach would be to produce a chimeric vaccine against CHIKV. Wang et al. developed a chimeric alphavirus vaccine that is uniformly attenuated and does not cause reactogenicity in mice [3] . Three different versions of this vaccine were made using three different backbone vectors: Venezuelan equine encephalitis virus (VEEV) attenuated vaccine strain T-83, naturally attenuated eastern equine encephalitis virus (EEEV), and attenuated Sindbis virus (SINV). In short, CHIKV structural proteins were engineered into the backbones of the aforementioned vaccines to produce the chimeras [3] . These chimeras were found to stimulate a strong humoral immunity, and even at doses of 5.3-5.8 log 10 PFU, they did not trigger reactogenicity. When vaccinated mice were challenged with CHIKV, neither adult nor neonatal mice gained weight, had fever, or displayed signs of neurological illness. Upon comparison of the chimeras with the Army181/25 vaccine, the Army vaccine resulted in higher", "levels of viremia and replication in the joints of neonatal mice. Because the joints are known targets of CHIKV, Wang et al. noted their vaccine might avoid the negative reactogenic side effects of the Army vaccine. After being subcutaneously vaccinated with 5.3-5.8 log 10 PFU of the chimeric vaccines, mice produced strong neutralizing antibody titers. The VEEV and EEEV chimeras yielded higher neutralizing antibody titers than the SINV chimera without being more virulent. On top of this, the VEEV and EEEV CHIKV chimeras seemed to be more immunogenic than the Army vaccine despite the chimeras' lower viremia and replication in the joints of neonatal mice [3] .", "Tiwari et al. [46] adopted a different strategy using formalin inactivated CHIKV in combination with alhydrogel (Aluminum Hydroxide) as an adjuvant. This study clearly suggests that this vaccine elicits both humoral and cell-mediated immune responses in mice, providing its immunogenic potential. A recent study by Couderc et al. [47] showed passive immunization as a potential treatment for CHIKV infection. Using purified immunoglobulin extracted from convalescent CHIKV patients, they demonstrated effective neutralizing activity against CHIKV infection both in vitro and in vivo. This thereby establishes a potential preventive and therapeutic approach to combat CHIKV infection. Pathogenesis studies conducted with related alpha virus, like RRV, have shown the role of macrophages in persistence on infection [48] . They also demonstrated the role of RRV-specific CD8 T cells in clearing viral load in infected patients, thereby warranting similar investigations with CHIKV and the importance", "of investigating a cell-mediated immune response-based vaccine against CHIKV [49] .", "There are always certain risks associated with live attenuated or inactivated viral vaccines [50] . One way to avoid these potential problems is to construct a consensus-based DNA vaccine. DNA based vaccines have an improved safety profile as compared to live or attenuated vaccines [51, 52] . A consequence of CHIKV's rapid evolution is difficulty in constructing a vaccine that will be able to Figure 3 . Levels of CHIKV-specific IgG in mice immunized with CHIKV vaccines. Each group of C57BL/6 mice (n = 5) was immunized with 12.5 mg of pVax1 control vector or CHIKV vaccine plasmids as indicated at 0 and 2 wk. Mice were bled 2 wk after each immunization, and each group's serum pool was diluted to 1:100 and 1:500 for reaction with specific vaccine constructs. Serum was incubated for 1 h at 37uC on 96-well plates coated with 2 mg/ml of respective CHIKV peptides, and antibody was detected using anti-mouse IgG-HRP and OD was measured at 405 nm. doi:10.1371/journal.pntd.0000623.g003", "www.plosntds.org effectively protect large populations from multiple strains of the virus. One of the strengths of DNA consensus vaccines is its ability to induce cross-reactive immune responses against the three distinct phylogenetic groups of CHIKV. Also DNA-based vaccines can be produced more rapidly than protein-based vaccines.", "Recently, Muthumani et al. constructed a vaccine that was shown to induce both humoral and cellular immunity in vivo in 3-4-wk-old female C57/BL6 mice [49] . These mice were immunized using an in vivo electroporation method to deliver the vaccine into the quadriceps muscle. The consensus construct was designed against E1, E2, and the core protein capsid. To design the construct, they aligned 21 sequences of CHIKV isolated between 1952 and 2006, using strains from differing countries, including La Reunion Island. The most common nucleotide among the sequences was chosen at each position to be used in the consensus construct, taking care not to alter the reading frame. They conducted codon and RNA optimization, added a strong Kozak sequence, and substituted signal peptide with an immunoglobulin E leader sequence to improve vaccine efficacy.", "After immunizing the mice, spleens were harvested along with serum and tested to determine antibody titer. After three immunizations, consensus E1, E2, and C vaccines were shown to induce T-cell immune responses leading to strong IFN-c responses and proliferation in C57/BL6 mice. Furthermore, when compared with control mice, immunized mice had higher total IgG levels as well as higher anti-E1 specific, anti-E2 specific, and anti-C specific IgG antibodies, suggesting a strong humoral immune response ( Figure 3 ) and also specificity for the antigens encoded in the vaccine constructs ( Figure 4 ). Because of its promising results and the need for a safer vaccine, this consensus DNA vaccine deserves further investigation. Determining longevity of protective effects of the vaccine and persistence of antibody and IFN-c responses could be the next step of investigation. Challenged studies of immunized mice must also be carried out.", "CHIKV mosquito-borne disease has caused massive outbreaks for at least half a century but is no longer confined to the www.plosntds.org developing nations. It began to encroach into the boundaries of the developing world. As a result, the NIAID has designated CHIKV as a Category C pathogen alongside the influenza and SARS-CoV viruses [3] . Realization of the potential severity of this disease is exigent; for instance, if used as a biological weapon, the world economy could be severely crippled; if enough members of the armed forces were to become infected during a military deployment, military operations could be significantly affected. Efforts to monitor the disease will only provide minimal warning in a global society, and steps to prevent the morbidity and mortality associated with pandemic are imperative [21, 31] . Despite the gravity of its infectious potency and the fear of it being a potential biological weapon, there is currently no vaccine for CHIKV infections. Live", "attenuated vaccine trials were carried out in 2000, but funding for the project was discontinued. Newer approaches such as DNA vaccines appear promising over conventional strategies like live attenuated or inactivated virus and thus call for further investigation. Recent advances such electroporation delivery and incorporation of adjuvants has boosted DNA vaccine efficacy [51, 53] . Despite the low antibody response to DNA vaccines, other numerous advantages have overshadowed these minor drawbacks (Table 2) , the most important one being the ability to induce both humoral and cellular immune responses [51, 54] .", "Judging by recent success, such as the immunogenic construct developed by Muthumani et al., DNA vaccines could play a major role in combating CHIKV [49] . Vaccines are literally a critical component of CHIKV disease control and therefore research in this area is highly encouraged. The dramatic spread of dengue viruses (DENV) throughout tropical America since 1980 via the same vectors and human hosts underscores the risk to public health in the Americas. The adverse events associated with the current live vaccine are well documented [55] . Realizing these drawbacks, earnest efforts should be taken to develop new strategies to forestall further spread and complications." ]	[ 9 ]	3,829	5,688
1,689	What is affected by CHIKV?	2,501	[ "fibroblasts" ]	[ "Chikungunya: A Potentially Emerging Epidemic?\n\nhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC2860491/\n\nSHA: f7c3160bef4169d29e2a8bdd79dd6e9056d4774c\n\nAuthors: Thiboutot, Michelle M.; Kannan, Senthil; Kawalekar, Omkar U.; Shedlock, Devon J.; Khan, Amir S.; Sarangan, Gopalsamy; Srikanth, Padma; Weiner, David B.; Muthumani, Karuppiah\nDate: 2010-04-27\nDOI: 10.1371/journal.pntd.0000623\nLicense: cc-by", "Abstract: Chikungunya virus is a mosquito-borne emerging pathogen that has a major health impact in humans and causes fever disease, headache, rash, nausea, vomiting, myalgia, and arthralgia. Indigenous to tropical Africa, recent large outbreaks have been reported in parts of South East Asia and several of its neighboring islands in 2005–07 and in Europe in 2007. Furthermore, positive cases have been confirmed in the United States in travelers returning from known outbreak areas. Currently, there is no vaccine or antiviral treatment. With the threat of an emerging global pandemic, the peculiar problems associated with the more immediate and seasonal epidemics warrant the development of an effective vaccine. In this review, we summarize the evidence supporting these concepts.", "Text: Chikungunya virus (CHIKV), a mosquito-borne pathogen listed by National Institute of Allergy and Infectious Diseases (NIAID) as a Category C Priority Pathogen that causes Chikungunya fever (CHIKF), has been spreading throughout Asia, Africa, and parts of Europe in recent times [1, 2, 3] . CHIKV is an arthropod-borne virus (arbovirus) and is transmitted to humans primarily by Aedes aegypti, the infamous yellow fever propagator [4, 5] . CHIKV infection is marked by severe joint pain, contorting its victims into unusual postures [6] . The disease gets its name from the Kimakonde vernacular language of Tanzania and Mozambique, and the word chikungunya means ''that which contorts or bends up'' and translates in Swahili to ''the illness of the bended walker'' [7, 8, 9] . In Africa, CHIKV is maintained in a sylvatic cycle among forest-dwelling Aedes spp. mosquitoes, wild primates, squirrels, birds, and rodents ( Figure 1 ) [10] . In Asia, the disease is vectored by Ae. aegypti and Ae.", "albopictus [11] . Transmission in Asia occurs in an urban cycle whereby the mosquito spreads the disease from an infected human to an uninfected human, following an epidemiological pattern similar to dengue fever [12] .", "The 2005-2006 epidemic of CHIKV in La Reunion islands in the Indian Ocean, spurred the discovery of a new vector species, Ae. albopictus [5] . Wrecking over one-third of the island's population, this epidemic peaked its devastation between January and February 2006, when over 46,000 cases came into light every week, including 284 deaths [5, 13] . Ae. albopictus is common in urban areas of the United States and is already flourishing in 36 states, raising grave concerns to the immunologically naive populace of the United States [14] .\n\nAccordingly, this review elaborately details the epidemiology and global expansion of CHIKV, describes its clinical features and pathogenesis and its symptoms and complications, and finally nominates a possible vaccine approach against CHIKV infection.", "CHIKV has been isolated into three genotypes based on phylogenetic studies. These genotypes, based on the gene sequences of an Envelope protein (E1), are Asian, East/Central/ South African, and West African [4, 11, 15] . Using phylogenetic models, Cherian et al. estimate that the Asian genotype of CHIKV emerged between 50 and 310 y ago, and the West and East African genotypes diverged between 100 and 840 y ago [15] . Since then, CHIKV has come a long way, with several mutations incorporated, and has continued to wreak epidemics in several regions. Recent activities of CHIKV include the Indian epidemic in 2005-2006, which was followed by a sudden explosion of cases in 2007. An estimated 1.3 million people across 13 states were reported to be infected in India [12, 16] , and CHIKV was also widespread in Malaysia, Sri Lanka, and Indonesia [17] . In July-August of 2007, CHIKV was reported in Italy, probably brought in by travelers from CHIKV-prone regions of India, Africa, and Indian", "Ocean islands such as Mauritius, Madagascar, and Seychelles. Few of the Italian isolates were found to have evolved from the Kerala isolate, which was associated with a A226V shift in E1 gene that represents a successful evolutionary adaptation in the mosquito vector similar to the ones observed in Reunion Island [2, 18, 19] .", "In recent times, with an increase in global travel, the risk for spreading CHIKV to non-endemic regions has heightened [1] . Several travelers have brought CHIKV home with them after visiting areas with actively infected populations [12, 20] . Such cases have been documented in European countries, Australia, Asia, and the United States [8, 21] . The United States has already reported at least twelve cases of travel-associated CHIKV, while France has reported 850 cases, and the United Kingdom 93 [8, 14] . Beyond this, CHIKV-infected travelers have also been diagnosed in Australia, Belgium, Canada, Czech Republic, French Guiana, Germany, Hong Kong, Italy, Japan, Kenya, Malaysia, Martinique, Norway, Switzerland, and Sri Lanka [21] . Some travelers were viremic, worrying public health officials about the spread of CHIKV to new areas [1, 8] .", "The incubation time for CHIKV is relatively short, requiring only 2-6 d with symptoms usually appearing 4-7 d post-infection [22] . Vazeille et al. detected CHIKV in the salivary glands of Ae. albopictus only 2 d after infection [5] . Upon infection, CHIKF tends to present itself in two phases. The first stage is acute, while the second stage, experienced by most but not all, is persistent, causing disabling polyarthritis. Characteristics of the acute phase include an abrupt onset of fever, arthralgia, and in some cases, maculopapular rash [6, 23] . The acute phase causes such intense joint and muscular pain that makes movement very difficult and prostrates its victims [6, 20] .", "Ninety-five percent of infected adults are symptomatic after infection, and of these, most become disabled for weeks to months as a result of decreased dexterity, loss of mobility, and delayed reaction. Eighteen months after disease onset, 40% of patients are found to still have anti-CHIKV IgM [6, 18, 23, 24] . The chronic stage of CHIKF is characterized by polyarthralgia that can last from weeks to years beyond the acute stage [6] . CHIKV has been shown to attack fibroblasts, explaining the involvement of muscles, joints, and skin connective tissues. The high number of nociceptive nerve endings found within the joints and muscle connective tissues can explain pain associated with CHIKF [25, 26] .", "More than 50% of patients who suffer from severe CHIKF are over 65 y old, and more than 33% of them die. Most adults who suffer from severe CHIKF have underlying medical conditions [6, 24, 27] . The other group that is disproportionately affected by severe CHIKV is children. Other complications associated with CHIKV, from most common to least common, include respiratory failure, cardiovascular decompensation, meningoencephalitis, severe acute hepatitis, severe cutaneous effects, other central nervous system problems, and kidney failure [6, 18, 20, 23, 24, 26, 27] .", "CHIKV undertakes a complex replication cycle upon host infection (Figure 2 ), which makes its genome susceptible to mutations [28, 29] . For instance, Ae. aegypti, responsible for epidemics in Kenya, Comoros, and Seychelles, carried CHIKV with an alanine in the 226 position of the E1 gene (E1-A226) [4, 18] . However, when the virus struck La Reunion Islands, a decline in population of Ae. aegypti, due to massive dichlorodiphenyltrichloroethane usage and dearth of Ae. albopictus species' www.plosntds.org population, resulted in an ecological pressure, favoring replacement of alanine at position 226 with valine (E1-A226V) [5] . This mutation allowed CHIKV's secondary vector species, Ae. albopictus, to supplement Ae. aegypti as its primary vector [5] .", "Within a year, the E1-A226V mutation was present in La Reunion Island, and Ae. albopictus apparently vectored the large epidemic infecting 34% of La Reunion Island's population [5] . All of the CHIKV strains isolated from Mayotte carried the E1-A226V mutation, and the mutation was also found in Madagascar in 2007 [5] . The E1-A226V mutation was not present at the beginning of the Indian Ocean Islands outbreak (before September 2005). However, more than 90% of later viral strains found there had incorporated the mutation (December-March 2006), indicating a genotype switch during the winter season [5, 18, 20] .", "The E1-A226V mutation also enabled an increase in infectivity of Ae. albopictus when compared to its infectivity of Ae. aegypti [4, 11, 18, 30] , and with several factors taken together, Ae. albopictus has become the new preferred and more lethal vector for CHIKV [4, 5, 11] . In fact, Tsetsarkin et al. found that a Green Fluorescent Protein tagged E1-A226V virus was 100 times more infective to Ae. albopictus than it was to Ae. aegypti [4] . In all the Indian Ocean Islands, Ae. albopictus became the main vector for CHIKV within 1-2 y after CHIKV was introduced to the region [31] .", "Of note is that Ae. aegypti has most likely been established in North America for over 300 y, while Ae. albopictus has been in many areas of the US, since 1985, primarily in Florida [32] and since then has expanded its range in the country. Reiskind et al. set out to determine if Ae. aegypti and Ae. albopictus mosquitoes captured in Florida were susceptible to CHIKV infection by a La Reunion isolate [32] . Each mosquito tested was highly susceptible to infection by a full-length infectious clone of the La Réunion Island isolate, CHIKV LR2006 OPY1 strain. Even though the Ae. albopictus strains were more susceptible to infection, overall ecology and differences in human biting patterns need to be studied further Characteristically, there are two rounds of translation: (+) sense genomic RNA (49S9 = 11.7 kb) acts directly as mRNA and is partially translated (59 end) to produce non-structural proteins (nsp's). These proteins are responsible for replication and formation of a complementary", "(2) strand, the template for further (+) strand synthesis. Subgenomic mRNA (26 S = 4.1 kb) replication occurs through the synthesis of full-length (2) intermediate RNA, which is regulated by nsp4 and p123 precursor in early infection and later by mature nsp's. Translation of the newly synthesized sub-genomic RNA results in production of structural proteins such as Capsid and protein E2-6k-E1 (from 39 end of genome). Assembly occurs at the cell surface, and the envelope is acquired as the virus buds from the cell and release and maturation almost simultaneous occurred. Replication occurs in the cytoplasm and is very rapid (,4 h) [28, 29] . doi:10.1371/journal.pntd.0000623.g002 www.plosntds.org to gain a more accurate understanding of a potential CHIKV epidemic in the US [32] .", "During the 7 d preceding birth, no human mother has been reported to transmit the disease vertically. However, about 50% of newborns delivered while the mother was infected with CHIKV contracted the disease from their mother, despite the method of delivery. Furthermore, there have been instances of CHIKV transmission from mother to fetus causing congenital illness and fetal death [33] .", "During the 2005-2006 La Reunion Island outbreaks, Ramful et al. discovered that mothers could transmit CHIKV to their progeny during the perinatal period (Day 24 to Day +1) [33, 34] , and it is associated with a high degree of morbidity. By mean Day 4 of life, all of the neonates were symptomatic for CHIKV, exhibiting common CHIKF symptoms. Six neonates were confirmed to have contracted CHIKV and developed mengoencephalitis. Of those mothers who, during the La Reunion Island epidemic, were infected long before delivery, only three fetal deaths were reported [12, 33] . Ramful et al. theorized that motherto-child transmission most likely happens transplacentally shortly before delivery [33] . A similar study by Gerardin et al. reported nineteen cases of neonatal infection associated with intrapartum maternal viremia that progressed to develop encephalitis owing to vertical transmission from infected mothers [34] .", "Clinical and epidemiological similarities with dengue fever make CHIKV diagnosis difficult, which may lead physicians to misdiagnose CHIKV as dengue fever; therefore, the incidence of CHIKV may actually be higher than currently believed (Table 1 ) [6, 12, 35] .", "The amount of time elapsed since disease onset is the most critical parameter when choosing a diagnostic test. CHIKV can be detected and isolated by culturing with mosquito cells (C6/36), Vero cells (mammalian), or in mice [26] . However, this method can take at least a week and only achieves a high sensitivity during the viremic phase, which usually only lasts up to 48 h after the bite. Five days post-infection, the viral isolation approach has a low sensitivity but is still the preferred method for detecting the CHIKV strain [12, 26, 31, 35] . RT-PCR on the other hand is a faster and more sensitive method that can be used within the first week of disease onset [26] , and it is currently the most sensitive method for detecting and quantifying viral mRNA [4, 36] .", "Classic serological detection, by assays such as ELISA [37] , immunofluorescence [5, 38] , complement binding, and haemagglutination inhibition [39] , constitutes the second diagnostic tool used for biological diagnosis of CHIKV infection. These proven techniques are useful for detection of Antigen in mosquitoes during epidemiological studies. These assays detect virus-specific IgM and IgG, however the sensitivity and specificity of these assays has been poorly characterized. Viral competence, or the potential of viral infection and transmission, is an important parameter that can be quantified by ELISA, viral culture, and PCR.", "A study by Ng et al. showed biomarkers indicative of severe CHIKV infection [40] . They found decreased levels of RANTES and increased levels of Interleukin-6 (IL-6) and Interleukin-1b (IL-1b) that could be sued for CHIKV detection in patients as indicators of CHIKV-driven cytokine storm. Couderc et al. demonstrate another cytokine, type-I IFN, as a key player in the progression to CHIKV infection [26] . Using an IFN-a/b null mouse model, they demonstrated evidence of muscles, joints, and skin as privileged CHIKV targets, which is consistent with human pathology. Although Ng et al. concluded that RANTES levels were significantly suppressed in severe CHIKF patients [40] , interestingly, an increase in levels of RANTES has been observed in dengue infection [41] . Since the symptoms of CHIKF mimic those of dengue fever, results obtained from this study strongly suggest that RANTES could be a potential distinctive biomarker that differentiates between these two clinically similar", "diseases.", "There are no approved antiviral treatments currently available for CHIKV [1, 3, 12, 42] . Currently, CHIKF is treated symptomatically, usually with non-steroidal anti-inflammatory drugs or steroids, bed rest, and fluids. Movement and mild exercise are thought to decrease stiffness and morning arthralgia, but heavy exercise may exacerbate rheumatic symptoms. Corticosteroids may be used in cases of debilitating chronic CHIKV infection. There is a debate about the appropriateness of chloroquine as treatment for unresolved, non-steroidal anti-inflammatory drugresistant arthritis [43] . A study showed that viral production was www.plosntds.org drastically reduced at 16 h post-infection after treatment with 100 mM dec-RVKR-cmk (Decanoyl-Arg-Val-Lys-Arg-chloromethylketone), a furine inhibitor [42, 44] . Chloroquine acted by raising the pH, blocking low pH-dependent entry of virus into the cell. It is important to note that dec-RVKR-cmk or chloroquine only inhibited viral spreading from cell", "to cell, not CHIKV replication once it had entered the cell [43] . However, most would agree that the best weapon against CHIKV is prevention. A live CHIKV vaccine developed by the United States reached phase II clinical trial encompassing 59 healthy volunteers [45] . Eight percent of the volunteers experienced transient arthralgia, while 98% of the volunteers had seroconversion [45] . However, live CHIKV vaccines are still questionable. One cannot discount the risk of a live vaccine possibly inducing chronic rheumatism. Also, there is the question as to whether widespread use among the public could trigger mosquito transmission or lead to chronic infection or viral reversion [1] .", "An alternative approach would be to produce a chimeric vaccine against CHIKV. Wang et al. developed a chimeric alphavirus vaccine that is uniformly attenuated and does not cause reactogenicity in mice [3] . Three different versions of this vaccine were made using three different backbone vectors: Venezuelan equine encephalitis virus (VEEV) attenuated vaccine strain T-83, naturally attenuated eastern equine encephalitis virus (EEEV), and attenuated Sindbis virus (SINV). In short, CHIKV structural proteins were engineered into the backbones of the aforementioned vaccines to produce the chimeras [3] . These chimeras were found to stimulate a strong humoral immunity, and even at doses of 5.3-5.8 log 10 PFU, they did not trigger reactogenicity. When vaccinated mice were challenged with CHIKV, neither adult nor neonatal mice gained weight, had fever, or displayed signs of neurological illness. Upon comparison of the chimeras with the Army181/25 vaccine, the Army vaccine resulted in higher", "levels of viremia and replication in the joints of neonatal mice. Because the joints are known targets of CHIKV, Wang et al. noted their vaccine might avoid the negative reactogenic side effects of the Army vaccine. After being subcutaneously vaccinated with 5.3-5.8 log 10 PFU of the chimeric vaccines, mice produced strong neutralizing antibody titers. The VEEV and EEEV chimeras yielded higher neutralizing antibody titers than the SINV chimera without being more virulent. On top of this, the VEEV and EEEV CHIKV chimeras seemed to be more immunogenic than the Army vaccine despite the chimeras' lower viremia and replication in the joints of neonatal mice [3] .", "Tiwari et al. [46] adopted a different strategy using formalin inactivated CHIKV in combination with alhydrogel (Aluminum Hydroxide) as an adjuvant. This study clearly suggests that this vaccine elicits both humoral and cell-mediated immune responses in mice, providing its immunogenic potential. A recent study by Couderc et al. [47] showed passive immunization as a potential treatment for CHIKV infection. Using purified immunoglobulin extracted from convalescent CHIKV patients, they demonstrated effective neutralizing activity against CHIKV infection both in vitro and in vivo. This thereby establishes a potential preventive and therapeutic approach to combat CHIKV infection. Pathogenesis studies conducted with related alpha virus, like RRV, have shown the role of macrophages in persistence on infection [48] . They also demonstrated the role of RRV-specific CD8 T cells in clearing viral load in infected patients, thereby warranting similar investigations with CHIKV and the importance", "of investigating a cell-mediated immune response-based vaccine against CHIKV [49] .", "There are always certain risks associated with live attenuated or inactivated viral vaccines [50] . One way to avoid these potential problems is to construct a consensus-based DNA vaccine. DNA based vaccines have an improved safety profile as compared to live or attenuated vaccines [51, 52] . A consequence of CHIKV's rapid evolution is difficulty in constructing a vaccine that will be able to Figure 3 . Levels of CHIKV-specific IgG in mice immunized with CHIKV vaccines. Each group of C57BL/6 mice (n = 5) was immunized with 12.5 mg of pVax1 control vector or CHIKV vaccine plasmids as indicated at 0 and 2 wk. Mice were bled 2 wk after each immunization, and each group's serum pool was diluted to 1:100 and 1:500 for reaction with specific vaccine constructs. Serum was incubated for 1 h at 37uC on 96-well plates coated with 2 mg/ml of respective CHIKV peptides, and antibody was detected using anti-mouse IgG-HRP and OD was measured at 405 nm. doi:10.1371/journal.pntd.0000623.g003", "www.plosntds.org effectively protect large populations from multiple strains of the virus. One of the strengths of DNA consensus vaccines is its ability to induce cross-reactive immune responses against the three distinct phylogenetic groups of CHIKV. Also DNA-based vaccines can be produced more rapidly than protein-based vaccines.", "Recently, Muthumani et al. constructed a vaccine that was shown to induce both humoral and cellular immunity in vivo in 3-4-wk-old female C57/BL6 mice [49] . These mice were immunized using an in vivo electroporation method to deliver the vaccine into the quadriceps muscle. The consensus construct was designed against E1, E2, and the core protein capsid. To design the construct, they aligned 21 sequences of CHIKV isolated between 1952 and 2006, using strains from differing countries, including La Reunion Island. The most common nucleotide among the sequences was chosen at each position to be used in the consensus construct, taking care not to alter the reading frame. They conducted codon and RNA optimization, added a strong Kozak sequence, and substituted signal peptide with an immunoglobulin E leader sequence to improve vaccine efficacy.", "After immunizing the mice, spleens were harvested along with serum and tested to determine antibody titer. After three immunizations, consensus E1, E2, and C vaccines were shown to induce T-cell immune responses leading to strong IFN-c responses and proliferation in C57/BL6 mice. Furthermore, when compared with control mice, immunized mice had higher total IgG levels as well as higher anti-E1 specific, anti-E2 specific, and anti-C specific IgG antibodies, suggesting a strong humoral immune response ( Figure 3 ) and also specificity for the antigens encoded in the vaccine constructs ( Figure 4 ). Because of its promising results and the need for a safer vaccine, this consensus DNA vaccine deserves further investigation. Determining longevity of protective effects of the vaccine and persistence of antibody and IFN-c responses could be the next step of investigation. Challenged studies of immunized mice must also be carried out.", "CHIKV mosquito-borne disease has caused massive outbreaks for at least half a century but is no longer confined to the www.plosntds.org developing nations. It began to encroach into the boundaries of the developing world. As a result, the NIAID has designated CHIKV as a Category C pathogen alongside the influenza and SARS-CoV viruses [3] . Realization of the potential severity of this disease is exigent; for instance, if used as a biological weapon, the world economy could be severely crippled; if enough members of the armed forces were to become infected during a military deployment, military operations could be significantly affected. Efforts to monitor the disease will only provide minimal warning in a global society, and steps to prevent the morbidity and mortality associated with pandemic are imperative [21, 31] . Despite the gravity of its infectious potency and the fear of it being a potential biological weapon, there is currently no vaccine for CHIKV infections. Live", "attenuated vaccine trials were carried out in 2000, but funding for the project was discontinued. Newer approaches such as DNA vaccines appear promising over conventional strategies like live attenuated or inactivated virus and thus call for further investigation. Recent advances such electroporation delivery and incorporation of adjuvants has boosted DNA vaccine efficacy [51, 53] . Despite the low antibody response to DNA vaccines, other numerous advantages have overshadowed these minor drawbacks (Table 2) , the most important one being the ability to induce both humoral and cellular immune responses [51, 54] .", "Judging by recent success, such as the immunogenic construct developed by Muthumani et al., DNA vaccines could play a major role in combating CHIKV [49] . Vaccines are literally a critical component of CHIKV disease control and therefore research in this area is highly encouraged. The dramatic spread of dengue viruses (DENV) throughout tropical America since 1980 via the same vectors and human hosts underscores the risk to public health in the Americas. The adverse events associated with the current live vaccine are well documented [55] . Realizing these drawbacks, earnest efforts should be taken to develop new strategies to forestall further spread and complications." ]	[ 9 ]	3,829	5,688
1,689	What explains the pain associated with CHIKV?	2,502	[ "The high number of nociceptive nerve endings found within the joints and muscle connective tissues" ]	[ "Chikungunya: A Potentially Emerging Epidemic?\n\nhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC2860491/\n\nSHA: f7c3160bef4169d29e2a8bdd79dd6e9056d4774c\n\nAuthors: Thiboutot, Michelle M.; Kannan, Senthil; Kawalekar, Omkar U.; Shedlock, Devon J.; Khan, Amir S.; Sarangan, Gopalsamy; Srikanth, Padma; Weiner, David B.; Muthumani, Karuppiah\nDate: 2010-04-27\nDOI: 10.1371/journal.pntd.0000623\nLicense: cc-by", "Abstract: Chikungunya virus is a mosquito-borne emerging pathogen that has a major health impact in humans and causes fever disease, headache, rash, nausea, vomiting, myalgia, and arthralgia. Indigenous to tropical Africa, recent large outbreaks have been reported in parts of South East Asia and several of its neighboring islands in 2005–07 and in Europe in 2007. Furthermore, positive cases have been confirmed in the United States in travelers returning from known outbreak areas. Currently, there is no vaccine or antiviral treatment. With the threat of an emerging global pandemic, the peculiar problems associated with the more immediate and seasonal epidemics warrant the development of an effective vaccine. In this review, we summarize the evidence supporting these concepts.", "Text: Chikungunya virus (CHIKV), a mosquito-borne pathogen listed by National Institute of Allergy and Infectious Diseases (NIAID) as a Category C Priority Pathogen that causes Chikungunya fever (CHIKF), has been spreading throughout Asia, Africa, and parts of Europe in recent times [1, 2, 3] . CHIKV is an arthropod-borne virus (arbovirus) and is transmitted to humans primarily by Aedes aegypti, the infamous yellow fever propagator [4, 5] . CHIKV infection is marked by severe joint pain, contorting its victims into unusual postures [6] . The disease gets its name from the Kimakonde vernacular language of Tanzania and Mozambique, and the word chikungunya means ''that which contorts or bends up'' and translates in Swahili to ''the illness of the bended walker'' [7, 8, 9] . In Africa, CHIKV is maintained in a sylvatic cycle among forest-dwelling Aedes spp. mosquitoes, wild primates, squirrels, birds, and rodents ( Figure 1 ) [10] . In Asia, the disease is vectored by Ae. aegypti and Ae.", "albopictus [11] . Transmission in Asia occurs in an urban cycle whereby the mosquito spreads the disease from an infected human to an uninfected human, following an epidemiological pattern similar to dengue fever [12] .", "The 2005-2006 epidemic of CHIKV in La Reunion islands in the Indian Ocean, spurred the discovery of a new vector species, Ae. albopictus [5] . Wrecking over one-third of the island's population, this epidemic peaked its devastation between January and February 2006, when over 46,000 cases came into light every week, including 284 deaths [5, 13] . Ae. albopictus is common in urban areas of the United States and is already flourishing in 36 states, raising grave concerns to the immunologically naive populace of the United States [14] .\n\nAccordingly, this review elaborately details the epidemiology and global expansion of CHIKV, describes its clinical features and pathogenesis and its symptoms and complications, and finally nominates a possible vaccine approach against CHIKV infection.", "CHIKV has been isolated into three genotypes based on phylogenetic studies. These genotypes, based on the gene sequences of an Envelope protein (E1), are Asian, East/Central/ South African, and West African [4, 11, 15] . Using phylogenetic models, Cherian et al. estimate that the Asian genotype of CHIKV emerged between 50 and 310 y ago, and the West and East African genotypes diverged between 100 and 840 y ago [15] . Since then, CHIKV has come a long way, with several mutations incorporated, and has continued to wreak epidemics in several regions. Recent activities of CHIKV include the Indian epidemic in 2005-2006, which was followed by a sudden explosion of cases in 2007. An estimated 1.3 million people across 13 states were reported to be infected in India [12, 16] , and CHIKV was also widespread in Malaysia, Sri Lanka, and Indonesia [17] . In July-August of 2007, CHIKV was reported in Italy, probably brought in by travelers from CHIKV-prone regions of India, Africa, and Indian", "Ocean islands such as Mauritius, Madagascar, and Seychelles. Few of the Italian isolates were found to have evolved from the Kerala isolate, which was associated with a A226V shift in E1 gene that represents a successful evolutionary adaptation in the mosquito vector similar to the ones observed in Reunion Island [2, 18, 19] .", "In recent times, with an increase in global travel, the risk for spreading CHIKV to non-endemic regions has heightened [1] . Several travelers have brought CHIKV home with them after visiting areas with actively infected populations [12, 20] . Such cases have been documented in European countries, Australia, Asia, and the United States [8, 21] . The United States has already reported at least twelve cases of travel-associated CHIKV, while France has reported 850 cases, and the United Kingdom 93 [8, 14] . Beyond this, CHIKV-infected travelers have also been diagnosed in Australia, Belgium, Canada, Czech Republic, French Guiana, Germany, Hong Kong, Italy, Japan, Kenya, Malaysia, Martinique, Norway, Switzerland, and Sri Lanka [21] . Some travelers were viremic, worrying public health officials about the spread of CHIKV to new areas [1, 8] .", "The incubation time for CHIKV is relatively short, requiring only 2-6 d with symptoms usually appearing 4-7 d post-infection [22] . Vazeille et al. detected CHIKV in the salivary glands of Ae. albopictus only 2 d after infection [5] . Upon infection, CHIKF tends to present itself in two phases. The first stage is acute, while the second stage, experienced by most but not all, is persistent, causing disabling polyarthritis. Characteristics of the acute phase include an abrupt onset of fever, arthralgia, and in some cases, maculopapular rash [6, 23] . The acute phase causes such intense joint and muscular pain that makes movement very difficult and prostrates its victims [6, 20] .", "Ninety-five percent of infected adults are symptomatic after infection, and of these, most become disabled for weeks to months as a result of decreased dexterity, loss of mobility, and delayed reaction. Eighteen months after disease onset, 40% of patients are found to still have anti-CHIKV IgM [6, 18, 23, 24] . The chronic stage of CHIKF is characterized by polyarthralgia that can last from weeks to years beyond the acute stage [6] . CHIKV has been shown to attack fibroblasts, explaining the involvement of muscles, joints, and skin connective tissues. The high number of nociceptive nerve endings found within the joints and muscle connective tissues can explain pain associated with CHIKF [25, 26] .", "More than 50% of patients who suffer from severe CHIKF are over 65 y old, and more than 33% of them die. Most adults who suffer from severe CHIKF have underlying medical conditions [6, 24, 27] . The other group that is disproportionately affected by severe CHIKV is children. Other complications associated with CHIKV, from most common to least common, include respiratory failure, cardiovascular decompensation, meningoencephalitis, severe acute hepatitis, severe cutaneous effects, other central nervous system problems, and kidney failure [6, 18, 20, 23, 24, 26, 27] .", "CHIKV undertakes a complex replication cycle upon host infection (Figure 2 ), which makes its genome susceptible to mutations [28, 29] . For instance, Ae. aegypti, responsible for epidemics in Kenya, Comoros, and Seychelles, carried CHIKV with an alanine in the 226 position of the E1 gene (E1-A226) [4, 18] . However, when the virus struck La Reunion Islands, a decline in population of Ae. aegypti, due to massive dichlorodiphenyltrichloroethane usage and dearth of Ae. albopictus species' www.plosntds.org population, resulted in an ecological pressure, favoring replacement of alanine at position 226 with valine (E1-A226V) [5] . This mutation allowed CHIKV's secondary vector species, Ae. albopictus, to supplement Ae. aegypti as its primary vector [5] .", "Within a year, the E1-A226V mutation was present in La Reunion Island, and Ae. albopictus apparently vectored the large epidemic infecting 34% of La Reunion Island's population [5] . All of the CHIKV strains isolated from Mayotte carried the E1-A226V mutation, and the mutation was also found in Madagascar in 2007 [5] . The E1-A226V mutation was not present at the beginning of the Indian Ocean Islands outbreak (before September 2005). However, more than 90% of later viral strains found there had incorporated the mutation (December-March 2006), indicating a genotype switch during the winter season [5, 18, 20] .", "The E1-A226V mutation also enabled an increase in infectivity of Ae. albopictus when compared to its infectivity of Ae. aegypti [4, 11, 18, 30] , and with several factors taken together, Ae. albopictus has become the new preferred and more lethal vector for CHIKV [4, 5, 11] . In fact, Tsetsarkin et al. found that a Green Fluorescent Protein tagged E1-A226V virus was 100 times more infective to Ae. albopictus than it was to Ae. aegypti [4] . In all the Indian Ocean Islands, Ae. albopictus became the main vector for CHIKV within 1-2 y after CHIKV was introduced to the region [31] .", "Of note is that Ae. aegypti has most likely been established in North America for over 300 y, while Ae. albopictus has been in many areas of the US, since 1985, primarily in Florida [32] and since then has expanded its range in the country. Reiskind et al. set out to determine if Ae. aegypti and Ae. albopictus mosquitoes captured in Florida were susceptible to CHIKV infection by a La Reunion isolate [32] . Each mosquito tested was highly susceptible to infection by a full-length infectious clone of the La Réunion Island isolate, CHIKV LR2006 OPY1 strain. Even though the Ae. albopictus strains were more susceptible to infection, overall ecology and differences in human biting patterns need to be studied further Characteristically, there are two rounds of translation: (+) sense genomic RNA (49S9 = 11.7 kb) acts directly as mRNA and is partially translated (59 end) to produce non-structural proteins (nsp's). These proteins are responsible for replication and formation of a complementary", "(2) strand, the template for further (+) strand synthesis. Subgenomic mRNA (26 S = 4.1 kb) replication occurs through the synthesis of full-length (2) intermediate RNA, which is regulated by nsp4 and p123 precursor in early infection and later by mature nsp's. Translation of the newly synthesized sub-genomic RNA results in production of structural proteins such as Capsid and protein E2-6k-E1 (from 39 end of genome). Assembly occurs at the cell surface, and the envelope is acquired as the virus buds from the cell and release and maturation almost simultaneous occurred. Replication occurs in the cytoplasm and is very rapid (,4 h) [28, 29] . doi:10.1371/journal.pntd.0000623.g002 www.plosntds.org to gain a more accurate understanding of a potential CHIKV epidemic in the US [32] .", "During the 7 d preceding birth, no human mother has been reported to transmit the disease vertically. However, about 50% of newborns delivered while the mother was infected with CHIKV contracted the disease from their mother, despite the method of delivery. Furthermore, there have been instances of CHIKV transmission from mother to fetus causing congenital illness and fetal death [33] .", "During the 2005-2006 La Reunion Island outbreaks, Ramful et al. discovered that mothers could transmit CHIKV to their progeny during the perinatal period (Day 24 to Day +1) [33, 34] , and it is associated with a high degree of morbidity. By mean Day 4 of life, all of the neonates were symptomatic for CHIKV, exhibiting common CHIKF symptoms. Six neonates were confirmed to have contracted CHIKV and developed mengoencephalitis. Of those mothers who, during the La Reunion Island epidemic, were infected long before delivery, only three fetal deaths were reported [12, 33] . Ramful et al. theorized that motherto-child transmission most likely happens transplacentally shortly before delivery [33] . A similar study by Gerardin et al. reported nineteen cases of neonatal infection associated with intrapartum maternal viremia that progressed to develop encephalitis owing to vertical transmission from infected mothers [34] .", "Clinical and epidemiological similarities with dengue fever make CHIKV diagnosis difficult, which may lead physicians to misdiagnose CHIKV as dengue fever; therefore, the incidence of CHIKV may actually be higher than currently believed (Table 1 ) [6, 12, 35] .", "The amount of time elapsed since disease onset is the most critical parameter when choosing a diagnostic test. CHIKV can be detected and isolated by culturing with mosquito cells (C6/36), Vero cells (mammalian), or in mice [26] . However, this method can take at least a week and only achieves a high sensitivity during the viremic phase, which usually only lasts up to 48 h after the bite. Five days post-infection, the viral isolation approach has a low sensitivity but is still the preferred method for detecting the CHIKV strain [12, 26, 31, 35] . RT-PCR on the other hand is a faster and more sensitive method that can be used within the first week of disease onset [26] , and it is currently the most sensitive method for detecting and quantifying viral mRNA [4, 36] .", "Classic serological detection, by assays such as ELISA [37] , immunofluorescence [5, 38] , complement binding, and haemagglutination inhibition [39] , constitutes the second diagnostic tool used for biological diagnosis of CHIKV infection. These proven techniques are useful for detection of Antigen in mosquitoes during epidemiological studies. These assays detect virus-specific IgM and IgG, however the sensitivity and specificity of these assays has been poorly characterized. Viral competence, or the potential of viral infection and transmission, is an important parameter that can be quantified by ELISA, viral culture, and PCR.", "A study by Ng et al. showed biomarkers indicative of severe CHIKV infection [40] . They found decreased levels of RANTES and increased levels of Interleukin-6 (IL-6) and Interleukin-1b (IL-1b) that could be sued for CHIKV detection in patients as indicators of CHIKV-driven cytokine storm. Couderc et al. demonstrate another cytokine, type-I IFN, as a key player in the progression to CHIKV infection [26] . Using an IFN-a/b null mouse model, they demonstrated evidence of muscles, joints, and skin as privileged CHIKV targets, which is consistent with human pathology. Although Ng et al. concluded that RANTES levels were significantly suppressed in severe CHIKF patients [40] , interestingly, an increase in levels of RANTES has been observed in dengue infection [41] . Since the symptoms of CHIKF mimic those of dengue fever, results obtained from this study strongly suggest that RANTES could be a potential distinctive biomarker that differentiates between these two clinically similar", "diseases.", "There are no approved antiviral treatments currently available for CHIKV [1, 3, 12, 42] . Currently, CHIKF is treated symptomatically, usually with non-steroidal anti-inflammatory drugs or steroids, bed rest, and fluids. Movement and mild exercise are thought to decrease stiffness and morning arthralgia, but heavy exercise may exacerbate rheumatic symptoms. Corticosteroids may be used in cases of debilitating chronic CHIKV infection. There is a debate about the appropriateness of chloroquine as treatment for unresolved, non-steroidal anti-inflammatory drugresistant arthritis [43] . A study showed that viral production was www.plosntds.org drastically reduced at 16 h post-infection after treatment with 100 mM dec-RVKR-cmk (Decanoyl-Arg-Val-Lys-Arg-chloromethylketone), a furine inhibitor [42, 44] . Chloroquine acted by raising the pH, blocking low pH-dependent entry of virus into the cell. It is important to note that dec-RVKR-cmk or chloroquine only inhibited viral spreading from cell", "to cell, not CHIKV replication once it had entered the cell [43] . However, most would agree that the best weapon against CHIKV is prevention. A live CHIKV vaccine developed by the United States reached phase II clinical trial encompassing 59 healthy volunteers [45] . Eight percent of the volunteers experienced transient arthralgia, while 98% of the volunteers had seroconversion [45] . However, live CHIKV vaccines are still questionable. One cannot discount the risk of a live vaccine possibly inducing chronic rheumatism. Also, there is the question as to whether widespread use among the public could trigger mosquito transmission or lead to chronic infection or viral reversion [1] .", "An alternative approach would be to produce a chimeric vaccine against CHIKV. Wang et al. developed a chimeric alphavirus vaccine that is uniformly attenuated and does not cause reactogenicity in mice [3] . Three different versions of this vaccine were made using three different backbone vectors: Venezuelan equine encephalitis virus (VEEV) attenuated vaccine strain T-83, naturally attenuated eastern equine encephalitis virus (EEEV), and attenuated Sindbis virus (SINV). In short, CHIKV structural proteins were engineered into the backbones of the aforementioned vaccines to produce the chimeras [3] . These chimeras were found to stimulate a strong humoral immunity, and even at doses of 5.3-5.8 log 10 PFU, they did not trigger reactogenicity. When vaccinated mice were challenged with CHIKV, neither adult nor neonatal mice gained weight, had fever, or displayed signs of neurological illness. Upon comparison of the chimeras with the Army181/25 vaccine, the Army vaccine resulted in higher", "levels of viremia and replication in the joints of neonatal mice. Because the joints are known targets of CHIKV, Wang et al. noted their vaccine might avoid the negative reactogenic side effects of the Army vaccine. After being subcutaneously vaccinated with 5.3-5.8 log 10 PFU of the chimeric vaccines, mice produced strong neutralizing antibody titers. The VEEV and EEEV chimeras yielded higher neutralizing antibody titers than the SINV chimera without being more virulent. On top of this, the VEEV and EEEV CHIKV chimeras seemed to be more immunogenic than the Army vaccine despite the chimeras' lower viremia and replication in the joints of neonatal mice [3] .", "Tiwari et al. [46] adopted a different strategy using formalin inactivated CHIKV in combination with alhydrogel (Aluminum Hydroxide) as an adjuvant. This study clearly suggests that this vaccine elicits both humoral and cell-mediated immune responses in mice, providing its immunogenic potential. A recent study by Couderc et al. [47] showed passive immunization as a potential treatment for CHIKV infection. Using purified immunoglobulin extracted from convalescent CHIKV patients, they demonstrated effective neutralizing activity against CHIKV infection both in vitro and in vivo. This thereby establishes a potential preventive and therapeutic approach to combat CHIKV infection. Pathogenesis studies conducted with related alpha virus, like RRV, have shown the role of macrophages in persistence on infection [48] . They also demonstrated the role of RRV-specific CD8 T cells in clearing viral load in infected patients, thereby warranting similar investigations with CHIKV and the importance", "of investigating a cell-mediated immune response-based vaccine against CHIKV [49] .", "There are always certain risks associated with live attenuated or inactivated viral vaccines [50] . One way to avoid these potential problems is to construct a consensus-based DNA vaccine. DNA based vaccines have an improved safety profile as compared to live or attenuated vaccines [51, 52] . A consequence of CHIKV's rapid evolution is difficulty in constructing a vaccine that will be able to Figure 3 . Levels of CHIKV-specific IgG in mice immunized with CHIKV vaccines. Each group of C57BL/6 mice (n = 5) was immunized with 12.5 mg of pVax1 control vector or CHIKV vaccine plasmids as indicated at 0 and 2 wk. Mice were bled 2 wk after each immunization, and each group's serum pool was diluted to 1:100 and 1:500 for reaction with specific vaccine constructs. Serum was incubated for 1 h at 37uC on 96-well plates coated with 2 mg/ml of respective CHIKV peptides, and antibody was detected using anti-mouse IgG-HRP and OD was measured at 405 nm. doi:10.1371/journal.pntd.0000623.g003", "www.plosntds.org effectively protect large populations from multiple strains of the virus. One of the strengths of DNA consensus vaccines is its ability to induce cross-reactive immune responses against the three distinct phylogenetic groups of CHIKV. Also DNA-based vaccines can be produced more rapidly than protein-based vaccines.", "Recently, Muthumani et al. constructed a vaccine that was shown to induce both humoral and cellular immunity in vivo in 3-4-wk-old female C57/BL6 mice [49] . These mice were immunized using an in vivo electroporation method to deliver the vaccine into the quadriceps muscle. The consensus construct was designed against E1, E2, and the core protein capsid. To design the construct, they aligned 21 sequences of CHIKV isolated between 1952 and 2006, using strains from differing countries, including La Reunion Island. The most common nucleotide among the sequences was chosen at each position to be used in the consensus construct, taking care not to alter the reading frame. They conducted codon and RNA optimization, added a strong Kozak sequence, and substituted signal peptide with an immunoglobulin E leader sequence to improve vaccine efficacy.", "After immunizing the mice, spleens were harvested along with serum and tested to determine antibody titer. After three immunizations, consensus E1, E2, and C vaccines were shown to induce T-cell immune responses leading to strong IFN-c responses and proliferation in C57/BL6 mice. Furthermore, when compared with control mice, immunized mice had higher total IgG levels as well as higher anti-E1 specific, anti-E2 specific, and anti-C specific IgG antibodies, suggesting a strong humoral immune response ( Figure 3 ) and also specificity for the antigens encoded in the vaccine constructs ( Figure 4 ). Because of its promising results and the need for a safer vaccine, this consensus DNA vaccine deserves further investigation. Determining longevity of protective effects of the vaccine and persistence of antibody and IFN-c responses could be the next step of investigation. Challenged studies of immunized mice must also be carried out.", "CHIKV mosquito-borne disease has caused massive outbreaks for at least half a century but is no longer confined to the www.plosntds.org developing nations. It began to encroach into the boundaries of the developing world. As a result, the NIAID has designated CHIKV as a Category C pathogen alongside the influenza and SARS-CoV viruses [3] . Realization of the potential severity of this disease is exigent; for instance, if used as a biological weapon, the world economy could be severely crippled; if enough members of the armed forces were to become infected during a military deployment, military operations could be significantly affected. Efforts to monitor the disease will only provide minimal warning in a global society, and steps to prevent the morbidity and mortality associated with pandemic are imperative [21, 31] . Despite the gravity of its infectious potency and the fear of it being a potential biological weapon, there is currently no vaccine for CHIKV infections. Live", "attenuated vaccine trials were carried out in 2000, but funding for the project was discontinued. Newer approaches such as DNA vaccines appear promising over conventional strategies like live attenuated or inactivated virus and thus call for further investigation. Recent advances such electroporation delivery and incorporation of adjuvants has boosted DNA vaccine efficacy [51, 53] . Despite the low antibody response to DNA vaccines, other numerous advantages have overshadowed these minor drawbacks (Table 2) , the most important one being the ability to induce both humoral and cellular immune responses [51, 54] .", "Judging by recent success, such as the immunogenic construct developed by Muthumani et al., DNA vaccines could play a major role in combating CHIKV [49] . Vaccines are literally a critical component of CHIKV disease control and therefore research in this area is highly encouraged. The dramatic spread of dengue viruses (DENV) throughout tropical America since 1980 via the same vectors and human hosts underscores the risk to public health in the Americas. The adverse events associated with the current live vaccine are well documented [55] . Realizing these drawbacks, earnest efforts should be taken to develop new strategies to forestall further spread and complications." ]	[ 9 ]	3,829	5,688
1,689	What percentage of people suffering from the CHIKF are over 65 years old?	2,503	[ "50%" ]	[ "Chikungunya: A Potentially Emerging Epidemic?\n\nhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC2860491/\n\nSHA: f7c3160bef4169d29e2a8bdd79dd6e9056d4774c\n\nAuthors: Thiboutot, Michelle M.; Kannan, Senthil; Kawalekar, Omkar U.; Shedlock, Devon J.; Khan, Amir S.; Sarangan, Gopalsamy; Srikanth, Padma; Weiner, David B.; Muthumani, Karuppiah\nDate: 2010-04-27\nDOI: 10.1371/journal.pntd.0000623\nLicense: cc-by", "Abstract: Chikungunya virus is a mosquito-borne emerging pathogen that has a major health impact in humans and causes fever disease, headache, rash, nausea, vomiting, myalgia, and arthralgia. Indigenous to tropical Africa, recent large outbreaks have been reported in parts of South East Asia and several of its neighboring islands in 2005–07 and in Europe in 2007. Furthermore, positive cases have been confirmed in the United States in travelers returning from known outbreak areas. Currently, there is no vaccine or antiviral treatment. With the threat of an emerging global pandemic, the peculiar problems associated with the more immediate and seasonal epidemics warrant the development of an effective vaccine. In this review, we summarize the evidence supporting these concepts.", "Text: Chikungunya virus (CHIKV), a mosquito-borne pathogen listed by National Institute of Allergy and Infectious Diseases (NIAID) as a Category C Priority Pathogen that causes Chikungunya fever (CHIKF), has been spreading throughout Asia, Africa, and parts of Europe in recent times [1, 2, 3] . CHIKV is an arthropod-borne virus (arbovirus) and is transmitted to humans primarily by Aedes aegypti, the infamous yellow fever propagator [4, 5] . CHIKV infection is marked by severe joint pain, contorting its victims into unusual postures [6] . The disease gets its name from the Kimakonde vernacular language of Tanzania and Mozambique, and the word chikungunya means ''that which contorts or bends up'' and translates in Swahili to ''the illness of the bended walker'' [7, 8, 9] . In Africa, CHIKV is maintained in a sylvatic cycle among forest-dwelling Aedes spp. mosquitoes, wild primates, squirrels, birds, and rodents ( Figure 1 ) [10] . In Asia, the disease is vectored by Ae. aegypti and Ae.", "albopictus [11] . Transmission in Asia occurs in an urban cycle whereby the mosquito spreads the disease from an infected human to an uninfected human, following an epidemiological pattern similar to dengue fever [12] .", "The 2005-2006 epidemic of CHIKV in La Reunion islands in the Indian Ocean, spurred the discovery of a new vector species, Ae. albopictus [5] . Wrecking over one-third of the island's population, this epidemic peaked its devastation between January and February 2006, when over 46,000 cases came into light every week, including 284 deaths [5, 13] . Ae. albopictus is common in urban areas of the United States and is already flourishing in 36 states, raising grave concerns to the immunologically naive populace of the United States [14] .\n\nAccordingly, this review elaborately details the epidemiology and global expansion of CHIKV, describes its clinical features and pathogenesis and its symptoms and complications, and finally nominates a possible vaccine approach against CHIKV infection.", "CHIKV has been isolated into three genotypes based on phylogenetic studies. These genotypes, based on the gene sequences of an Envelope protein (E1), are Asian, East/Central/ South African, and West African [4, 11, 15] . Using phylogenetic models, Cherian et al. estimate that the Asian genotype of CHIKV emerged between 50 and 310 y ago, and the West and East African genotypes diverged between 100 and 840 y ago [15] . Since then, CHIKV has come a long way, with several mutations incorporated, and has continued to wreak epidemics in several regions. Recent activities of CHIKV include the Indian epidemic in 2005-2006, which was followed by a sudden explosion of cases in 2007. An estimated 1.3 million people across 13 states were reported to be infected in India [12, 16] , and CHIKV was also widespread in Malaysia, Sri Lanka, and Indonesia [17] . In July-August of 2007, CHIKV was reported in Italy, probably brought in by travelers from CHIKV-prone regions of India, Africa, and Indian", "Ocean islands such as Mauritius, Madagascar, and Seychelles. Few of the Italian isolates were found to have evolved from the Kerala isolate, which was associated with a A226V shift in E1 gene that represents a successful evolutionary adaptation in the mosquito vector similar to the ones observed in Reunion Island [2, 18, 19] .", "In recent times, with an increase in global travel, the risk for spreading CHIKV to non-endemic regions has heightened [1] . Several travelers have brought CHIKV home with them after visiting areas with actively infected populations [12, 20] . Such cases have been documented in European countries, Australia, Asia, and the United States [8, 21] . The United States has already reported at least twelve cases of travel-associated CHIKV, while France has reported 850 cases, and the United Kingdom 93 [8, 14] . Beyond this, CHIKV-infected travelers have also been diagnosed in Australia, Belgium, Canada, Czech Republic, French Guiana, Germany, Hong Kong, Italy, Japan, Kenya, Malaysia, Martinique, Norway, Switzerland, and Sri Lanka [21] . Some travelers were viremic, worrying public health officials about the spread of CHIKV to new areas [1, 8] .", "The incubation time for CHIKV is relatively short, requiring only 2-6 d with symptoms usually appearing 4-7 d post-infection [22] . Vazeille et al. detected CHIKV in the salivary glands of Ae. albopictus only 2 d after infection [5] . Upon infection, CHIKF tends to present itself in two phases. The first stage is acute, while the second stage, experienced by most but not all, is persistent, causing disabling polyarthritis. Characteristics of the acute phase include an abrupt onset of fever, arthralgia, and in some cases, maculopapular rash [6, 23] . The acute phase causes such intense joint and muscular pain that makes movement very difficult and prostrates its victims [6, 20] .", "Ninety-five percent of infected adults are symptomatic after infection, and of these, most become disabled for weeks to months as a result of decreased dexterity, loss of mobility, and delayed reaction. Eighteen months after disease onset, 40% of patients are found to still have anti-CHIKV IgM [6, 18, 23, 24] . The chronic stage of CHIKF is characterized by polyarthralgia that can last from weeks to years beyond the acute stage [6] . CHIKV has been shown to attack fibroblasts, explaining the involvement of muscles, joints, and skin connective tissues. The high number of nociceptive nerve endings found within the joints and muscle connective tissues can explain pain associated with CHIKF [25, 26] .", "More than 50% of patients who suffer from severe CHIKF are over 65 y old, and more than 33% of them die. Most adults who suffer from severe CHIKF have underlying medical conditions [6, 24, 27] . The other group that is disproportionately affected by severe CHIKV is children. Other complications associated with CHIKV, from most common to least common, include respiratory failure, cardiovascular decompensation, meningoencephalitis, severe acute hepatitis, severe cutaneous effects, other central nervous system problems, and kidney failure [6, 18, 20, 23, 24, 26, 27] .", "CHIKV undertakes a complex replication cycle upon host infection (Figure 2 ), which makes its genome susceptible to mutations [28, 29] . For instance, Ae. aegypti, responsible for epidemics in Kenya, Comoros, and Seychelles, carried CHIKV with an alanine in the 226 position of the E1 gene (E1-A226) [4, 18] . However, when the virus struck La Reunion Islands, a decline in population of Ae. aegypti, due to massive dichlorodiphenyltrichloroethane usage and dearth of Ae. albopictus species' www.plosntds.org population, resulted in an ecological pressure, favoring replacement of alanine at position 226 with valine (E1-A226V) [5] . This mutation allowed CHIKV's secondary vector species, Ae. albopictus, to supplement Ae. aegypti as its primary vector [5] .", "Within a year, the E1-A226V mutation was present in La Reunion Island, and Ae. albopictus apparently vectored the large epidemic infecting 34% of La Reunion Island's population [5] . All of the CHIKV strains isolated from Mayotte carried the E1-A226V mutation, and the mutation was also found in Madagascar in 2007 [5] . The E1-A226V mutation was not present at the beginning of the Indian Ocean Islands outbreak (before September 2005). However, more than 90% of later viral strains found there had incorporated the mutation (December-March 2006), indicating a genotype switch during the winter season [5, 18, 20] .", "The E1-A226V mutation also enabled an increase in infectivity of Ae. albopictus when compared to its infectivity of Ae. aegypti [4, 11, 18, 30] , and with several factors taken together, Ae. albopictus has become the new preferred and more lethal vector for CHIKV [4, 5, 11] . In fact, Tsetsarkin et al. found that a Green Fluorescent Protein tagged E1-A226V virus was 100 times more infective to Ae. albopictus than it was to Ae. aegypti [4] . In all the Indian Ocean Islands, Ae. albopictus became the main vector for CHIKV within 1-2 y after CHIKV was introduced to the region [31] .", "Of note is that Ae. aegypti has most likely been established in North America for over 300 y, while Ae. albopictus has been in many areas of the US, since 1985, primarily in Florida [32] and since then has expanded its range in the country. Reiskind et al. set out to determine if Ae. aegypti and Ae. albopictus mosquitoes captured in Florida were susceptible to CHIKV infection by a La Reunion isolate [32] . Each mosquito tested was highly susceptible to infection by a full-length infectious clone of the La Réunion Island isolate, CHIKV LR2006 OPY1 strain. Even though the Ae. albopictus strains were more susceptible to infection, overall ecology and differences in human biting patterns need to be studied further Characteristically, there are two rounds of translation: (+) sense genomic RNA (49S9 = 11.7 kb) acts directly as mRNA and is partially translated (59 end) to produce non-structural proteins (nsp's). These proteins are responsible for replication and formation of a complementary", "(2) strand, the template for further (+) strand synthesis. Subgenomic mRNA (26 S = 4.1 kb) replication occurs through the synthesis of full-length (2) intermediate RNA, which is regulated by nsp4 and p123 precursor in early infection and later by mature nsp's. Translation of the newly synthesized sub-genomic RNA results in production of structural proteins such as Capsid and protein E2-6k-E1 (from 39 end of genome). Assembly occurs at the cell surface, and the envelope is acquired as the virus buds from the cell and release and maturation almost simultaneous occurred. Replication occurs in the cytoplasm and is very rapid (,4 h) [28, 29] . doi:10.1371/journal.pntd.0000623.g002 www.plosntds.org to gain a more accurate understanding of a potential CHIKV epidemic in the US [32] .", "During the 7 d preceding birth, no human mother has been reported to transmit the disease vertically. However, about 50% of newborns delivered while the mother was infected with CHIKV contracted the disease from their mother, despite the method of delivery. Furthermore, there have been instances of CHIKV transmission from mother to fetus causing congenital illness and fetal death [33] .", "During the 2005-2006 La Reunion Island outbreaks, Ramful et al. discovered that mothers could transmit CHIKV to their progeny during the perinatal period (Day 24 to Day +1) [33, 34] , and it is associated with a high degree of morbidity. By mean Day 4 of life, all of the neonates were symptomatic for CHIKV, exhibiting common CHIKF symptoms. Six neonates were confirmed to have contracted CHIKV and developed mengoencephalitis. Of those mothers who, during the La Reunion Island epidemic, were infected long before delivery, only three fetal deaths were reported [12, 33] . Ramful et al. theorized that motherto-child transmission most likely happens transplacentally shortly before delivery [33] . A similar study by Gerardin et al. reported nineteen cases of neonatal infection associated with intrapartum maternal viremia that progressed to develop encephalitis owing to vertical transmission from infected mothers [34] .", "Clinical and epidemiological similarities with dengue fever make CHIKV diagnosis difficult, which may lead physicians to misdiagnose CHIKV as dengue fever; therefore, the incidence of CHIKV may actually be higher than currently believed (Table 1 ) [6, 12, 35] .", "The amount of time elapsed since disease onset is the most critical parameter when choosing a diagnostic test. CHIKV can be detected and isolated by culturing with mosquito cells (C6/36), Vero cells (mammalian), or in mice [26] . However, this method can take at least a week and only achieves a high sensitivity during the viremic phase, which usually only lasts up to 48 h after the bite. Five days post-infection, the viral isolation approach has a low sensitivity but is still the preferred method for detecting the CHIKV strain [12, 26, 31, 35] . RT-PCR on the other hand is a faster and more sensitive method that can be used within the first week of disease onset [26] , and it is currently the most sensitive method for detecting and quantifying viral mRNA [4, 36] .", "Classic serological detection, by assays such as ELISA [37] , immunofluorescence [5, 38] , complement binding, and haemagglutination inhibition [39] , constitutes the second diagnostic tool used for biological diagnosis of CHIKV infection. These proven techniques are useful for detection of Antigen in mosquitoes during epidemiological studies. These assays detect virus-specific IgM and IgG, however the sensitivity and specificity of these assays has been poorly characterized. Viral competence, or the potential of viral infection and transmission, is an important parameter that can be quantified by ELISA, viral culture, and PCR.", "A study by Ng et al. showed biomarkers indicative of severe CHIKV infection [40] . They found decreased levels of RANTES and increased levels of Interleukin-6 (IL-6) and Interleukin-1b (IL-1b) that could be sued for CHIKV detection in patients as indicators of CHIKV-driven cytokine storm. Couderc et al. demonstrate another cytokine, type-I IFN, as a key player in the progression to CHIKV infection [26] . Using an IFN-a/b null mouse model, they demonstrated evidence of muscles, joints, and skin as privileged CHIKV targets, which is consistent with human pathology. Although Ng et al. concluded that RANTES levels were significantly suppressed in severe CHIKF patients [40] , interestingly, an increase in levels of RANTES has been observed in dengue infection [41] . Since the symptoms of CHIKF mimic those of dengue fever, results obtained from this study strongly suggest that RANTES could be a potential distinctive biomarker that differentiates between these two clinically similar", "diseases.", "There are no approved antiviral treatments currently available for CHIKV [1, 3, 12, 42] . Currently, CHIKF is treated symptomatically, usually with non-steroidal anti-inflammatory drugs or steroids, bed rest, and fluids. Movement and mild exercise are thought to decrease stiffness and morning arthralgia, but heavy exercise may exacerbate rheumatic symptoms. Corticosteroids may be used in cases of debilitating chronic CHIKV infection. There is a debate about the appropriateness of chloroquine as treatment for unresolved, non-steroidal anti-inflammatory drugresistant arthritis [43] . A study showed that viral production was www.plosntds.org drastically reduced at 16 h post-infection after treatment with 100 mM dec-RVKR-cmk (Decanoyl-Arg-Val-Lys-Arg-chloromethylketone), a furine inhibitor [42, 44] . Chloroquine acted by raising the pH, blocking low pH-dependent entry of virus into the cell. It is important to note that dec-RVKR-cmk or chloroquine only inhibited viral spreading from cell", "to cell, not CHIKV replication once it had entered the cell [43] . However, most would agree that the best weapon against CHIKV is prevention. A live CHIKV vaccine developed by the United States reached phase II clinical trial encompassing 59 healthy volunteers [45] . Eight percent of the volunteers experienced transient arthralgia, while 98% of the volunteers had seroconversion [45] . However, live CHIKV vaccines are still questionable. One cannot discount the risk of a live vaccine possibly inducing chronic rheumatism. Also, there is the question as to whether widespread use among the public could trigger mosquito transmission or lead to chronic infection or viral reversion [1] .", "An alternative approach would be to produce a chimeric vaccine against CHIKV. Wang et al. developed a chimeric alphavirus vaccine that is uniformly attenuated and does not cause reactogenicity in mice [3] . Three different versions of this vaccine were made using three different backbone vectors: Venezuelan equine encephalitis virus (VEEV) attenuated vaccine strain T-83, naturally attenuated eastern equine encephalitis virus (EEEV), and attenuated Sindbis virus (SINV). In short, CHIKV structural proteins were engineered into the backbones of the aforementioned vaccines to produce the chimeras [3] . These chimeras were found to stimulate a strong humoral immunity, and even at doses of 5.3-5.8 log 10 PFU, they did not trigger reactogenicity. When vaccinated mice were challenged with CHIKV, neither adult nor neonatal mice gained weight, had fever, or displayed signs of neurological illness. Upon comparison of the chimeras with the Army181/25 vaccine, the Army vaccine resulted in higher", "levels of viremia and replication in the joints of neonatal mice. Because the joints are known targets of CHIKV, Wang et al. noted their vaccine might avoid the negative reactogenic side effects of the Army vaccine. After being subcutaneously vaccinated with 5.3-5.8 log 10 PFU of the chimeric vaccines, mice produced strong neutralizing antibody titers. The VEEV and EEEV chimeras yielded higher neutralizing antibody titers than the SINV chimera without being more virulent. On top of this, the VEEV and EEEV CHIKV chimeras seemed to be more immunogenic than the Army vaccine despite the chimeras' lower viremia and replication in the joints of neonatal mice [3] .", "Tiwari et al. [46] adopted a different strategy using formalin inactivated CHIKV in combination with alhydrogel (Aluminum Hydroxide) as an adjuvant. This study clearly suggests that this vaccine elicits both humoral and cell-mediated immune responses in mice, providing its immunogenic potential. A recent study by Couderc et al. [47] showed passive immunization as a potential treatment for CHIKV infection. Using purified immunoglobulin extracted from convalescent CHIKV patients, they demonstrated effective neutralizing activity against CHIKV infection both in vitro and in vivo. This thereby establishes a potential preventive and therapeutic approach to combat CHIKV infection. Pathogenesis studies conducted with related alpha virus, like RRV, have shown the role of macrophages in persistence on infection [48] . They also demonstrated the role of RRV-specific CD8 T cells in clearing viral load in infected patients, thereby warranting similar investigations with CHIKV and the importance", "of investigating a cell-mediated immune response-based vaccine against CHIKV [49] .", "There are always certain risks associated with live attenuated or inactivated viral vaccines [50] . One way to avoid these potential problems is to construct a consensus-based DNA vaccine. DNA based vaccines have an improved safety profile as compared to live or attenuated vaccines [51, 52] . A consequence of CHIKV's rapid evolution is difficulty in constructing a vaccine that will be able to Figure 3 . Levels of CHIKV-specific IgG in mice immunized with CHIKV vaccines. Each group of C57BL/6 mice (n = 5) was immunized with 12.5 mg of pVax1 control vector or CHIKV vaccine plasmids as indicated at 0 and 2 wk. Mice were bled 2 wk after each immunization, and each group's serum pool was diluted to 1:100 and 1:500 for reaction with specific vaccine constructs. Serum was incubated for 1 h at 37uC on 96-well plates coated with 2 mg/ml of respective CHIKV peptides, and antibody was detected using anti-mouse IgG-HRP and OD was measured at 405 nm. doi:10.1371/journal.pntd.0000623.g003", "www.plosntds.org effectively protect large populations from multiple strains of the virus. One of the strengths of DNA consensus vaccines is its ability to induce cross-reactive immune responses against the three distinct phylogenetic groups of CHIKV. Also DNA-based vaccines can be produced more rapidly than protein-based vaccines.", "Recently, Muthumani et al. constructed a vaccine that was shown to induce both humoral and cellular immunity in vivo in 3-4-wk-old female C57/BL6 mice [49] . These mice were immunized using an in vivo electroporation method to deliver the vaccine into the quadriceps muscle. The consensus construct was designed against E1, E2, and the core protein capsid. To design the construct, they aligned 21 sequences of CHIKV isolated between 1952 and 2006, using strains from differing countries, including La Reunion Island. The most common nucleotide among the sequences was chosen at each position to be used in the consensus construct, taking care not to alter the reading frame. They conducted codon and RNA optimization, added a strong Kozak sequence, and substituted signal peptide with an immunoglobulin E leader sequence to improve vaccine efficacy.", "After immunizing the mice, spleens were harvested along with serum and tested to determine antibody titer. After three immunizations, consensus E1, E2, and C vaccines were shown to induce T-cell immune responses leading to strong IFN-c responses and proliferation in C57/BL6 mice. Furthermore, when compared with control mice, immunized mice had higher total IgG levels as well as higher anti-E1 specific, anti-E2 specific, and anti-C specific IgG antibodies, suggesting a strong humoral immune response ( Figure 3 ) and also specificity for the antigens encoded in the vaccine constructs ( Figure 4 ). Because of its promising results and the need for a safer vaccine, this consensus DNA vaccine deserves further investigation. Determining longevity of protective effects of the vaccine and persistence of antibody and IFN-c responses could be the next step of investigation. Challenged studies of immunized mice must also be carried out.", "CHIKV mosquito-borne disease has caused massive outbreaks for at least half a century but is no longer confined to the www.plosntds.org developing nations. It began to encroach into the boundaries of the developing world. As a result, the NIAID has designated CHIKV as a Category C pathogen alongside the influenza and SARS-CoV viruses [3] . Realization of the potential severity of this disease is exigent; for instance, if used as a biological weapon, the world economy could be severely crippled; if enough members of the armed forces were to become infected during a military deployment, military operations could be significantly affected. Efforts to monitor the disease will only provide minimal warning in a global society, and steps to prevent the morbidity and mortality associated with pandemic are imperative [21, 31] . Despite the gravity of its infectious potency and the fear of it being a potential biological weapon, there is currently no vaccine for CHIKV infections. Live", "attenuated vaccine trials were carried out in 2000, but funding for the project was discontinued. Newer approaches such as DNA vaccines appear promising over conventional strategies like live attenuated or inactivated virus and thus call for further investigation. Recent advances such electroporation delivery and incorporation of adjuvants has boosted DNA vaccine efficacy [51, 53] . Despite the low antibody response to DNA vaccines, other numerous advantages have overshadowed these minor drawbacks (Table 2) , the most important one being the ability to induce both humoral and cellular immune responses [51, 54] .", "Judging by recent success, such as the immunogenic construct developed by Muthumani et al., DNA vaccines could play a major role in combating CHIKV [49] . Vaccines are literally a critical component of CHIKV disease control and therefore research in this area is highly encouraged. The dramatic spread of dengue viruses (DENV) throughout tropical America since 1980 via the same vectors and human hosts underscores the risk to public health in the Americas. The adverse events associated with the current live vaccine are well documented [55] . Realizing these drawbacks, earnest efforts should be taken to develop new strategies to forestall further spread and complications." ]	[ 10 ]	3,829	5,688
1,689	What percentage die?	2,504	[ "33%" ]	[ "Chikungunya: A Potentially Emerging Epidemic?\n\nhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC2860491/\n\nSHA: f7c3160bef4169d29e2a8bdd79dd6e9056d4774c\n\nAuthors: Thiboutot, Michelle M.; Kannan, Senthil; Kawalekar, Omkar U.; Shedlock, Devon J.; Khan, Amir S.; Sarangan, Gopalsamy; Srikanth, Padma; Weiner, David B.; Muthumani, Karuppiah\nDate: 2010-04-27\nDOI: 10.1371/journal.pntd.0000623\nLicense: cc-by", "Abstract: Chikungunya virus is a mosquito-borne emerging pathogen that has a major health impact in humans and causes fever disease, headache, rash, nausea, vomiting, myalgia, and arthralgia. Indigenous to tropical Africa, recent large outbreaks have been reported in parts of South East Asia and several of its neighboring islands in 2005–07 and in Europe in 2007. Furthermore, positive cases have been confirmed in the United States in travelers returning from known outbreak areas. Currently, there is no vaccine or antiviral treatment. With the threat of an emerging global pandemic, the peculiar problems associated with the more immediate and seasonal epidemics warrant the development of an effective vaccine. In this review, we summarize the evidence supporting these concepts.", "Text: Chikungunya virus (CHIKV), a mosquito-borne pathogen listed by National Institute of Allergy and Infectious Diseases (NIAID) as a Category C Priority Pathogen that causes Chikungunya fever (CHIKF), has been spreading throughout Asia, Africa, and parts of Europe in recent times [1, 2, 3] . CHIKV is an arthropod-borne virus (arbovirus) and is transmitted to humans primarily by Aedes aegypti, the infamous yellow fever propagator [4, 5] . CHIKV infection is marked by severe joint pain, contorting its victims into unusual postures [6] . The disease gets its name from the Kimakonde vernacular language of Tanzania and Mozambique, and the word chikungunya means ''that which contorts or bends up'' and translates in Swahili to ''the illness of the bended walker'' [7, 8, 9] . In Africa, CHIKV is maintained in a sylvatic cycle among forest-dwelling Aedes spp. mosquitoes, wild primates, squirrels, birds, and rodents ( Figure 1 ) [10] . In Asia, the disease is vectored by Ae. aegypti and Ae.", "albopictus [11] . Transmission in Asia occurs in an urban cycle whereby the mosquito spreads the disease from an infected human to an uninfected human, following an epidemiological pattern similar to dengue fever [12] .", "The 2005-2006 epidemic of CHIKV in La Reunion islands in the Indian Ocean, spurred the discovery of a new vector species, Ae. albopictus [5] . Wrecking over one-third of the island's population, this epidemic peaked its devastation between January and February 2006, when over 46,000 cases came into light every week, including 284 deaths [5, 13] . Ae. albopictus is common in urban areas of the United States and is already flourishing in 36 states, raising grave concerns to the immunologically naive populace of the United States [14] .\n\nAccordingly, this review elaborately details the epidemiology and global expansion of CHIKV, describes its clinical features and pathogenesis and its symptoms and complications, and finally nominates a possible vaccine approach against CHIKV infection.", "CHIKV has been isolated into three genotypes based on phylogenetic studies. These genotypes, based on the gene sequences of an Envelope protein (E1), are Asian, East/Central/ South African, and West African [4, 11, 15] . Using phylogenetic models, Cherian et al. estimate that the Asian genotype of CHIKV emerged between 50 and 310 y ago, and the West and East African genotypes diverged between 100 and 840 y ago [15] . Since then, CHIKV has come a long way, with several mutations incorporated, and has continued to wreak epidemics in several regions. Recent activities of CHIKV include the Indian epidemic in 2005-2006, which was followed by a sudden explosion of cases in 2007. An estimated 1.3 million people across 13 states were reported to be infected in India [12, 16] , and CHIKV was also widespread in Malaysia, Sri Lanka, and Indonesia [17] . In July-August of 2007, CHIKV was reported in Italy, probably brought in by travelers from CHIKV-prone regions of India, Africa, and Indian", "Ocean islands such as Mauritius, Madagascar, and Seychelles. Few of the Italian isolates were found to have evolved from the Kerala isolate, which was associated with a A226V shift in E1 gene that represents a successful evolutionary adaptation in the mosquito vector similar to the ones observed in Reunion Island [2, 18, 19] .", "In recent times, with an increase in global travel, the risk for spreading CHIKV to non-endemic regions has heightened [1] . Several travelers have brought CHIKV home with them after visiting areas with actively infected populations [12, 20] . Such cases have been documented in European countries, Australia, Asia, and the United States [8, 21] . The United States has already reported at least twelve cases of travel-associated CHIKV, while France has reported 850 cases, and the United Kingdom 93 [8, 14] . Beyond this, CHIKV-infected travelers have also been diagnosed in Australia, Belgium, Canada, Czech Republic, French Guiana, Germany, Hong Kong, Italy, Japan, Kenya, Malaysia, Martinique, Norway, Switzerland, and Sri Lanka [21] . Some travelers were viremic, worrying public health officials about the spread of CHIKV to new areas [1, 8] .", "The incubation time for CHIKV is relatively short, requiring only 2-6 d with symptoms usually appearing 4-7 d post-infection [22] . Vazeille et al. detected CHIKV in the salivary glands of Ae. albopictus only 2 d after infection [5] . Upon infection, CHIKF tends to present itself in two phases. The first stage is acute, while the second stage, experienced by most but not all, is persistent, causing disabling polyarthritis. Characteristics of the acute phase include an abrupt onset of fever, arthralgia, and in some cases, maculopapular rash [6, 23] . The acute phase causes such intense joint and muscular pain that makes movement very difficult and prostrates its victims [6, 20] .", "Ninety-five percent of infected adults are symptomatic after infection, and of these, most become disabled for weeks to months as a result of decreased dexterity, loss of mobility, and delayed reaction. Eighteen months after disease onset, 40% of patients are found to still have anti-CHIKV IgM [6, 18, 23, 24] . The chronic stage of CHIKF is characterized by polyarthralgia that can last from weeks to years beyond the acute stage [6] . CHIKV has been shown to attack fibroblasts, explaining the involvement of muscles, joints, and skin connective tissues. The high number of nociceptive nerve endings found within the joints and muscle connective tissues can explain pain associated with CHIKF [25, 26] .", "More than 50% of patients who suffer from severe CHIKF are over 65 y old, and more than 33% of them die. Most adults who suffer from severe CHIKF have underlying medical conditions [6, 24, 27] . The other group that is disproportionately affected by severe CHIKV is children. Other complications associated with CHIKV, from most common to least common, include respiratory failure, cardiovascular decompensation, meningoencephalitis, severe acute hepatitis, severe cutaneous effects, other central nervous system problems, and kidney failure [6, 18, 20, 23, 24, 26, 27] .", "CHIKV undertakes a complex replication cycle upon host infection (Figure 2 ), which makes its genome susceptible to mutations [28, 29] . For instance, Ae. aegypti, responsible for epidemics in Kenya, Comoros, and Seychelles, carried CHIKV with an alanine in the 226 position of the E1 gene (E1-A226) [4, 18] . However, when the virus struck La Reunion Islands, a decline in population of Ae. aegypti, due to massive dichlorodiphenyltrichloroethane usage and dearth of Ae. albopictus species' www.plosntds.org population, resulted in an ecological pressure, favoring replacement of alanine at position 226 with valine (E1-A226V) [5] . This mutation allowed CHIKV's secondary vector species, Ae. albopictus, to supplement Ae. aegypti as its primary vector [5] .", "Within a year, the E1-A226V mutation was present in La Reunion Island, and Ae. albopictus apparently vectored the large epidemic infecting 34% of La Reunion Island's population [5] . All of the CHIKV strains isolated from Mayotte carried the E1-A226V mutation, and the mutation was also found in Madagascar in 2007 [5] . The E1-A226V mutation was not present at the beginning of the Indian Ocean Islands outbreak (before September 2005). However, more than 90% of later viral strains found there had incorporated the mutation (December-March 2006), indicating a genotype switch during the winter season [5, 18, 20] .", "The E1-A226V mutation also enabled an increase in infectivity of Ae. albopictus when compared to its infectivity of Ae. aegypti [4, 11, 18, 30] , and with several factors taken together, Ae. albopictus has become the new preferred and more lethal vector for CHIKV [4, 5, 11] . In fact, Tsetsarkin et al. found that a Green Fluorescent Protein tagged E1-A226V virus was 100 times more infective to Ae. albopictus than it was to Ae. aegypti [4] . In all the Indian Ocean Islands, Ae. albopictus became the main vector for CHIKV within 1-2 y after CHIKV was introduced to the region [31] .", "Of note is that Ae. aegypti has most likely been established in North America for over 300 y, while Ae. albopictus has been in many areas of the US, since 1985, primarily in Florida [32] and since then has expanded its range in the country. Reiskind et al. set out to determine if Ae. aegypti and Ae. albopictus mosquitoes captured in Florida were susceptible to CHIKV infection by a La Reunion isolate [32] . Each mosquito tested was highly susceptible to infection by a full-length infectious clone of the La Réunion Island isolate, CHIKV LR2006 OPY1 strain. Even though the Ae. albopictus strains were more susceptible to infection, overall ecology and differences in human biting patterns need to be studied further Characteristically, there are two rounds of translation: (+) sense genomic RNA (49S9 = 11.7 kb) acts directly as mRNA and is partially translated (59 end) to produce non-structural proteins (nsp's). These proteins are responsible for replication and formation of a complementary", "(2) strand, the template for further (+) strand synthesis. Subgenomic mRNA (26 S = 4.1 kb) replication occurs through the synthesis of full-length (2) intermediate RNA, which is regulated by nsp4 and p123 precursor in early infection and later by mature nsp's. Translation of the newly synthesized sub-genomic RNA results in production of structural proteins such as Capsid and protein E2-6k-E1 (from 39 end of genome). Assembly occurs at the cell surface, and the envelope is acquired as the virus buds from the cell and release and maturation almost simultaneous occurred. Replication occurs in the cytoplasm and is very rapid (,4 h) [28, 29] . doi:10.1371/journal.pntd.0000623.g002 www.plosntds.org to gain a more accurate understanding of a potential CHIKV epidemic in the US [32] .", "During the 7 d preceding birth, no human mother has been reported to transmit the disease vertically. However, about 50% of newborns delivered while the mother was infected with CHIKV contracted the disease from their mother, despite the method of delivery. Furthermore, there have been instances of CHIKV transmission from mother to fetus causing congenital illness and fetal death [33] .", "During the 2005-2006 La Reunion Island outbreaks, Ramful et al. discovered that mothers could transmit CHIKV to their progeny during the perinatal period (Day 24 to Day +1) [33, 34] , and it is associated with a high degree of morbidity. By mean Day 4 of life, all of the neonates were symptomatic for CHIKV, exhibiting common CHIKF symptoms. Six neonates were confirmed to have contracted CHIKV and developed mengoencephalitis. Of those mothers who, during the La Reunion Island epidemic, were infected long before delivery, only three fetal deaths were reported [12, 33] . Ramful et al. theorized that motherto-child transmission most likely happens transplacentally shortly before delivery [33] . A similar study by Gerardin et al. reported nineteen cases of neonatal infection associated with intrapartum maternal viremia that progressed to develop encephalitis owing to vertical transmission from infected mothers [34] .", "Clinical and epidemiological similarities with dengue fever make CHIKV diagnosis difficult, which may lead physicians to misdiagnose CHIKV as dengue fever; therefore, the incidence of CHIKV may actually be higher than currently believed (Table 1 ) [6, 12, 35] .", "The amount of time elapsed since disease onset is the most critical parameter when choosing a diagnostic test. CHIKV can be detected and isolated by culturing with mosquito cells (C6/36), Vero cells (mammalian), or in mice [26] . However, this method can take at least a week and only achieves a high sensitivity during the viremic phase, which usually only lasts up to 48 h after the bite. Five days post-infection, the viral isolation approach has a low sensitivity but is still the preferred method for detecting the CHIKV strain [12, 26, 31, 35] . RT-PCR on the other hand is a faster and more sensitive method that can be used within the first week of disease onset [26] , and it is currently the most sensitive method for detecting and quantifying viral mRNA [4, 36] .", "Classic serological detection, by assays such as ELISA [37] , immunofluorescence [5, 38] , complement binding, and haemagglutination inhibition [39] , constitutes the second diagnostic tool used for biological diagnosis of CHIKV infection. These proven techniques are useful for detection of Antigen in mosquitoes during epidemiological studies. These assays detect virus-specific IgM and IgG, however the sensitivity and specificity of these assays has been poorly characterized. Viral competence, or the potential of viral infection and transmission, is an important parameter that can be quantified by ELISA, viral culture, and PCR.", "A study by Ng et al. showed biomarkers indicative of severe CHIKV infection [40] . They found decreased levels of RANTES and increased levels of Interleukin-6 (IL-6) and Interleukin-1b (IL-1b) that could be sued for CHIKV detection in patients as indicators of CHIKV-driven cytokine storm. Couderc et al. demonstrate another cytokine, type-I IFN, as a key player in the progression to CHIKV infection [26] . Using an IFN-a/b null mouse model, they demonstrated evidence of muscles, joints, and skin as privileged CHIKV targets, which is consistent with human pathology. Although Ng et al. concluded that RANTES levels were significantly suppressed in severe CHIKF patients [40] , interestingly, an increase in levels of RANTES has been observed in dengue infection [41] . Since the symptoms of CHIKF mimic those of dengue fever, results obtained from this study strongly suggest that RANTES could be a potential distinctive biomarker that differentiates between these two clinically similar", "diseases.", "There are no approved antiviral treatments currently available for CHIKV [1, 3, 12, 42] . Currently, CHIKF is treated symptomatically, usually with non-steroidal anti-inflammatory drugs or steroids, bed rest, and fluids. Movement and mild exercise are thought to decrease stiffness and morning arthralgia, but heavy exercise may exacerbate rheumatic symptoms. Corticosteroids may be used in cases of debilitating chronic CHIKV infection. There is a debate about the appropriateness of chloroquine as treatment for unresolved, non-steroidal anti-inflammatory drugresistant arthritis [43] . A study showed that viral production was www.plosntds.org drastically reduced at 16 h post-infection after treatment with 100 mM dec-RVKR-cmk (Decanoyl-Arg-Val-Lys-Arg-chloromethylketone), a furine inhibitor [42, 44] . Chloroquine acted by raising the pH, blocking low pH-dependent entry of virus into the cell. It is important to note that dec-RVKR-cmk or chloroquine only inhibited viral spreading from cell", "to cell, not CHIKV replication once it had entered the cell [43] . However, most would agree that the best weapon against CHIKV is prevention. A live CHIKV vaccine developed by the United States reached phase II clinical trial encompassing 59 healthy volunteers [45] . Eight percent of the volunteers experienced transient arthralgia, while 98% of the volunteers had seroconversion [45] . However, live CHIKV vaccines are still questionable. One cannot discount the risk of a live vaccine possibly inducing chronic rheumatism. Also, there is the question as to whether widespread use among the public could trigger mosquito transmission or lead to chronic infection or viral reversion [1] .", "An alternative approach would be to produce a chimeric vaccine against CHIKV. Wang et al. developed a chimeric alphavirus vaccine that is uniformly attenuated and does not cause reactogenicity in mice [3] . Three different versions of this vaccine were made using three different backbone vectors: Venezuelan equine encephalitis virus (VEEV) attenuated vaccine strain T-83, naturally attenuated eastern equine encephalitis virus (EEEV), and attenuated Sindbis virus (SINV). In short, CHIKV structural proteins were engineered into the backbones of the aforementioned vaccines to produce the chimeras [3] . These chimeras were found to stimulate a strong humoral immunity, and even at doses of 5.3-5.8 log 10 PFU, they did not trigger reactogenicity. When vaccinated mice were challenged with CHIKV, neither adult nor neonatal mice gained weight, had fever, or displayed signs of neurological illness. Upon comparison of the chimeras with the Army181/25 vaccine, the Army vaccine resulted in higher", "levels of viremia and replication in the joints of neonatal mice. Because the joints are known targets of CHIKV, Wang et al. noted their vaccine might avoid the negative reactogenic side effects of the Army vaccine. After being subcutaneously vaccinated with 5.3-5.8 log 10 PFU of the chimeric vaccines, mice produced strong neutralizing antibody titers. The VEEV and EEEV chimeras yielded higher neutralizing antibody titers than the SINV chimera without being more virulent. On top of this, the VEEV and EEEV CHIKV chimeras seemed to be more immunogenic than the Army vaccine despite the chimeras' lower viremia and replication in the joints of neonatal mice [3] .", "Tiwari et al. [46] adopted a different strategy using formalin inactivated CHIKV in combination with alhydrogel (Aluminum Hydroxide) as an adjuvant. This study clearly suggests that this vaccine elicits both humoral and cell-mediated immune responses in mice, providing its immunogenic potential. A recent study by Couderc et al. [47] showed passive immunization as a potential treatment for CHIKV infection. Using purified immunoglobulin extracted from convalescent CHIKV patients, they demonstrated effective neutralizing activity against CHIKV infection both in vitro and in vivo. This thereby establishes a potential preventive and therapeutic approach to combat CHIKV infection. Pathogenesis studies conducted with related alpha virus, like RRV, have shown the role of macrophages in persistence on infection [48] . They also demonstrated the role of RRV-specific CD8 T cells in clearing viral load in infected patients, thereby warranting similar investigations with CHIKV and the importance", "of investigating a cell-mediated immune response-based vaccine against CHIKV [49] .", "There are always certain risks associated with live attenuated or inactivated viral vaccines [50] . One way to avoid these potential problems is to construct a consensus-based DNA vaccine. DNA based vaccines have an improved safety profile as compared to live or attenuated vaccines [51, 52] . A consequence of CHIKV's rapid evolution is difficulty in constructing a vaccine that will be able to Figure 3 . Levels of CHIKV-specific IgG in mice immunized with CHIKV vaccines. Each group of C57BL/6 mice (n = 5) was immunized with 12.5 mg of pVax1 control vector or CHIKV vaccine plasmids as indicated at 0 and 2 wk. Mice were bled 2 wk after each immunization, and each group's serum pool was diluted to 1:100 and 1:500 for reaction with specific vaccine constructs. Serum was incubated for 1 h at 37uC on 96-well plates coated with 2 mg/ml of respective CHIKV peptides, and antibody was detected using anti-mouse IgG-HRP and OD was measured at 405 nm. doi:10.1371/journal.pntd.0000623.g003", "www.plosntds.org effectively protect large populations from multiple strains of the virus. One of the strengths of DNA consensus vaccines is its ability to induce cross-reactive immune responses against the three distinct phylogenetic groups of CHIKV. Also DNA-based vaccines can be produced more rapidly than protein-based vaccines.", "Recently, Muthumani et al. constructed a vaccine that was shown to induce both humoral and cellular immunity in vivo in 3-4-wk-old female C57/BL6 mice [49] . These mice were immunized using an in vivo electroporation method to deliver the vaccine into the quadriceps muscle. The consensus construct was designed against E1, E2, and the core protein capsid. To design the construct, they aligned 21 sequences of CHIKV isolated between 1952 and 2006, using strains from differing countries, including La Reunion Island. The most common nucleotide among the sequences was chosen at each position to be used in the consensus construct, taking care not to alter the reading frame. They conducted codon and RNA optimization, added a strong Kozak sequence, and substituted signal peptide with an immunoglobulin E leader sequence to improve vaccine efficacy.", "After immunizing the mice, spleens were harvested along with serum and tested to determine antibody titer. After three immunizations, consensus E1, E2, and C vaccines were shown to induce T-cell immune responses leading to strong IFN-c responses and proliferation in C57/BL6 mice. Furthermore, when compared with control mice, immunized mice had higher total IgG levels as well as higher anti-E1 specific, anti-E2 specific, and anti-C specific IgG antibodies, suggesting a strong humoral immune response ( Figure 3 ) and also specificity for the antigens encoded in the vaccine constructs ( Figure 4 ). Because of its promising results and the need for a safer vaccine, this consensus DNA vaccine deserves further investigation. Determining longevity of protective effects of the vaccine and persistence of antibody and IFN-c responses could be the next step of investigation. Challenged studies of immunized mice must also be carried out.", "CHIKV mosquito-borne disease has caused massive outbreaks for at least half a century but is no longer confined to the www.plosntds.org developing nations. It began to encroach into the boundaries of the developing world. As a result, the NIAID has designated CHIKV as a Category C pathogen alongside the influenza and SARS-CoV viruses [3] . Realization of the potential severity of this disease is exigent; for instance, if used as a biological weapon, the world economy could be severely crippled; if enough members of the armed forces were to become infected during a military deployment, military operations could be significantly affected. Efforts to monitor the disease will only provide minimal warning in a global society, and steps to prevent the morbidity and mortality associated with pandemic are imperative [21, 31] . Despite the gravity of its infectious potency and the fear of it being a potential biological weapon, there is currently no vaccine for CHIKV infections. Live", "attenuated vaccine trials were carried out in 2000, but funding for the project was discontinued. Newer approaches such as DNA vaccines appear promising over conventional strategies like live attenuated or inactivated virus and thus call for further investigation. Recent advances such electroporation delivery and incorporation of adjuvants has boosted DNA vaccine efficacy [51, 53] . Despite the low antibody response to DNA vaccines, other numerous advantages have overshadowed these minor drawbacks (Table 2) , the most important one being the ability to induce both humoral and cellular immune responses [51, 54] .", "Judging by recent success, such as the immunogenic construct developed by Muthumani et al., DNA vaccines could play a major role in combating CHIKV [49] . Vaccines are literally a critical component of CHIKV disease control and therefore research in this area is highly encouraged. The dramatic spread of dengue viruses (DENV) throughout tropical America since 1980 via the same vectors and human hosts underscores the risk to public health in the Americas. The adverse events associated with the current live vaccine are well documented [55] . Realizing these drawbacks, earnest efforts should be taken to develop new strategies to forestall further spread and complications." ]	[ 10 ]	3,829	5,688
1,689	What other group is disproportionately affected?	2,505	[ "children" ]	[ "Chikungunya: A Potentially Emerging Epidemic?\n\nhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC2860491/\n\nSHA: f7c3160bef4169d29e2a8bdd79dd6e9056d4774c\n\nAuthors: Thiboutot, Michelle M.; Kannan, Senthil; Kawalekar, Omkar U.; Shedlock, Devon J.; Khan, Amir S.; Sarangan, Gopalsamy; Srikanth, Padma; Weiner, David B.; Muthumani, Karuppiah\nDate: 2010-04-27\nDOI: 10.1371/journal.pntd.0000623\nLicense: cc-by", "Abstract: Chikungunya virus is a mosquito-borne emerging pathogen that has a major health impact in humans and causes fever disease, headache, rash, nausea, vomiting, myalgia, and arthralgia. Indigenous to tropical Africa, recent large outbreaks have been reported in parts of South East Asia and several of its neighboring islands in 2005–07 and in Europe in 2007. Furthermore, positive cases have been confirmed in the United States in travelers returning from known outbreak areas. Currently, there is no vaccine or antiviral treatment. With the threat of an emerging global pandemic, the peculiar problems associated with the more immediate and seasonal epidemics warrant the development of an effective vaccine. In this review, we summarize the evidence supporting these concepts.", "Text: Chikungunya virus (CHIKV), a mosquito-borne pathogen listed by National Institute of Allergy and Infectious Diseases (NIAID) as a Category C Priority Pathogen that causes Chikungunya fever (CHIKF), has been spreading throughout Asia, Africa, and parts of Europe in recent times [1, 2, 3] . CHIKV is an arthropod-borne virus (arbovirus) and is transmitted to humans primarily by Aedes aegypti, the infamous yellow fever propagator [4, 5] . CHIKV infection is marked by severe joint pain, contorting its victims into unusual postures [6] . The disease gets its name from the Kimakonde vernacular language of Tanzania and Mozambique, and the word chikungunya means ''that which contorts or bends up'' and translates in Swahili to ''the illness of the bended walker'' [7, 8, 9] . In Africa, CHIKV is maintained in a sylvatic cycle among forest-dwelling Aedes spp. mosquitoes, wild primates, squirrels, birds, and rodents ( Figure 1 ) [10] . In Asia, the disease is vectored by Ae. aegypti and Ae.", "albopictus [11] . Transmission in Asia occurs in an urban cycle whereby the mosquito spreads the disease from an infected human to an uninfected human, following an epidemiological pattern similar to dengue fever [12] .", "The 2005-2006 epidemic of CHIKV in La Reunion islands in the Indian Ocean, spurred the discovery of a new vector species, Ae. albopictus [5] . Wrecking over one-third of the island's population, this epidemic peaked its devastation between January and February 2006, when over 46,000 cases came into light every week, including 284 deaths [5, 13] . Ae. albopictus is common in urban areas of the United States and is already flourishing in 36 states, raising grave concerns to the immunologically naive populace of the United States [14] .\n\nAccordingly, this review elaborately details the epidemiology and global expansion of CHIKV, describes its clinical features and pathogenesis and its symptoms and complications, and finally nominates a possible vaccine approach against CHIKV infection.", "CHIKV has been isolated into three genotypes based on phylogenetic studies. These genotypes, based on the gene sequences of an Envelope protein (E1), are Asian, East/Central/ South African, and West African [4, 11, 15] . Using phylogenetic models, Cherian et al. estimate that the Asian genotype of CHIKV emerged between 50 and 310 y ago, and the West and East African genotypes diverged between 100 and 840 y ago [15] . Since then, CHIKV has come a long way, with several mutations incorporated, and has continued to wreak epidemics in several regions. Recent activities of CHIKV include the Indian epidemic in 2005-2006, which was followed by a sudden explosion of cases in 2007. An estimated 1.3 million people across 13 states were reported to be infected in India [12, 16] , and CHIKV was also widespread in Malaysia, Sri Lanka, and Indonesia [17] . In July-August of 2007, CHIKV was reported in Italy, probably brought in by travelers from CHIKV-prone regions of India, Africa, and Indian", "Ocean islands such as Mauritius, Madagascar, and Seychelles. Few of the Italian isolates were found to have evolved from the Kerala isolate, which was associated with a A226V shift in E1 gene that represents a successful evolutionary adaptation in the mosquito vector similar to the ones observed in Reunion Island [2, 18, 19] .", "In recent times, with an increase in global travel, the risk for spreading CHIKV to non-endemic regions has heightened [1] . Several travelers have brought CHIKV home with them after visiting areas with actively infected populations [12, 20] . Such cases have been documented in European countries, Australia, Asia, and the United States [8, 21] . The United States has already reported at least twelve cases of travel-associated CHIKV, while France has reported 850 cases, and the United Kingdom 93 [8, 14] . Beyond this, CHIKV-infected travelers have also been diagnosed in Australia, Belgium, Canada, Czech Republic, French Guiana, Germany, Hong Kong, Italy, Japan, Kenya, Malaysia, Martinique, Norway, Switzerland, and Sri Lanka [21] . Some travelers were viremic, worrying public health officials about the spread of CHIKV to new areas [1, 8] .", "The incubation time for CHIKV is relatively short, requiring only 2-6 d with symptoms usually appearing 4-7 d post-infection [22] . Vazeille et al. detected CHIKV in the salivary glands of Ae. albopictus only 2 d after infection [5] . Upon infection, CHIKF tends to present itself in two phases. The first stage is acute, while the second stage, experienced by most but not all, is persistent, causing disabling polyarthritis. Characteristics of the acute phase include an abrupt onset of fever, arthralgia, and in some cases, maculopapular rash [6, 23] . The acute phase causes such intense joint and muscular pain that makes movement very difficult and prostrates its victims [6, 20] .", "Ninety-five percent of infected adults are symptomatic after infection, and of these, most become disabled for weeks to months as a result of decreased dexterity, loss of mobility, and delayed reaction. Eighteen months after disease onset, 40% of patients are found to still have anti-CHIKV IgM [6, 18, 23, 24] . The chronic stage of CHIKF is characterized by polyarthralgia that can last from weeks to years beyond the acute stage [6] . CHIKV has been shown to attack fibroblasts, explaining the involvement of muscles, joints, and skin connective tissues. The high number of nociceptive nerve endings found within the joints and muscle connective tissues can explain pain associated with CHIKF [25, 26] .", "More than 50% of patients who suffer from severe CHIKF are over 65 y old, and more than 33% of them die. Most adults who suffer from severe CHIKF have underlying medical conditions [6, 24, 27] . The other group that is disproportionately affected by severe CHIKV is children. Other complications associated with CHIKV, from most common to least common, include respiratory failure, cardiovascular decompensation, meningoencephalitis, severe acute hepatitis, severe cutaneous effects, other central nervous system problems, and kidney failure [6, 18, 20, 23, 24, 26, 27] .", "CHIKV undertakes a complex replication cycle upon host infection (Figure 2 ), which makes its genome susceptible to mutations [28, 29] . For instance, Ae. aegypti, responsible for epidemics in Kenya, Comoros, and Seychelles, carried CHIKV with an alanine in the 226 position of the E1 gene (E1-A226) [4, 18] . However, when the virus struck La Reunion Islands, a decline in population of Ae. aegypti, due to massive dichlorodiphenyltrichloroethane usage and dearth of Ae. albopictus species' www.plosntds.org population, resulted in an ecological pressure, favoring replacement of alanine at position 226 with valine (E1-A226V) [5] . This mutation allowed CHIKV's secondary vector species, Ae. albopictus, to supplement Ae. aegypti as its primary vector [5] .", "Within a year, the E1-A226V mutation was present in La Reunion Island, and Ae. albopictus apparently vectored the large epidemic infecting 34% of La Reunion Island's population [5] . All of the CHIKV strains isolated from Mayotte carried the E1-A226V mutation, and the mutation was also found in Madagascar in 2007 [5] . The E1-A226V mutation was not present at the beginning of the Indian Ocean Islands outbreak (before September 2005). However, more than 90% of later viral strains found there had incorporated the mutation (December-March 2006), indicating a genotype switch during the winter season [5, 18, 20] .", "The E1-A226V mutation also enabled an increase in infectivity of Ae. albopictus when compared to its infectivity of Ae. aegypti [4, 11, 18, 30] , and with several factors taken together, Ae. albopictus has become the new preferred and more lethal vector for CHIKV [4, 5, 11] . In fact, Tsetsarkin et al. found that a Green Fluorescent Protein tagged E1-A226V virus was 100 times more infective to Ae. albopictus than it was to Ae. aegypti [4] . In all the Indian Ocean Islands, Ae. albopictus became the main vector for CHIKV within 1-2 y after CHIKV was introduced to the region [31] .", "Of note is that Ae. aegypti has most likely been established in North America for over 300 y, while Ae. albopictus has been in many areas of the US, since 1985, primarily in Florida [32] and since then has expanded its range in the country. Reiskind et al. set out to determine if Ae. aegypti and Ae. albopictus mosquitoes captured in Florida were susceptible to CHIKV infection by a La Reunion isolate [32] . Each mosquito tested was highly susceptible to infection by a full-length infectious clone of the La Réunion Island isolate, CHIKV LR2006 OPY1 strain. Even though the Ae. albopictus strains were more susceptible to infection, overall ecology and differences in human biting patterns need to be studied further Characteristically, there are two rounds of translation: (+) sense genomic RNA (49S9 = 11.7 kb) acts directly as mRNA and is partially translated (59 end) to produce non-structural proteins (nsp's). These proteins are responsible for replication and formation of a complementary", "(2) strand, the template for further (+) strand synthesis. Subgenomic mRNA (26 S = 4.1 kb) replication occurs through the synthesis of full-length (2) intermediate RNA, which is regulated by nsp4 and p123 precursor in early infection and later by mature nsp's. Translation of the newly synthesized sub-genomic RNA results in production of structural proteins such as Capsid and protein E2-6k-E1 (from 39 end of genome). Assembly occurs at the cell surface, and the envelope is acquired as the virus buds from the cell and release and maturation almost simultaneous occurred. Replication occurs in the cytoplasm and is very rapid (,4 h) [28, 29] . doi:10.1371/journal.pntd.0000623.g002 www.plosntds.org to gain a more accurate understanding of a potential CHIKV epidemic in the US [32] .", "During the 7 d preceding birth, no human mother has been reported to transmit the disease vertically. However, about 50% of newborns delivered while the mother was infected with CHIKV contracted the disease from their mother, despite the method of delivery. Furthermore, there have been instances of CHIKV transmission from mother to fetus causing congenital illness and fetal death [33] .", "During the 2005-2006 La Reunion Island outbreaks, Ramful et al. discovered that mothers could transmit CHIKV to their progeny during the perinatal period (Day 24 to Day +1) [33, 34] , and it is associated with a high degree of morbidity. By mean Day 4 of life, all of the neonates were symptomatic for CHIKV, exhibiting common CHIKF symptoms. Six neonates were confirmed to have contracted CHIKV and developed mengoencephalitis. Of those mothers who, during the La Reunion Island epidemic, were infected long before delivery, only three fetal deaths were reported [12, 33] . Ramful et al. theorized that motherto-child transmission most likely happens transplacentally shortly before delivery [33] . A similar study by Gerardin et al. reported nineteen cases of neonatal infection associated with intrapartum maternal viremia that progressed to develop encephalitis owing to vertical transmission from infected mothers [34] .", "Clinical and epidemiological similarities with dengue fever make CHIKV diagnosis difficult, which may lead physicians to misdiagnose CHIKV as dengue fever; therefore, the incidence of CHIKV may actually be higher than currently believed (Table 1 ) [6, 12, 35] .", "The amount of time elapsed since disease onset is the most critical parameter when choosing a diagnostic test. CHIKV can be detected and isolated by culturing with mosquito cells (C6/36), Vero cells (mammalian), or in mice [26] . However, this method can take at least a week and only achieves a high sensitivity during the viremic phase, which usually only lasts up to 48 h after the bite. Five days post-infection, the viral isolation approach has a low sensitivity but is still the preferred method for detecting the CHIKV strain [12, 26, 31, 35] . RT-PCR on the other hand is a faster and more sensitive method that can be used within the first week of disease onset [26] , and it is currently the most sensitive method for detecting and quantifying viral mRNA [4, 36] .", "Classic serological detection, by assays such as ELISA [37] , immunofluorescence [5, 38] , complement binding, and haemagglutination inhibition [39] , constitutes the second diagnostic tool used for biological diagnosis of CHIKV infection. These proven techniques are useful for detection of Antigen in mosquitoes during epidemiological studies. These assays detect virus-specific IgM and IgG, however the sensitivity and specificity of these assays has been poorly characterized. Viral competence, or the potential of viral infection and transmission, is an important parameter that can be quantified by ELISA, viral culture, and PCR.", "A study by Ng et al. showed biomarkers indicative of severe CHIKV infection [40] . They found decreased levels of RANTES and increased levels of Interleukin-6 (IL-6) and Interleukin-1b (IL-1b) that could be sued for CHIKV detection in patients as indicators of CHIKV-driven cytokine storm. Couderc et al. demonstrate another cytokine, type-I IFN, as a key player in the progression to CHIKV infection [26] . Using an IFN-a/b null mouse model, they demonstrated evidence of muscles, joints, and skin as privileged CHIKV targets, which is consistent with human pathology. Although Ng et al. concluded that RANTES levels were significantly suppressed in severe CHIKF patients [40] , interestingly, an increase in levels of RANTES has been observed in dengue infection [41] . Since the symptoms of CHIKF mimic those of dengue fever, results obtained from this study strongly suggest that RANTES could be a potential distinctive biomarker that differentiates between these two clinically similar", "diseases.", "There are no approved antiviral treatments currently available for CHIKV [1, 3, 12, 42] . Currently, CHIKF is treated symptomatically, usually with non-steroidal anti-inflammatory drugs or steroids, bed rest, and fluids. Movement and mild exercise are thought to decrease stiffness and morning arthralgia, but heavy exercise may exacerbate rheumatic symptoms. Corticosteroids may be used in cases of debilitating chronic CHIKV infection. There is a debate about the appropriateness of chloroquine as treatment for unresolved, non-steroidal anti-inflammatory drugresistant arthritis [43] . A study showed that viral production was www.plosntds.org drastically reduced at 16 h post-infection after treatment with 100 mM dec-RVKR-cmk (Decanoyl-Arg-Val-Lys-Arg-chloromethylketone), a furine inhibitor [42, 44] . Chloroquine acted by raising the pH, blocking low pH-dependent entry of virus into the cell. It is important to note that dec-RVKR-cmk or chloroquine only inhibited viral spreading from cell", "to cell, not CHIKV replication once it had entered the cell [43] . However, most would agree that the best weapon against CHIKV is prevention. A live CHIKV vaccine developed by the United States reached phase II clinical trial encompassing 59 healthy volunteers [45] . Eight percent of the volunteers experienced transient arthralgia, while 98% of the volunteers had seroconversion [45] . However, live CHIKV vaccines are still questionable. One cannot discount the risk of a live vaccine possibly inducing chronic rheumatism. Also, there is the question as to whether widespread use among the public could trigger mosquito transmission or lead to chronic infection or viral reversion [1] .", "An alternative approach would be to produce a chimeric vaccine against CHIKV. Wang et al. developed a chimeric alphavirus vaccine that is uniformly attenuated and does not cause reactogenicity in mice [3] . Three different versions of this vaccine were made using three different backbone vectors: Venezuelan equine encephalitis virus (VEEV) attenuated vaccine strain T-83, naturally attenuated eastern equine encephalitis virus (EEEV), and attenuated Sindbis virus (SINV). In short, CHIKV structural proteins were engineered into the backbones of the aforementioned vaccines to produce the chimeras [3] . These chimeras were found to stimulate a strong humoral immunity, and even at doses of 5.3-5.8 log 10 PFU, they did not trigger reactogenicity. When vaccinated mice were challenged with CHIKV, neither adult nor neonatal mice gained weight, had fever, or displayed signs of neurological illness. Upon comparison of the chimeras with the Army181/25 vaccine, the Army vaccine resulted in higher", "levels of viremia and replication in the joints of neonatal mice. Because the joints are known targets of CHIKV, Wang et al. noted their vaccine might avoid the negative reactogenic side effects of the Army vaccine. After being subcutaneously vaccinated with 5.3-5.8 log 10 PFU of the chimeric vaccines, mice produced strong neutralizing antibody titers. The VEEV and EEEV chimeras yielded higher neutralizing antibody titers than the SINV chimera without being more virulent. On top of this, the VEEV and EEEV CHIKV chimeras seemed to be more immunogenic than the Army vaccine despite the chimeras' lower viremia and replication in the joints of neonatal mice [3] .", "Tiwari et al. [46] adopted a different strategy using formalin inactivated CHIKV in combination with alhydrogel (Aluminum Hydroxide) as an adjuvant. This study clearly suggests that this vaccine elicits both humoral and cell-mediated immune responses in mice, providing its immunogenic potential. A recent study by Couderc et al. [47] showed passive immunization as a potential treatment for CHIKV infection. Using purified immunoglobulin extracted from convalescent CHIKV patients, they demonstrated effective neutralizing activity against CHIKV infection both in vitro and in vivo. This thereby establishes a potential preventive and therapeutic approach to combat CHIKV infection. Pathogenesis studies conducted with related alpha virus, like RRV, have shown the role of macrophages in persistence on infection [48] . They also demonstrated the role of RRV-specific CD8 T cells in clearing viral load in infected patients, thereby warranting similar investigations with CHIKV and the importance", "of investigating a cell-mediated immune response-based vaccine against CHIKV [49] .", "There are always certain risks associated with live attenuated or inactivated viral vaccines [50] . One way to avoid these potential problems is to construct a consensus-based DNA vaccine. DNA based vaccines have an improved safety profile as compared to live or attenuated vaccines [51, 52] . A consequence of CHIKV's rapid evolution is difficulty in constructing a vaccine that will be able to Figure 3 . Levels of CHIKV-specific IgG in mice immunized with CHIKV vaccines. Each group of C57BL/6 mice (n = 5) was immunized with 12.5 mg of pVax1 control vector or CHIKV vaccine plasmids as indicated at 0 and 2 wk. Mice were bled 2 wk after each immunization, and each group's serum pool was diluted to 1:100 and 1:500 for reaction with specific vaccine constructs. Serum was incubated for 1 h at 37uC on 96-well plates coated with 2 mg/ml of respective CHIKV peptides, and antibody was detected using anti-mouse IgG-HRP and OD was measured at 405 nm. doi:10.1371/journal.pntd.0000623.g003", "www.plosntds.org effectively protect large populations from multiple strains of the virus. One of the strengths of DNA consensus vaccines is its ability to induce cross-reactive immune responses against the three distinct phylogenetic groups of CHIKV. Also DNA-based vaccines can be produced more rapidly than protein-based vaccines.", "Recently, Muthumani et al. constructed a vaccine that was shown to induce both humoral and cellular immunity in vivo in 3-4-wk-old female C57/BL6 mice [49] . These mice were immunized using an in vivo electroporation method to deliver the vaccine into the quadriceps muscle. The consensus construct was designed against E1, E2, and the core protein capsid. To design the construct, they aligned 21 sequences of CHIKV isolated between 1952 and 2006, using strains from differing countries, including La Reunion Island. The most common nucleotide among the sequences was chosen at each position to be used in the consensus construct, taking care not to alter the reading frame. They conducted codon and RNA optimization, added a strong Kozak sequence, and substituted signal peptide with an immunoglobulin E leader sequence to improve vaccine efficacy.", "After immunizing the mice, spleens were harvested along with serum and tested to determine antibody titer. After three immunizations, consensus E1, E2, and C vaccines were shown to induce T-cell immune responses leading to strong IFN-c responses and proliferation in C57/BL6 mice. Furthermore, when compared with control mice, immunized mice had higher total IgG levels as well as higher anti-E1 specific, anti-E2 specific, and anti-C specific IgG antibodies, suggesting a strong humoral immune response ( Figure 3 ) and also specificity for the antigens encoded in the vaccine constructs ( Figure 4 ). Because of its promising results and the need for a safer vaccine, this consensus DNA vaccine deserves further investigation. Determining longevity of protective effects of the vaccine and persistence of antibody and IFN-c responses could be the next step of investigation. Challenged studies of immunized mice must also be carried out.", "CHIKV mosquito-borne disease has caused massive outbreaks for at least half a century but is no longer confined to the www.plosntds.org developing nations. It began to encroach into the boundaries of the developing world. As a result, the NIAID has designated CHIKV as a Category C pathogen alongside the influenza and SARS-CoV viruses [3] . Realization of the potential severity of this disease is exigent; for instance, if used as a biological weapon, the world economy could be severely crippled; if enough members of the armed forces were to become infected during a military deployment, military operations could be significantly affected. Efforts to monitor the disease will only provide minimal warning in a global society, and steps to prevent the morbidity and mortality associated with pandemic are imperative [21, 31] . Despite the gravity of its infectious potency and the fear of it being a potential biological weapon, there is currently no vaccine for CHIKV infections. Live", "attenuated vaccine trials were carried out in 2000, but funding for the project was discontinued. Newer approaches such as DNA vaccines appear promising over conventional strategies like live attenuated or inactivated virus and thus call for further investigation. Recent advances such electroporation delivery and incorporation of adjuvants has boosted DNA vaccine efficacy [51, 53] . Despite the low antibody response to DNA vaccines, other numerous advantages have overshadowed these minor drawbacks (Table 2) , the most important one being the ability to induce both humoral and cellular immune responses [51, 54] .", "Judging by recent success, such as the immunogenic construct developed by Muthumani et al., DNA vaccines could play a major role in combating CHIKV [49] . Vaccines are literally a critical component of CHIKV disease control and therefore research in this area is highly encouraged. The dramatic spread of dengue viruses (DENV) throughout tropical America since 1980 via the same vectors and human hosts underscores the risk to public health in the Americas. The adverse events associated with the current live vaccine are well documented [55] . Realizing these drawbacks, earnest efforts should be taken to develop new strategies to forestall further spread and complications." ]	[ 10 ]	3,829	5,688
1,689	What complications are associated with CHIKV?	2,506	[ "from most common to least common, include respiratory failure, cardiovascular decompensation, meningoencephalitis, severe acute hepatitis, severe cutaneous effects, other central nervous system problems, and kidney failure" ]	[ "Chikungunya: A Potentially Emerging Epidemic?\n\nhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC2860491/\n\nSHA: f7c3160bef4169d29e2a8bdd79dd6e9056d4774c\n\nAuthors: Thiboutot, Michelle M.; Kannan, Senthil; Kawalekar, Omkar U.; Shedlock, Devon J.; Khan, Amir S.; Sarangan, Gopalsamy; Srikanth, Padma; Weiner, David B.; Muthumani, Karuppiah\nDate: 2010-04-27\nDOI: 10.1371/journal.pntd.0000623\nLicense: cc-by", "Abstract: Chikungunya virus is a mosquito-borne emerging pathogen that has a major health impact in humans and causes fever disease, headache, rash, nausea, vomiting, myalgia, and arthralgia. Indigenous to tropical Africa, recent large outbreaks have been reported in parts of South East Asia and several of its neighboring islands in 2005–07 and in Europe in 2007. Furthermore, positive cases have been confirmed in the United States in travelers returning from known outbreak areas. Currently, there is no vaccine or antiviral treatment. With the threat of an emerging global pandemic, the peculiar problems associated with the more immediate and seasonal epidemics warrant the development of an effective vaccine. In this review, we summarize the evidence supporting these concepts.", "Text: Chikungunya virus (CHIKV), a mosquito-borne pathogen listed by National Institute of Allergy and Infectious Diseases (NIAID) as a Category C Priority Pathogen that causes Chikungunya fever (CHIKF), has been spreading throughout Asia, Africa, and parts of Europe in recent times [1, 2, 3] . CHIKV is an arthropod-borne virus (arbovirus) and is transmitted to humans primarily by Aedes aegypti, the infamous yellow fever propagator [4, 5] . CHIKV infection is marked by severe joint pain, contorting its victims into unusual postures [6] . The disease gets its name from the Kimakonde vernacular language of Tanzania and Mozambique, and the word chikungunya means ''that which contorts or bends up'' and translates in Swahili to ''the illness of the bended walker'' [7, 8, 9] . In Africa, CHIKV is maintained in a sylvatic cycle among forest-dwelling Aedes spp. mosquitoes, wild primates, squirrels, birds, and rodents ( Figure 1 ) [10] . In Asia, the disease is vectored by Ae. aegypti and Ae.", "albopictus [11] . Transmission in Asia occurs in an urban cycle whereby the mosquito spreads the disease from an infected human to an uninfected human, following an epidemiological pattern similar to dengue fever [12] .", "The 2005-2006 epidemic of CHIKV in La Reunion islands in the Indian Ocean, spurred the discovery of a new vector species, Ae. albopictus [5] . Wrecking over one-third of the island's population, this epidemic peaked its devastation between January and February 2006, when over 46,000 cases came into light every week, including 284 deaths [5, 13] . Ae. albopictus is common in urban areas of the United States and is already flourishing in 36 states, raising grave concerns to the immunologically naive populace of the United States [14] .\n\nAccordingly, this review elaborately details the epidemiology and global expansion of CHIKV, describes its clinical features and pathogenesis and its symptoms and complications, and finally nominates a possible vaccine approach against CHIKV infection.", "CHIKV has been isolated into three genotypes based on phylogenetic studies. These genotypes, based on the gene sequences of an Envelope protein (E1), are Asian, East/Central/ South African, and West African [4, 11, 15] . Using phylogenetic models, Cherian et al. estimate that the Asian genotype of CHIKV emerged between 50 and 310 y ago, and the West and East African genotypes diverged between 100 and 840 y ago [15] . Since then, CHIKV has come a long way, with several mutations incorporated, and has continued to wreak epidemics in several regions. Recent activities of CHIKV include the Indian epidemic in 2005-2006, which was followed by a sudden explosion of cases in 2007. An estimated 1.3 million people across 13 states were reported to be infected in India [12, 16] , and CHIKV was also widespread in Malaysia, Sri Lanka, and Indonesia [17] . In July-August of 2007, CHIKV was reported in Italy, probably brought in by travelers from CHIKV-prone regions of India, Africa, and Indian", "Ocean islands such as Mauritius, Madagascar, and Seychelles. Few of the Italian isolates were found to have evolved from the Kerala isolate, which was associated with a A226V shift in E1 gene that represents a successful evolutionary adaptation in the mosquito vector similar to the ones observed in Reunion Island [2, 18, 19] .", "In recent times, with an increase in global travel, the risk for spreading CHIKV to non-endemic regions has heightened [1] . Several travelers have brought CHIKV home with them after visiting areas with actively infected populations [12, 20] . Such cases have been documented in European countries, Australia, Asia, and the United States [8, 21] . The United States has already reported at least twelve cases of travel-associated CHIKV, while France has reported 850 cases, and the United Kingdom 93 [8, 14] . Beyond this, CHIKV-infected travelers have also been diagnosed in Australia, Belgium, Canada, Czech Republic, French Guiana, Germany, Hong Kong, Italy, Japan, Kenya, Malaysia, Martinique, Norway, Switzerland, and Sri Lanka [21] . Some travelers were viremic, worrying public health officials about the spread of CHIKV to new areas [1, 8] .", "The incubation time for CHIKV is relatively short, requiring only 2-6 d with symptoms usually appearing 4-7 d post-infection [22] . Vazeille et al. detected CHIKV in the salivary glands of Ae. albopictus only 2 d after infection [5] . Upon infection, CHIKF tends to present itself in two phases. The first stage is acute, while the second stage, experienced by most but not all, is persistent, causing disabling polyarthritis. Characteristics of the acute phase include an abrupt onset of fever, arthralgia, and in some cases, maculopapular rash [6, 23] . The acute phase causes such intense joint and muscular pain that makes movement very difficult and prostrates its victims [6, 20] .", "Ninety-five percent of infected adults are symptomatic after infection, and of these, most become disabled for weeks to months as a result of decreased dexterity, loss of mobility, and delayed reaction. Eighteen months after disease onset, 40% of patients are found to still have anti-CHIKV IgM [6, 18, 23, 24] . The chronic stage of CHIKF is characterized by polyarthralgia that can last from weeks to years beyond the acute stage [6] . CHIKV has been shown to attack fibroblasts, explaining the involvement of muscles, joints, and skin connective tissues. The high number of nociceptive nerve endings found within the joints and muscle connective tissues can explain pain associated with CHIKF [25, 26] .", "More than 50% of patients who suffer from severe CHIKF are over 65 y old, and more than 33% of them die. Most adults who suffer from severe CHIKF have underlying medical conditions [6, 24, 27] . The other group that is disproportionately affected by severe CHIKV is children. Other complications associated with CHIKV, from most common to least common, include respiratory failure, cardiovascular decompensation, meningoencephalitis, severe acute hepatitis, severe cutaneous effects, other central nervous system problems, and kidney failure [6, 18, 20, 23, 24, 26, 27] .", "CHIKV undertakes a complex replication cycle upon host infection (Figure 2 ), which makes its genome susceptible to mutations [28, 29] . For instance, Ae. aegypti, responsible for epidemics in Kenya, Comoros, and Seychelles, carried CHIKV with an alanine in the 226 position of the E1 gene (E1-A226) [4, 18] . However, when the virus struck La Reunion Islands, a decline in population of Ae. aegypti, due to massive dichlorodiphenyltrichloroethane usage and dearth of Ae. albopictus species' www.plosntds.org population, resulted in an ecological pressure, favoring replacement of alanine at position 226 with valine (E1-A226V) [5] . This mutation allowed CHIKV's secondary vector species, Ae. albopictus, to supplement Ae. aegypti as its primary vector [5] .", "Within a year, the E1-A226V mutation was present in La Reunion Island, and Ae. albopictus apparently vectored the large epidemic infecting 34% of La Reunion Island's population [5] . All of the CHIKV strains isolated from Mayotte carried the E1-A226V mutation, and the mutation was also found in Madagascar in 2007 [5] . The E1-A226V mutation was not present at the beginning of the Indian Ocean Islands outbreak (before September 2005). However, more than 90% of later viral strains found there had incorporated the mutation (December-March 2006), indicating a genotype switch during the winter season [5, 18, 20] .", "The E1-A226V mutation also enabled an increase in infectivity of Ae. albopictus when compared to its infectivity of Ae. aegypti [4, 11, 18, 30] , and with several factors taken together, Ae. albopictus has become the new preferred and more lethal vector for CHIKV [4, 5, 11] . In fact, Tsetsarkin et al. found that a Green Fluorescent Protein tagged E1-A226V virus was 100 times more infective to Ae. albopictus than it was to Ae. aegypti [4] . In all the Indian Ocean Islands, Ae. albopictus became the main vector for CHIKV within 1-2 y after CHIKV was introduced to the region [31] .", "Of note is that Ae. aegypti has most likely been established in North America for over 300 y, while Ae. albopictus has been in many areas of the US, since 1985, primarily in Florida [32] and since then has expanded its range in the country. Reiskind et al. set out to determine if Ae. aegypti and Ae. albopictus mosquitoes captured in Florida were susceptible to CHIKV infection by a La Reunion isolate [32] . Each mosquito tested was highly susceptible to infection by a full-length infectious clone of the La Réunion Island isolate, CHIKV LR2006 OPY1 strain. Even though the Ae. albopictus strains were more susceptible to infection, overall ecology and differences in human biting patterns need to be studied further Characteristically, there are two rounds of translation: (+) sense genomic RNA (49S9 = 11.7 kb) acts directly as mRNA and is partially translated (59 end) to produce non-structural proteins (nsp's). These proteins are responsible for replication and formation of a complementary", "(2) strand, the template for further (+) strand synthesis. Subgenomic mRNA (26 S = 4.1 kb) replication occurs through the synthesis of full-length (2) intermediate RNA, which is regulated by nsp4 and p123 precursor in early infection and later by mature nsp's. Translation of the newly synthesized sub-genomic RNA results in production of structural proteins such as Capsid and protein E2-6k-E1 (from 39 end of genome). Assembly occurs at the cell surface, and the envelope is acquired as the virus buds from the cell and release and maturation almost simultaneous occurred. Replication occurs in the cytoplasm and is very rapid (,4 h) [28, 29] . doi:10.1371/journal.pntd.0000623.g002 www.plosntds.org to gain a more accurate understanding of a potential CHIKV epidemic in the US [32] .", "During the 7 d preceding birth, no human mother has been reported to transmit the disease vertically. However, about 50% of newborns delivered while the mother was infected with CHIKV contracted the disease from their mother, despite the method of delivery. Furthermore, there have been instances of CHIKV transmission from mother to fetus causing congenital illness and fetal death [33] .", "During the 2005-2006 La Reunion Island outbreaks, Ramful et al. discovered that mothers could transmit CHIKV to their progeny during the perinatal period (Day 24 to Day +1) [33, 34] , and it is associated with a high degree of morbidity. By mean Day 4 of life, all of the neonates were symptomatic for CHIKV, exhibiting common CHIKF symptoms. Six neonates were confirmed to have contracted CHIKV and developed mengoencephalitis. Of those mothers who, during the La Reunion Island epidemic, were infected long before delivery, only three fetal deaths were reported [12, 33] . Ramful et al. theorized that motherto-child transmission most likely happens transplacentally shortly before delivery [33] . A similar study by Gerardin et al. reported nineteen cases of neonatal infection associated with intrapartum maternal viremia that progressed to develop encephalitis owing to vertical transmission from infected mothers [34] .", "Clinical and epidemiological similarities with dengue fever make CHIKV diagnosis difficult, which may lead physicians to misdiagnose CHIKV as dengue fever; therefore, the incidence of CHIKV may actually be higher than currently believed (Table 1 ) [6, 12, 35] .", "The amount of time elapsed since disease onset is the most critical parameter when choosing a diagnostic test. CHIKV can be detected and isolated by culturing with mosquito cells (C6/36), Vero cells (mammalian), or in mice [26] . However, this method can take at least a week and only achieves a high sensitivity during the viremic phase, which usually only lasts up to 48 h after the bite. Five days post-infection, the viral isolation approach has a low sensitivity but is still the preferred method for detecting the CHIKV strain [12, 26, 31, 35] . RT-PCR on the other hand is a faster and more sensitive method that can be used within the first week of disease onset [26] , and it is currently the most sensitive method for detecting and quantifying viral mRNA [4, 36] .", "Classic serological detection, by assays such as ELISA [37] , immunofluorescence [5, 38] , complement binding, and haemagglutination inhibition [39] , constitutes the second diagnostic tool used for biological diagnosis of CHIKV infection. These proven techniques are useful for detection of Antigen in mosquitoes during epidemiological studies. These assays detect virus-specific IgM and IgG, however the sensitivity and specificity of these assays has been poorly characterized. Viral competence, or the potential of viral infection and transmission, is an important parameter that can be quantified by ELISA, viral culture, and PCR.", "A study by Ng et al. showed biomarkers indicative of severe CHIKV infection [40] . They found decreased levels of RANTES and increased levels of Interleukin-6 (IL-6) and Interleukin-1b (IL-1b) that could be sued for CHIKV detection in patients as indicators of CHIKV-driven cytokine storm. Couderc et al. demonstrate another cytokine, type-I IFN, as a key player in the progression to CHIKV infection [26] . Using an IFN-a/b null mouse model, they demonstrated evidence of muscles, joints, and skin as privileged CHIKV targets, which is consistent with human pathology. Although Ng et al. concluded that RANTES levels were significantly suppressed in severe CHIKF patients [40] , interestingly, an increase in levels of RANTES has been observed in dengue infection [41] . Since the symptoms of CHIKF mimic those of dengue fever, results obtained from this study strongly suggest that RANTES could be a potential distinctive biomarker that differentiates between these two clinically similar", "diseases.", "There are no approved antiviral treatments currently available for CHIKV [1, 3, 12, 42] . Currently, CHIKF is treated symptomatically, usually with non-steroidal anti-inflammatory drugs or steroids, bed rest, and fluids. Movement and mild exercise are thought to decrease stiffness and morning arthralgia, but heavy exercise may exacerbate rheumatic symptoms. Corticosteroids may be used in cases of debilitating chronic CHIKV infection. There is a debate about the appropriateness of chloroquine as treatment for unresolved, non-steroidal anti-inflammatory drugresistant arthritis [43] . A study showed that viral production was www.plosntds.org drastically reduced at 16 h post-infection after treatment with 100 mM dec-RVKR-cmk (Decanoyl-Arg-Val-Lys-Arg-chloromethylketone), a furine inhibitor [42, 44] . Chloroquine acted by raising the pH, blocking low pH-dependent entry of virus into the cell. It is important to note that dec-RVKR-cmk or chloroquine only inhibited viral spreading from cell", "to cell, not CHIKV replication once it had entered the cell [43] . However, most would agree that the best weapon against CHIKV is prevention. A live CHIKV vaccine developed by the United States reached phase II clinical trial encompassing 59 healthy volunteers [45] . Eight percent of the volunteers experienced transient arthralgia, while 98% of the volunteers had seroconversion [45] . However, live CHIKV vaccines are still questionable. One cannot discount the risk of a live vaccine possibly inducing chronic rheumatism. Also, there is the question as to whether widespread use among the public could trigger mosquito transmission or lead to chronic infection or viral reversion [1] .", "An alternative approach would be to produce a chimeric vaccine against CHIKV. Wang et al. developed a chimeric alphavirus vaccine that is uniformly attenuated and does not cause reactogenicity in mice [3] . Three different versions of this vaccine were made using three different backbone vectors: Venezuelan equine encephalitis virus (VEEV) attenuated vaccine strain T-83, naturally attenuated eastern equine encephalitis virus (EEEV), and attenuated Sindbis virus (SINV). In short, CHIKV structural proteins were engineered into the backbones of the aforementioned vaccines to produce the chimeras [3] . These chimeras were found to stimulate a strong humoral immunity, and even at doses of 5.3-5.8 log 10 PFU, they did not trigger reactogenicity. When vaccinated mice were challenged with CHIKV, neither adult nor neonatal mice gained weight, had fever, or displayed signs of neurological illness. Upon comparison of the chimeras with the Army181/25 vaccine, the Army vaccine resulted in higher", "levels of viremia and replication in the joints of neonatal mice. Because the joints are known targets of CHIKV, Wang et al. noted their vaccine might avoid the negative reactogenic side effects of the Army vaccine. After being subcutaneously vaccinated with 5.3-5.8 log 10 PFU of the chimeric vaccines, mice produced strong neutralizing antibody titers. The VEEV and EEEV chimeras yielded higher neutralizing antibody titers than the SINV chimera without being more virulent. On top of this, the VEEV and EEEV CHIKV chimeras seemed to be more immunogenic than the Army vaccine despite the chimeras' lower viremia and replication in the joints of neonatal mice [3] .", "Tiwari et al. [46] adopted a different strategy using formalin inactivated CHIKV in combination with alhydrogel (Aluminum Hydroxide) as an adjuvant. This study clearly suggests that this vaccine elicits both humoral and cell-mediated immune responses in mice, providing its immunogenic potential. A recent study by Couderc et al. [47] showed passive immunization as a potential treatment for CHIKV infection. Using purified immunoglobulin extracted from convalescent CHIKV patients, they demonstrated effective neutralizing activity against CHIKV infection both in vitro and in vivo. This thereby establishes a potential preventive and therapeutic approach to combat CHIKV infection. Pathogenesis studies conducted with related alpha virus, like RRV, have shown the role of macrophages in persistence on infection [48] . They also demonstrated the role of RRV-specific CD8 T cells in clearing viral load in infected patients, thereby warranting similar investigations with CHIKV and the importance", "of investigating a cell-mediated immune response-based vaccine against CHIKV [49] .", "There are always certain risks associated with live attenuated or inactivated viral vaccines [50] . One way to avoid these potential problems is to construct a consensus-based DNA vaccine. DNA based vaccines have an improved safety profile as compared to live or attenuated vaccines [51, 52] . A consequence of CHIKV's rapid evolution is difficulty in constructing a vaccine that will be able to Figure 3 . Levels of CHIKV-specific IgG in mice immunized with CHIKV vaccines. Each group of C57BL/6 mice (n = 5) was immunized with 12.5 mg of pVax1 control vector or CHIKV vaccine plasmids as indicated at 0 and 2 wk. Mice were bled 2 wk after each immunization, and each group's serum pool was diluted to 1:100 and 1:500 for reaction with specific vaccine constructs. Serum was incubated for 1 h at 37uC on 96-well plates coated with 2 mg/ml of respective CHIKV peptides, and antibody was detected using anti-mouse IgG-HRP and OD was measured at 405 nm. doi:10.1371/journal.pntd.0000623.g003", "www.plosntds.org effectively protect large populations from multiple strains of the virus. One of the strengths of DNA consensus vaccines is its ability to induce cross-reactive immune responses against the three distinct phylogenetic groups of CHIKV. Also DNA-based vaccines can be produced more rapidly than protein-based vaccines.", "Recently, Muthumani et al. constructed a vaccine that was shown to induce both humoral and cellular immunity in vivo in 3-4-wk-old female C57/BL6 mice [49] . These mice were immunized using an in vivo electroporation method to deliver the vaccine into the quadriceps muscle. The consensus construct was designed against E1, E2, and the core protein capsid. To design the construct, they aligned 21 sequences of CHIKV isolated between 1952 and 2006, using strains from differing countries, including La Reunion Island. The most common nucleotide among the sequences was chosen at each position to be used in the consensus construct, taking care not to alter the reading frame. They conducted codon and RNA optimization, added a strong Kozak sequence, and substituted signal peptide with an immunoglobulin E leader sequence to improve vaccine efficacy.", "After immunizing the mice, spleens were harvested along with serum and tested to determine antibody titer. After three immunizations, consensus E1, E2, and C vaccines were shown to induce T-cell immune responses leading to strong IFN-c responses and proliferation in C57/BL6 mice. Furthermore, when compared with control mice, immunized mice had higher total IgG levels as well as higher anti-E1 specific, anti-E2 specific, and anti-C specific IgG antibodies, suggesting a strong humoral immune response ( Figure 3 ) and also specificity for the antigens encoded in the vaccine constructs ( Figure 4 ). Because of its promising results and the need for a safer vaccine, this consensus DNA vaccine deserves further investigation. Determining longevity of protective effects of the vaccine and persistence of antibody and IFN-c responses could be the next step of investigation. Challenged studies of immunized mice must also be carried out.", "CHIKV mosquito-borne disease has caused massive outbreaks for at least half a century but is no longer confined to the www.plosntds.org developing nations. It began to encroach into the boundaries of the developing world. As a result, the NIAID has designated CHIKV as a Category C pathogen alongside the influenza and SARS-CoV viruses [3] . Realization of the potential severity of this disease is exigent; for instance, if used as a biological weapon, the world economy could be severely crippled; if enough members of the armed forces were to become infected during a military deployment, military operations could be significantly affected. Efforts to monitor the disease will only provide minimal warning in a global society, and steps to prevent the morbidity and mortality associated with pandemic are imperative [21, 31] . Despite the gravity of its infectious potency and the fear of it being a potential biological weapon, there is currently no vaccine for CHIKV infections. Live", "attenuated vaccine trials were carried out in 2000, but funding for the project was discontinued. Newer approaches such as DNA vaccines appear promising over conventional strategies like live attenuated or inactivated virus and thus call for further investigation. Recent advances such electroporation delivery and incorporation of adjuvants has boosted DNA vaccine efficacy [51, 53] . Despite the low antibody response to DNA vaccines, other numerous advantages have overshadowed these minor drawbacks (Table 2) , the most important one being the ability to induce both humoral and cellular immune responses [51, 54] .", "Judging by recent success, such as the immunogenic construct developed by Muthumani et al., DNA vaccines could play a major role in combating CHIKV [49] . Vaccines are literally a critical component of CHIKV disease control and therefore research in this area is highly encouraged. The dramatic spread of dengue viruses (DENV) throughout tropical America since 1980 via the same vectors and human hosts underscores the risk to public health in the Americas. The adverse events associated with the current live vaccine are well documented [55] . Realizing these drawbacks, earnest efforts should be taken to develop new strategies to forestall further spread and complications." ]	[ 10 ]	3,829	5,688
1,689	What happens after host infection?	2,507	[ "CHIKV undertakes a complex replication cycle upon host infection (Figure 2 ), which makes its genome susceptible to mutations" ]	[ "Chikungunya: A Potentially Emerging Epidemic?\n\nhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC2860491/\n\nSHA: f7c3160bef4169d29e2a8bdd79dd6e9056d4774c\n\nAuthors: Thiboutot, Michelle M.; Kannan, Senthil; Kawalekar, Omkar U.; Shedlock, Devon J.; Khan, Amir S.; Sarangan, Gopalsamy; Srikanth, Padma; Weiner, David B.; Muthumani, Karuppiah\nDate: 2010-04-27\nDOI: 10.1371/journal.pntd.0000623\nLicense: cc-by", "Abstract: Chikungunya virus is a mosquito-borne emerging pathogen that has a major health impact in humans and causes fever disease, headache, rash, nausea, vomiting, myalgia, and arthralgia. Indigenous to tropical Africa, recent large outbreaks have been reported in parts of South East Asia and several of its neighboring islands in 2005–07 and in Europe in 2007. Furthermore, positive cases have been confirmed in the United States in travelers returning from known outbreak areas. Currently, there is no vaccine or antiviral treatment. With the threat of an emerging global pandemic, the peculiar problems associated with the more immediate and seasonal epidemics warrant the development of an effective vaccine. In this review, we summarize the evidence supporting these concepts.", "Text: Chikungunya virus (CHIKV), a mosquito-borne pathogen listed by National Institute of Allergy and Infectious Diseases (NIAID) as a Category C Priority Pathogen that causes Chikungunya fever (CHIKF), has been spreading throughout Asia, Africa, and parts of Europe in recent times [1, 2, 3] . CHIKV is an arthropod-borne virus (arbovirus) and is transmitted to humans primarily by Aedes aegypti, the infamous yellow fever propagator [4, 5] . CHIKV infection is marked by severe joint pain, contorting its victims into unusual postures [6] . The disease gets its name from the Kimakonde vernacular language of Tanzania and Mozambique, and the word chikungunya means ''that which contorts or bends up'' and translates in Swahili to ''the illness of the bended walker'' [7, 8, 9] . In Africa, CHIKV is maintained in a sylvatic cycle among forest-dwelling Aedes spp. mosquitoes, wild primates, squirrels, birds, and rodents ( Figure 1 ) [10] . In Asia, the disease is vectored by Ae. aegypti and Ae.", "albopictus [11] . Transmission in Asia occurs in an urban cycle whereby the mosquito spreads the disease from an infected human to an uninfected human, following an epidemiological pattern similar to dengue fever [12] .", "The 2005-2006 epidemic of CHIKV in La Reunion islands in the Indian Ocean, spurred the discovery of a new vector species, Ae. albopictus [5] . Wrecking over one-third of the island's population, this epidemic peaked its devastation between January and February 2006, when over 46,000 cases came into light every week, including 284 deaths [5, 13] . Ae. albopictus is common in urban areas of the United States and is already flourishing in 36 states, raising grave concerns to the immunologically naive populace of the United States [14] .\n\nAccordingly, this review elaborately details the epidemiology and global expansion of CHIKV, describes its clinical features and pathogenesis and its symptoms and complications, and finally nominates a possible vaccine approach against CHIKV infection.", "CHIKV has been isolated into three genotypes based on phylogenetic studies. These genotypes, based on the gene sequences of an Envelope protein (E1), are Asian, East/Central/ South African, and West African [4, 11, 15] . Using phylogenetic models, Cherian et al. estimate that the Asian genotype of CHIKV emerged between 50 and 310 y ago, and the West and East African genotypes diverged between 100 and 840 y ago [15] . Since then, CHIKV has come a long way, with several mutations incorporated, and has continued to wreak epidemics in several regions. Recent activities of CHIKV include the Indian epidemic in 2005-2006, which was followed by a sudden explosion of cases in 2007. An estimated 1.3 million people across 13 states were reported to be infected in India [12, 16] , and CHIKV was also widespread in Malaysia, Sri Lanka, and Indonesia [17] . In July-August of 2007, CHIKV was reported in Italy, probably brought in by travelers from CHIKV-prone regions of India, Africa, and Indian", "Ocean islands such as Mauritius, Madagascar, and Seychelles. Few of the Italian isolates were found to have evolved from the Kerala isolate, which was associated with a A226V shift in E1 gene that represents a successful evolutionary adaptation in the mosquito vector similar to the ones observed in Reunion Island [2, 18, 19] .", "In recent times, with an increase in global travel, the risk for spreading CHIKV to non-endemic regions has heightened [1] . Several travelers have brought CHIKV home with them after visiting areas with actively infected populations [12, 20] . Such cases have been documented in European countries, Australia, Asia, and the United States [8, 21] . The United States has already reported at least twelve cases of travel-associated CHIKV, while France has reported 850 cases, and the United Kingdom 93 [8, 14] . Beyond this, CHIKV-infected travelers have also been diagnosed in Australia, Belgium, Canada, Czech Republic, French Guiana, Germany, Hong Kong, Italy, Japan, Kenya, Malaysia, Martinique, Norway, Switzerland, and Sri Lanka [21] . Some travelers were viremic, worrying public health officials about the spread of CHIKV to new areas [1, 8] .", "The incubation time for CHIKV is relatively short, requiring only 2-6 d with symptoms usually appearing 4-7 d post-infection [22] . Vazeille et al. detected CHIKV in the salivary glands of Ae. albopictus only 2 d after infection [5] . Upon infection, CHIKF tends to present itself in two phases. The first stage is acute, while the second stage, experienced by most but not all, is persistent, causing disabling polyarthritis. Characteristics of the acute phase include an abrupt onset of fever, arthralgia, and in some cases, maculopapular rash [6, 23] . The acute phase causes such intense joint and muscular pain that makes movement very difficult and prostrates its victims [6, 20] .", "Ninety-five percent of infected adults are symptomatic after infection, and of these, most become disabled for weeks to months as a result of decreased dexterity, loss of mobility, and delayed reaction. Eighteen months after disease onset, 40% of patients are found to still have anti-CHIKV IgM [6, 18, 23, 24] . The chronic stage of CHIKF is characterized by polyarthralgia that can last from weeks to years beyond the acute stage [6] . CHIKV has been shown to attack fibroblasts, explaining the involvement of muscles, joints, and skin connective tissues. The high number of nociceptive nerve endings found within the joints and muscle connective tissues can explain pain associated with CHIKF [25, 26] .", "More than 50% of patients who suffer from severe CHIKF are over 65 y old, and more than 33% of them die. Most adults who suffer from severe CHIKF have underlying medical conditions [6, 24, 27] . The other group that is disproportionately affected by severe CHIKV is children. Other complications associated with CHIKV, from most common to least common, include respiratory failure, cardiovascular decompensation, meningoencephalitis, severe acute hepatitis, severe cutaneous effects, other central nervous system problems, and kidney failure [6, 18, 20, 23, 24, 26, 27] .", "CHIKV undertakes a complex replication cycle upon host infection (Figure 2 ), which makes its genome susceptible to mutations [28, 29] . For instance, Ae. aegypti, responsible for epidemics in Kenya, Comoros, and Seychelles, carried CHIKV with an alanine in the 226 position of the E1 gene (E1-A226) [4, 18] . However, when the virus struck La Reunion Islands, a decline in population of Ae. aegypti, due to massive dichlorodiphenyltrichloroethane usage and dearth of Ae. albopictus species' www.plosntds.org population, resulted in an ecological pressure, favoring replacement of alanine at position 226 with valine (E1-A226V) [5] . This mutation allowed CHIKV's secondary vector species, Ae. albopictus, to supplement Ae. aegypti as its primary vector [5] .", "Within a year, the E1-A226V mutation was present in La Reunion Island, and Ae. albopictus apparently vectored the large epidemic infecting 34% of La Reunion Island's population [5] . All of the CHIKV strains isolated from Mayotte carried the E1-A226V mutation, and the mutation was also found in Madagascar in 2007 [5] . The E1-A226V mutation was not present at the beginning of the Indian Ocean Islands outbreak (before September 2005). However, more than 90% of later viral strains found there had incorporated the mutation (December-March 2006), indicating a genotype switch during the winter season [5, 18, 20] .", "The E1-A226V mutation also enabled an increase in infectivity of Ae. albopictus when compared to its infectivity of Ae. aegypti [4, 11, 18, 30] , and with several factors taken together, Ae. albopictus has become the new preferred and more lethal vector for CHIKV [4, 5, 11] . In fact, Tsetsarkin et al. found that a Green Fluorescent Protein tagged E1-A226V virus was 100 times more infective to Ae. albopictus than it was to Ae. aegypti [4] . In all the Indian Ocean Islands, Ae. albopictus became the main vector for CHIKV within 1-2 y after CHIKV was introduced to the region [31] .", "Of note is that Ae. aegypti has most likely been established in North America for over 300 y, while Ae. albopictus has been in many areas of the US, since 1985, primarily in Florida [32] and since then has expanded its range in the country. Reiskind et al. set out to determine if Ae. aegypti and Ae. albopictus mosquitoes captured in Florida were susceptible to CHIKV infection by a La Reunion isolate [32] . Each mosquito tested was highly susceptible to infection by a full-length infectious clone of the La Réunion Island isolate, CHIKV LR2006 OPY1 strain. Even though the Ae. albopictus strains were more susceptible to infection, overall ecology and differences in human biting patterns need to be studied further Characteristically, there are two rounds of translation: (+) sense genomic RNA (49S9 = 11.7 kb) acts directly as mRNA and is partially translated (59 end) to produce non-structural proteins (nsp's). These proteins are responsible for replication and formation of a complementary", "(2) strand, the template for further (+) strand synthesis. Subgenomic mRNA (26 S = 4.1 kb) replication occurs through the synthesis of full-length (2) intermediate RNA, which is regulated by nsp4 and p123 precursor in early infection and later by mature nsp's. Translation of the newly synthesized sub-genomic RNA results in production of structural proteins such as Capsid and protein E2-6k-E1 (from 39 end of genome). Assembly occurs at the cell surface, and the envelope is acquired as the virus buds from the cell and release and maturation almost simultaneous occurred. Replication occurs in the cytoplasm and is very rapid (,4 h) [28, 29] . doi:10.1371/journal.pntd.0000623.g002 www.plosntds.org to gain a more accurate understanding of a potential CHIKV epidemic in the US [32] .", "During the 7 d preceding birth, no human mother has been reported to transmit the disease vertically. However, about 50% of newborns delivered while the mother was infected with CHIKV contracted the disease from their mother, despite the method of delivery. Furthermore, there have been instances of CHIKV transmission from mother to fetus causing congenital illness and fetal death [33] .", "During the 2005-2006 La Reunion Island outbreaks, Ramful et al. discovered that mothers could transmit CHIKV to their progeny during the perinatal period (Day 24 to Day +1) [33, 34] , and it is associated with a high degree of morbidity. By mean Day 4 of life, all of the neonates were symptomatic for CHIKV, exhibiting common CHIKF symptoms. Six neonates were confirmed to have contracted CHIKV and developed mengoencephalitis. Of those mothers who, during the La Reunion Island epidemic, were infected long before delivery, only three fetal deaths were reported [12, 33] . Ramful et al. theorized that motherto-child transmission most likely happens transplacentally shortly before delivery [33] . A similar study by Gerardin et al. reported nineteen cases of neonatal infection associated with intrapartum maternal viremia that progressed to develop encephalitis owing to vertical transmission from infected mothers [34] .", "Clinical and epidemiological similarities with dengue fever make CHIKV diagnosis difficult, which may lead physicians to misdiagnose CHIKV as dengue fever; therefore, the incidence of CHIKV may actually be higher than currently believed (Table 1 ) [6, 12, 35] .", "The amount of time elapsed since disease onset is the most critical parameter when choosing a diagnostic test. CHIKV can be detected and isolated by culturing with mosquito cells (C6/36), Vero cells (mammalian), or in mice [26] . However, this method can take at least a week and only achieves a high sensitivity during the viremic phase, which usually only lasts up to 48 h after the bite. Five days post-infection, the viral isolation approach has a low sensitivity but is still the preferred method for detecting the CHIKV strain [12, 26, 31, 35] . RT-PCR on the other hand is a faster and more sensitive method that can be used within the first week of disease onset [26] , and it is currently the most sensitive method for detecting and quantifying viral mRNA [4, 36] .", "Classic serological detection, by assays such as ELISA [37] , immunofluorescence [5, 38] , complement binding, and haemagglutination inhibition [39] , constitutes the second diagnostic tool used for biological diagnosis of CHIKV infection. These proven techniques are useful for detection of Antigen in mosquitoes during epidemiological studies. These assays detect virus-specific IgM and IgG, however the sensitivity and specificity of these assays has been poorly characterized. Viral competence, or the potential of viral infection and transmission, is an important parameter that can be quantified by ELISA, viral culture, and PCR.", "A study by Ng et al. showed biomarkers indicative of severe CHIKV infection [40] . They found decreased levels of RANTES and increased levels of Interleukin-6 (IL-6) and Interleukin-1b (IL-1b) that could be sued for CHIKV detection in patients as indicators of CHIKV-driven cytokine storm. Couderc et al. demonstrate another cytokine, type-I IFN, as a key player in the progression to CHIKV infection [26] . Using an IFN-a/b null mouse model, they demonstrated evidence of muscles, joints, and skin as privileged CHIKV targets, which is consistent with human pathology. Although Ng et al. concluded that RANTES levels were significantly suppressed in severe CHIKF patients [40] , interestingly, an increase in levels of RANTES has been observed in dengue infection [41] . Since the symptoms of CHIKF mimic those of dengue fever, results obtained from this study strongly suggest that RANTES could be a potential distinctive biomarker that differentiates between these two clinically similar", "diseases.", "There are no approved antiviral treatments currently available for CHIKV [1, 3, 12, 42] . Currently, CHIKF is treated symptomatically, usually with non-steroidal anti-inflammatory drugs or steroids, bed rest, and fluids. Movement and mild exercise are thought to decrease stiffness and morning arthralgia, but heavy exercise may exacerbate rheumatic symptoms. Corticosteroids may be used in cases of debilitating chronic CHIKV infection. There is a debate about the appropriateness of chloroquine as treatment for unresolved, non-steroidal anti-inflammatory drugresistant arthritis [43] . A study showed that viral production was www.plosntds.org drastically reduced at 16 h post-infection after treatment with 100 mM dec-RVKR-cmk (Decanoyl-Arg-Val-Lys-Arg-chloromethylketone), a furine inhibitor [42, 44] . Chloroquine acted by raising the pH, blocking low pH-dependent entry of virus into the cell. It is important to note that dec-RVKR-cmk or chloroquine only inhibited viral spreading from cell", "to cell, not CHIKV replication once it had entered the cell [43] . However, most would agree that the best weapon against CHIKV is prevention. A live CHIKV vaccine developed by the United States reached phase II clinical trial encompassing 59 healthy volunteers [45] . Eight percent of the volunteers experienced transient arthralgia, while 98% of the volunteers had seroconversion [45] . However, live CHIKV vaccines are still questionable. One cannot discount the risk of a live vaccine possibly inducing chronic rheumatism. Also, there is the question as to whether widespread use among the public could trigger mosquito transmission or lead to chronic infection or viral reversion [1] .", "An alternative approach would be to produce a chimeric vaccine against CHIKV. Wang et al. developed a chimeric alphavirus vaccine that is uniformly attenuated and does not cause reactogenicity in mice [3] . Three different versions of this vaccine were made using three different backbone vectors: Venezuelan equine encephalitis virus (VEEV) attenuated vaccine strain T-83, naturally attenuated eastern equine encephalitis virus (EEEV), and attenuated Sindbis virus (SINV). In short, CHIKV structural proteins were engineered into the backbones of the aforementioned vaccines to produce the chimeras [3] . These chimeras were found to stimulate a strong humoral immunity, and even at doses of 5.3-5.8 log 10 PFU, they did not trigger reactogenicity. When vaccinated mice were challenged with CHIKV, neither adult nor neonatal mice gained weight, had fever, or displayed signs of neurological illness. Upon comparison of the chimeras with the Army181/25 vaccine, the Army vaccine resulted in higher", "levels of viremia and replication in the joints of neonatal mice. Because the joints are known targets of CHIKV, Wang et al. noted their vaccine might avoid the negative reactogenic side effects of the Army vaccine. After being subcutaneously vaccinated with 5.3-5.8 log 10 PFU of the chimeric vaccines, mice produced strong neutralizing antibody titers. The VEEV and EEEV chimeras yielded higher neutralizing antibody titers than the SINV chimera without being more virulent. On top of this, the VEEV and EEEV CHIKV chimeras seemed to be more immunogenic than the Army vaccine despite the chimeras' lower viremia and replication in the joints of neonatal mice [3] .", "Tiwari et al. [46] adopted a different strategy using formalin inactivated CHIKV in combination with alhydrogel (Aluminum Hydroxide) as an adjuvant. This study clearly suggests that this vaccine elicits both humoral and cell-mediated immune responses in mice, providing its immunogenic potential. A recent study by Couderc et al. [47] showed passive immunization as a potential treatment for CHIKV infection. Using purified immunoglobulin extracted from convalescent CHIKV patients, they demonstrated effective neutralizing activity against CHIKV infection both in vitro and in vivo. This thereby establishes a potential preventive and therapeutic approach to combat CHIKV infection. Pathogenesis studies conducted with related alpha virus, like RRV, have shown the role of macrophages in persistence on infection [48] . They also demonstrated the role of RRV-specific CD8 T cells in clearing viral load in infected patients, thereby warranting similar investigations with CHIKV and the importance", "of investigating a cell-mediated immune response-based vaccine against CHIKV [49] .", "There are always certain risks associated with live attenuated or inactivated viral vaccines [50] . One way to avoid these potential problems is to construct a consensus-based DNA vaccine. DNA based vaccines have an improved safety profile as compared to live or attenuated vaccines [51, 52] . A consequence of CHIKV's rapid evolution is difficulty in constructing a vaccine that will be able to Figure 3 . Levels of CHIKV-specific IgG in mice immunized with CHIKV vaccines. Each group of C57BL/6 mice (n = 5) was immunized with 12.5 mg of pVax1 control vector or CHIKV vaccine plasmids as indicated at 0 and 2 wk. Mice were bled 2 wk after each immunization, and each group's serum pool was diluted to 1:100 and 1:500 for reaction with specific vaccine constructs. Serum was incubated for 1 h at 37uC on 96-well plates coated with 2 mg/ml of respective CHIKV peptides, and antibody was detected using anti-mouse IgG-HRP and OD was measured at 405 nm. doi:10.1371/journal.pntd.0000623.g003", "www.plosntds.org effectively protect large populations from multiple strains of the virus. One of the strengths of DNA consensus vaccines is its ability to induce cross-reactive immune responses against the three distinct phylogenetic groups of CHIKV. Also DNA-based vaccines can be produced more rapidly than protein-based vaccines.", "Recently, Muthumani et al. constructed a vaccine that was shown to induce both humoral and cellular immunity in vivo in 3-4-wk-old female C57/BL6 mice [49] . These mice were immunized using an in vivo electroporation method to deliver the vaccine into the quadriceps muscle. The consensus construct was designed against E1, E2, and the core protein capsid. To design the construct, they aligned 21 sequences of CHIKV isolated between 1952 and 2006, using strains from differing countries, including La Reunion Island. The most common nucleotide among the sequences was chosen at each position to be used in the consensus construct, taking care not to alter the reading frame. They conducted codon and RNA optimization, added a strong Kozak sequence, and substituted signal peptide with an immunoglobulin E leader sequence to improve vaccine efficacy.", "After immunizing the mice, spleens were harvested along with serum and tested to determine antibody titer. After three immunizations, consensus E1, E2, and C vaccines were shown to induce T-cell immune responses leading to strong IFN-c responses and proliferation in C57/BL6 mice. Furthermore, when compared with control mice, immunized mice had higher total IgG levels as well as higher anti-E1 specific, anti-E2 specific, and anti-C specific IgG antibodies, suggesting a strong humoral immune response ( Figure 3 ) and also specificity for the antigens encoded in the vaccine constructs ( Figure 4 ). Because of its promising results and the need for a safer vaccine, this consensus DNA vaccine deserves further investigation. Determining longevity of protective effects of the vaccine and persistence of antibody and IFN-c responses could be the next step of investigation. Challenged studies of immunized mice must also be carried out.", "CHIKV mosquito-borne disease has caused massive outbreaks for at least half a century but is no longer confined to the www.plosntds.org developing nations. It began to encroach into the boundaries of the developing world. As a result, the NIAID has designated CHIKV as a Category C pathogen alongside the influenza and SARS-CoV viruses [3] . Realization of the potential severity of this disease is exigent; for instance, if used as a biological weapon, the world economy could be severely crippled; if enough members of the armed forces were to become infected during a military deployment, military operations could be significantly affected. Efforts to monitor the disease will only provide minimal warning in a global society, and steps to prevent the morbidity and mortality associated with pandemic are imperative [21, 31] . Despite the gravity of its infectious potency and the fear of it being a potential biological weapon, there is currently no vaccine for CHIKV infections. Live", "attenuated vaccine trials were carried out in 2000, but funding for the project was discontinued. Newer approaches such as DNA vaccines appear promising over conventional strategies like live attenuated or inactivated virus and thus call for further investigation. Recent advances such electroporation delivery and incorporation of adjuvants has boosted DNA vaccine efficacy [51, 53] . Despite the low antibody response to DNA vaccines, other numerous advantages have overshadowed these minor drawbacks (Table 2) , the most important one being the ability to induce both humoral and cellular immune responses [51, 54] .", "Judging by recent success, such as the immunogenic construct developed by Muthumani et al., DNA vaccines could play a major role in combating CHIKV [49] . Vaccines are literally a critical component of CHIKV disease control and therefore research in this area is highly encouraged. The dramatic spread of dengue viruses (DENV) throughout tropical America since 1980 via the same vectors and human hosts underscores the risk to public health in the Americas. The adverse events associated with the current live vaccine are well documented [55] . Realizing these drawbacks, earnest efforts should be taken to develop new strategies to forestall further spread and complications." ]	[ 11 ]	3,829	5,688
1,689	What did the Ae.Aegypti which is responsible for epidemics in Kenya, Comoros and Seychelles carry?	2,508	[ "CHIKV with an alanine in the 226 position of the E1 gene (E1-A226)" ]	[ "Chikungunya: A Potentially Emerging Epidemic?\n\nhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC2860491/\n\nSHA: f7c3160bef4169d29e2a8bdd79dd6e9056d4774c\n\nAuthors: Thiboutot, Michelle M.; Kannan, Senthil; Kawalekar, Omkar U.; Shedlock, Devon J.; Khan, Amir S.; Sarangan, Gopalsamy; Srikanth, Padma; Weiner, David B.; Muthumani, Karuppiah\nDate: 2010-04-27\nDOI: 10.1371/journal.pntd.0000623\nLicense: cc-by", "Abstract: Chikungunya virus is a mosquito-borne emerging pathogen that has a major health impact in humans and causes fever disease, headache, rash, nausea, vomiting, myalgia, and arthralgia. Indigenous to tropical Africa, recent large outbreaks have been reported in parts of South East Asia and several of its neighboring islands in 2005–07 and in Europe in 2007. Furthermore, positive cases have been confirmed in the United States in travelers returning from known outbreak areas. Currently, there is no vaccine or antiviral treatment. With the threat of an emerging global pandemic, the peculiar problems associated with the more immediate and seasonal epidemics warrant the development of an effective vaccine. In this review, we summarize the evidence supporting these concepts.", "Text: Chikungunya virus (CHIKV), a mosquito-borne pathogen listed by National Institute of Allergy and Infectious Diseases (NIAID) as a Category C Priority Pathogen that causes Chikungunya fever (CHIKF), has been spreading throughout Asia, Africa, and parts of Europe in recent times [1, 2, 3] . CHIKV is an arthropod-borne virus (arbovirus) and is transmitted to humans primarily by Aedes aegypti, the infamous yellow fever propagator [4, 5] . CHIKV infection is marked by severe joint pain, contorting its victims into unusual postures [6] . The disease gets its name from the Kimakonde vernacular language of Tanzania and Mozambique, and the word chikungunya means ''that which contorts or bends up'' and translates in Swahili to ''the illness of the bended walker'' [7, 8, 9] . In Africa, CHIKV is maintained in a sylvatic cycle among forest-dwelling Aedes spp. mosquitoes, wild primates, squirrels, birds, and rodents ( Figure 1 ) [10] . In Asia, the disease is vectored by Ae. aegypti and Ae.", "albopictus [11] . Transmission in Asia occurs in an urban cycle whereby the mosquito spreads the disease from an infected human to an uninfected human, following an epidemiological pattern similar to dengue fever [12] .", "The 2005-2006 epidemic of CHIKV in La Reunion islands in the Indian Ocean, spurred the discovery of a new vector species, Ae. albopictus [5] . Wrecking over one-third of the island's population, this epidemic peaked its devastation between January and February 2006, when over 46,000 cases came into light every week, including 284 deaths [5, 13] . Ae. albopictus is common in urban areas of the United States and is already flourishing in 36 states, raising grave concerns to the immunologically naive populace of the United States [14] .\n\nAccordingly, this review elaborately details the epidemiology and global expansion of CHIKV, describes its clinical features and pathogenesis and its symptoms and complications, and finally nominates a possible vaccine approach against CHIKV infection.", "CHIKV has been isolated into three genotypes based on phylogenetic studies. These genotypes, based on the gene sequences of an Envelope protein (E1), are Asian, East/Central/ South African, and West African [4, 11, 15] . Using phylogenetic models, Cherian et al. estimate that the Asian genotype of CHIKV emerged between 50 and 310 y ago, and the West and East African genotypes diverged between 100 and 840 y ago [15] . Since then, CHIKV has come a long way, with several mutations incorporated, and has continued to wreak epidemics in several regions. Recent activities of CHIKV include the Indian epidemic in 2005-2006, which was followed by a sudden explosion of cases in 2007. An estimated 1.3 million people across 13 states were reported to be infected in India [12, 16] , and CHIKV was also widespread in Malaysia, Sri Lanka, and Indonesia [17] . In July-August of 2007, CHIKV was reported in Italy, probably brought in by travelers from CHIKV-prone regions of India, Africa, and Indian", "Ocean islands such as Mauritius, Madagascar, and Seychelles. Few of the Italian isolates were found to have evolved from the Kerala isolate, which was associated with a A226V shift in E1 gene that represents a successful evolutionary adaptation in the mosquito vector similar to the ones observed in Reunion Island [2, 18, 19] .", "In recent times, with an increase in global travel, the risk for spreading CHIKV to non-endemic regions has heightened [1] . Several travelers have brought CHIKV home with them after visiting areas with actively infected populations [12, 20] . Such cases have been documented in European countries, Australia, Asia, and the United States [8, 21] . The United States has already reported at least twelve cases of travel-associated CHIKV, while France has reported 850 cases, and the United Kingdom 93 [8, 14] . Beyond this, CHIKV-infected travelers have also been diagnosed in Australia, Belgium, Canada, Czech Republic, French Guiana, Germany, Hong Kong, Italy, Japan, Kenya, Malaysia, Martinique, Norway, Switzerland, and Sri Lanka [21] . Some travelers were viremic, worrying public health officials about the spread of CHIKV to new areas [1, 8] .", "The incubation time for CHIKV is relatively short, requiring only 2-6 d with symptoms usually appearing 4-7 d post-infection [22] . Vazeille et al. detected CHIKV in the salivary glands of Ae. albopictus only 2 d after infection [5] . Upon infection, CHIKF tends to present itself in two phases. The first stage is acute, while the second stage, experienced by most but not all, is persistent, causing disabling polyarthritis. Characteristics of the acute phase include an abrupt onset of fever, arthralgia, and in some cases, maculopapular rash [6, 23] . The acute phase causes such intense joint and muscular pain that makes movement very difficult and prostrates its victims [6, 20] .", "Ninety-five percent of infected adults are symptomatic after infection, and of these, most become disabled for weeks to months as a result of decreased dexterity, loss of mobility, and delayed reaction. Eighteen months after disease onset, 40% of patients are found to still have anti-CHIKV IgM [6, 18, 23, 24] . The chronic stage of CHIKF is characterized by polyarthralgia that can last from weeks to years beyond the acute stage [6] . CHIKV has been shown to attack fibroblasts, explaining the involvement of muscles, joints, and skin connective tissues. The high number of nociceptive nerve endings found within the joints and muscle connective tissues can explain pain associated with CHIKF [25, 26] .", "More than 50% of patients who suffer from severe CHIKF are over 65 y old, and more than 33% of them die. Most adults who suffer from severe CHIKF have underlying medical conditions [6, 24, 27] . The other group that is disproportionately affected by severe CHIKV is children. Other complications associated with CHIKV, from most common to least common, include respiratory failure, cardiovascular decompensation, meningoencephalitis, severe acute hepatitis, severe cutaneous effects, other central nervous system problems, and kidney failure [6, 18, 20, 23, 24, 26, 27] .", "CHIKV undertakes a complex replication cycle upon host infection (Figure 2 ), which makes its genome susceptible to mutations [28, 29] . For instance, Ae. aegypti, responsible for epidemics in Kenya, Comoros, and Seychelles, carried CHIKV with an alanine in the 226 position of the E1 gene (E1-A226) [4, 18] . However, when the virus struck La Reunion Islands, a decline in population of Ae. aegypti, due to massive dichlorodiphenyltrichloroethane usage and dearth of Ae. albopictus species' www.plosntds.org population, resulted in an ecological pressure, favoring replacement of alanine at position 226 with valine (E1-A226V) [5] . This mutation allowed CHIKV's secondary vector species, Ae. albopictus, to supplement Ae. aegypti as its primary vector [5] .", "Within a year, the E1-A226V mutation was present in La Reunion Island, and Ae. albopictus apparently vectored the large epidemic infecting 34% of La Reunion Island's population [5] . All of the CHIKV strains isolated from Mayotte carried the E1-A226V mutation, and the mutation was also found in Madagascar in 2007 [5] . The E1-A226V mutation was not present at the beginning of the Indian Ocean Islands outbreak (before September 2005). However, more than 90% of later viral strains found there had incorporated the mutation (December-March 2006), indicating a genotype switch during the winter season [5, 18, 20] .", "The E1-A226V mutation also enabled an increase in infectivity of Ae. albopictus when compared to its infectivity of Ae. aegypti [4, 11, 18, 30] , and with several factors taken together, Ae. albopictus has become the new preferred and more lethal vector for CHIKV [4, 5, 11] . In fact, Tsetsarkin et al. found that a Green Fluorescent Protein tagged E1-A226V virus was 100 times more infective to Ae. albopictus than it was to Ae. aegypti [4] . In all the Indian Ocean Islands, Ae. albopictus became the main vector for CHIKV within 1-2 y after CHIKV was introduced to the region [31] .", "Of note is that Ae. aegypti has most likely been established in North America for over 300 y, while Ae. albopictus has been in many areas of the US, since 1985, primarily in Florida [32] and since then has expanded its range in the country. Reiskind et al. set out to determine if Ae. aegypti and Ae. albopictus mosquitoes captured in Florida were susceptible to CHIKV infection by a La Reunion isolate [32] . Each mosquito tested was highly susceptible to infection by a full-length infectious clone of the La Réunion Island isolate, CHIKV LR2006 OPY1 strain. Even though the Ae. albopictus strains were more susceptible to infection, overall ecology and differences in human biting patterns need to be studied further Characteristically, there are two rounds of translation: (+) sense genomic RNA (49S9 = 11.7 kb) acts directly as mRNA and is partially translated (59 end) to produce non-structural proteins (nsp's). These proteins are responsible for replication and formation of a complementary", "(2) strand, the template for further (+) strand synthesis. Subgenomic mRNA (26 S = 4.1 kb) replication occurs through the synthesis of full-length (2) intermediate RNA, which is regulated by nsp4 and p123 precursor in early infection and later by mature nsp's. Translation of the newly synthesized sub-genomic RNA results in production of structural proteins such as Capsid and protein E2-6k-E1 (from 39 end of genome). Assembly occurs at the cell surface, and the envelope is acquired as the virus buds from the cell and release and maturation almost simultaneous occurred. Replication occurs in the cytoplasm and is very rapid (,4 h) [28, 29] . doi:10.1371/journal.pntd.0000623.g002 www.plosntds.org to gain a more accurate understanding of a potential CHIKV epidemic in the US [32] .", "During the 7 d preceding birth, no human mother has been reported to transmit the disease vertically. However, about 50% of newborns delivered while the mother was infected with CHIKV contracted the disease from their mother, despite the method of delivery. Furthermore, there have been instances of CHIKV transmission from mother to fetus causing congenital illness and fetal death [33] .", "During the 2005-2006 La Reunion Island outbreaks, Ramful et al. discovered that mothers could transmit CHIKV to their progeny during the perinatal period (Day 24 to Day +1) [33, 34] , and it is associated with a high degree of morbidity. By mean Day 4 of life, all of the neonates were symptomatic for CHIKV, exhibiting common CHIKF symptoms. Six neonates were confirmed to have contracted CHIKV and developed mengoencephalitis. Of those mothers who, during the La Reunion Island epidemic, were infected long before delivery, only three fetal deaths were reported [12, 33] . Ramful et al. theorized that motherto-child transmission most likely happens transplacentally shortly before delivery [33] . A similar study by Gerardin et al. reported nineteen cases of neonatal infection associated with intrapartum maternal viremia that progressed to develop encephalitis owing to vertical transmission from infected mothers [34] .", "Clinical and epidemiological similarities with dengue fever make CHIKV diagnosis difficult, which may lead physicians to misdiagnose CHIKV as dengue fever; therefore, the incidence of CHIKV may actually be higher than currently believed (Table 1 ) [6, 12, 35] .", "The amount of time elapsed since disease onset is the most critical parameter when choosing a diagnostic test. CHIKV can be detected and isolated by culturing with mosquito cells (C6/36), Vero cells (mammalian), or in mice [26] . However, this method can take at least a week and only achieves a high sensitivity during the viremic phase, which usually only lasts up to 48 h after the bite. Five days post-infection, the viral isolation approach has a low sensitivity but is still the preferred method for detecting the CHIKV strain [12, 26, 31, 35] . RT-PCR on the other hand is a faster and more sensitive method that can be used within the first week of disease onset [26] , and it is currently the most sensitive method for detecting and quantifying viral mRNA [4, 36] .", "Classic serological detection, by assays such as ELISA [37] , immunofluorescence [5, 38] , complement binding, and haemagglutination inhibition [39] , constitutes the second diagnostic tool used for biological diagnosis of CHIKV infection. These proven techniques are useful for detection of Antigen in mosquitoes during epidemiological studies. These assays detect virus-specific IgM and IgG, however the sensitivity and specificity of these assays has been poorly characterized. Viral competence, or the potential of viral infection and transmission, is an important parameter that can be quantified by ELISA, viral culture, and PCR.", "A study by Ng et al. showed biomarkers indicative of severe CHIKV infection [40] . They found decreased levels of RANTES and increased levels of Interleukin-6 (IL-6) and Interleukin-1b (IL-1b) that could be sued for CHIKV detection in patients as indicators of CHIKV-driven cytokine storm. Couderc et al. demonstrate another cytokine, type-I IFN, as a key player in the progression to CHIKV infection [26] . Using an IFN-a/b null mouse model, they demonstrated evidence of muscles, joints, and skin as privileged CHIKV targets, which is consistent with human pathology. Although Ng et al. concluded that RANTES levels were significantly suppressed in severe CHIKF patients [40] , interestingly, an increase in levels of RANTES has been observed in dengue infection [41] . Since the symptoms of CHIKF mimic those of dengue fever, results obtained from this study strongly suggest that RANTES could be a potential distinctive biomarker that differentiates between these two clinically similar", "diseases.", "There are no approved antiviral treatments currently available for CHIKV [1, 3, 12, 42] . Currently, CHIKF is treated symptomatically, usually with non-steroidal anti-inflammatory drugs or steroids, bed rest, and fluids. Movement and mild exercise are thought to decrease stiffness and morning arthralgia, but heavy exercise may exacerbate rheumatic symptoms. Corticosteroids may be used in cases of debilitating chronic CHIKV infection. There is a debate about the appropriateness of chloroquine as treatment for unresolved, non-steroidal anti-inflammatory drugresistant arthritis [43] . A study showed that viral production was www.plosntds.org drastically reduced at 16 h post-infection after treatment with 100 mM dec-RVKR-cmk (Decanoyl-Arg-Val-Lys-Arg-chloromethylketone), a furine inhibitor [42, 44] . Chloroquine acted by raising the pH, blocking low pH-dependent entry of virus into the cell. It is important to note that dec-RVKR-cmk or chloroquine only inhibited viral spreading from cell", "to cell, not CHIKV replication once it had entered the cell [43] . However, most would agree that the best weapon against CHIKV is prevention. A live CHIKV vaccine developed by the United States reached phase II clinical trial encompassing 59 healthy volunteers [45] . Eight percent of the volunteers experienced transient arthralgia, while 98% of the volunteers had seroconversion [45] . However, live CHIKV vaccines are still questionable. One cannot discount the risk of a live vaccine possibly inducing chronic rheumatism. Also, there is the question as to whether widespread use among the public could trigger mosquito transmission or lead to chronic infection or viral reversion [1] .", "An alternative approach would be to produce a chimeric vaccine against CHIKV. Wang et al. developed a chimeric alphavirus vaccine that is uniformly attenuated and does not cause reactogenicity in mice [3] . Three different versions of this vaccine were made using three different backbone vectors: Venezuelan equine encephalitis virus (VEEV) attenuated vaccine strain T-83, naturally attenuated eastern equine encephalitis virus (EEEV), and attenuated Sindbis virus (SINV). In short, CHIKV structural proteins were engineered into the backbones of the aforementioned vaccines to produce the chimeras [3] . These chimeras were found to stimulate a strong humoral immunity, and even at doses of 5.3-5.8 log 10 PFU, they did not trigger reactogenicity. When vaccinated mice were challenged with CHIKV, neither adult nor neonatal mice gained weight, had fever, or displayed signs of neurological illness. Upon comparison of the chimeras with the Army181/25 vaccine, the Army vaccine resulted in higher", "levels of viremia and replication in the joints of neonatal mice. Because the joints are known targets of CHIKV, Wang et al. noted their vaccine might avoid the negative reactogenic side effects of the Army vaccine. After being subcutaneously vaccinated with 5.3-5.8 log 10 PFU of the chimeric vaccines, mice produced strong neutralizing antibody titers. The VEEV and EEEV chimeras yielded higher neutralizing antibody titers than the SINV chimera without being more virulent. On top of this, the VEEV and EEEV CHIKV chimeras seemed to be more immunogenic than the Army vaccine despite the chimeras' lower viremia and replication in the joints of neonatal mice [3] .", "Tiwari et al. [46] adopted a different strategy using formalin inactivated CHIKV in combination with alhydrogel (Aluminum Hydroxide) as an adjuvant. This study clearly suggests that this vaccine elicits both humoral and cell-mediated immune responses in mice, providing its immunogenic potential. A recent study by Couderc et al. [47] showed passive immunization as a potential treatment for CHIKV infection. Using purified immunoglobulin extracted from convalescent CHIKV patients, they demonstrated effective neutralizing activity against CHIKV infection both in vitro and in vivo. This thereby establishes a potential preventive and therapeutic approach to combat CHIKV infection. Pathogenesis studies conducted with related alpha virus, like RRV, have shown the role of macrophages in persistence on infection [48] . They also demonstrated the role of RRV-specific CD8 T cells in clearing viral load in infected patients, thereby warranting similar investigations with CHIKV and the importance", "of investigating a cell-mediated immune response-based vaccine against CHIKV [49] .", "There are always certain risks associated with live attenuated or inactivated viral vaccines [50] . One way to avoid these potential problems is to construct a consensus-based DNA vaccine. DNA based vaccines have an improved safety profile as compared to live or attenuated vaccines [51, 52] . A consequence of CHIKV's rapid evolution is difficulty in constructing a vaccine that will be able to Figure 3 . Levels of CHIKV-specific IgG in mice immunized with CHIKV vaccines. Each group of C57BL/6 mice (n = 5) was immunized with 12.5 mg of pVax1 control vector or CHIKV vaccine plasmids as indicated at 0 and 2 wk. Mice were bled 2 wk after each immunization, and each group's serum pool was diluted to 1:100 and 1:500 for reaction with specific vaccine constructs. Serum was incubated for 1 h at 37uC on 96-well plates coated with 2 mg/ml of respective CHIKV peptides, and antibody was detected using anti-mouse IgG-HRP and OD was measured at 405 nm. doi:10.1371/journal.pntd.0000623.g003", "www.plosntds.org effectively protect large populations from multiple strains of the virus. One of the strengths of DNA consensus vaccines is its ability to induce cross-reactive immune responses against the three distinct phylogenetic groups of CHIKV. Also DNA-based vaccines can be produced more rapidly than protein-based vaccines.", "Recently, Muthumani et al. constructed a vaccine that was shown to induce both humoral and cellular immunity in vivo in 3-4-wk-old female C57/BL6 mice [49] . These mice were immunized using an in vivo electroporation method to deliver the vaccine into the quadriceps muscle. The consensus construct was designed against E1, E2, and the core protein capsid. To design the construct, they aligned 21 sequences of CHIKV isolated between 1952 and 2006, using strains from differing countries, including La Reunion Island. The most common nucleotide among the sequences was chosen at each position to be used in the consensus construct, taking care not to alter the reading frame. They conducted codon and RNA optimization, added a strong Kozak sequence, and substituted signal peptide with an immunoglobulin E leader sequence to improve vaccine efficacy.", "After immunizing the mice, spleens were harvested along with serum and tested to determine antibody titer. After three immunizations, consensus E1, E2, and C vaccines were shown to induce T-cell immune responses leading to strong IFN-c responses and proliferation in C57/BL6 mice. Furthermore, when compared with control mice, immunized mice had higher total IgG levels as well as higher anti-E1 specific, anti-E2 specific, and anti-C specific IgG antibodies, suggesting a strong humoral immune response ( Figure 3 ) and also specificity for the antigens encoded in the vaccine constructs ( Figure 4 ). Because of its promising results and the need for a safer vaccine, this consensus DNA vaccine deserves further investigation. Determining longevity of protective effects of the vaccine and persistence of antibody and IFN-c responses could be the next step of investigation. Challenged studies of immunized mice must also be carried out.", "CHIKV mosquito-borne disease has caused massive outbreaks for at least half a century but is no longer confined to the www.plosntds.org developing nations. It began to encroach into the boundaries of the developing world. As a result, the NIAID has designated CHIKV as a Category C pathogen alongside the influenza and SARS-CoV viruses [3] . Realization of the potential severity of this disease is exigent; for instance, if used as a biological weapon, the world economy could be severely crippled; if enough members of the armed forces were to become infected during a military deployment, military operations could be significantly affected. Efforts to monitor the disease will only provide minimal warning in a global society, and steps to prevent the morbidity and mortality associated with pandemic are imperative [21, 31] . Despite the gravity of its infectious potency and the fear of it being a potential biological weapon, there is currently no vaccine for CHIKV infections. Live", "attenuated vaccine trials were carried out in 2000, but funding for the project was discontinued. Newer approaches such as DNA vaccines appear promising over conventional strategies like live attenuated or inactivated virus and thus call for further investigation. Recent advances such electroporation delivery and incorporation of adjuvants has boosted DNA vaccine efficacy [51, 53] . Despite the low antibody response to DNA vaccines, other numerous advantages have overshadowed these minor drawbacks (Table 2) , the most important one being the ability to induce both humoral and cellular immune responses [51, 54] .", "Judging by recent success, such as the immunogenic construct developed by Muthumani et al., DNA vaccines could play a major role in combating CHIKV [49] . Vaccines are literally a critical component of CHIKV disease control and therefore research in this area is highly encouraged. The dramatic spread of dengue viruses (DENV) throughout tropical America since 1980 via the same vectors and human hosts underscores the risk to public health in the Americas. The adverse events associated with the current live vaccine are well documented [55] . Realizing these drawbacks, earnest efforts should be taken to develop new strategies to forestall further spread and complications." ]	[ 11 ]	3,829	5,688
1,689	what was the result of the decline in population of Ae. Aegyptus when the virus struck the Reunion Islands, due to massive use dichlorodiphenyltrichloroethane usage?	2,509	[ "in an ecological pressure, favoring replacement of alanine at position 226 with valine (E1-A226V)" ]	[ "Chikungunya: A Potentially Emerging Epidemic?\n\nhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC2860491/\n\nSHA: f7c3160bef4169d29e2a8bdd79dd6e9056d4774c\n\nAuthors: Thiboutot, Michelle M.; Kannan, Senthil; Kawalekar, Omkar U.; Shedlock, Devon J.; Khan, Amir S.; Sarangan, Gopalsamy; Srikanth, Padma; Weiner, David B.; Muthumani, Karuppiah\nDate: 2010-04-27\nDOI: 10.1371/journal.pntd.0000623\nLicense: cc-by", "Abstract: Chikungunya virus is a mosquito-borne emerging pathogen that has a major health impact in humans and causes fever disease, headache, rash, nausea, vomiting, myalgia, and arthralgia. Indigenous to tropical Africa, recent large outbreaks have been reported in parts of South East Asia and several of its neighboring islands in 2005–07 and in Europe in 2007. Furthermore, positive cases have been confirmed in the United States in travelers returning from known outbreak areas. Currently, there is no vaccine or antiviral treatment. With the threat of an emerging global pandemic, the peculiar problems associated with the more immediate and seasonal epidemics warrant the development of an effective vaccine. In this review, we summarize the evidence supporting these concepts.", "Text: Chikungunya virus (CHIKV), a mosquito-borne pathogen listed by National Institute of Allergy and Infectious Diseases (NIAID) as a Category C Priority Pathogen that causes Chikungunya fever (CHIKF), has been spreading throughout Asia, Africa, and parts of Europe in recent times [1, 2, 3] . CHIKV is an arthropod-borne virus (arbovirus) and is transmitted to humans primarily by Aedes aegypti, the infamous yellow fever propagator [4, 5] . CHIKV infection is marked by severe joint pain, contorting its victims into unusual postures [6] . The disease gets its name from the Kimakonde vernacular language of Tanzania and Mozambique, and the word chikungunya means ''that which contorts or bends up'' and translates in Swahili to ''the illness of the bended walker'' [7, 8, 9] . In Africa, CHIKV is maintained in a sylvatic cycle among forest-dwelling Aedes spp. mosquitoes, wild primates, squirrels, birds, and rodents ( Figure 1 ) [10] . In Asia, the disease is vectored by Ae. aegypti and Ae.", "albopictus [11] . Transmission in Asia occurs in an urban cycle whereby the mosquito spreads the disease from an infected human to an uninfected human, following an epidemiological pattern similar to dengue fever [12] .", "The 2005-2006 epidemic of CHIKV in La Reunion islands in the Indian Ocean, spurred the discovery of a new vector species, Ae. albopictus [5] . Wrecking over one-third of the island's population, this epidemic peaked its devastation between January and February 2006, when over 46,000 cases came into light every week, including 284 deaths [5, 13] . Ae. albopictus is common in urban areas of the United States and is already flourishing in 36 states, raising grave concerns to the immunologically naive populace of the United States [14] .\n\nAccordingly, this review elaborately details the epidemiology and global expansion of CHIKV, describes its clinical features and pathogenesis and its symptoms and complications, and finally nominates a possible vaccine approach against CHIKV infection.", "CHIKV has been isolated into three genotypes based on phylogenetic studies. These genotypes, based on the gene sequences of an Envelope protein (E1), are Asian, East/Central/ South African, and West African [4, 11, 15] . Using phylogenetic models, Cherian et al. estimate that the Asian genotype of CHIKV emerged between 50 and 310 y ago, and the West and East African genotypes diverged between 100 and 840 y ago [15] . Since then, CHIKV has come a long way, with several mutations incorporated, and has continued to wreak epidemics in several regions. Recent activities of CHIKV include the Indian epidemic in 2005-2006, which was followed by a sudden explosion of cases in 2007. An estimated 1.3 million people across 13 states were reported to be infected in India [12, 16] , and CHIKV was also widespread in Malaysia, Sri Lanka, and Indonesia [17] . In July-August of 2007, CHIKV was reported in Italy, probably brought in by travelers from CHIKV-prone regions of India, Africa, and Indian", "Ocean islands such as Mauritius, Madagascar, and Seychelles. Few of the Italian isolates were found to have evolved from the Kerala isolate, which was associated with a A226V shift in E1 gene that represents a successful evolutionary adaptation in the mosquito vector similar to the ones observed in Reunion Island [2, 18, 19] .", "In recent times, with an increase in global travel, the risk for spreading CHIKV to non-endemic regions has heightened [1] . Several travelers have brought CHIKV home with them after visiting areas with actively infected populations [12, 20] . Such cases have been documented in European countries, Australia, Asia, and the United States [8, 21] . The United States has already reported at least twelve cases of travel-associated CHIKV, while France has reported 850 cases, and the United Kingdom 93 [8, 14] . Beyond this, CHIKV-infected travelers have also been diagnosed in Australia, Belgium, Canada, Czech Republic, French Guiana, Germany, Hong Kong, Italy, Japan, Kenya, Malaysia, Martinique, Norway, Switzerland, and Sri Lanka [21] . Some travelers were viremic, worrying public health officials about the spread of CHIKV to new areas [1, 8] .", "The incubation time for CHIKV is relatively short, requiring only 2-6 d with symptoms usually appearing 4-7 d post-infection [22] . Vazeille et al. detected CHIKV in the salivary glands of Ae. albopictus only 2 d after infection [5] . Upon infection, CHIKF tends to present itself in two phases. The first stage is acute, while the second stage, experienced by most but not all, is persistent, causing disabling polyarthritis. Characteristics of the acute phase include an abrupt onset of fever, arthralgia, and in some cases, maculopapular rash [6, 23] . The acute phase causes such intense joint and muscular pain that makes movement very difficult and prostrates its victims [6, 20] .", "Ninety-five percent of infected adults are symptomatic after infection, and of these, most become disabled for weeks to months as a result of decreased dexterity, loss of mobility, and delayed reaction. Eighteen months after disease onset, 40% of patients are found to still have anti-CHIKV IgM [6, 18, 23, 24] . The chronic stage of CHIKF is characterized by polyarthralgia that can last from weeks to years beyond the acute stage [6] . CHIKV has been shown to attack fibroblasts, explaining the involvement of muscles, joints, and skin connective tissues. The high number of nociceptive nerve endings found within the joints and muscle connective tissues can explain pain associated with CHIKF [25, 26] .", "More than 50% of patients who suffer from severe CHIKF are over 65 y old, and more than 33% of them die. Most adults who suffer from severe CHIKF have underlying medical conditions [6, 24, 27] . The other group that is disproportionately affected by severe CHIKV is children. Other complications associated with CHIKV, from most common to least common, include respiratory failure, cardiovascular decompensation, meningoencephalitis, severe acute hepatitis, severe cutaneous effects, other central nervous system problems, and kidney failure [6, 18, 20, 23, 24, 26, 27] .", "CHIKV undertakes a complex replication cycle upon host infection (Figure 2 ), which makes its genome susceptible to mutations [28, 29] . For instance, Ae. aegypti, responsible for epidemics in Kenya, Comoros, and Seychelles, carried CHIKV with an alanine in the 226 position of the E1 gene (E1-A226) [4, 18] . However, when the virus struck La Reunion Islands, a decline in population of Ae. aegypti, due to massive dichlorodiphenyltrichloroethane usage and dearth of Ae. albopictus species' www.plosntds.org population, resulted in an ecological pressure, favoring replacement of alanine at position 226 with valine (E1-A226V) [5] . This mutation allowed CHIKV's secondary vector species, Ae. albopictus, to supplement Ae. aegypti as its primary vector [5] .", "Within a year, the E1-A226V mutation was present in La Reunion Island, and Ae. albopictus apparently vectored the large epidemic infecting 34% of La Reunion Island's population [5] . All of the CHIKV strains isolated from Mayotte carried the E1-A226V mutation, and the mutation was also found in Madagascar in 2007 [5] . The E1-A226V mutation was not present at the beginning of the Indian Ocean Islands outbreak (before September 2005). However, more than 90% of later viral strains found there had incorporated the mutation (December-March 2006), indicating a genotype switch during the winter season [5, 18, 20] .", "The E1-A226V mutation also enabled an increase in infectivity of Ae. albopictus when compared to its infectivity of Ae. aegypti [4, 11, 18, 30] , and with several factors taken together, Ae. albopictus has become the new preferred and more lethal vector for CHIKV [4, 5, 11] . In fact, Tsetsarkin et al. found that a Green Fluorescent Protein tagged E1-A226V virus was 100 times more infective to Ae. albopictus than it was to Ae. aegypti [4] . In all the Indian Ocean Islands, Ae. albopictus became the main vector for CHIKV within 1-2 y after CHIKV was introduced to the region [31] .", "Of note is that Ae. aegypti has most likely been established in North America for over 300 y, while Ae. albopictus has been in many areas of the US, since 1985, primarily in Florida [32] and since then has expanded its range in the country. Reiskind et al. set out to determine if Ae. aegypti and Ae. albopictus mosquitoes captured in Florida were susceptible to CHIKV infection by a La Reunion isolate [32] . Each mosquito tested was highly susceptible to infection by a full-length infectious clone of the La Réunion Island isolate, CHIKV LR2006 OPY1 strain. Even though the Ae. albopictus strains were more susceptible to infection, overall ecology and differences in human biting patterns need to be studied further Characteristically, there are two rounds of translation: (+) sense genomic RNA (49S9 = 11.7 kb) acts directly as mRNA and is partially translated (59 end) to produce non-structural proteins (nsp's). These proteins are responsible for replication and formation of a complementary", "(2) strand, the template for further (+) strand synthesis. Subgenomic mRNA (26 S = 4.1 kb) replication occurs through the synthesis of full-length (2) intermediate RNA, which is regulated by nsp4 and p123 precursor in early infection and later by mature nsp's. Translation of the newly synthesized sub-genomic RNA results in production of structural proteins such as Capsid and protein E2-6k-E1 (from 39 end of genome). Assembly occurs at the cell surface, and the envelope is acquired as the virus buds from the cell and release and maturation almost simultaneous occurred. Replication occurs in the cytoplasm and is very rapid (,4 h) [28, 29] . doi:10.1371/journal.pntd.0000623.g002 www.plosntds.org to gain a more accurate understanding of a potential CHIKV epidemic in the US [32] .", "During the 7 d preceding birth, no human mother has been reported to transmit the disease vertically. However, about 50% of newborns delivered while the mother was infected with CHIKV contracted the disease from their mother, despite the method of delivery. Furthermore, there have been instances of CHIKV transmission from mother to fetus causing congenital illness and fetal death [33] .", "During the 2005-2006 La Reunion Island outbreaks, Ramful et al. discovered that mothers could transmit CHIKV to their progeny during the perinatal period (Day 24 to Day +1) [33, 34] , and it is associated with a high degree of morbidity. By mean Day 4 of life, all of the neonates were symptomatic for CHIKV, exhibiting common CHIKF symptoms. Six neonates were confirmed to have contracted CHIKV and developed mengoencephalitis. Of those mothers who, during the La Reunion Island epidemic, were infected long before delivery, only three fetal deaths were reported [12, 33] . Ramful et al. theorized that motherto-child transmission most likely happens transplacentally shortly before delivery [33] . A similar study by Gerardin et al. reported nineteen cases of neonatal infection associated with intrapartum maternal viremia that progressed to develop encephalitis owing to vertical transmission from infected mothers [34] .", "Clinical and epidemiological similarities with dengue fever make CHIKV diagnosis difficult, which may lead physicians to misdiagnose CHIKV as dengue fever; therefore, the incidence of CHIKV may actually be higher than currently believed (Table 1 ) [6, 12, 35] .", "The amount of time elapsed since disease onset is the most critical parameter when choosing a diagnostic test. CHIKV can be detected and isolated by culturing with mosquito cells (C6/36), Vero cells (mammalian), or in mice [26] . However, this method can take at least a week and only achieves a high sensitivity during the viremic phase, which usually only lasts up to 48 h after the bite. Five days post-infection, the viral isolation approach has a low sensitivity but is still the preferred method for detecting the CHIKV strain [12, 26, 31, 35] . RT-PCR on the other hand is a faster and more sensitive method that can be used within the first week of disease onset [26] , and it is currently the most sensitive method for detecting and quantifying viral mRNA [4, 36] .", "Classic serological detection, by assays such as ELISA [37] , immunofluorescence [5, 38] , complement binding, and haemagglutination inhibition [39] , constitutes the second diagnostic tool used for biological diagnosis of CHIKV infection. These proven techniques are useful for detection of Antigen in mosquitoes during epidemiological studies. These assays detect virus-specific IgM and IgG, however the sensitivity and specificity of these assays has been poorly characterized. Viral competence, or the potential of viral infection and transmission, is an important parameter that can be quantified by ELISA, viral culture, and PCR.", "A study by Ng et al. showed biomarkers indicative of severe CHIKV infection [40] . They found decreased levels of RANTES and increased levels of Interleukin-6 (IL-6) and Interleukin-1b (IL-1b) that could be sued for CHIKV detection in patients as indicators of CHIKV-driven cytokine storm. Couderc et al. demonstrate another cytokine, type-I IFN, as a key player in the progression to CHIKV infection [26] . Using an IFN-a/b null mouse model, they demonstrated evidence of muscles, joints, and skin as privileged CHIKV targets, which is consistent with human pathology. Although Ng et al. concluded that RANTES levels were significantly suppressed in severe CHIKF patients [40] , interestingly, an increase in levels of RANTES has been observed in dengue infection [41] . Since the symptoms of CHIKF mimic those of dengue fever, results obtained from this study strongly suggest that RANTES could be a potential distinctive biomarker that differentiates between these two clinically similar", "diseases.", "There are no approved antiviral treatments currently available for CHIKV [1, 3, 12, 42] . Currently, CHIKF is treated symptomatically, usually with non-steroidal anti-inflammatory drugs or steroids, bed rest, and fluids. Movement and mild exercise are thought to decrease stiffness and morning arthralgia, but heavy exercise may exacerbate rheumatic symptoms. Corticosteroids may be used in cases of debilitating chronic CHIKV infection. There is a debate about the appropriateness of chloroquine as treatment for unresolved, non-steroidal anti-inflammatory drugresistant arthritis [43] . A study showed that viral production was www.plosntds.org drastically reduced at 16 h post-infection after treatment with 100 mM dec-RVKR-cmk (Decanoyl-Arg-Val-Lys-Arg-chloromethylketone), a furine inhibitor [42, 44] . Chloroquine acted by raising the pH, blocking low pH-dependent entry of virus into the cell. It is important to note that dec-RVKR-cmk or chloroquine only inhibited viral spreading from cell", "to cell, not CHIKV replication once it had entered the cell [43] . However, most would agree that the best weapon against CHIKV is prevention. A live CHIKV vaccine developed by the United States reached phase II clinical trial encompassing 59 healthy volunteers [45] . Eight percent of the volunteers experienced transient arthralgia, while 98% of the volunteers had seroconversion [45] . However, live CHIKV vaccines are still questionable. One cannot discount the risk of a live vaccine possibly inducing chronic rheumatism. Also, there is the question as to whether widespread use among the public could trigger mosquito transmission or lead to chronic infection or viral reversion [1] .", "An alternative approach would be to produce a chimeric vaccine against CHIKV. Wang et al. developed a chimeric alphavirus vaccine that is uniformly attenuated and does not cause reactogenicity in mice [3] . Three different versions of this vaccine were made using three different backbone vectors: Venezuelan equine encephalitis virus (VEEV) attenuated vaccine strain T-83, naturally attenuated eastern equine encephalitis virus (EEEV), and attenuated Sindbis virus (SINV). In short, CHIKV structural proteins were engineered into the backbones of the aforementioned vaccines to produce the chimeras [3] . These chimeras were found to stimulate a strong humoral immunity, and even at doses of 5.3-5.8 log 10 PFU, they did not trigger reactogenicity. When vaccinated mice were challenged with CHIKV, neither adult nor neonatal mice gained weight, had fever, or displayed signs of neurological illness. Upon comparison of the chimeras with the Army181/25 vaccine, the Army vaccine resulted in higher", "levels of viremia and replication in the joints of neonatal mice. Because the joints are known targets of CHIKV, Wang et al. noted their vaccine might avoid the negative reactogenic side effects of the Army vaccine. After being subcutaneously vaccinated with 5.3-5.8 log 10 PFU of the chimeric vaccines, mice produced strong neutralizing antibody titers. The VEEV and EEEV chimeras yielded higher neutralizing antibody titers than the SINV chimera without being more virulent. On top of this, the VEEV and EEEV CHIKV chimeras seemed to be more immunogenic than the Army vaccine despite the chimeras' lower viremia and replication in the joints of neonatal mice [3] .", "Tiwari et al. [46] adopted a different strategy using formalin inactivated CHIKV in combination with alhydrogel (Aluminum Hydroxide) as an adjuvant. This study clearly suggests that this vaccine elicits both humoral and cell-mediated immune responses in mice, providing its immunogenic potential. A recent study by Couderc et al. [47] showed passive immunization as a potential treatment for CHIKV infection. Using purified immunoglobulin extracted from convalescent CHIKV patients, they demonstrated effective neutralizing activity against CHIKV infection both in vitro and in vivo. This thereby establishes a potential preventive and therapeutic approach to combat CHIKV infection. Pathogenesis studies conducted with related alpha virus, like RRV, have shown the role of macrophages in persistence on infection [48] . They also demonstrated the role of RRV-specific CD8 T cells in clearing viral load in infected patients, thereby warranting similar investigations with CHIKV and the importance", "of investigating a cell-mediated immune response-based vaccine against CHIKV [49] .", "There are always certain risks associated with live attenuated or inactivated viral vaccines [50] . One way to avoid these potential problems is to construct a consensus-based DNA vaccine. DNA based vaccines have an improved safety profile as compared to live or attenuated vaccines [51, 52] . A consequence of CHIKV's rapid evolution is difficulty in constructing a vaccine that will be able to Figure 3 . Levels of CHIKV-specific IgG in mice immunized with CHIKV vaccines. Each group of C57BL/6 mice (n = 5) was immunized with 12.5 mg of pVax1 control vector or CHIKV vaccine plasmids as indicated at 0 and 2 wk. Mice were bled 2 wk after each immunization, and each group's serum pool was diluted to 1:100 and 1:500 for reaction with specific vaccine constructs. Serum was incubated for 1 h at 37uC on 96-well plates coated with 2 mg/ml of respective CHIKV peptides, and antibody was detected using anti-mouse IgG-HRP and OD was measured at 405 nm. doi:10.1371/journal.pntd.0000623.g003", "www.plosntds.org effectively protect large populations from multiple strains of the virus. One of the strengths of DNA consensus vaccines is its ability to induce cross-reactive immune responses against the three distinct phylogenetic groups of CHIKV. Also DNA-based vaccines can be produced more rapidly than protein-based vaccines.", "Recently, Muthumani et al. constructed a vaccine that was shown to induce both humoral and cellular immunity in vivo in 3-4-wk-old female C57/BL6 mice [49] . These mice were immunized using an in vivo electroporation method to deliver the vaccine into the quadriceps muscle. The consensus construct was designed against E1, E2, and the core protein capsid. To design the construct, they aligned 21 sequences of CHIKV isolated between 1952 and 2006, using strains from differing countries, including La Reunion Island. The most common nucleotide among the sequences was chosen at each position to be used in the consensus construct, taking care not to alter the reading frame. They conducted codon and RNA optimization, added a strong Kozak sequence, and substituted signal peptide with an immunoglobulin E leader sequence to improve vaccine efficacy.", "After immunizing the mice, spleens were harvested along with serum and tested to determine antibody titer. After three immunizations, consensus E1, E2, and C vaccines were shown to induce T-cell immune responses leading to strong IFN-c responses and proliferation in C57/BL6 mice. Furthermore, when compared with control mice, immunized mice had higher total IgG levels as well as higher anti-E1 specific, anti-E2 specific, and anti-C specific IgG antibodies, suggesting a strong humoral immune response ( Figure 3 ) and also specificity for the antigens encoded in the vaccine constructs ( Figure 4 ). Because of its promising results and the need for a safer vaccine, this consensus DNA vaccine deserves further investigation. Determining longevity of protective effects of the vaccine and persistence of antibody and IFN-c responses could be the next step of investigation. Challenged studies of immunized mice must also be carried out.", "CHIKV mosquito-borne disease has caused massive outbreaks for at least half a century but is no longer confined to the www.plosntds.org developing nations. It began to encroach into the boundaries of the developing world. As a result, the NIAID has designated CHIKV as a Category C pathogen alongside the influenza and SARS-CoV viruses [3] . Realization of the potential severity of this disease is exigent; for instance, if used as a biological weapon, the world economy could be severely crippled; if enough members of the armed forces were to become infected during a military deployment, military operations could be significantly affected. Efforts to monitor the disease will only provide minimal warning in a global society, and steps to prevent the morbidity and mortality associated with pandemic are imperative [21, 31] . Despite the gravity of its infectious potency and the fear of it being a potential biological weapon, there is currently no vaccine for CHIKV infections. Live", "attenuated vaccine trials were carried out in 2000, but funding for the project was discontinued. Newer approaches such as DNA vaccines appear promising over conventional strategies like live attenuated or inactivated virus and thus call for further investigation. Recent advances such electroporation delivery and incorporation of adjuvants has boosted DNA vaccine efficacy [51, 53] . Despite the low antibody response to DNA vaccines, other numerous advantages have overshadowed these minor drawbacks (Table 2) , the most important one being the ability to induce both humoral and cellular immune responses [51, 54] .", "Judging by recent success, such as the immunogenic construct developed by Muthumani et al., DNA vaccines could play a major role in combating CHIKV [49] . Vaccines are literally a critical component of CHIKV disease control and therefore research in this area is highly encouraged. The dramatic spread of dengue viruses (DENV) throughout tropical America since 1980 via the same vectors and human hosts underscores the risk to public health in the Americas. The adverse events associated with the current live vaccine are well documented [55] . Realizing these drawbacks, earnest efforts should be taken to develop new strategies to forestall further spread and complications." ]	[ 11 ]	3,829	5,688
1,689	What did this mutation allow?	2,510	[ "CHIKV's secondary vector species, Ae. albopictus, to supplement Ae. aegypti as its primary vector" ]	[ "Chikungunya: A Potentially Emerging Epidemic?\n\nhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC2860491/\n\nSHA: f7c3160bef4169d29e2a8bdd79dd6e9056d4774c\n\nAuthors: Thiboutot, Michelle M.; Kannan, Senthil; Kawalekar, Omkar U.; Shedlock, Devon J.; Khan, Amir S.; Sarangan, Gopalsamy; Srikanth, Padma; Weiner, David B.; Muthumani, Karuppiah\nDate: 2010-04-27\nDOI: 10.1371/journal.pntd.0000623\nLicense: cc-by", "Abstract: Chikungunya virus is a mosquito-borne emerging pathogen that has a major health impact in humans and causes fever disease, headache, rash, nausea, vomiting, myalgia, and arthralgia. Indigenous to tropical Africa, recent large outbreaks have been reported in parts of South East Asia and several of its neighboring islands in 2005–07 and in Europe in 2007. Furthermore, positive cases have been confirmed in the United States in travelers returning from known outbreak areas. Currently, there is no vaccine or antiviral treatment. With the threat of an emerging global pandemic, the peculiar problems associated with the more immediate and seasonal epidemics warrant the development of an effective vaccine. In this review, we summarize the evidence supporting these concepts.", "Text: Chikungunya virus (CHIKV), a mosquito-borne pathogen listed by National Institute of Allergy and Infectious Diseases (NIAID) as a Category C Priority Pathogen that causes Chikungunya fever (CHIKF), has been spreading throughout Asia, Africa, and parts of Europe in recent times [1, 2, 3] . CHIKV is an arthropod-borne virus (arbovirus) and is transmitted to humans primarily by Aedes aegypti, the infamous yellow fever propagator [4, 5] . CHIKV infection is marked by severe joint pain, contorting its victims into unusual postures [6] . The disease gets its name from the Kimakonde vernacular language of Tanzania and Mozambique, and the word chikungunya means ''that which contorts or bends up'' and translates in Swahili to ''the illness of the bended walker'' [7, 8, 9] . In Africa, CHIKV is maintained in a sylvatic cycle among forest-dwelling Aedes spp. mosquitoes, wild primates, squirrels, birds, and rodents ( Figure 1 ) [10] . In Asia, the disease is vectored by Ae. aegypti and Ae.", "albopictus [11] . Transmission in Asia occurs in an urban cycle whereby the mosquito spreads the disease from an infected human to an uninfected human, following an epidemiological pattern similar to dengue fever [12] .", "The 2005-2006 epidemic of CHIKV in La Reunion islands in the Indian Ocean, spurred the discovery of a new vector species, Ae. albopictus [5] . Wrecking over one-third of the island's population, this epidemic peaked its devastation between January and February 2006, when over 46,000 cases came into light every week, including 284 deaths [5, 13] . Ae. albopictus is common in urban areas of the United States and is already flourishing in 36 states, raising grave concerns to the immunologically naive populace of the United States [14] .\n\nAccordingly, this review elaborately details the epidemiology and global expansion of CHIKV, describes its clinical features and pathogenesis and its symptoms and complications, and finally nominates a possible vaccine approach against CHIKV infection.", "CHIKV has been isolated into three genotypes based on phylogenetic studies. These genotypes, based on the gene sequences of an Envelope protein (E1), are Asian, East/Central/ South African, and West African [4, 11, 15] . Using phylogenetic models, Cherian et al. estimate that the Asian genotype of CHIKV emerged between 50 and 310 y ago, and the West and East African genotypes diverged between 100 and 840 y ago [15] . Since then, CHIKV has come a long way, with several mutations incorporated, and has continued to wreak epidemics in several regions. Recent activities of CHIKV include the Indian epidemic in 2005-2006, which was followed by a sudden explosion of cases in 2007. An estimated 1.3 million people across 13 states were reported to be infected in India [12, 16] , and CHIKV was also widespread in Malaysia, Sri Lanka, and Indonesia [17] . In July-August of 2007, CHIKV was reported in Italy, probably brought in by travelers from CHIKV-prone regions of India, Africa, and Indian", "Ocean islands such as Mauritius, Madagascar, and Seychelles. Few of the Italian isolates were found to have evolved from the Kerala isolate, which was associated with a A226V shift in E1 gene that represents a successful evolutionary adaptation in the mosquito vector similar to the ones observed in Reunion Island [2, 18, 19] .", "In recent times, with an increase in global travel, the risk for spreading CHIKV to non-endemic regions has heightened [1] . Several travelers have brought CHIKV home with them after visiting areas with actively infected populations [12, 20] . Such cases have been documented in European countries, Australia, Asia, and the United States [8, 21] . The United States has already reported at least twelve cases of travel-associated CHIKV, while France has reported 850 cases, and the United Kingdom 93 [8, 14] . Beyond this, CHIKV-infected travelers have also been diagnosed in Australia, Belgium, Canada, Czech Republic, French Guiana, Germany, Hong Kong, Italy, Japan, Kenya, Malaysia, Martinique, Norway, Switzerland, and Sri Lanka [21] . Some travelers were viremic, worrying public health officials about the spread of CHIKV to new areas [1, 8] .", "The incubation time for CHIKV is relatively short, requiring only 2-6 d with symptoms usually appearing 4-7 d post-infection [22] . Vazeille et al. detected CHIKV in the salivary glands of Ae. albopictus only 2 d after infection [5] . Upon infection, CHIKF tends to present itself in two phases. The first stage is acute, while the second stage, experienced by most but not all, is persistent, causing disabling polyarthritis. Characteristics of the acute phase include an abrupt onset of fever, arthralgia, and in some cases, maculopapular rash [6, 23] . The acute phase causes such intense joint and muscular pain that makes movement very difficult and prostrates its victims [6, 20] .", "Ninety-five percent of infected adults are symptomatic after infection, and of these, most become disabled for weeks to months as a result of decreased dexterity, loss of mobility, and delayed reaction. Eighteen months after disease onset, 40% of patients are found to still have anti-CHIKV IgM [6, 18, 23, 24] . The chronic stage of CHIKF is characterized by polyarthralgia that can last from weeks to years beyond the acute stage [6] . CHIKV has been shown to attack fibroblasts, explaining the involvement of muscles, joints, and skin connective tissues. The high number of nociceptive nerve endings found within the joints and muscle connective tissues can explain pain associated with CHIKF [25, 26] .", "More than 50% of patients who suffer from severe CHIKF are over 65 y old, and more than 33% of them die. Most adults who suffer from severe CHIKF have underlying medical conditions [6, 24, 27] . The other group that is disproportionately affected by severe CHIKV is children. Other complications associated with CHIKV, from most common to least common, include respiratory failure, cardiovascular decompensation, meningoencephalitis, severe acute hepatitis, severe cutaneous effects, other central nervous system problems, and kidney failure [6, 18, 20, 23, 24, 26, 27] .", "CHIKV undertakes a complex replication cycle upon host infection (Figure 2 ), which makes its genome susceptible to mutations [28, 29] . For instance, Ae. aegypti, responsible for epidemics in Kenya, Comoros, and Seychelles, carried CHIKV with an alanine in the 226 position of the E1 gene (E1-A226) [4, 18] . However, when the virus struck La Reunion Islands, a decline in population of Ae. aegypti, due to massive dichlorodiphenyltrichloroethane usage and dearth of Ae. albopictus species' www.plosntds.org population, resulted in an ecological pressure, favoring replacement of alanine at position 226 with valine (E1-A226V) [5] . This mutation allowed CHIKV's secondary vector species, Ae. albopictus, to supplement Ae. aegypti as its primary vector [5] .", "Within a year, the E1-A226V mutation was present in La Reunion Island, and Ae. albopictus apparently vectored the large epidemic infecting 34% of La Reunion Island's population [5] . All of the CHIKV strains isolated from Mayotte carried the E1-A226V mutation, and the mutation was also found in Madagascar in 2007 [5] . The E1-A226V mutation was not present at the beginning of the Indian Ocean Islands outbreak (before September 2005). However, more than 90% of later viral strains found there had incorporated the mutation (December-March 2006), indicating a genotype switch during the winter season [5, 18, 20] .", "The E1-A226V mutation also enabled an increase in infectivity of Ae. albopictus when compared to its infectivity of Ae. aegypti [4, 11, 18, 30] , and with several factors taken together, Ae. albopictus has become the new preferred and more lethal vector for CHIKV [4, 5, 11] . In fact, Tsetsarkin et al. found that a Green Fluorescent Protein tagged E1-A226V virus was 100 times more infective to Ae. albopictus than it was to Ae. aegypti [4] . In all the Indian Ocean Islands, Ae. albopictus became the main vector for CHIKV within 1-2 y after CHIKV was introduced to the region [31] .", "Of note is that Ae. aegypti has most likely been established in North America for over 300 y, while Ae. albopictus has been in many areas of the US, since 1985, primarily in Florida [32] and since then has expanded its range in the country. Reiskind et al. set out to determine if Ae. aegypti and Ae. albopictus mosquitoes captured in Florida were susceptible to CHIKV infection by a La Reunion isolate [32] . Each mosquito tested was highly susceptible to infection by a full-length infectious clone of the La Réunion Island isolate, CHIKV LR2006 OPY1 strain. Even though the Ae. albopictus strains were more susceptible to infection, overall ecology and differences in human biting patterns need to be studied further Characteristically, there are two rounds of translation: (+) sense genomic RNA (49S9 = 11.7 kb) acts directly as mRNA and is partially translated (59 end) to produce non-structural proteins (nsp's). These proteins are responsible for replication and formation of a complementary", "(2) strand, the template for further (+) strand synthesis. Subgenomic mRNA (26 S = 4.1 kb) replication occurs through the synthesis of full-length (2) intermediate RNA, which is regulated by nsp4 and p123 precursor in early infection and later by mature nsp's. Translation of the newly synthesized sub-genomic RNA results in production of structural proteins such as Capsid and protein E2-6k-E1 (from 39 end of genome). Assembly occurs at the cell surface, and the envelope is acquired as the virus buds from the cell and release and maturation almost simultaneous occurred. Replication occurs in the cytoplasm and is very rapid (,4 h) [28, 29] . doi:10.1371/journal.pntd.0000623.g002 www.plosntds.org to gain a more accurate understanding of a potential CHIKV epidemic in the US [32] .", "During the 7 d preceding birth, no human mother has been reported to transmit the disease vertically. However, about 50% of newborns delivered while the mother was infected with CHIKV contracted the disease from their mother, despite the method of delivery. Furthermore, there have been instances of CHIKV transmission from mother to fetus causing congenital illness and fetal death [33] .", "During the 2005-2006 La Reunion Island outbreaks, Ramful et al. discovered that mothers could transmit CHIKV to their progeny during the perinatal period (Day 24 to Day +1) [33, 34] , and it is associated with a high degree of morbidity. By mean Day 4 of life, all of the neonates were symptomatic for CHIKV, exhibiting common CHIKF symptoms. Six neonates were confirmed to have contracted CHIKV and developed mengoencephalitis. Of those mothers who, during the La Reunion Island epidemic, were infected long before delivery, only three fetal deaths were reported [12, 33] . Ramful et al. theorized that motherto-child transmission most likely happens transplacentally shortly before delivery [33] . A similar study by Gerardin et al. reported nineteen cases of neonatal infection associated with intrapartum maternal viremia that progressed to develop encephalitis owing to vertical transmission from infected mothers [34] .", "Clinical and epidemiological similarities with dengue fever make CHIKV diagnosis difficult, which may lead physicians to misdiagnose CHIKV as dengue fever; therefore, the incidence of CHIKV may actually be higher than currently believed (Table 1 ) [6, 12, 35] .", "The amount of time elapsed since disease onset is the most critical parameter when choosing a diagnostic test. CHIKV can be detected and isolated by culturing with mosquito cells (C6/36), Vero cells (mammalian), or in mice [26] . However, this method can take at least a week and only achieves a high sensitivity during the viremic phase, which usually only lasts up to 48 h after the bite. Five days post-infection, the viral isolation approach has a low sensitivity but is still the preferred method for detecting the CHIKV strain [12, 26, 31, 35] . RT-PCR on the other hand is a faster and more sensitive method that can be used within the first week of disease onset [26] , and it is currently the most sensitive method for detecting and quantifying viral mRNA [4, 36] .", "Classic serological detection, by assays such as ELISA [37] , immunofluorescence [5, 38] , complement binding, and haemagglutination inhibition [39] , constitutes the second diagnostic tool used for biological diagnosis of CHIKV infection. These proven techniques are useful for detection of Antigen in mosquitoes during epidemiological studies. These assays detect virus-specific IgM and IgG, however the sensitivity and specificity of these assays has been poorly characterized. Viral competence, or the potential of viral infection and transmission, is an important parameter that can be quantified by ELISA, viral culture, and PCR.", "A study by Ng et al. showed biomarkers indicative of severe CHIKV infection [40] . They found decreased levels of RANTES and increased levels of Interleukin-6 (IL-6) and Interleukin-1b (IL-1b) that could be sued for CHIKV detection in patients as indicators of CHIKV-driven cytokine storm. Couderc et al. demonstrate another cytokine, type-I IFN, as a key player in the progression to CHIKV infection [26] . Using an IFN-a/b null mouse model, they demonstrated evidence of muscles, joints, and skin as privileged CHIKV targets, which is consistent with human pathology. Although Ng et al. concluded that RANTES levels were significantly suppressed in severe CHIKF patients [40] , interestingly, an increase in levels of RANTES has been observed in dengue infection [41] . Since the symptoms of CHIKF mimic those of dengue fever, results obtained from this study strongly suggest that RANTES could be a potential distinctive biomarker that differentiates between these two clinically similar", "diseases.", "There are no approved antiviral treatments currently available for CHIKV [1, 3, 12, 42] . Currently, CHIKF is treated symptomatically, usually with non-steroidal anti-inflammatory drugs or steroids, bed rest, and fluids. Movement and mild exercise are thought to decrease stiffness and morning arthralgia, but heavy exercise may exacerbate rheumatic symptoms. Corticosteroids may be used in cases of debilitating chronic CHIKV infection. There is a debate about the appropriateness of chloroquine as treatment for unresolved, non-steroidal anti-inflammatory drugresistant arthritis [43] . A study showed that viral production was www.plosntds.org drastically reduced at 16 h post-infection after treatment with 100 mM dec-RVKR-cmk (Decanoyl-Arg-Val-Lys-Arg-chloromethylketone), a furine inhibitor [42, 44] . Chloroquine acted by raising the pH, blocking low pH-dependent entry of virus into the cell. It is important to note that dec-RVKR-cmk or chloroquine only inhibited viral spreading from cell", "to cell, not CHIKV replication once it had entered the cell [43] . However, most would agree that the best weapon against CHIKV is prevention. A live CHIKV vaccine developed by the United States reached phase II clinical trial encompassing 59 healthy volunteers [45] . Eight percent of the volunteers experienced transient arthralgia, while 98% of the volunteers had seroconversion [45] . However, live CHIKV vaccines are still questionable. One cannot discount the risk of a live vaccine possibly inducing chronic rheumatism. Also, there is the question as to whether widespread use among the public could trigger mosquito transmission or lead to chronic infection or viral reversion [1] .", "An alternative approach would be to produce a chimeric vaccine against CHIKV. Wang et al. developed a chimeric alphavirus vaccine that is uniformly attenuated and does not cause reactogenicity in mice [3] . Three different versions of this vaccine were made using three different backbone vectors: Venezuelan equine encephalitis virus (VEEV) attenuated vaccine strain T-83, naturally attenuated eastern equine encephalitis virus (EEEV), and attenuated Sindbis virus (SINV). In short, CHIKV structural proteins were engineered into the backbones of the aforementioned vaccines to produce the chimeras [3] . These chimeras were found to stimulate a strong humoral immunity, and even at doses of 5.3-5.8 log 10 PFU, they did not trigger reactogenicity. When vaccinated mice were challenged with CHIKV, neither adult nor neonatal mice gained weight, had fever, or displayed signs of neurological illness. Upon comparison of the chimeras with the Army181/25 vaccine, the Army vaccine resulted in higher", "levels of viremia and replication in the joints of neonatal mice. Because the joints are known targets of CHIKV, Wang et al. noted their vaccine might avoid the negative reactogenic side effects of the Army vaccine. After being subcutaneously vaccinated with 5.3-5.8 log 10 PFU of the chimeric vaccines, mice produced strong neutralizing antibody titers. The VEEV and EEEV chimeras yielded higher neutralizing antibody titers than the SINV chimera without being more virulent. On top of this, the VEEV and EEEV CHIKV chimeras seemed to be more immunogenic than the Army vaccine despite the chimeras' lower viremia and replication in the joints of neonatal mice [3] .", "Tiwari et al. [46] adopted a different strategy using formalin inactivated CHIKV in combination with alhydrogel (Aluminum Hydroxide) as an adjuvant. This study clearly suggests that this vaccine elicits both humoral and cell-mediated immune responses in mice, providing its immunogenic potential. A recent study by Couderc et al. [47] showed passive immunization as a potential treatment for CHIKV infection. Using purified immunoglobulin extracted from convalescent CHIKV patients, they demonstrated effective neutralizing activity against CHIKV infection both in vitro and in vivo. This thereby establishes a potential preventive and therapeutic approach to combat CHIKV infection. Pathogenesis studies conducted with related alpha virus, like RRV, have shown the role of macrophages in persistence on infection [48] . They also demonstrated the role of RRV-specific CD8 T cells in clearing viral load in infected patients, thereby warranting similar investigations with CHIKV and the importance", "of investigating a cell-mediated immune response-based vaccine against CHIKV [49] .", "There are always certain risks associated with live attenuated or inactivated viral vaccines [50] . One way to avoid these potential problems is to construct a consensus-based DNA vaccine. DNA based vaccines have an improved safety profile as compared to live or attenuated vaccines [51, 52] . A consequence of CHIKV's rapid evolution is difficulty in constructing a vaccine that will be able to Figure 3 . Levels of CHIKV-specific IgG in mice immunized with CHIKV vaccines. Each group of C57BL/6 mice (n = 5) was immunized with 12.5 mg of pVax1 control vector or CHIKV vaccine plasmids as indicated at 0 and 2 wk. Mice were bled 2 wk after each immunization, and each group's serum pool was diluted to 1:100 and 1:500 for reaction with specific vaccine constructs. Serum was incubated for 1 h at 37uC on 96-well plates coated with 2 mg/ml of respective CHIKV peptides, and antibody was detected using anti-mouse IgG-HRP and OD was measured at 405 nm. doi:10.1371/journal.pntd.0000623.g003", "www.plosntds.org effectively protect large populations from multiple strains of the virus. One of the strengths of DNA consensus vaccines is its ability to induce cross-reactive immune responses against the three distinct phylogenetic groups of CHIKV. Also DNA-based vaccines can be produced more rapidly than protein-based vaccines.", "Recently, Muthumani et al. constructed a vaccine that was shown to induce both humoral and cellular immunity in vivo in 3-4-wk-old female C57/BL6 mice [49] . These mice were immunized using an in vivo electroporation method to deliver the vaccine into the quadriceps muscle. The consensus construct was designed against E1, E2, and the core protein capsid. To design the construct, they aligned 21 sequences of CHIKV isolated between 1952 and 2006, using strains from differing countries, including La Reunion Island. The most common nucleotide among the sequences was chosen at each position to be used in the consensus construct, taking care not to alter the reading frame. They conducted codon and RNA optimization, added a strong Kozak sequence, and substituted signal peptide with an immunoglobulin E leader sequence to improve vaccine efficacy.", "After immunizing the mice, spleens were harvested along with serum and tested to determine antibody titer. After three immunizations, consensus E1, E2, and C vaccines were shown to induce T-cell immune responses leading to strong IFN-c responses and proliferation in C57/BL6 mice. Furthermore, when compared with control mice, immunized mice had higher total IgG levels as well as higher anti-E1 specific, anti-E2 specific, and anti-C specific IgG antibodies, suggesting a strong humoral immune response ( Figure 3 ) and also specificity for the antigens encoded in the vaccine constructs ( Figure 4 ). Because of its promising results and the need for a safer vaccine, this consensus DNA vaccine deserves further investigation. Determining longevity of protective effects of the vaccine and persistence of antibody and IFN-c responses could be the next step of investigation. Challenged studies of immunized mice must also be carried out.", "CHIKV mosquito-borne disease has caused massive outbreaks for at least half a century but is no longer confined to the www.plosntds.org developing nations. It began to encroach into the boundaries of the developing world. As a result, the NIAID has designated CHIKV as a Category C pathogen alongside the influenza and SARS-CoV viruses [3] . Realization of the potential severity of this disease is exigent; for instance, if used as a biological weapon, the world economy could be severely crippled; if enough members of the armed forces were to become infected during a military deployment, military operations could be significantly affected. Efforts to monitor the disease will only provide minimal warning in a global society, and steps to prevent the morbidity and mortality associated with pandemic are imperative [21, 31] . Despite the gravity of its infectious potency and the fear of it being a potential biological weapon, there is currently no vaccine for CHIKV infections. Live", "attenuated vaccine trials were carried out in 2000, but funding for the project was discontinued. Newer approaches such as DNA vaccines appear promising over conventional strategies like live attenuated or inactivated virus and thus call for further investigation. Recent advances such electroporation delivery and incorporation of adjuvants has boosted DNA vaccine efficacy [51, 53] . Despite the low antibody response to DNA vaccines, other numerous advantages have overshadowed these minor drawbacks (Table 2) , the most important one being the ability to induce both humoral and cellular immune responses [51, 54] .", "Judging by recent success, such as the immunogenic construct developed by Muthumani et al., DNA vaccines could play a major role in combating CHIKV [49] . Vaccines are literally a critical component of CHIKV disease control and therefore research in this area is highly encouraged. The dramatic spread of dengue viruses (DENV) throughout tropical America since 1980 via the same vectors and human hosts underscores the risk to public health in the Americas. The adverse events associated with the current live vaccine are well documented [55] . Realizing these drawbacks, earnest efforts should be taken to develop new strategies to forestall further spread and complications." ]	[ 11 ]	3,829	5,688
1,689	What vectored the large epidemic in La Reunion Islands?	2,511	[ "Ae. albopictus" ]	[ "Chikungunya: A Potentially Emerging Epidemic?\n\nhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC2860491/\n\nSHA: f7c3160bef4169d29e2a8bdd79dd6e9056d4774c\n\nAuthors: Thiboutot, Michelle M.; Kannan, Senthil; Kawalekar, Omkar U.; Shedlock, Devon J.; Khan, Amir S.; Sarangan, Gopalsamy; Srikanth, Padma; Weiner, David B.; Muthumani, Karuppiah\nDate: 2010-04-27\nDOI: 10.1371/journal.pntd.0000623\nLicense: cc-by", "Abstract: Chikungunya virus is a mosquito-borne emerging pathogen that has a major health impact in humans and causes fever disease, headache, rash, nausea, vomiting, myalgia, and arthralgia. Indigenous to tropical Africa, recent large outbreaks have been reported in parts of South East Asia and several of its neighboring islands in 2005–07 and in Europe in 2007. Furthermore, positive cases have been confirmed in the United States in travelers returning from known outbreak areas. Currently, there is no vaccine or antiviral treatment. With the threat of an emerging global pandemic, the peculiar problems associated with the more immediate and seasonal epidemics warrant the development of an effective vaccine. In this review, we summarize the evidence supporting these concepts.", "Text: Chikungunya virus (CHIKV), a mosquito-borne pathogen listed by National Institute of Allergy and Infectious Diseases (NIAID) as a Category C Priority Pathogen that causes Chikungunya fever (CHIKF), has been spreading throughout Asia, Africa, and parts of Europe in recent times [1, 2, 3] . CHIKV is an arthropod-borne virus (arbovirus) and is transmitted to humans primarily by Aedes aegypti, the infamous yellow fever propagator [4, 5] . CHIKV infection is marked by severe joint pain, contorting its victims into unusual postures [6] . The disease gets its name from the Kimakonde vernacular language of Tanzania and Mozambique, and the word chikungunya means ''that which contorts or bends up'' and translates in Swahili to ''the illness of the bended walker'' [7, 8, 9] . In Africa, CHIKV is maintained in a sylvatic cycle among forest-dwelling Aedes spp. mosquitoes, wild primates, squirrels, birds, and rodents ( Figure 1 ) [10] . In Asia, the disease is vectored by Ae. aegypti and Ae.", "albopictus [11] . Transmission in Asia occurs in an urban cycle whereby the mosquito spreads the disease from an infected human to an uninfected human, following an epidemiological pattern similar to dengue fever [12] .", "The 2005-2006 epidemic of CHIKV in La Reunion islands in the Indian Ocean, spurred the discovery of a new vector species, Ae. albopictus [5] . Wrecking over one-third of the island's population, this epidemic peaked its devastation between January and February 2006, when over 46,000 cases came into light every week, including 284 deaths [5, 13] . Ae. albopictus is common in urban areas of the United States and is already flourishing in 36 states, raising grave concerns to the immunologically naive populace of the United States [14] .\n\nAccordingly, this review elaborately details the epidemiology and global expansion of CHIKV, describes its clinical features and pathogenesis and its symptoms and complications, and finally nominates a possible vaccine approach against CHIKV infection.", "CHIKV has been isolated into three genotypes based on phylogenetic studies. These genotypes, based on the gene sequences of an Envelope protein (E1), are Asian, East/Central/ South African, and West African [4, 11, 15] . Using phylogenetic models, Cherian et al. estimate that the Asian genotype of CHIKV emerged between 50 and 310 y ago, and the West and East African genotypes diverged between 100 and 840 y ago [15] . Since then, CHIKV has come a long way, with several mutations incorporated, and has continued to wreak epidemics in several regions. Recent activities of CHIKV include the Indian epidemic in 2005-2006, which was followed by a sudden explosion of cases in 2007. An estimated 1.3 million people across 13 states were reported to be infected in India [12, 16] , and CHIKV was also widespread in Malaysia, Sri Lanka, and Indonesia [17] . In July-August of 2007, CHIKV was reported in Italy, probably brought in by travelers from CHIKV-prone regions of India, Africa, and Indian", "Ocean islands such as Mauritius, Madagascar, and Seychelles. Few of the Italian isolates were found to have evolved from the Kerala isolate, which was associated with a A226V shift in E1 gene that represents a successful evolutionary adaptation in the mosquito vector similar to the ones observed in Reunion Island [2, 18, 19] .", "In recent times, with an increase in global travel, the risk for spreading CHIKV to non-endemic regions has heightened [1] . Several travelers have brought CHIKV home with them after visiting areas with actively infected populations [12, 20] . Such cases have been documented in European countries, Australia, Asia, and the United States [8, 21] . The United States has already reported at least twelve cases of travel-associated CHIKV, while France has reported 850 cases, and the United Kingdom 93 [8, 14] . Beyond this, CHIKV-infected travelers have also been diagnosed in Australia, Belgium, Canada, Czech Republic, French Guiana, Germany, Hong Kong, Italy, Japan, Kenya, Malaysia, Martinique, Norway, Switzerland, and Sri Lanka [21] . Some travelers were viremic, worrying public health officials about the spread of CHIKV to new areas [1, 8] .", "The incubation time for CHIKV is relatively short, requiring only 2-6 d with symptoms usually appearing 4-7 d post-infection [22] . Vazeille et al. detected CHIKV in the salivary glands of Ae. albopictus only 2 d after infection [5] . Upon infection, CHIKF tends to present itself in two phases. The first stage is acute, while the second stage, experienced by most but not all, is persistent, causing disabling polyarthritis. Characteristics of the acute phase include an abrupt onset of fever, arthralgia, and in some cases, maculopapular rash [6, 23] . The acute phase causes such intense joint and muscular pain that makes movement very difficult and prostrates its victims [6, 20] .", "Ninety-five percent of infected adults are symptomatic after infection, and of these, most become disabled for weeks to months as a result of decreased dexterity, loss of mobility, and delayed reaction. Eighteen months after disease onset, 40% of patients are found to still have anti-CHIKV IgM [6, 18, 23, 24] . The chronic stage of CHIKF is characterized by polyarthralgia that can last from weeks to years beyond the acute stage [6] . CHIKV has been shown to attack fibroblasts, explaining the involvement of muscles, joints, and skin connective tissues. The high number of nociceptive nerve endings found within the joints and muscle connective tissues can explain pain associated with CHIKF [25, 26] .", "More than 50% of patients who suffer from severe CHIKF are over 65 y old, and more than 33% of them die. Most adults who suffer from severe CHIKF have underlying medical conditions [6, 24, 27] . The other group that is disproportionately affected by severe CHIKV is children. Other complications associated with CHIKV, from most common to least common, include respiratory failure, cardiovascular decompensation, meningoencephalitis, severe acute hepatitis, severe cutaneous effects, other central nervous system problems, and kidney failure [6, 18, 20, 23, 24, 26, 27] .", "CHIKV undertakes a complex replication cycle upon host infection (Figure 2 ), which makes its genome susceptible to mutations [28, 29] . For instance, Ae. aegypti, responsible for epidemics in Kenya, Comoros, and Seychelles, carried CHIKV with an alanine in the 226 position of the E1 gene (E1-A226) [4, 18] . However, when the virus struck La Reunion Islands, a decline in population of Ae. aegypti, due to massive dichlorodiphenyltrichloroethane usage and dearth of Ae. albopictus species' www.plosntds.org population, resulted in an ecological pressure, favoring replacement of alanine at position 226 with valine (E1-A226V) [5] . This mutation allowed CHIKV's secondary vector species, Ae. albopictus, to supplement Ae. aegypti as its primary vector [5] .", "Within a year, the E1-A226V mutation was present in La Reunion Island, and Ae. albopictus apparently vectored the large epidemic infecting 34% of La Reunion Island's population [5] . All of the CHIKV strains isolated from Mayotte carried the E1-A226V mutation, and the mutation was also found in Madagascar in 2007 [5] . The E1-A226V mutation was not present at the beginning of the Indian Ocean Islands outbreak (before September 2005). However, more than 90% of later viral strains found there had incorporated the mutation (December-March 2006), indicating a genotype switch during the winter season [5, 18, 20] .", "The E1-A226V mutation also enabled an increase in infectivity of Ae. albopictus when compared to its infectivity of Ae. aegypti [4, 11, 18, 30] , and with several factors taken together, Ae. albopictus has become the new preferred and more lethal vector for CHIKV [4, 5, 11] . In fact, Tsetsarkin et al. found that a Green Fluorescent Protein tagged E1-A226V virus was 100 times more infective to Ae. albopictus than it was to Ae. aegypti [4] . In all the Indian Ocean Islands, Ae. albopictus became the main vector for CHIKV within 1-2 y after CHIKV was introduced to the region [31] .", "Of note is that Ae. aegypti has most likely been established in North America for over 300 y, while Ae. albopictus has been in many areas of the US, since 1985, primarily in Florida [32] and since then has expanded its range in the country. Reiskind et al. set out to determine if Ae. aegypti and Ae. albopictus mosquitoes captured in Florida were susceptible to CHIKV infection by a La Reunion isolate [32] . Each mosquito tested was highly susceptible to infection by a full-length infectious clone of the La Réunion Island isolate, CHIKV LR2006 OPY1 strain. Even though the Ae. albopictus strains were more susceptible to infection, overall ecology and differences in human biting patterns need to be studied further Characteristically, there are two rounds of translation: (+) sense genomic RNA (49S9 = 11.7 kb) acts directly as mRNA and is partially translated (59 end) to produce non-structural proteins (nsp's). These proteins are responsible for replication and formation of a complementary", "(2) strand, the template for further (+) strand synthesis. Subgenomic mRNA (26 S = 4.1 kb) replication occurs through the synthesis of full-length (2) intermediate RNA, which is regulated by nsp4 and p123 precursor in early infection and later by mature nsp's. Translation of the newly synthesized sub-genomic RNA results in production of structural proteins such as Capsid and protein E2-6k-E1 (from 39 end of genome). Assembly occurs at the cell surface, and the envelope is acquired as the virus buds from the cell and release and maturation almost simultaneous occurred. Replication occurs in the cytoplasm and is very rapid (,4 h) [28, 29] . doi:10.1371/journal.pntd.0000623.g002 www.plosntds.org to gain a more accurate understanding of a potential CHIKV epidemic in the US [32] .", "During the 7 d preceding birth, no human mother has been reported to transmit the disease vertically. However, about 50% of newborns delivered while the mother was infected with CHIKV contracted the disease from their mother, despite the method of delivery. Furthermore, there have been instances of CHIKV transmission from mother to fetus causing congenital illness and fetal death [33] .", "During the 2005-2006 La Reunion Island outbreaks, Ramful et al. discovered that mothers could transmit CHIKV to their progeny during the perinatal period (Day 24 to Day +1) [33, 34] , and it is associated with a high degree of morbidity. By mean Day 4 of life, all of the neonates were symptomatic for CHIKV, exhibiting common CHIKF symptoms. Six neonates were confirmed to have contracted CHIKV and developed mengoencephalitis. Of those mothers who, during the La Reunion Island epidemic, were infected long before delivery, only three fetal deaths were reported [12, 33] . Ramful et al. theorized that motherto-child transmission most likely happens transplacentally shortly before delivery [33] . A similar study by Gerardin et al. reported nineteen cases of neonatal infection associated with intrapartum maternal viremia that progressed to develop encephalitis owing to vertical transmission from infected mothers [34] .", "Clinical and epidemiological similarities with dengue fever make CHIKV diagnosis difficult, which may lead physicians to misdiagnose CHIKV as dengue fever; therefore, the incidence of CHIKV may actually be higher than currently believed (Table 1 ) [6, 12, 35] .", "The amount of time elapsed since disease onset is the most critical parameter when choosing a diagnostic test. CHIKV can be detected and isolated by culturing with mosquito cells (C6/36), Vero cells (mammalian), or in mice [26] . However, this method can take at least a week and only achieves a high sensitivity during the viremic phase, which usually only lasts up to 48 h after the bite. Five days post-infection, the viral isolation approach has a low sensitivity but is still the preferred method for detecting the CHIKV strain [12, 26, 31, 35] . RT-PCR on the other hand is a faster and more sensitive method that can be used within the first week of disease onset [26] , and it is currently the most sensitive method for detecting and quantifying viral mRNA [4, 36] .", "Classic serological detection, by assays such as ELISA [37] , immunofluorescence [5, 38] , complement binding, and haemagglutination inhibition [39] , constitutes the second diagnostic tool used for biological diagnosis of CHIKV infection. These proven techniques are useful for detection of Antigen in mosquitoes during epidemiological studies. These assays detect virus-specific IgM and IgG, however the sensitivity and specificity of these assays has been poorly characterized. Viral competence, or the potential of viral infection and transmission, is an important parameter that can be quantified by ELISA, viral culture, and PCR.", "A study by Ng et al. showed biomarkers indicative of severe CHIKV infection [40] . They found decreased levels of RANTES and increased levels of Interleukin-6 (IL-6) and Interleukin-1b (IL-1b) that could be sued for CHIKV detection in patients as indicators of CHIKV-driven cytokine storm. Couderc et al. demonstrate another cytokine, type-I IFN, as a key player in the progression to CHIKV infection [26] . Using an IFN-a/b null mouse model, they demonstrated evidence of muscles, joints, and skin as privileged CHIKV targets, which is consistent with human pathology. Although Ng et al. concluded that RANTES levels were significantly suppressed in severe CHIKF patients [40] , interestingly, an increase in levels of RANTES has been observed in dengue infection [41] . Since the symptoms of CHIKF mimic those of dengue fever, results obtained from this study strongly suggest that RANTES could be a potential distinctive biomarker that differentiates between these two clinically similar", "diseases.", "There are no approved antiviral treatments currently available for CHIKV [1, 3, 12, 42] . Currently, CHIKF is treated symptomatically, usually with non-steroidal anti-inflammatory drugs or steroids, bed rest, and fluids. Movement and mild exercise are thought to decrease stiffness and morning arthralgia, but heavy exercise may exacerbate rheumatic symptoms. Corticosteroids may be used in cases of debilitating chronic CHIKV infection. There is a debate about the appropriateness of chloroquine as treatment for unresolved, non-steroidal anti-inflammatory drugresistant arthritis [43] . A study showed that viral production was www.plosntds.org drastically reduced at 16 h post-infection after treatment with 100 mM dec-RVKR-cmk (Decanoyl-Arg-Val-Lys-Arg-chloromethylketone), a furine inhibitor [42, 44] . Chloroquine acted by raising the pH, blocking low pH-dependent entry of virus into the cell. It is important to note that dec-RVKR-cmk or chloroquine only inhibited viral spreading from cell", "to cell, not CHIKV replication once it had entered the cell [43] . However, most would agree that the best weapon against CHIKV is prevention. A live CHIKV vaccine developed by the United States reached phase II clinical trial encompassing 59 healthy volunteers [45] . Eight percent of the volunteers experienced transient arthralgia, while 98% of the volunteers had seroconversion [45] . However, live CHIKV vaccines are still questionable. One cannot discount the risk of a live vaccine possibly inducing chronic rheumatism. Also, there is the question as to whether widespread use among the public could trigger mosquito transmission or lead to chronic infection or viral reversion [1] .", "An alternative approach would be to produce a chimeric vaccine against CHIKV. Wang et al. developed a chimeric alphavirus vaccine that is uniformly attenuated and does not cause reactogenicity in mice [3] . Three different versions of this vaccine were made using three different backbone vectors: Venezuelan equine encephalitis virus (VEEV) attenuated vaccine strain T-83, naturally attenuated eastern equine encephalitis virus (EEEV), and attenuated Sindbis virus (SINV). In short, CHIKV structural proteins were engineered into the backbones of the aforementioned vaccines to produce the chimeras [3] . These chimeras were found to stimulate a strong humoral immunity, and even at doses of 5.3-5.8 log 10 PFU, they did not trigger reactogenicity. When vaccinated mice were challenged with CHIKV, neither adult nor neonatal mice gained weight, had fever, or displayed signs of neurological illness. Upon comparison of the chimeras with the Army181/25 vaccine, the Army vaccine resulted in higher", "levels of viremia and replication in the joints of neonatal mice. Because the joints are known targets of CHIKV, Wang et al. noted their vaccine might avoid the negative reactogenic side effects of the Army vaccine. After being subcutaneously vaccinated with 5.3-5.8 log 10 PFU of the chimeric vaccines, mice produced strong neutralizing antibody titers. The VEEV and EEEV chimeras yielded higher neutralizing antibody titers than the SINV chimera without being more virulent. On top of this, the VEEV and EEEV CHIKV chimeras seemed to be more immunogenic than the Army vaccine despite the chimeras' lower viremia and replication in the joints of neonatal mice [3] .", "Tiwari et al. [46] adopted a different strategy using formalin inactivated CHIKV in combination with alhydrogel (Aluminum Hydroxide) as an adjuvant. This study clearly suggests that this vaccine elicits both humoral and cell-mediated immune responses in mice, providing its immunogenic potential. A recent study by Couderc et al. [47] showed passive immunization as a potential treatment for CHIKV infection. Using purified immunoglobulin extracted from convalescent CHIKV patients, they demonstrated effective neutralizing activity against CHIKV infection both in vitro and in vivo. This thereby establishes a potential preventive and therapeutic approach to combat CHIKV infection. Pathogenesis studies conducted with related alpha virus, like RRV, have shown the role of macrophages in persistence on infection [48] . They also demonstrated the role of RRV-specific CD8 T cells in clearing viral load in infected patients, thereby warranting similar investigations with CHIKV and the importance", "of investigating a cell-mediated immune response-based vaccine against CHIKV [49] .", "There are always certain risks associated with live attenuated or inactivated viral vaccines [50] . One way to avoid these potential problems is to construct a consensus-based DNA vaccine. DNA based vaccines have an improved safety profile as compared to live or attenuated vaccines [51, 52] . A consequence of CHIKV's rapid evolution is difficulty in constructing a vaccine that will be able to Figure 3 . Levels of CHIKV-specific IgG in mice immunized with CHIKV vaccines. Each group of C57BL/6 mice (n = 5) was immunized with 12.5 mg of pVax1 control vector or CHIKV vaccine plasmids as indicated at 0 and 2 wk. Mice were bled 2 wk after each immunization, and each group's serum pool was diluted to 1:100 and 1:500 for reaction with specific vaccine constructs. Serum was incubated for 1 h at 37uC on 96-well plates coated with 2 mg/ml of respective CHIKV peptides, and antibody was detected using anti-mouse IgG-HRP and OD was measured at 405 nm. doi:10.1371/journal.pntd.0000623.g003", "www.plosntds.org effectively protect large populations from multiple strains of the virus. One of the strengths of DNA consensus vaccines is its ability to induce cross-reactive immune responses against the three distinct phylogenetic groups of CHIKV. Also DNA-based vaccines can be produced more rapidly than protein-based vaccines.", "Recently, Muthumani et al. constructed a vaccine that was shown to induce both humoral and cellular immunity in vivo in 3-4-wk-old female C57/BL6 mice [49] . These mice were immunized using an in vivo electroporation method to deliver the vaccine into the quadriceps muscle. The consensus construct was designed against E1, E2, and the core protein capsid. To design the construct, they aligned 21 sequences of CHIKV isolated between 1952 and 2006, using strains from differing countries, including La Reunion Island. The most common nucleotide among the sequences was chosen at each position to be used in the consensus construct, taking care not to alter the reading frame. They conducted codon and RNA optimization, added a strong Kozak sequence, and substituted signal peptide with an immunoglobulin E leader sequence to improve vaccine efficacy.", "After immunizing the mice, spleens were harvested along with serum and tested to determine antibody titer. After three immunizations, consensus E1, E2, and C vaccines were shown to induce T-cell immune responses leading to strong IFN-c responses and proliferation in C57/BL6 mice. Furthermore, when compared with control mice, immunized mice had higher total IgG levels as well as higher anti-E1 specific, anti-E2 specific, and anti-C specific IgG antibodies, suggesting a strong humoral immune response ( Figure 3 ) and also specificity for the antigens encoded in the vaccine constructs ( Figure 4 ). Because of its promising results and the need for a safer vaccine, this consensus DNA vaccine deserves further investigation. Determining longevity of protective effects of the vaccine and persistence of antibody and IFN-c responses could be the next step of investigation. Challenged studies of immunized mice must also be carried out.", "CHIKV mosquito-borne disease has caused massive outbreaks for at least half a century but is no longer confined to the www.plosntds.org developing nations. It began to encroach into the boundaries of the developing world. As a result, the NIAID has designated CHIKV as a Category C pathogen alongside the influenza and SARS-CoV viruses [3] . Realization of the potential severity of this disease is exigent; for instance, if used as a biological weapon, the world economy could be severely crippled; if enough members of the armed forces were to become infected during a military deployment, military operations could be significantly affected. Efforts to monitor the disease will only provide minimal warning in a global society, and steps to prevent the morbidity and mortality associated with pandemic are imperative [21, 31] . Despite the gravity of its infectious potency and the fear of it being a potential biological weapon, there is currently no vaccine for CHIKV infections. Live", "attenuated vaccine trials were carried out in 2000, but funding for the project was discontinued. Newer approaches such as DNA vaccines appear promising over conventional strategies like live attenuated or inactivated virus and thus call for further investigation. Recent advances such electroporation delivery and incorporation of adjuvants has boosted DNA vaccine efficacy [51, 53] . Despite the low antibody response to DNA vaccines, other numerous advantages have overshadowed these minor drawbacks (Table 2) , the most important one being the ability to induce both humoral and cellular immune responses [51, 54] .", "Judging by recent success, such as the immunogenic construct developed by Muthumani et al., DNA vaccines could play a major role in combating CHIKV [49] . Vaccines are literally a critical component of CHIKV disease control and therefore research in this area is highly encouraged. The dramatic spread of dengue viruses (DENV) throughout tropical America since 1980 via the same vectors and human hosts underscores the risk to public health in the Americas. The adverse events associated with the current live vaccine are well documented [55] . Realizing these drawbacks, earnest efforts should be taken to develop new strategies to forestall further spread and complications." ]	[ 4 ]	3,829	5,688
1,689	What percentage of population was affected?	2,512	[ "34%" ]	[ "Chikungunya: A Potentially Emerging Epidemic?\n\nhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC2860491/\n\nSHA: f7c3160bef4169d29e2a8bdd79dd6e9056d4774c\n\nAuthors: Thiboutot, Michelle M.; Kannan, Senthil; Kawalekar, Omkar U.; Shedlock, Devon J.; Khan, Amir S.; Sarangan, Gopalsamy; Srikanth, Padma; Weiner, David B.; Muthumani, Karuppiah\nDate: 2010-04-27\nDOI: 10.1371/journal.pntd.0000623\nLicense: cc-by", "Abstract: Chikungunya virus is a mosquito-borne emerging pathogen that has a major health impact in humans and causes fever disease, headache, rash, nausea, vomiting, myalgia, and arthralgia. Indigenous to tropical Africa, recent large outbreaks have been reported in parts of South East Asia and several of its neighboring islands in 2005–07 and in Europe in 2007. Furthermore, positive cases have been confirmed in the United States in travelers returning from known outbreak areas. Currently, there is no vaccine or antiviral treatment. With the threat of an emerging global pandemic, the peculiar problems associated with the more immediate and seasonal epidemics warrant the development of an effective vaccine. In this review, we summarize the evidence supporting these concepts.", "Text: Chikungunya virus (CHIKV), a mosquito-borne pathogen listed by National Institute of Allergy and Infectious Diseases (NIAID) as a Category C Priority Pathogen that causes Chikungunya fever (CHIKF), has been spreading throughout Asia, Africa, and parts of Europe in recent times [1, 2, 3] . CHIKV is an arthropod-borne virus (arbovirus) and is transmitted to humans primarily by Aedes aegypti, the infamous yellow fever propagator [4, 5] . CHIKV infection is marked by severe joint pain, contorting its victims into unusual postures [6] . The disease gets its name from the Kimakonde vernacular language of Tanzania and Mozambique, and the word chikungunya means ''that which contorts or bends up'' and translates in Swahili to ''the illness of the bended walker'' [7, 8, 9] . In Africa, CHIKV is maintained in a sylvatic cycle among forest-dwelling Aedes spp. mosquitoes, wild primates, squirrels, birds, and rodents ( Figure 1 ) [10] . In Asia, the disease is vectored by Ae. aegypti and Ae.", "albopictus [11] . Transmission in Asia occurs in an urban cycle whereby the mosquito spreads the disease from an infected human to an uninfected human, following an epidemiological pattern similar to dengue fever [12] .", "The 2005-2006 epidemic of CHIKV in La Reunion islands in the Indian Ocean, spurred the discovery of a new vector species, Ae. albopictus [5] . Wrecking over one-third of the island's population, this epidemic peaked its devastation between January and February 2006, when over 46,000 cases came into light every week, including 284 deaths [5, 13] . Ae. albopictus is common in urban areas of the United States and is already flourishing in 36 states, raising grave concerns to the immunologically naive populace of the United States [14] .\n\nAccordingly, this review elaborately details the epidemiology and global expansion of CHIKV, describes its clinical features and pathogenesis and its symptoms and complications, and finally nominates a possible vaccine approach against CHIKV infection.", "CHIKV has been isolated into three genotypes based on phylogenetic studies. These genotypes, based on the gene sequences of an Envelope protein (E1), are Asian, East/Central/ South African, and West African [4, 11, 15] . Using phylogenetic models, Cherian et al. estimate that the Asian genotype of CHIKV emerged between 50 and 310 y ago, and the West and East African genotypes diverged between 100 and 840 y ago [15] . Since then, CHIKV has come a long way, with several mutations incorporated, and has continued to wreak epidemics in several regions. Recent activities of CHIKV include the Indian epidemic in 2005-2006, which was followed by a sudden explosion of cases in 2007. An estimated 1.3 million people across 13 states were reported to be infected in India [12, 16] , and CHIKV was also widespread in Malaysia, Sri Lanka, and Indonesia [17] . In July-August of 2007, CHIKV was reported in Italy, probably brought in by travelers from CHIKV-prone regions of India, Africa, and Indian", "Ocean islands such as Mauritius, Madagascar, and Seychelles. Few of the Italian isolates were found to have evolved from the Kerala isolate, which was associated with a A226V shift in E1 gene that represents a successful evolutionary adaptation in the mosquito vector similar to the ones observed in Reunion Island [2, 18, 19] .", "In recent times, with an increase in global travel, the risk for spreading CHIKV to non-endemic regions has heightened [1] . Several travelers have brought CHIKV home with them after visiting areas with actively infected populations [12, 20] . Such cases have been documented in European countries, Australia, Asia, and the United States [8, 21] . The United States has already reported at least twelve cases of travel-associated CHIKV, while France has reported 850 cases, and the United Kingdom 93 [8, 14] . Beyond this, CHIKV-infected travelers have also been diagnosed in Australia, Belgium, Canada, Czech Republic, French Guiana, Germany, Hong Kong, Italy, Japan, Kenya, Malaysia, Martinique, Norway, Switzerland, and Sri Lanka [21] . Some travelers were viremic, worrying public health officials about the spread of CHIKV to new areas [1, 8] .", "The incubation time for CHIKV is relatively short, requiring only 2-6 d with symptoms usually appearing 4-7 d post-infection [22] . Vazeille et al. detected CHIKV in the salivary glands of Ae. albopictus only 2 d after infection [5] . Upon infection, CHIKF tends to present itself in two phases. The first stage is acute, while the second stage, experienced by most but not all, is persistent, causing disabling polyarthritis. Characteristics of the acute phase include an abrupt onset of fever, arthralgia, and in some cases, maculopapular rash [6, 23] . The acute phase causes such intense joint and muscular pain that makes movement very difficult and prostrates its victims [6, 20] .", "Ninety-five percent of infected adults are symptomatic after infection, and of these, most become disabled for weeks to months as a result of decreased dexterity, loss of mobility, and delayed reaction. Eighteen months after disease onset, 40% of patients are found to still have anti-CHIKV IgM [6, 18, 23, 24] . The chronic stage of CHIKF is characterized by polyarthralgia that can last from weeks to years beyond the acute stage [6] . CHIKV has been shown to attack fibroblasts, explaining the involvement of muscles, joints, and skin connective tissues. The high number of nociceptive nerve endings found within the joints and muscle connective tissues can explain pain associated with CHIKF [25, 26] .", "More than 50% of patients who suffer from severe CHIKF are over 65 y old, and more than 33% of them die. Most adults who suffer from severe CHIKF have underlying medical conditions [6, 24, 27] . The other group that is disproportionately affected by severe CHIKV is children. Other complications associated with CHIKV, from most common to least common, include respiratory failure, cardiovascular decompensation, meningoencephalitis, severe acute hepatitis, severe cutaneous effects, other central nervous system problems, and kidney failure [6, 18, 20, 23, 24, 26, 27] .", "CHIKV undertakes a complex replication cycle upon host infection (Figure 2 ), which makes its genome susceptible to mutations [28, 29] . For instance, Ae. aegypti, responsible for epidemics in Kenya, Comoros, and Seychelles, carried CHIKV with an alanine in the 226 position of the E1 gene (E1-A226) [4, 18] . However, when the virus struck La Reunion Islands, a decline in population of Ae. aegypti, due to massive dichlorodiphenyltrichloroethane usage and dearth of Ae. albopictus species' www.plosntds.org population, resulted in an ecological pressure, favoring replacement of alanine at position 226 with valine (E1-A226V) [5] . This mutation allowed CHIKV's secondary vector species, Ae. albopictus, to supplement Ae. aegypti as its primary vector [5] .", "Within a year, the E1-A226V mutation was present in La Reunion Island, and Ae. albopictus apparently vectored the large epidemic infecting 34% of La Reunion Island's population [5] . All of the CHIKV strains isolated from Mayotte carried the E1-A226V mutation, and the mutation was also found in Madagascar in 2007 [5] . The E1-A226V mutation was not present at the beginning of the Indian Ocean Islands outbreak (before September 2005). However, more than 90% of later viral strains found there had incorporated the mutation (December-March 2006), indicating a genotype switch during the winter season [5, 18, 20] .", "The E1-A226V mutation also enabled an increase in infectivity of Ae. albopictus when compared to its infectivity of Ae. aegypti [4, 11, 18, 30] , and with several factors taken together, Ae. albopictus has become the new preferred and more lethal vector for CHIKV [4, 5, 11] . In fact, Tsetsarkin et al. found that a Green Fluorescent Protein tagged E1-A226V virus was 100 times more infective to Ae. albopictus than it was to Ae. aegypti [4] . In all the Indian Ocean Islands, Ae. albopictus became the main vector for CHIKV within 1-2 y after CHIKV was introduced to the region [31] .", "Of note is that Ae. aegypti has most likely been established in North America for over 300 y, while Ae. albopictus has been in many areas of the US, since 1985, primarily in Florida [32] and since then has expanded its range in the country. Reiskind et al. set out to determine if Ae. aegypti and Ae. albopictus mosquitoes captured in Florida were susceptible to CHIKV infection by a La Reunion isolate [32] . Each mosquito tested was highly susceptible to infection by a full-length infectious clone of the La Réunion Island isolate, CHIKV LR2006 OPY1 strain. Even though the Ae. albopictus strains were more susceptible to infection, overall ecology and differences in human biting patterns need to be studied further Characteristically, there are two rounds of translation: (+) sense genomic RNA (49S9 = 11.7 kb) acts directly as mRNA and is partially translated (59 end) to produce non-structural proteins (nsp's). These proteins are responsible for replication and formation of a complementary", "(2) strand, the template for further (+) strand synthesis. Subgenomic mRNA (26 S = 4.1 kb) replication occurs through the synthesis of full-length (2) intermediate RNA, which is regulated by nsp4 and p123 precursor in early infection and later by mature nsp's. Translation of the newly synthesized sub-genomic RNA results in production of structural proteins such as Capsid and protein E2-6k-E1 (from 39 end of genome). Assembly occurs at the cell surface, and the envelope is acquired as the virus buds from the cell and release and maturation almost simultaneous occurred. Replication occurs in the cytoplasm and is very rapid (,4 h) [28, 29] . doi:10.1371/journal.pntd.0000623.g002 www.plosntds.org to gain a more accurate understanding of a potential CHIKV epidemic in the US [32] .", "During the 7 d preceding birth, no human mother has been reported to transmit the disease vertically. However, about 50% of newborns delivered while the mother was infected with CHIKV contracted the disease from their mother, despite the method of delivery. Furthermore, there have been instances of CHIKV transmission from mother to fetus causing congenital illness and fetal death [33] .", "During the 2005-2006 La Reunion Island outbreaks, Ramful et al. discovered that mothers could transmit CHIKV to their progeny during the perinatal period (Day 24 to Day +1) [33, 34] , and it is associated with a high degree of morbidity. By mean Day 4 of life, all of the neonates were symptomatic for CHIKV, exhibiting common CHIKF symptoms. Six neonates were confirmed to have contracted CHIKV and developed mengoencephalitis. Of those mothers who, during the La Reunion Island epidemic, were infected long before delivery, only three fetal deaths were reported [12, 33] . Ramful et al. theorized that motherto-child transmission most likely happens transplacentally shortly before delivery [33] . A similar study by Gerardin et al. reported nineteen cases of neonatal infection associated with intrapartum maternal viremia that progressed to develop encephalitis owing to vertical transmission from infected mothers [34] .", "Clinical and epidemiological similarities with dengue fever make CHIKV diagnosis difficult, which may lead physicians to misdiagnose CHIKV as dengue fever; therefore, the incidence of CHIKV may actually be higher than currently believed (Table 1 ) [6, 12, 35] .", "The amount of time elapsed since disease onset is the most critical parameter when choosing a diagnostic test. CHIKV can be detected and isolated by culturing with mosquito cells (C6/36), Vero cells (mammalian), or in mice [26] . However, this method can take at least a week and only achieves a high sensitivity during the viremic phase, which usually only lasts up to 48 h after the bite. Five days post-infection, the viral isolation approach has a low sensitivity but is still the preferred method for detecting the CHIKV strain [12, 26, 31, 35] . RT-PCR on the other hand is a faster and more sensitive method that can be used within the first week of disease onset [26] , and it is currently the most sensitive method for detecting and quantifying viral mRNA [4, 36] .", "Classic serological detection, by assays such as ELISA [37] , immunofluorescence [5, 38] , complement binding, and haemagglutination inhibition [39] , constitutes the second diagnostic tool used for biological diagnosis of CHIKV infection. These proven techniques are useful for detection of Antigen in mosquitoes during epidemiological studies. These assays detect virus-specific IgM and IgG, however the sensitivity and specificity of these assays has been poorly characterized. Viral competence, or the potential of viral infection and transmission, is an important parameter that can be quantified by ELISA, viral culture, and PCR.", "A study by Ng et al. showed biomarkers indicative of severe CHIKV infection [40] . They found decreased levels of RANTES and increased levels of Interleukin-6 (IL-6) and Interleukin-1b (IL-1b) that could be sued for CHIKV detection in patients as indicators of CHIKV-driven cytokine storm. Couderc et al. demonstrate another cytokine, type-I IFN, as a key player in the progression to CHIKV infection [26] . Using an IFN-a/b null mouse model, they demonstrated evidence of muscles, joints, and skin as privileged CHIKV targets, which is consistent with human pathology. Although Ng et al. concluded that RANTES levels were significantly suppressed in severe CHIKF patients [40] , interestingly, an increase in levels of RANTES has been observed in dengue infection [41] . Since the symptoms of CHIKF mimic those of dengue fever, results obtained from this study strongly suggest that RANTES could be a potential distinctive biomarker that differentiates between these two clinically similar", "diseases.", "There are no approved antiviral treatments currently available for CHIKV [1, 3, 12, 42] . Currently, CHIKF is treated symptomatically, usually with non-steroidal anti-inflammatory drugs or steroids, bed rest, and fluids. Movement and mild exercise are thought to decrease stiffness and morning arthralgia, but heavy exercise may exacerbate rheumatic symptoms. Corticosteroids may be used in cases of debilitating chronic CHIKV infection. There is a debate about the appropriateness of chloroquine as treatment for unresolved, non-steroidal anti-inflammatory drugresistant arthritis [43] . A study showed that viral production was www.plosntds.org drastically reduced at 16 h post-infection after treatment with 100 mM dec-RVKR-cmk (Decanoyl-Arg-Val-Lys-Arg-chloromethylketone), a furine inhibitor [42, 44] . Chloroquine acted by raising the pH, blocking low pH-dependent entry of virus into the cell. It is important to note that dec-RVKR-cmk or chloroquine only inhibited viral spreading from cell", "to cell, not CHIKV replication once it had entered the cell [43] . However, most would agree that the best weapon against CHIKV is prevention. A live CHIKV vaccine developed by the United States reached phase II clinical trial encompassing 59 healthy volunteers [45] . Eight percent of the volunteers experienced transient arthralgia, while 98% of the volunteers had seroconversion [45] . However, live CHIKV vaccines are still questionable. One cannot discount the risk of a live vaccine possibly inducing chronic rheumatism. Also, there is the question as to whether widespread use among the public could trigger mosquito transmission or lead to chronic infection or viral reversion [1] .", "An alternative approach would be to produce a chimeric vaccine against CHIKV. Wang et al. developed a chimeric alphavirus vaccine that is uniformly attenuated and does not cause reactogenicity in mice [3] . Three different versions of this vaccine were made using three different backbone vectors: Venezuelan equine encephalitis virus (VEEV) attenuated vaccine strain T-83, naturally attenuated eastern equine encephalitis virus (EEEV), and attenuated Sindbis virus (SINV). In short, CHIKV structural proteins were engineered into the backbones of the aforementioned vaccines to produce the chimeras [3] . These chimeras were found to stimulate a strong humoral immunity, and even at doses of 5.3-5.8 log 10 PFU, they did not trigger reactogenicity. When vaccinated mice were challenged with CHIKV, neither adult nor neonatal mice gained weight, had fever, or displayed signs of neurological illness. Upon comparison of the chimeras with the Army181/25 vaccine, the Army vaccine resulted in higher", "levels of viremia and replication in the joints of neonatal mice. Because the joints are known targets of CHIKV, Wang et al. noted their vaccine might avoid the negative reactogenic side effects of the Army vaccine. After being subcutaneously vaccinated with 5.3-5.8 log 10 PFU of the chimeric vaccines, mice produced strong neutralizing antibody titers. The VEEV and EEEV chimeras yielded higher neutralizing antibody titers than the SINV chimera without being more virulent. On top of this, the VEEV and EEEV CHIKV chimeras seemed to be more immunogenic than the Army vaccine despite the chimeras' lower viremia and replication in the joints of neonatal mice [3] .", "Tiwari et al. [46] adopted a different strategy using formalin inactivated CHIKV in combination with alhydrogel (Aluminum Hydroxide) as an adjuvant. This study clearly suggests that this vaccine elicits both humoral and cell-mediated immune responses in mice, providing its immunogenic potential. A recent study by Couderc et al. [47] showed passive immunization as a potential treatment for CHIKV infection. Using purified immunoglobulin extracted from convalescent CHIKV patients, they demonstrated effective neutralizing activity against CHIKV infection both in vitro and in vivo. This thereby establishes a potential preventive and therapeutic approach to combat CHIKV infection. Pathogenesis studies conducted with related alpha virus, like RRV, have shown the role of macrophages in persistence on infection [48] . They also demonstrated the role of RRV-specific CD8 T cells in clearing viral load in infected patients, thereby warranting similar investigations with CHIKV and the importance", "of investigating a cell-mediated immune response-based vaccine against CHIKV [49] .", "There are always certain risks associated with live attenuated or inactivated viral vaccines [50] . One way to avoid these potential problems is to construct a consensus-based DNA vaccine. DNA based vaccines have an improved safety profile as compared to live or attenuated vaccines [51, 52] . A consequence of CHIKV's rapid evolution is difficulty in constructing a vaccine that will be able to Figure 3 . Levels of CHIKV-specific IgG in mice immunized with CHIKV vaccines. Each group of C57BL/6 mice (n = 5) was immunized with 12.5 mg of pVax1 control vector or CHIKV vaccine plasmids as indicated at 0 and 2 wk. Mice were bled 2 wk after each immunization, and each group's serum pool was diluted to 1:100 and 1:500 for reaction with specific vaccine constructs. Serum was incubated for 1 h at 37uC on 96-well plates coated with 2 mg/ml of respective CHIKV peptides, and antibody was detected using anti-mouse IgG-HRP and OD was measured at 405 nm. doi:10.1371/journal.pntd.0000623.g003", "www.plosntds.org effectively protect large populations from multiple strains of the virus. One of the strengths of DNA consensus vaccines is its ability to induce cross-reactive immune responses against the three distinct phylogenetic groups of CHIKV. Also DNA-based vaccines can be produced more rapidly than protein-based vaccines.", "Recently, Muthumani et al. constructed a vaccine that was shown to induce both humoral and cellular immunity in vivo in 3-4-wk-old female C57/BL6 mice [49] . These mice were immunized using an in vivo electroporation method to deliver the vaccine into the quadriceps muscle. The consensus construct was designed against E1, E2, and the core protein capsid. To design the construct, they aligned 21 sequences of CHIKV isolated between 1952 and 2006, using strains from differing countries, including La Reunion Island. The most common nucleotide among the sequences was chosen at each position to be used in the consensus construct, taking care not to alter the reading frame. They conducted codon and RNA optimization, added a strong Kozak sequence, and substituted signal peptide with an immunoglobulin E leader sequence to improve vaccine efficacy.", "After immunizing the mice, spleens were harvested along with serum and tested to determine antibody titer. After three immunizations, consensus E1, E2, and C vaccines were shown to induce T-cell immune responses leading to strong IFN-c responses and proliferation in C57/BL6 mice. Furthermore, when compared with control mice, immunized mice had higher total IgG levels as well as higher anti-E1 specific, anti-E2 specific, and anti-C specific IgG antibodies, suggesting a strong humoral immune response ( Figure 3 ) and also specificity for the antigens encoded in the vaccine constructs ( Figure 4 ). Because of its promising results and the need for a safer vaccine, this consensus DNA vaccine deserves further investigation. Determining longevity of protective effects of the vaccine and persistence of antibody and IFN-c responses could be the next step of investigation. Challenged studies of immunized mice must also be carried out.", "CHIKV mosquito-borne disease has caused massive outbreaks for at least half a century but is no longer confined to the www.plosntds.org developing nations. It began to encroach into the boundaries of the developing world. As a result, the NIAID has designated CHIKV as a Category C pathogen alongside the influenza and SARS-CoV viruses [3] . Realization of the potential severity of this disease is exigent; for instance, if used as a biological weapon, the world economy could be severely crippled; if enough members of the armed forces were to become infected during a military deployment, military operations could be significantly affected. Efforts to monitor the disease will only provide minimal warning in a global society, and steps to prevent the morbidity and mortality associated with pandemic are imperative [21, 31] . Despite the gravity of its infectious potency and the fear of it being a potential biological weapon, there is currently no vaccine for CHIKV infections. Live", "attenuated vaccine trials were carried out in 2000, but funding for the project was discontinued. Newer approaches such as DNA vaccines appear promising over conventional strategies like live attenuated or inactivated virus and thus call for further investigation. Recent advances such electroporation delivery and incorporation of adjuvants has boosted DNA vaccine efficacy [51, 53] . Despite the low antibody response to DNA vaccines, other numerous advantages have overshadowed these minor drawbacks (Table 2) , the most important one being the ability to induce both humoral and cellular immune responses [51, 54] .", "Judging by recent success, such as the immunogenic construct developed by Muthumani et al., DNA vaccines could play a major role in combating CHIKV [49] . Vaccines are literally a critical component of CHIKV disease control and therefore research in this area is highly encouraged. The dramatic spread of dengue viruses (DENV) throughout tropical America since 1980 via the same vectors and human hosts underscores the risk to public health in the Americas. The adverse events associated with the current live vaccine are well documented [55] . Realizing these drawbacks, earnest efforts should be taken to develop new strategies to forestall further spread and complications." ]	[ 12 ]	3,829	5,688
1,689	Where were the CHIKV strain found?	2,513	[ "All of the CHIKV strains isolated from Mayotte carried the E1-A226V mutation, and the mutation was also found in Madagascar in 2007 [" ]	[ "Chikungunya: A Potentially Emerging Epidemic?\n\nhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC2860491/\n\nSHA: f7c3160bef4169d29e2a8bdd79dd6e9056d4774c\n\nAuthors: Thiboutot, Michelle M.; Kannan, Senthil; Kawalekar, Omkar U.; Shedlock, Devon J.; Khan, Amir S.; Sarangan, Gopalsamy; Srikanth, Padma; Weiner, David B.; Muthumani, Karuppiah\nDate: 2010-04-27\nDOI: 10.1371/journal.pntd.0000623\nLicense: cc-by", "Abstract: Chikungunya virus is a mosquito-borne emerging pathogen that has a major health impact in humans and causes fever disease, headache, rash, nausea, vomiting, myalgia, and arthralgia. Indigenous to tropical Africa, recent large outbreaks have been reported in parts of South East Asia and several of its neighboring islands in 2005–07 and in Europe in 2007. Furthermore, positive cases have been confirmed in the United States in travelers returning from known outbreak areas. Currently, there is no vaccine or antiviral treatment. With the threat of an emerging global pandemic, the peculiar problems associated with the more immediate and seasonal epidemics warrant the development of an effective vaccine. In this review, we summarize the evidence supporting these concepts.", "Text: Chikungunya virus (CHIKV), a mosquito-borne pathogen listed by National Institute of Allergy and Infectious Diseases (NIAID) as a Category C Priority Pathogen that causes Chikungunya fever (CHIKF), has been spreading throughout Asia, Africa, and parts of Europe in recent times [1, 2, 3] . CHIKV is an arthropod-borne virus (arbovirus) and is transmitted to humans primarily by Aedes aegypti, the infamous yellow fever propagator [4, 5] . CHIKV infection is marked by severe joint pain, contorting its victims into unusual postures [6] . The disease gets its name from the Kimakonde vernacular language of Tanzania and Mozambique, and the word chikungunya means ''that which contorts or bends up'' and translates in Swahili to ''the illness of the bended walker'' [7, 8, 9] . In Africa, CHIKV is maintained in a sylvatic cycle among forest-dwelling Aedes spp. mosquitoes, wild primates, squirrels, birds, and rodents ( Figure 1 ) [10] . In Asia, the disease is vectored by Ae. aegypti and Ae.", "albopictus [11] . Transmission in Asia occurs in an urban cycle whereby the mosquito spreads the disease from an infected human to an uninfected human, following an epidemiological pattern similar to dengue fever [12] .", "The 2005-2006 epidemic of CHIKV in La Reunion islands in the Indian Ocean, spurred the discovery of a new vector species, Ae. albopictus [5] . Wrecking over one-third of the island's population, this epidemic peaked its devastation between January and February 2006, when over 46,000 cases came into light every week, including 284 deaths [5, 13] . Ae. albopictus is common in urban areas of the United States and is already flourishing in 36 states, raising grave concerns to the immunologically naive populace of the United States [14] .\n\nAccordingly, this review elaborately details the epidemiology and global expansion of CHIKV, describes its clinical features and pathogenesis and its symptoms and complications, and finally nominates a possible vaccine approach against CHIKV infection.", "CHIKV has been isolated into three genotypes based on phylogenetic studies. These genotypes, based on the gene sequences of an Envelope protein (E1), are Asian, East/Central/ South African, and West African [4, 11, 15] . Using phylogenetic models, Cherian et al. estimate that the Asian genotype of CHIKV emerged between 50 and 310 y ago, and the West and East African genotypes diverged between 100 and 840 y ago [15] . Since then, CHIKV has come a long way, with several mutations incorporated, and has continued to wreak epidemics in several regions. Recent activities of CHIKV include the Indian epidemic in 2005-2006, which was followed by a sudden explosion of cases in 2007. An estimated 1.3 million people across 13 states were reported to be infected in India [12, 16] , and CHIKV was also widespread in Malaysia, Sri Lanka, and Indonesia [17] . In July-August of 2007, CHIKV was reported in Italy, probably brought in by travelers from CHIKV-prone regions of India, Africa, and Indian", "Ocean islands such as Mauritius, Madagascar, and Seychelles. Few of the Italian isolates were found to have evolved from the Kerala isolate, which was associated with a A226V shift in E1 gene that represents a successful evolutionary adaptation in the mosquito vector similar to the ones observed in Reunion Island [2, 18, 19] .", "In recent times, with an increase in global travel, the risk for spreading CHIKV to non-endemic regions has heightened [1] . Several travelers have brought CHIKV home with them after visiting areas with actively infected populations [12, 20] . Such cases have been documented in European countries, Australia, Asia, and the United States [8, 21] . The United States has already reported at least twelve cases of travel-associated CHIKV, while France has reported 850 cases, and the United Kingdom 93 [8, 14] . Beyond this, CHIKV-infected travelers have also been diagnosed in Australia, Belgium, Canada, Czech Republic, French Guiana, Germany, Hong Kong, Italy, Japan, Kenya, Malaysia, Martinique, Norway, Switzerland, and Sri Lanka [21] . Some travelers were viremic, worrying public health officials about the spread of CHIKV to new areas [1, 8] .", "The incubation time for CHIKV is relatively short, requiring only 2-6 d with symptoms usually appearing 4-7 d post-infection [22] . Vazeille et al. detected CHIKV in the salivary glands of Ae. albopictus only 2 d after infection [5] . Upon infection, CHIKF tends to present itself in two phases. The first stage is acute, while the second stage, experienced by most but not all, is persistent, causing disabling polyarthritis. Characteristics of the acute phase include an abrupt onset of fever, arthralgia, and in some cases, maculopapular rash [6, 23] . The acute phase causes such intense joint and muscular pain that makes movement very difficult and prostrates its victims [6, 20] .", "Ninety-five percent of infected adults are symptomatic after infection, and of these, most become disabled for weeks to months as a result of decreased dexterity, loss of mobility, and delayed reaction. Eighteen months after disease onset, 40% of patients are found to still have anti-CHIKV IgM [6, 18, 23, 24] . The chronic stage of CHIKF is characterized by polyarthralgia that can last from weeks to years beyond the acute stage [6] . CHIKV has been shown to attack fibroblasts, explaining the involvement of muscles, joints, and skin connective tissues. The high number of nociceptive nerve endings found within the joints and muscle connective tissues can explain pain associated with CHIKF [25, 26] .", "More than 50% of patients who suffer from severe CHIKF are over 65 y old, and more than 33% of them die. Most adults who suffer from severe CHIKF have underlying medical conditions [6, 24, 27] . The other group that is disproportionately affected by severe CHIKV is children. Other complications associated with CHIKV, from most common to least common, include respiratory failure, cardiovascular decompensation, meningoencephalitis, severe acute hepatitis, severe cutaneous effects, other central nervous system problems, and kidney failure [6, 18, 20, 23, 24, 26, 27] .", "CHIKV undertakes a complex replication cycle upon host infection (Figure 2 ), which makes its genome susceptible to mutations [28, 29] . For instance, Ae. aegypti, responsible for epidemics in Kenya, Comoros, and Seychelles, carried CHIKV with an alanine in the 226 position of the E1 gene (E1-A226) [4, 18] . However, when the virus struck La Reunion Islands, a decline in population of Ae. aegypti, due to massive dichlorodiphenyltrichloroethane usage and dearth of Ae. albopictus species' www.plosntds.org population, resulted in an ecological pressure, favoring replacement of alanine at position 226 with valine (E1-A226V) [5] . This mutation allowed CHIKV's secondary vector species, Ae. albopictus, to supplement Ae. aegypti as its primary vector [5] .", "Within a year, the E1-A226V mutation was present in La Reunion Island, and Ae. albopictus apparently vectored the large epidemic infecting 34% of La Reunion Island's population [5] . All of the CHIKV strains isolated from Mayotte carried the E1-A226V mutation, and the mutation was also found in Madagascar in 2007 [5] . The E1-A226V mutation was not present at the beginning of the Indian Ocean Islands outbreak (before September 2005). However, more than 90% of later viral strains found there had incorporated the mutation (December-March 2006), indicating a genotype switch during the winter season [5, 18, 20] .", "The E1-A226V mutation also enabled an increase in infectivity of Ae. albopictus when compared to its infectivity of Ae. aegypti [4, 11, 18, 30] , and with several factors taken together, Ae. albopictus has become the new preferred and more lethal vector for CHIKV [4, 5, 11] . In fact, Tsetsarkin et al. found that a Green Fluorescent Protein tagged E1-A226V virus was 100 times more infective to Ae. albopictus than it was to Ae. aegypti [4] . In all the Indian Ocean Islands, Ae. albopictus became the main vector for CHIKV within 1-2 y after CHIKV was introduced to the region [31] .", "Of note is that Ae. aegypti has most likely been established in North America for over 300 y, while Ae. albopictus has been in many areas of the US, since 1985, primarily in Florida [32] and since then has expanded its range in the country. Reiskind et al. set out to determine if Ae. aegypti and Ae. albopictus mosquitoes captured in Florida were susceptible to CHIKV infection by a La Reunion isolate [32] . Each mosquito tested was highly susceptible to infection by a full-length infectious clone of the La Réunion Island isolate, CHIKV LR2006 OPY1 strain. Even though the Ae. albopictus strains were more susceptible to infection, overall ecology and differences in human biting patterns need to be studied further Characteristically, there are two rounds of translation: (+) sense genomic RNA (49S9 = 11.7 kb) acts directly as mRNA and is partially translated (59 end) to produce non-structural proteins (nsp's). These proteins are responsible for replication and formation of a complementary", "(2) strand, the template for further (+) strand synthesis. Subgenomic mRNA (26 S = 4.1 kb) replication occurs through the synthesis of full-length (2) intermediate RNA, which is regulated by nsp4 and p123 precursor in early infection and later by mature nsp's. Translation of the newly synthesized sub-genomic RNA results in production of structural proteins such as Capsid and protein E2-6k-E1 (from 39 end of genome). Assembly occurs at the cell surface, and the envelope is acquired as the virus buds from the cell and release and maturation almost simultaneous occurred. Replication occurs in the cytoplasm and is very rapid (,4 h) [28, 29] . doi:10.1371/journal.pntd.0000623.g002 www.plosntds.org to gain a more accurate understanding of a potential CHIKV epidemic in the US [32] .", "During the 7 d preceding birth, no human mother has been reported to transmit the disease vertically. However, about 50% of newborns delivered while the mother was infected with CHIKV contracted the disease from their mother, despite the method of delivery. Furthermore, there have been instances of CHIKV transmission from mother to fetus causing congenital illness and fetal death [33] .", "During the 2005-2006 La Reunion Island outbreaks, Ramful et al. discovered that mothers could transmit CHIKV to their progeny during the perinatal period (Day 24 to Day +1) [33, 34] , and it is associated with a high degree of morbidity. By mean Day 4 of life, all of the neonates were symptomatic for CHIKV, exhibiting common CHIKF symptoms. Six neonates were confirmed to have contracted CHIKV and developed mengoencephalitis. Of those mothers who, during the La Reunion Island epidemic, were infected long before delivery, only three fetal deaths were reported [12, 33] . Ramful et al. theorized that motherto-child transmission most likely happens transplacentally shortly before delivery [33] . A similar study by Gerardin et al. reported nineteen cases of neonatal infection associated with intrapartum maternal viremia that progressed to develop encephalitis owing to vertical transmission from infected mothers [34] .", "Clinical and epidemiological similarities with dengue fever make CHIKV diagnosis difficult, which may lead physicians to misdiagnose CHIKV as dengue fever; therefore, the incidence of CHIKV may actually be higher than currently believed (Table 1 ) [6, 12, 35] .", "The amount of time elapsed since disease onset is the most critical parameter when choosing a diagnostic test. CHIKV can be detected and isolated by culturing with mosquito cells (C6/36), Vero cells (mammalian), or in mice [26] . However, this method can take at least a week and only achieves a high sensitivity during the viremic phase, which usually only lasts up to 48 h after the bite. Five days post-infection, the viral isolation approach has a low sensitivity but is still the preferred method for detecting the CHIKV strain [12, 26, 31, 35] . RT-PCR on the other hand is a faster and more sensitive method that can be used within the first week of disease onset [26] , and it is currently the most sensitive method for detecting and quantifying viral mRNA [4, 36] .", "Classic serological detection, by assays such as ELISA [37] , immunofluorescence [5, 38] , complement binding, and haemagglutination inhibition [39] , constitutes the second diagnostic tool used for biological diagnosis of CHIKV infection. These proven techniques are useful for detection of Antigen in mosquitoes during epidemiological studies. These assays detect virus-specific IgM and IgG, however the sensitivity and specificity of these assays has been poorly characterized. Viral competence, or the potential of viral infection and transmission, is an important parameter that can be quantified by ELISA, viral culture, and PCR.", "A study by Ng et al. showed biomarkers indicative of severe CHIKV infection [40] . They found decreased levels of RANTES and increased levels of Interleukin-6 (IL-6) and Interleukin-1b (IL-1b) that could be sued for CHIKV detection in patients as indicators of CHIKV-driven cytokine storm. Couderc et al. demonstrate another cytokine, type-I IFN, as a key player in the progression to CHIKV infection [26] . Using an IFN-a/b null mouse model, they demonstrated evidence of muscles, joints, and skin as privileged CHIKV targets, which is consistent with human pathology. Although Ng et al. concluded that RANTES levels were significantly suppressed in severe CHIKF patients [40] , interestingly, an increase in levels of RANTES has been observed in dengue infection [41] . Since the symptoms of CHIKF mimic those of dengue fever, results obtained from this study strongly suggest that RANTES could be a potential distinctive biomarker that differentiates between these two clinically similar", "diseases.", "There are no approved antiviral treatments currently available for CHIKV [1, 3, 12, 42] . Currently, CHIKF is treated symptomatically, usually with non-steroidal anti-inflammatory drugs or steroids, bed rest, and fluids. Movement and mild exercise are thought to decrease stiffness and morning arthralgia, but heavy exercise may exacerbate rheumatic symptoms. Corticosteroids may be used in cases of debilitating chronic CHIKV infection. There is a debate about the appropriateness of chloroquine as treatment for unresolved, non-steroidal anti-inflammatory drugresistant arthritis [43] . A study showed that viral production was www.plosntds.org drastically reduced at 16 h post-infection after treatment with 100 mM dec-RVKR-cmk (Decanoyl-Arg-Val-Lys-Arg-chloromethylketone), a furine inhibitor [42, 44] . Chloroquine acted by raising the pH, blocking low pH-dependent entry of virus into the cell. It is important to note that dec-RVKR-cmk or chloroquine only inhibited viral spreading from cell", "to cell, not CHIKV replication once it had entered the cell [43] . However, most would agree that the best weapon against CHIKV is prevention. A live CHIKV vaccine developed by the United States reached phase II clinical trial encompassing 59 healthy volunteers [45] . Eight percent of the volunteers experienced transient arthralgia, while 98% of the volunteers had seroconversion [45] . However, live CHIKV vaccines are still questionable. One cannot discount the risk of a live vaccine possibly inducing chronic rheumatism. Also, there is the question as to whether widespread use among the public could trigger mosquito transmission or lead to chronic infection or viral reversion [1] .", "An alternative approach would be to produce a chimeric vaccine against CHIKV. Wang et al. developed a chimeric alphavirus vaccine that is uniformly attenuated and does not cause reactogenicity in mice [3] . Three different versions of this vaccine were made using three different backbone vectors: Venezuelan equine encephalitis virus (VEEV) attenuated vaccine strain T-83, naturally attenuated eastern equine encephalitis virus (EEEV), and attenuated Sindbis virus (SINV). In short, CHIKV structural proteins were engineered into the backbones of the aforementioned vaccines to produce the chimeras [3] . These chimeras were found to stimulate a strong humoral immunity, and even at doses of 5.3-5.8 log 10 PFU, they did not trigger reactogenicity. When vaccinated mice were challenged with CHIKV, neither adult nor neonatal mice gained weight, had fever, or displayed signs of neurological illness. Upon comparison of the chimeras with the Army181/25 vaccine, the Army vaccine resulted in higher", "levels of viremia and replication in the joints of neonatal mice. Because the joints are known targets of CHIKV, Wang et al. noted their vaccine might avoid the negative reactogenic side effects of the Army vaccine. After being subcutaneously vaccinated with 5.3-5.8 log 10 PFU of the chimeric vaccines, mice produced strong neutralizing antibody titers. The VEEV and EEEV chimeras yielded higher neutralizing antibody titers than the SINV chimera without being more virulent. On top of this, the VEEV and EEEV CHIKV chimeras seemed to be more immunogenic than the Army vaccine despite the chimeras' lower viremia and replication in the joints of neonatal mice [3] .", "Tiwari et al. [46] adopted a different strategy using formalin inactivated CHIKV in combination with alhydrogel (Aluminum Hydroxide) as an adjuvant. This study clearly suggests that this vaccine elicits both humoral and cell-mediated immune responses in mice, providing its immunogenic potential. A recent study by Couderc et al. [47] showed passive immunization as a potential treatment for CHIKV infection. Using purified immunoglobulin extracted from convalescent CHIKV patients, they demonstrated effective neutralizing activity against CHIKV infection both in vitro and in vivo. This thereby establishes a potential preventive and therapeutic approach to combat CHIKV infection. Pathogenesis studies conducted with related alpha virus, like RRV, have shown the role of macrophages in persistence on infection [48] . They also demonstrated the role of RRV-specific CD8 T cells in clearing viral load in infected patients, thereby warranting similar investigations with CHIKV and the importance", "of investigating a cell-mediated immune response-based vaccine against CHIKV [49] .", "There are always certain risks associated with live attenuated or inactivated viral vaccines [50] . One way to avoid these potential problems is to construct a consensus-based DNA vaccine. DNA based vaccines have an improved safety profile as compared to live or attenuated vaccines [51, 52] . A consequence of CHIKV's rapid evolution is difficulty in constructing a vaccine that will be able to Figure 3 . Levels of CHIKV-specific IgG in mice immunized with CHIKV vaccines. Each group of C57BL/6 mice (n = 5) was immunized with 12.5 mg of pVax1 control vector or CHIKV vaccine plasmids as indicated at 0 and 2 wk. Mice were bled 2 wk after each immunization, and each group's serum pool was diluted to 1:100 and 1:500 for reaction with specific vaccine constructs. Serum was incubated for 1 h at 37uC on 96-well plates coated with 2 mg/ml of respective CHIKV peptides, and antibody was detected using anti-mouse IgG-HRP and OD was measured at 405 nm. doi:10.1371/journal.pntd.0000623.g003", "www.plosntds.org effectively protect large populations from multiple strains of the virus. One of the strengths of DNA consensus vaccines is its ability to induce cross-reactive immune responses against the three distinct phylogenetic groups of CHIKV. Also DNA-based vaccines can be produced more rapidly than protein-based vaccines.", "Recently, Muthumani et al. constructed a vaccine that was shown to induce both humoral and cellular immunity in vivo in 3-4-wk-old female C57/BL6 mice [49] . These mice were immunized using an in vivo electroporation method to deliver the vaccine into the quadriceps muscle. The consensus construct was designed against E1, E2, and the core protein capsid. To design the construct, they aligned 21 sequences of CHIKV isolated between 1952 and 2006, using strains from differing countries, including La Reunion Island. The most common nucleotide among the sequences was chosen at each position to be used in the consensus construct, taking care not to alter the reading frame. They conducted codon and RNA optimization, added a strong Kozak sequence, and substituted signal peptide with an immunoglobulin E leader sequence to improve vaccine efficacy.", "After immunizing the mice, spleens were harvested along with serum and tested to determine antibody titer. After three immunizations, consensus E1, E2, and C vaccines were shown to induce T-cell immune responses leading to strong IFN-c responses and proliferation in C57/BL6 mice. Furthermore, when compared with control mice, immunized mice had higher total IgG levels as well as higher anti-E1 specific, anti-E2 specific, and anti-C specific IgG antibodies, suggesting a strong humoral immune response ( Figure 3 ) and also specificity for the antigens encoded in the vaccine constructs ( Figure 4 ). Because of its promising results and the need for a safer vaccine, this consensus DNA vaccine deserves further investigation. Determining longevity of protective effects of the vaccine and persistence of antibody and IFN-c responses could be the next step of investigation. Challenged studies of immunized mice must also be carried out.", "CHIKV mosquito-borne disease has caused massive outbreaks for at least half a century but is no longer confined to the www.plosntds.org developing nations. It began to encroach into the boundaries of the developing world. As a result, the NIAID has designated CHIKV as a Category C pathogen alongside the influenza and SARS-CoV viruses [3] . Realization of the potential severity of this disease is exigent; for instance, if used as a biological weapon, the world economy could be severely crippled; if enough members of the armed forces were to become infected during a military deployment, military operations could be significantly affected. Efforts to monitor the disease will only provide minimal warning in a global society, and steps to prevent the morbidity and mortality associated with pandemic are imperative [21, 31] . Despite the gravity of its infectious potency and the fear of it being a potential biological weapon, there is currently no vaccine for CHIKV infections. Live", "attenuated vaccine trials were carried out in 2000, but funding for the project was discontinued. Newer approaches such as DNA vaccines appear promising over conventional strategies like live attenuated or inactivated virus and thus call for further investigation. Recent advances such electroporation delivery and incorporation of adjuvants has boosted DNA vaccine efficacy [51, 53] . Despite the low antibody response to DNA vaccines, other numerous advantages have overshadowed these minor drawbacks (Table 2) , the most important one being the ability to induce both humoral and cellular immune responses [51, 54] .", "Judging by recent success, such as the immunogenic construct developed by Muthumani et al., DNA vaccines could play a major role in combating CHIKV [49] . Vaccines are literally a critical component of CHIKV disease control and therefore research in this area is highly encouraged. The dramatic spread of dengue viruses (DENV) throughout tropical America since 1980 via the same vectors and human hosts underscores the risk to public health in the Americas. The adverse events associated with the current live vaccine are well documented [55] . Realizing these drawbacks, earnest efforts should be taken to develop new strategies to forestall further spread and complications." ]	[ 12 ]	3,829	5,688
1,689	What is the finding on E1-A226V in Indian Ocean?	2,514	[ "mutation was not present at the beginning of the Indian Ocean Islands outbreak (before September 2005). However, more than 90% of later viral strains found there had incorporated the mutation (December-March 2006), indicating a genotype switch during the winter season" ]	[ "Chikungunya: A Potentially Emerging Epidemic?\n\nhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC2860491/\n\nSHA: f7c3160bef4169d29e2a8bdd79dd6e9056d4774c\n\nAuthors: Thiboutot, Michelle M.; Kannan, Senthil; Kawalekar, Omkar U.; Shedlock, Devon J.; Khan, Amir S.; Sarangan, Gopalsamy; Srikanth, Padma; Weiner, David B.; Muthumani, Karuppiah\nDate: 2010-04-27\nDOI: 10.1371/journal.pntd.0000623\nLicense: cc-by", "Abstract: Chikungunya virus is a mosquito-borne emerging pathogen that has a major health impact in humans and causes fever disease, headache, rash, nausea, vomiting, myalgia, and arthralgia. Indigenous to tropical Africa, recent large outbreaks have been reported in parts of South East Asia and several of its neighboring islands in 2005–07 and in Europe in 2007. Furthermore, positive cases have been confirmed in the United States in travelers returning from known outbreak areas. Currently, there is no vaccine or antiviral treatment. With the threat of an emerging global pandemic, the peculiar problems associated with the more immediate and seasonal epidemics warrant the development of an effective vaccine. In this review, we summarize the evidence supporting these concepts.", "Text: Chikungunya virus (CHIKV), a mosquito-borne pathogen listed by National Institute of Allergy and Infectious Diseases (NIAID) as a Category C Priority Pathogen that causes Chikungunya fever (CHIKF), has been spreading throughout Asia, Africa, and parts of Europe in recent times [1, 2, 3] . CHIKV is an arthropod-borne virus (arbovirus) and is transmitted to humans primarily by Aedes aegypti, the infamous yellow fever propagator [4, 5] . CHIKV infection is marked by severe joint pain, contorting its victims into unusual postures [6] . The disease gets its name from the Kimakonde vernacular language of Tanzania and Mozambique, and the word chikungunya means ''that which contorts or bends up'' and translates in Swahili to ''the illness of the bended walker'' [7, 8, 9] . In Africa, CHIKV is maintained in a sylvatic cycle among forest-dwelling Aedes spp. mosquitoes, wild primates, squirrels, birds, and rodents ( Figure 1 ) [10] . In Asia, the disease is vectored by Ae. aegypti and Ae.", "albopictus [11] . Transmission in Asia occurs in an urban cycle whereby the mosquito spreads the disease from an infected human to an uninfected human, following an epidemiological pattern similar to dengue fever [12] .", "The 2005-2006 epidemic of CHIKV in La Reunion islands in the Indian Ocean, spurred the discovery of a new vector species, Ae. albopictus [5] . Wrecking over one-third of the island's population, this epidemic peaked its devastation between January and February 2006, when over 46,000 cases came into light every week, including 284 deaths [5, 13] . Ae. albopictus is common in urban areas of the United States and is already flourishing in 36 states, raising grave concerns to the immunologically naive populace of the United States [14] .\n\nAccordingly, this review elaborately details the epidemiology and global expansion of CHIKV, describes its clinical features and pathogenesis and its symptoms and complications, and finally nominates a possible vaccine approach against CHIKV infection.", "CHIKV has been isolated into three genotypes based on phylogenetic studies. These genotypes, based on the gene sequences of an Envelope protein (E1), are Asian, East/Central/ South African, and West African [4, 11, 15] . Using phylogenetic models, Cherian et al. estimate that the Asian genotype of CHIKV emerged between 50 and 310 y ago, and the West and East African genotypes diverged between 100 and 840 y ago [15] . Since then, CHIKV has come a long way, with several mutations incorporated, and has continued to wreak epidemics in several regions. Recent activities of CHIKV include the Indian epidemic in 2005-2006, which was followed by a sudden explosion of cases in 2007. An estimated 1.3 million people across 13 states were reported to be infected in India [12, 16] , and CHIKV was also widespread in Malaysia, Sri Lanka, and Indonesia [17] . In July-August of 2007, CHIKV was reported in Italy, probably brought in by travelers from CHIKV-prone regions of India, Africa, and Indian", "Ocean islands such as Mauritius, Madagascar, and Seychelles. Few of the Italian isolates were found to have evolved from the Kerala isolate, which was associated with a A226V shift in E1 gene that represents a successful evolutionary adaptation in the mosquito vector similar to the ones observed in Reunion Island [2, 18, 19] .", "In recent times, with an increase in global travel, the risk for spreading CHIKV to non-endemic regions has heightened [1] . Several travelers have brought CHIKV home with them after visiting areas with actively infected populations [12, 20] . Such cases have been documented in European countries, Australia, Asia, and the United States [8, 21] . The United States has already reported at least twelve cases of travel-associated CHIKV, while France has reported 850 cases, and the United Kingdom 93 [8, 14] . Beyond this, CHIKV-infected travelers have also been diagnosed in Australia, Belgium, Canada, Czech Republic, French Guiana, Germany, Hong Kong, Italy, Japan, Kenya, Malaysia, Martinique, Norway, Switzerland, and Sri Lanka [21] . Some travelers were viremic, worrying public health officials about the spread of CHIKV to new areas [1, 8] .", "The incubation time for CHIKV is relatively short, requiring only 2-6 d with symptoms usually appearing 4-7 d post-infection [22] . Vazeille et al. detected CHIKV in the salivary glands of Ae. albopictus only 2 d after infection [5] . Upon infection, CHIKF tends to present itself in two phases. The first stage is acute, while the second stage, experienced by most but not all, is persistent, causing disabling polyarthritis. Characteristics of the acute phase include an abrupt onset of fever, arthralgia, and in some cases, maculopapular rash [6, 23] . The acute phase causes such intense joint and muscular pain that makes movement very difficult and prostrates its victims [6, 20] .", "Ninety-five percent of infected adults are symptomatic after infection, and of these, most become disabled for weeks to months as a result of decreased dexterity, loss of mobility, and delayed reaction. Eighteen months after disease onset, 40% of patients are found to still have anti-CHIKV IgM [6, 18, 23, 24] . The chronic stage of CHIKF is characterized by polyarthralgia that can last from weeks to years beyond the acute stage [6] . CHIKV has been shown to attack fibroblasts, explaining the involvement of muscles, joints, and skin connective tissues. The high number of nociceptive nerve endings found within the joints and muscle connective tissues can explain pain associated with CHIKF [25, 26] .", "More than 50% of patients who suffer from severe CHIKF are over 65 y old, and more than 33% of them die. Most adults who suffer from severe CHIKF have underlying medical conditions [6, 24, 27] . The other group that is disproportionately affected by severe CHIKV is children. Other complications associated with CHIKV, from most common to least common, include respiratory failure, cardiovascular decompensation, meningoencephalitis, severe acute hepatitis, severe cutaneous effects, other central nervous system problems, and kidney failure [6, 18, 20, 23, 24, 26, 27] .", "CHIKV undertakes a complex replication cycle upon host infection (Figure 2 ), which makes its genome susceptible to mutations [28, 29] . For instance, Ae. aegypti, responsible for epidemics in Kenya, Comoros, and Seychelles, carried CHIKV with an alanine in the 226 position of the E1 gene (E1-A226) [4, 18] . However, when the virus struck La Reunion Islands, a decline in population of Ae. aegypti, due to massive dichlorodiphenyltrichloroethane usage and dearth of Ae. albopictus species' www.plosntds.org population, resulted in an ecological pressure, favoring replacement of alanine at position 226 with valine (E1-A226V) [5] . This mutation allowed CHIKV's secondary vector species, Ae. albopictus, to supplement Ae. aegypti as its primary vector [5] .", "Within a year, the E1-A226V mutation was present in La Reunion Island, and Ae. albopictus apparently vectored the large epidemic infecting 34% of La Reunion Island's population [5] . All of the CHIKV strains isolated from Mayotte carried the E1-A226V mutation, and the mutation was also found in Madagascar in 2007 [5] . The E1-A226V mutation was not present at the beginning of the Indian Ocean Islands outbreak (before September 2005). However, more than 90% of later viral strains found there had incorporated the mutation (December-March 2006), indicating a genotype switch during the winter season [5, 18, 20] .", "The E1-A226V mutation also enabled an increase in infectivity of Ae. albopictus when compared to its infectivity of Ae. aegypti [4, 11, 18, 30] , and with several factors taken together, Ae. albopictus has become the new preferred and more lethal vector for CHIKV [4, 5, 11] . In fact, Tsetsarkin et al. found that a Green Fluorescent Protein tagged E1-A226V virus was 100 times more infective to Ae. albopictus than it was to Ae. aegypti [4] . In all the Indian Ocean Islands, Ae. albopictus became the main vector for CHIKV within 1-2 y after CHIKV was introduced to the region [31] .", "Of note is that Ae. aegypti has most likely been established in North America for over 300 y, while Ae. albopictus has been in many areas of the US, since 1985, primarily in Florida [32] and since then has expanded its range in the country. Reiskind et al. set out to determine if Ae. aegypti and Ae. albopictus mosquitoes captured in Florida were susceptible to CHIKV infection by a La Reunion isolate [32] . Each mosquito tested was highly susceptible to infection by a full-length infectious clone of the La Réunion Island isolate, CHIKV LR2006 OPY1 strain. Even though the Ae. albopictus strains were more susceptible to infection, overall ecology and differences in human biting patterns need to be studied further Characteristically, there are two rounds of translation: (+) sense genomic RNA (49S9 = 11.7 kb) acts directly as mRNA and is partially translated (59 end) to produce non-structural proteins (nsp's). These proteins are responsible for replication and formation of a complementary", "(2) strand, the template for further (+) strand synthesis. Subgenomic mRNA (26 S = 4.1 kb) replication occurs through the synthesis of full-length (2) intermediate RNA, which is regulated by nsp4 and p123 precursor in early infection and later by mature nsp's. Translation of the newly synthesized sub-genomic RNA results in production of structural proteins such as Capsid and protein E2-6k-E1 (from 39 end of genome). Assembly occurs at the cell surface, and the envelope is acquired as the virus buds from the cell and release and maturation almost simultaneous occurred. Replication occurs in the cytoplasm and is very rapid (,4 h) [28, 29] . doi:10.1371/journal.pntd.0000623.g002 www.plosntds.org to gain a more accurate understanding of a potential CHIKV epidemic in the US [32] .", "During the 7 d preceding birth, no human mother has been reported to transmit the disease vertically. However, about 50% of newborns delivered while the mother was infected with CHIKV contracted the disease from their mother, despite the method of delivery. Furthermore, there have been instances of CHIKV transmission from mother to fetus causing congenital illness and fetal death [33] .", "During the 2005-2006 La Reunion Island outbreaks, Ramful et al. discovered that mothers could transmit CHIKV to their progeny during the perinatal period (Day 24 to Day +1) [33, 34] , and it is associated with a high degree of morbidity. By mean Day 4 of life, all of the neonates were symptomatic for CHIKV, exhibiting common CHIKF symptoms. Six neonates were confirmed to have contracted CHIKV and developed mengoencephalitis. Of those mothers who, during the La Reunion Island epidemic, were infected long before delivery, only three fetal deaths were reported [12, 33] . Ramful et al. theorized that motherto-child transmission most likely happens transplacentally shortly before delivery [33] . A similar study by Gerardin et al. reported nineteen cases of neonatal infection associated with intrapartum maternal viremia that progressed to develop encephalitis owing to vertical transmission from infected mothers [34] .", "Clinical and epidemiological similarities with dengue fever make CHIKV diagnosis difficult, which may lead physicians to misdiagnose CHIKV as dengue fever; therefore, the incidence of CHIKV may actually be higher than currently believed (Table 1 ) [6, 12, 35] .", "The amount of time elapsed since disease onset is the most critical parameter when choosing a diagnostic test. CHIKV can be detected and isolated by culturing with mosquito cells (C6/36), Vero cells (mammalian), or in mice [26] . However, this method can take at least a week and only achieves a high sensitivity during the viremic phase, which usually only lasts up to 48 h after the bite. Five days post-infection, the viral isolation approach has a low sensitivity but is still the preferred method for detecting the CHIKV strain [12, 26, 31, 35] . RT-PCR on the other hand is a faster and more sensitive method that can be used within the first week of disease onset [26] , and it is currently the most sensitive method for detecting and quantifying viral mRNA [4, 36] .", "Classic serological detection, by assays such as ELISA [37] , immunofluorescence [5, 38] , complement binding, and haemagglutination inhibition [39] , constitutes the second diagnostic tool used for biological diagnosis of CHIKV infection. These proven techniques are useful for detection of Antigen in mosquitoes during epidemiological studies. These assays detect virus-specific IgM and IgG, however the sensitivity and specificity of these assays has been poorly characterized. Viral competence, or the potential of viral infection and transmission, is an important parameter that can be quantified by ELISA, viral culture, and PCR.", "A study by Ng et al. showed biomarkers indicative of severe CHIKV infection [40] . They found decreased levels of RANTES and increased levels of Interleukin-6 (IL-6) and Interleukin-1b (IL-1b) that could be sued for CHIKV detection in patients as indicators of CHIKV-driven cytokine storm. Couderc et al. demonstrate another cytokine, type-I IFN, as a key player in the progression to CHIKV infection [26] . Using an IFN-a/b null mouse model, they demonstrated evidence of muscles, joints, and skin as privileged CHIKV targets, which is consistent with human pathology. Although Ng et al. concluded that RANTES levels were significantly suppressed in severe CHIKF patients [40] , interestingly, an increase in levels of RANTES has been observed in dengue infection [41] . Since the symptoms of CHIKF mimic those of dengue fever, results obtained from this study strongly suggest that RANTES could be a potential distinctive biomarker that differentiates between these two clinically similar", "diseases.", "There are no approved antiviral treatments currently available for CHIKV [1, 3, 12, 42] . Currently, CHIKF is treated symptomatically, usually with non-steroidal anti-inflammatory drugs or steroids, bed rest, and fluids. Movement and mild exercise are thought to decrease stiffness and morning arthralgia, but heavy exercise may exacerbate rheumatic symptoms. Corticosteroids may be used in cases of debilitating chronic CHIKV infection. There is a debate about the appropriateness of chloroquine as treatment for unresolved, non-steroidal anti-inflammatory drugresistant arthritis [43] . A study showed that viral production was www.plosntds.org drastically reduced at 16 h post-infection after treatment with 100 mM dec-RVKR-cmk (Decanoyl-Arg-Val-Lys-Arg-chloromethylketone), a furine inhibitor [42, 44] . Chloroquine acted by raising the pH, blocking low pH-dependent entry of virus into the cell. It is important to note that dec-RVKR-cmk or chloroquine only inhibited viral spreading from cell", "to cell, not CHIKV replication once it had entered the cell [43] . However, most would agree that the best weapon against CHIKV is prevention. A live CHIKV vaccine developed by the United States reached phase II clinical trial encompassing 59 healthy volunteers [45] . Eight percent of the volunteers experienced transient arthralgia, while 98% of the volunteers had seroconversion [45] . However, live CHIKV vaccines are still questionable. One cannot discount the risk of a live vaccine possibly inducing chronic rheumatism. Also, there is the question as to whether widespread use among the public could trigger mosquito transmission or lead to chronic infection or viral reversion [1] .", "An alternative approach would be to produce a chimeric vaccine against CHIKV. Wang et al. developed a chimeric alphavirus vaccine that is uniformly attenuated and does not cause reactogenicity in mice [3] . Three different versions of this vaccine were made using three different backbone vectors: Venezuelan equine encephalitis virus (VEEV) attenuated vaccine strain T-83, naturally attenuated eastern equine encephalitis virus (EEEV), and attenuated Sindbis virus (SINV). In short, CHIKV structural proteins were engineered into the backbones of the aforementioned vaccines to produce the chimeras [3] . These chimeras were found to stimulate a strong humoral immunity, and even at doses of 5.3-5.8 log 10 PFU, they did not trigger reactogenicity. When vaccinated mice were challenged with CHIKV, neither adult nor neonatal mice gained weight, had fever, or displayed signs of neurological illness. Upon comparison of the chimeras with the Army181/25 vaccine, the Army vaccine resulted in higher", "levels of viremia and replication in the joints of neonatal mice. Because the joints are known targets of CHIKV, Wang et al. noted their vaccine might avoid the negative reactogenic side effects of the Army vaccine. After being subcutaneously vaccinated with 5.3-5.8 log 10 PFU of the chimeric vaccines, mice produced strong neutralizing antibody titers. The VEEV and EEEV chimeras yielded higher neutralizing antibody titers than the SINV chimera without being more virulent. On top of this, the VEEV and EEEV CHIKV chimeras seemed to be more immunogenic than the Army vaccine despite the chimeras' lower viremia and replication in the joints of neonatal mice [3] .", "Tiwari et al. [46] adopted a different strategy using formalin inactivated CHIKV in combination with alhydrogel (Aluminum Hydroxide) as an adjuvant. This study clearly suggests that this vaccine elicits both humoral and cell-mediated immune responses in mice, providing its immunogenic potential. A recent study by Couderc et al. [47] showed passive immunization as a potential treatment for CHIKV infection. Using purified immunoglobulin extracted from convalescent CHIKV patients, they demonstrated effective neutralizing activity against CHIKV infection both in vitro and in vivo. This thereby establishes a potential preventive and therapeutic approach to combat CHIKV infection. Pathogenesis studies conducted with related alpha virus, like RRV, have shown the role of macrophages in persistence on infection [48] . They also demonstrated the role of RRV-specific CD8 T cells in clearing viral load in infected patients, thereby warranting similar investigations with CHIKV and the importance", "of investigating a cell-mediated immune response-based vaccine against CHIKV [49] .", "There are always certain risks associated with live attenuated or inactivated viral vaccines [50] . One way to avoid these potential problems is to construct a consensus-based DNA vaccine. DNA based vaccines have an improved safety profile as compared to live or attenuated vaccines [51, 52] . A consequence of CHIKV's rapid evolution is difficulty in constructing a vaccine that will be able to Figure 3 . Levels of CHIKV-specific IgG in mice immunized with CHIKV vaccines. Each group of C57BL/6 mice (n = 5) was immunized with 12.5 mg of pVax1 control vector or CHIKV vaccine plasmids as indicated at 0 and 2 wk. Mice were bled 2 wk after each immunization, and each group's serum pool was diluted to 1:100 and 1:500 for reaction with specific vaccine constructs. Serum was incubated for 1 h at 37uC on 96-well plates coated with 2 mg/ml of respective CHIKV peptides, and antibody was detected using anti-mouse IgG-HRP and OD was measured at 405 nm. doi:10.1371/journal.pntd.0000623.g003", "www.plosntds.org effectively protect large populations from multiple strains of the virus. One of the strengths of DNA consensus vaccines is its ability to induce cross-reactive immune responses against the three distinct phylogenetic groups of CHIKV. Also DNA-based vaccines can be produced more rapidly than protein-based vaccines.", "Recently, Muthumani et al. constructed a vaccine that was shown to induce both humoral and cellular immunity in vivo in 3-4-wk-old female C57/BL6 mice [49] . These mice were immunized using an in vivo electroporation method to deliver the vaccine into the quadriceps muscle. The consensus construct was designed against E1, E2, and the core protein capsid. To design the construct, they aligned 21 sequences of CHIKV isolated between 1952 and 2006, using strains from differing countries, including La Reunion Island. The most common nucleotide among the sequences was chosen at each position to be used in the consensus construct, taking care not to alter the reading frame. They conducted codon and RNA optimization, added a strong Kozak sequence, and substituted signal peptide with an immunoglobulin E leader sequence to improve vaccine efficacy.", "After immunizing the mice, spleens were harvested along with serum and tested to determine antibody titer. After three immunizations, consensus E1, E2, and C vaccines were shown to induce T-cell immune responses leading to strong IFN-c responses and proliferation in C57/BL6 mice. Furthermore, when compared with control mice, immunized mice had higher total IgG levels as well as higher anti-E1 specific, anti-E2 specific, and anti-C specific IgG antibodies, suggesting a strong humoral immune response ( Figure 3 ) and also specificity for the antigens encoded in the vaccine constructs ( Figure 4 ). Because of its promising results and the need for a safer vaccine, this consensus DNA vaccine deserves further investigation. Determining longevity of protective effects of the vaccine and persistence of antibody and IFN-c responses could be the next step of investigation. Challenged studies of immunized mice must also be carried out.", "CHIKV mosquito-borne disease has caused massive outbreaks for at least half a century but is no longer confined to the www.plosntds.org developing nations. It began to encroach into the boundaries of the developing world. As a result, the NIAID has designated CHIKV as a Category C pathogen alongside the influenza and SARS-CoV viruses [3] . Realization of the potential severity of this disease is exigent; for instance, if used as a biological weapon, the world economy could be severely crippled; if enough members of the armed forces were to become infected during a military deployment, military operations could be significantly affected. Efforts to monitor the disease will only provide minimal warning in a global society, and steps to prevent the morbidity and mortality associated with pandemic are imperative [21, 31] . Despite the gravity of its infectious potency and the fear of it being a potential biological weapon, there is currently no vaccine for CHIKV infections. Live", "attenuated vaccine trials were carried out in 2000, but funding for the project was discontinued. Newer approaches such as DNA vaccines appear promising over conventional strategies like live attenuated or inactivated virus and thus call for further investigation. Recent advances such electroporation delivery and incorporation of adjuvants has boosted DNA vaccine efficacy [51, 53] . Despite the low antibody response to DNA vaccines, other numerous advantages have overshadowed these minor drawbacks (Table 2) , the most important one being the ability to induce both humoral and cellular immune responses [51, 54] .", "Judging by recent success, such as the immunogenic construct developed by Muthumani et al., DNA vaccines could play a major role in combating CHIKV [49] . Vaccines are literally a critical component of CHIKV disease control and therefore research in this area is highly encouraged. The dramatic spread of dengue viruses (DENV) throughout tropical America since 1980 via the same vectors and human hosts underscores the risk to public health in the Americas. The adverse events associated with the current live vaccine are well documented [55] . Realizing these drawbacks, earnest efforts should be taken to develop new strategies to forestall further spread and complications." ]	[ 12 ]	3,829	5,688
1,689	What has the E1-A226V enabled?	2,515	[ "an increase in infectivity of Ae. albopictus when compared to its infectivity of Ae. aegypti" ]	[ "Chikungunya: A Potentially Emerging Epidemic?\n\nhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC2860491/\n\nSHA: f7c3160bef4169d29e2a8bdd79dd6e9056d4774c\n\nAuthors: Thiboutot, Michelle M.; Kannan, Senthil; Kawalekar, Omkar U.; Shedlock, Devon J.; Khan, Amir S.; Sarangan, Gopalsamy; Srikanth, Padma; Weiner, David B.; Muthumani, Karuppiah\nDate: 2010-04-27\nDOI: 10.1371/journal.pntd.0000623\nLicense: cc-by", "Abstract: Chikungunya virus is a mosquito-borne emerging pathogen that has a major health impact in humans and causes fever disease, headache, rash, nausea, vomiting, myalgia, and arthralgia. Indigenous to tropical Africa, recent large outbreaks have been reported in parts of South East Asia and several of its neighboring islands in 2005–07 and in Europe in 2007. Furthermore, positive cases have been confirmed in the United States in travelers returning from known outbreak areas. Currently, there is no vaccine or antiviral treatment. With the threat of an emerging global pandemic, the peculiar problems associated with the more immediate and seasonal epidemics warrant the development of an effective vaccine. In this review, we summarize the evidence supporting these concepts.", "Text: Chikungunya virus (CHIKV), a mosquito-borne pathogen listed by National Institute of Allergy and Infectious Diseases (NIAID) as a Category C Priority Pathogen that causes Chikungunya fever (CHIKF), has been spreading throughout Asia, Africa, and parts of Europe in recent times [1, 2, 3] . CHIKV is an arthropod-borne virus (arbovirus) and is transmitted to humans primarily by Aedes aegypti, the infamous yellow fever propagator [4, 5] . CHIKV infection is marked by severe joint pain, contorting its victims into unusual postures [6] . The disease gets its name from the Kimakonde vernacular language of Tanzania and Mozambique, and the word chikungunya means ''that which contorts or bends up'' and translates in Swahili to ''the illness of the bended walker'' [7, 8, 9] . In Africa, CHIKV is maintained in a sylvatic cycle among forest-dwelling Aedes spp. mosquitoes, wild primates, squirrels, birds, and rodents ( Figure 1 ) [10] . In Asia, the disease is vectored by Ae. aegypti and Ae.", "albopictus [11] . Transmission in Asia occurs in an urban cycle whereby the mosquito spreads the disease from an infected human to an uninfected human, following an epidemiological pattern similar to dengue fever [12] .", "The 2005-2006 epidemic of CHIKV in La Reunion islands in the Indian Ocean, spurred the discovery of a new vector species, Ae. albopictus [5] . Wrecking over one-third of the island's population, this epidemic peaked its devastation between January and February 2006, when over 46,000 cases came into light every week, including 284 deaths [5, 13] . Ae. albopictus is common in urban areas of the United States and is already flourishing in 36 states, raising grave concerns to the immunologically naive populace of the United States [14] .\n\nAccordingly, this review elaborately details the epidemiology and global expansion of CHIKV, describes its clinical features and pathogenesis and its symptoms and complications, and finally nominates a possible vaccine approach against CHIKV infection.", "CHIKV has been isolated into three genotypes based on phylogenetic studies. These genotypes, based on the gene sequences of an Envelope protein (E1), are Asian, East/Central/ South African, and West African [4, 11, 15] . Using phylogenetic models, Cherian et al. estimate that the Asian genotype of CHIKV emerged between 50 and 310 y ago, and the West and East African genotypes diverged between 100 and 840 y ago [15] . Since then, CHIKV has come a long way, with several mutations incorporated, and has continued to wreak epidemics in several regions. Recent activities of CHIKV include the Indian epidemic in 2005-2006, which was followed by a sudden explosion of cases in 2007. An estimated 1.3 million people across 13 states were reported to be infected in India [12, 16] , and CHIKV was also widespread in Malaysia, Sri Lanka, and Indonesia [17] . In July-August of 2007, CHIKV was reported in Italy, probably brought in by travelers from CHIKV-prone regions of India, Africa, and Indian", "Ocean islands such as Mauritius, Madagascar, and Seychelles. Few of the Italian isolates were found to have evolved from the Kerala isolate, which was associated with a A226V shift in E1 gene that represents a successful evolutionary adaptation in the mosquito vector similar to the ones observed in Reunion Island [2, 18, 19] .", "In recent times, with an increase in global travel, the risk for spreading CHIKV to non-endemic regions has heightened [1] . Several travelers have brought CHIKV home with them after visiting areas with actively infected populations [12, 20] . Such cases have been documented in European countries, Australia, Asia, and the United States [8, 21] . The United States has already reported at least twelve cases of travel-associated CHIKV, while France has reported 850 cases, and the United Kingdom 93 [8, 14] . Beyond this, CHIKV-infected travelers have also been diagnosed in Australia, Belgium, Canada, Czech Republic, French Guiana, Germany, Hong Kong, Italy, Japan, Kenya, Malaysia, Martinique, Norway, Switzerland, and Sri Lanka [21] . Some travelers were viremic, worrying public health officials about the spread of CHIKV to new areas [1, 8] .", "The incubation time for CHIKV is relatively short, requiring only 2-6 d with symptoms usually appearing 4-7 d post-infection [22] . Vazeille et al. detected CHIKV in the salivary glands of Ae. albopictus only 2 d after infection [5] . Upon infection, CHIKF tends to present itself in two phases. The first stage is acute, while the second stage, experienced by most but not all, is persistent, causing disabling polyarthritis. Characteristics of the acute phase include an abrupt onset of fever, arthralgia, and in some cases, maculopapular rash [6, 23] . The acute phase causes such intense joint and muscular pain that makes movement very difficult and prostrates its victims [6, 20] .", "Ninety-five percent of infected adults are symptomatic after infection, and of these, most become disabled for weeks to months as a result of decreased dexterity, loss of mobility, and delayed reaction. Eighteen months after disease onset, 40% of patients are found to still have anti-CHIKV IgM [6, 18, 23, 24] . The chronic stage of CHIKF is characterized by polyarthralgia that can last from weeks to years beyond the acute stage [6] . CHIKV has been shown to attack fibroblasts, explaining the involvement of muscles, joints, and skin connective tissues. The high number of nociceptive nerve endings found within the joints and muscle connective tissues can explain pain associated with CHIKF [25, 26] .", "More than 50% of patients who suffer from severe CHIKF are over 65 y old, and more than 33% of them die. Most adults who suffer from severe CHIKF have underlying medical conditions [6, 24, 27] . The other group that is disproportionately affected by severe CHIKV is children. Other complications associated with CHIKV, from most common to least common, include respiratory failure, cardiovascular decompensation, meningoencephalitis, severe acute hepatitis, severe cutaneous effects, other central nervous system problems, and kidney failure [6, 18, 20, 23, 24, 26, 27] .", "CHIKV undertakes a complex replication cycle upon host infection (Figure 2 ), which makes its genome susceptible to mutations [28, 29] . For instance, Ae. aegypti, responsible for epidemics in Kenya, Comoros, and Seychelles, carried CHIKV with an alanine in the 226 position of the E1 gene (E1-A226) [4, 18] . However, when the virus struck La Reunion Islands, a decline in population of Ae. aegypti, due to massive dichlorodiphenyltrichloroethane usage and dearth of Ae. albopictus species' www.plosntds.org population, resulted in an ecological pressure, favoring replacement of alanine at position 226 with valine (E1-A226V) [5] . This mutation allowed CHIKV's secondary vector species, Ae. albopictus, to supplement Ae. aegypti as its primary vector [5] .", "Within a year, the E1-A226V mutation was present in La Reunion Island, and Ae. albopictus apparently vectored the large epidemic infecting 34% of La Reunion Island's population [5] . All of the CHIKV strains isolated from Mayotte carried the E1-A226V mutation, and the mutation was also found in Madagascar in 2007 [5] . The E1-A226V mutation was not present at the beginning of the Indian Ocean Islands outbreak (before September 2005). However, more than 90% of later viral strains found there had incorporated the mutation (December-March 2006), indicating a genotype switch during the winter season [5, 18, 20] .", "The E1-A226V mutation also enabled an increase in infectivity of Ae. albopictus when compared to its infectivity of Ae. aegypti [4, 11, 18, 30] , and with several factors taken together, Ae. albopictus has become the new preferred and more lethal vector for CHIKV [4, 5, 11] . In fact, Tsetsarkin et al. found that a Green Fluorescent Protein tagged E1-A226V virus was 100 times more infective to Ae. albopictus than it was to Ae. aegypti [4] . In all the Indian Ocean Islands, Ae. albopictus became the main vector for CHIKV within 1-2 y after CHIKV was introduced to the region [31] .", "Of note is that Ae. aegypti has most likely been established in North America for over 300 y, while Ae. albopictus has been in many areas of the US, since 1985, primarily in Florida [32] and since then has expanded its range in the country. Reiskind et al. set out to determine if Ae. aegypti and Ae. albopictus mosquitoes captured in Florida were susceptible to CHIKV infection by a La Reunion isolate [32] . Each mosquito tested was highly susceptible to infection by a full-length infectious clone of the La Réunion Island isolate, CHIKV LR2006 OPY1 strain. Even though the Ae. albopictus strains were more susceptible to infection, overall ecology and differences in human biting patterns need to be studied further Characteristically, there are two rounds of translation: (+) sense genomic RNA (49S9 = 11.7 kb) acts directly as mRNA and is partially translated (59 end) to produce non-structural proteins (nsp's). These proteins are responsible for replication and formation of a complementary", "(2) strand, the template for further (+) strand synthesis. Subgenomic mRNA (26 S = 4.1 kb) replication occurs through the synthesis of full-length (2) intermediate RNA, which is regulated by nsp4 and p123 precursor in early infection and later by mature nsp's. Translation of the newly synthesized sub-genomic RNA results in production of structural proteins such as Capsid and protein E2-6k-E1 (from 39 end of genome). Assembly occurs at the cell surface, and the envelope is acquired as the virus buds from the cell and release and maturation almost simultaneous occurred. Replication occurs in the cytoplasm and is very rapid (,4 h) [28, 29] . doi:10.1371/journal.pntd.0000623.g002 www.plosntds.org to gain a more accurate understanding of a potential CHIKV epidemic in the US [32] .", "During the 7 d preceding birth, no human mother has been reported to transmit the disease vertically. However, about 50% of newborns delivered while the mother was infected with CHIKV contracted the disease from their mother, despite the method of delivery. Furthermore, there have been instances of CHIKV transmission from mother to fetus causing congenital illness and fetal death [33] .", "During the 2005-2006 La Reunion Island outbreaks, Ramful et al. discovered that mothers could transmit CHIKV to their progeny during the perinatal period (Day 24 to Day +1) [33, 34] , and it is associated with a high degree of morbidity. By mean Day 4 of life, all of the neonates were symptomatic for CHIKV, exhibiting common CHIKF symptoms. Six neonates were confirmed to have contracted CHIKV and developed mengoencephalitis. Of those mothers who, during the La Reunion Island epidemic, were infected long before delivery, only three fetal deaths were reported [12, 33] . Ramful et al. theorized that motherto-child transmission most likely happens transplacentally shortly before delivery [33] . A similar study by Gerardin et al. reported nineteen cases of neonatal infection associated with intrapartum maternal viremia that progressed to develop encephalitis owing to vertical transmission from infected mothers [34] .", "Clinical and epidemiological similarities with dengue fever make CHIKV diagnosis difficult, which may lead physicians to misdiagnose CHIKV as dengue fever; therefore, the incidence of CHIKV may actually be higher than currently believed (Table 1 ) [6, 12, 35] .", "The amount of time elapsed since disease onset is the most critical parameter when choosing a diagnostic test. CHIKV can be detected and isolated by culturing with mosquito cells (C6/36), Vero cells (mammalian), or in mice [26] . However, this method can take at least a week and only achieves a high sensitivity during the viremic phase, which usually only lasts up to 48 h after the bite. Five days post-infection, the viral isolation approach has a low sensitivity but is still the preferred method for detecting the CHIKV strain [12, 26, 31, 35] . RT-PCR on the other hand is a faster and more sensitive method that can be used within the first week of disease onset [26] , and it is currently the most sensitive method for detecting and quantifying viral mRNA [4, 36] .", "Classic serological detection, by assays such as ELISA [37] , immunofluorescence [5, 38] , complement binding, and haemagglutination inhibition [39] , constitutes the second diagnostic tool used for biological diagnosis of CHIKV infection. These proven techniques are useful for detection of Antigen in mosquitoes during epidemiological studies. These assays detect virus-specific IgM and IgG, however the sensitivity and specificity of these assays has been poorly characterized. Viral competence, or the potential of viral infection and transmission, is an important parameter that can be quantified by ELISA, viral culture, and PCR.", "A study by Ng et al. showed biomarkers indicative of severe CHIKV infection [40] . They found decreased levels of RANTES and increased levels of Interleukin-6 (IL-6) and Interleukin-1b (IL-1b) that could be sued for CHIKV detection in patients as indicators of CHIKV-driven cytokine storm. Couderc et al. demonstrate another cytokine, type-I IFN, as a key player in the progression to CHIKV infection [26] . Using an IFN-a/b null mouse model, they demonstrated evidence of muscles, joints, and skin as privileged CHIKV targets, which is consistent with human pathology. Although Ng et al. concluded that RANTES levels were significantly suppressed in severe CHIKF patients [40] , interestingly, an increase in levels of RANTES has been observed in dengue infection [41] . Since the symptoms of CHIKF mimic those of dengue fever, results obtained from this study strongly suggest that RANTES could be a potential distinctive biomarker that differentiates between these two clinically similar", "diseases.", "There are no approved antiviral treatments currently available for CHIKV [1, 3, 12, 42] . Currently, CHIKF is treated symptomatically, usually with non-steroidal anti-inflammatory drugs or steroids, bed rest, and fluids. Movement and mild exercise are thought to decrease stiffness and morning arthralgia, but heavy exercise may exacerbate rheumatic symptoms. Corticosteroids may be used in cases of debilitating chronic CHIKV infection. There is a debate about the appropriateness of chloroquine as treatment for unresolved, non-steroidal anti-inflammatory drugresistant arthritis [43] . A study showed that viral production was www.plosntds.org drastically reduced at 16 h post-infection after treatment with 100 mM dec-RVKR-cmk (Decanoyl-Arg-Val-Lys-Arg-chloromethylketone), a furine inhibitor [42, 44] . Chloroquine acted by raising the pH, blocking low pH-dependent entry of virus into the cell. It is important to note that dec-RVKR-cmk or chloroquine only inhibited viral spreading from cell", "to cell, not CHIKV replication once it had entered the cell [43] . However, most would agree that the best weapon against CHIKV is prevention. A live CHIKV vaccine developed by the United States reached phase II clinical trial encompassing 59 healthy volunteers [45] . Eight percent of the volunteers experienced transient arthralgia, while 98% of the volunteers had seroconversion [45] . However, live CHIKV vaccines are still questionable. One cannot discount the risk of a live vaccine possibly inducing chronic rheumatism. Also, there is the question as to whether widespread use among the public could trigger mosquito transmission or lead to chronic infection or viral reversion [1] .", "An alternative approach would be to produce a chimeric vaccine against CHIKV. Wang et al. developed a chimeric alphavirus vaccine that is uniformly attenuated and does not cause reactogenicity in mice [3] . Three different versions of this vaccine were made using three different backbone vectors: Venezuelan equine encephalitis virus (VEEV) attenuated vaccine strain T-83, naturally attenuated eastern equine encephalitis virus (EEEV), and attenuated Sindbis virus (SINV). In short, CHIKV structural proteins were engineered into the backbones of the aforementioned vaccines to produce the chimeras [3] . These chimeras were found to stimulate a strong humoral immunity, and even at doses of 5.3-5.8 log 10 PFU, they did not trigger reactogenicity. When vaccinated mice were challenged with CHIKV, neither adult nor neonatal mice gained weight, had fever, or displayed signs of neurological illness. Upon comparison of the chimeras with the Army181/25 vaccine, the Army vaccine resulted in higher", "levels of viremia and replication in the joints of neonatal mice. Because the joints are known targets of CHIKV, Wang et al. noted their vaccine might avoid the negative reactogenic side effects of the Army vaccine. After being subcutaneously vaccinated with 5.3-5.8 log 10 PFU of the chimeric vaccines, mice produced strong neutralizing antibody titers. The VEEV and EEEV chimeras yielded higher neutralizing antibody titers than the SINV chimera without being more virulent. On top of this, the VEEV and EEEV CHIKV chimeras seemed to be more immunogenic than the Army vaccine despite the chimeras' lower viremia and replication in the joints of neonatal mice [3] .", "Tiwari et al. [46] adopted a different strategy using formalin inactivated CHIKV in combination with alhydrogel (Aluminum Hydroxide) as an adjuvant. This study clearly suggests that this vaccine elicits both humoral and cell-mediated immune responses in mice, providing its immunogenic potential. A recent study by Couderc et al. [47] showed passive immunization as a potential treatment for CHIKV infection. Using purified immunoglobulin extracted from convalescent CHIKV patients, they demonstrated effective neutralizing activity against CHIKV infection both in vitro and in vivo. This thereby establishes a potential preventive and therapeutic approach to combat CHIKV infection. Pathogenesis studies conducted with related alpha virus, like RRV, have shown the role of macrophages in persistence on infection [48] . They also demonstrated the role of RRV-specific CD8 T cells in clearing viral load in infected patients, thereby warranting similar investigations with CHIKV and the importance", "of investigating a cell-mediated immune response-based vaccine against CHIKV [49] .", "There are always certain risks associated with live attenuated or inactivated viral vaccines [50] . One way to avoid these potential problems is to construct a consensus-based DNA vaccine. DNA based vaccines have an improved safety profile as compared to live or attenuated vaccines [51, 52] . A consequence of CHIKV's rapid evolution is difficulty in constructing a vaccine that will be able to Figure 3 . Levels of CHIKV-specific IgG in mice immunized with CHIKV vaccines. Each group of C57BL/6 mice (n = 5) was immunized with 12.5 mg of pVax1 control vector or CHIKV vaccine plasmids as indicated at 0 and 2 wk. Mice were bled 2 wk after each immunization, and each group's serum pool was diluted to 1:100 and 1:500 for reaction with specific vaccine constructs. Serum was incubated for 1 h at 37uC on 96-well plates coated with 2 mg/ml of respective CHIKV peptides, and antibody was detected using anti-mouse IgG-HRP and OD was measured at 405 nm. doi:10.1371/journal.pntd.0000623.g003", "www.plosntds.org effectively protect large populations from multiple strains of the virus. One of the strengths of DNA consensus vaccines is its ability to induce cross-reactive immune responses against the three distinct phylogenetic groups of CHIKV. Also DNA-based vaccines can be produced more rapidly than protein-based vaccines.", "Recently, Muthumani et al. constructed a vaccine that was shown to induce both humoral and cellular immunity in vivo in 3-4-wk-old female C57/BL6 mice [49] . These mice were immunized using an in vivo electroporation method to deliver the vaccine into the quadriceps muscle. The consensus construct was designed against E1, E2, and the core protein capsid. To design the construct, they aligned 21 sequences of CHIKV isolated between 1952 and 2006, using strains from differing countries, including La Reunion Island. The most common nucleotide among the sequences was chosen at each position to be used in the consensus construct, taking care not to alter the reading frame. They conducted codon and RNA optimization, added a strong Kozak sequence, and substituted signal peptide with an immunoglobulin E leader sequence to improve vaccine efficacy.", "After immunizing the mice, spleens were harvested along with serum and tested to determine antibody titer. After three immunizations, consensus E1, E2, and C vaccines were shown to induce T-cell immune responses leading to strong IFN-c responses and proliferation in C57/BL6 mice. Furthermore, when compared with control mice, immunized mice had higher total IgG levels as well as higher anti-E1 specific, anti-E2 specific, and anti-C specific IgG antibodies, suggesting a strong humoral immune response ( Figure 3 ) and also specificity for the antigens encoded in the vaccine constructs ( Figure 4 ). Because of its promising results and the need for a safer vaccine, this consensus DNA vaccine deserves further investigation. Determining longevity of protective effects of the vaccine and persistence of antibody and IFN-c responses could be the next step of investigation. Challenged studies of immunized mice must also be carried out.", "CHIKV mosquito-borne disease has caused massive outbreaks for at least half a century but is no longer confined to the www.plosntds.org developing nations. It began to encroach into the boundaries of the developing world. As a result, the NIAID has designated CHIKV as a Category C pathogen alongside the influenza and SARS-CoV viruses [3] . Realization of the potential severity of this disease is exigent; for instance, if used as a biological weapon, the world economy could be severely crippled; if enough members of the armed forces were to become infected during a military deployment, military operations could be significantly affected. Efforts to monitor the disease will only provide minimal warning in a global society, and steps to prevent the morbidity and mortality associated with pandemic are imperative [21, 31] . Despite the gravity of its infectious potency and the fear of it being a potential biological weapon, there is currently no vaccine for CHIKV infections. Live", "attenuated vaccine trials were carried out in 2000, but funding for the project was discontinued. Newer approaches such as DNA vaccines appear promising over conventional strategies like live attenuated or inactivated virus and thus call for further investigation. Recent advances such electroporation delivery and incorporation of adjuvants has boosted DNA vaccine efficacy [51, 53] . Despite the low antibody response to DNA vaccines, other numerous advantages have overshadowed these minor drawbacks (Table 2) , the most important one being the ability to induce both humoral and cellular immune responses [51, 54] .", "Judging by recent success, such as the immunogenic construct developed by Muthumani et al., DNA vaccines could play a major role in combating CHIKV [49] . Vaccines are literally a critical component of CHIKV disease control and therefore research in this area is highly encouraged. The dramatic spread of dengue viruses (DENV) throughout tropical America since 1980 via the same vectors and human hosts underscores the risk to public health in the Americas. The adverse events associated with the current live vaccine are well documented [55] . Realizing these drawbacks, earnest efforts should be taken to develop new strategies to forestall further spread and complications." ]	[ 13 ]	3,829	5,688
1,689	What has become the preferred and lethal vector?	2,516	[ "Ae. albopictus" ]	[ "Chikungunya: A Potentially Emerging Epidemic?\n\nhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC2860491/\n\nSHA: f7c3160bef4169d29e2a8bdd79dd6e9056d4774c\n\nAuthors: Thiboutot, Michelle M.; Kannan, Senthil; Kawalekar, Omkar U.; Shedlock, Devon J.; Khan, Amir S.; Sarangan, Gopalsamy; Srikanth, Padma; Weiner, David B.; Muthumani, Karuppiah\nDate: 2010-04-27\nDOI: 10.1371/journal.pntd.0000623\nLicense: cc-by", "Abstract: Chikungunya virus is a mosquito-borne emerging pathogen that has a major health impact in humans and causes fever disease, headache, rash, nausea, vomiting, myalgia, and arthralgia. Indigenous to tropical Africa, recent large outbreaks have been reported in parts of South East Asia and several of its neighboring islands in 2005–07 and in Europe in 2007. Furthermore, positive cases have been confirmed in the United States in travelers returning from known outbreak areas. Currently, there is no vaccine or antiviral treatment. With the threat of an emerging global pandemic, the peculiar problems associated with the more immediate and seasonal epidemics warrant the development of an effective vaccine. In this review, we summarize the evidence supporting these concepts.", "Text: Chikungunya virus (CHIKV), a mosquito-borne pathogen listed by National Institute of Allergy and Infectious Diseases (NIAID) as a Category C Priority Pathogen that causes Chikungunya fever (CHIKF), has been spreading throughout Asia, Africa, and parts of Europe in recent times [1, 2, 3] . CHIKV is an arthropod-borne virus (arbovirus) and is transmitted to humans primarily by Aedes aegypti, the infamous yellow fever propagator [4, 5] . CHIKV infection is marked by severe joint pain, contorting its victims into unusual postures [6] . The disease gets its name from the Kimakonde vernacular language of Tanzania and Mozambique, and the word chikungunya means ''that which contorts or bends up'' and translates in Swahili to ''the illness of the bended walker'' [7, 8, 9] . In Africa, CHIKV is maintained in a sylvatic cycle among forest-dwelling Aedes spp. mosquitoes, wild primates, squirrels, birds, and rodents ( Figure 1 ) [10] . In Asia, the disease is vectored by Ae. aegypti and Ae.", "albopictus [11] . Transmission in Asia occurs in an urban cycle whereby the mosquito spreads the disease from an infected human to an uninfected human, following an epidemiological pattern similar to dengue fever [12] .", "The 2005-2006 epidemic of CHIKV in La Reunion islands in the Indian Ocean, spurred the discovery of a new vector species, Ae. albopictus [5] . Wrecking over one-third of the island's population, this epidemic peaked its devastation between January and February 2006, when over 46,000 cases came into light every week, including 284 deaths [5, 13] . Ae. albopictus is common in urban areas of the United States and is already flourishing in 36 states, raising grave concerns to the immunologically naive populace of the United States [14] .\n\nAccordingly, this review elaborately details the epidemiology and global expansion of CHIKV, describes its clinical features and pathogenesis and its symptoms and complications, and finally nominates a possible vaccine approach against CHIKV infection.", "CHIKV has been isolated into three genotypes based on phylogenetic studies. These genotypes, based on the gene sequences of an Envelope protein (E1), are Asian, East/Central/ South African, and West African [4, 11, 15] . Using phylogenetic models, Cherian et al. estimate that the Asian genotype of CHIKV emerged between 50 and 310 y ago, and the West and East African genotypes diverged between 100 and 840 y ago [15] . Since then, CHIKV has come a long way, with several mutations incorporated, and has continued to wreak epidemics in several regions. Recent activities of CHIKV include the Indian epidemic in 2005-2006, which was followed by a sudden explosion of cases in 2007. An estimated 1.3 million people across 13 states were reported to be infected in India [12, 16] , and CHIKV was also widespread in Malaysia, Sri Lanka, and Indonesia [17] . In July-August of 2007, CHIKV was reported in Italy, probably brought in by travelers from CHIKV-prone regions of India, Africa, and Indian", "Ocean islands such as Mauritius, Madagascar, and Seychelles. Few of the Italian isolates were found to have evolved from the Kerala isolate, which was associated with a A226V shift in E1 gene that represents a successful evolutionary adaptation in the mosquito vector similar to the ones observed in Reunion Island [2, 18, 19] .", "In recent times, with an increase in global travel, the risk for spreading CHIKV to non-endemic regions has heightened [1] . Several travelers have brought CHIKV home with them after visiting areas with actively infected populations [12, 20] . Such cases have been documented in European countries, Australia, Asia, and the United States [8, 21] . The United States has already reported at least twelve cases of travel-associated CHIKV, while France has reported 850 cases, and the United Kingdom 93 [8, 14] . Beyond this, CHIKV-infected travelers have also been diagnosed in Australia, Belgium, Canada, Czech Republic, French Guiana, Germany, Hong Kong, Italy, Japan, Kenya, Malaysia, Martinique, Norway, Switzerland, and Sri Lanka [21] . Some travelers were viremic, worrying public health officials about the spread of CHIKV to new areas [1, 8] .", "The incubation time for CHIKV is relatively short, requiring only 2-6 d with symptoms usually appearing 4-7 d post-infection [22] . Vazeille et al. detected CHIKV in the salivary glands of Ae. albopictus only 2 d after infection [5] . Upon infection, CHIKF tends to present itself in two phases. The first stage is acute, while the second stage, experienced by most but not all, is persistent, causing disabling polyarthritis. Characteristics of the acute phase include an abrupt onset of fever, arthralgia, and in some cases, maculopapular rash [6, 23] . The acute phase causes such intense joint and muscular pain that makes movement very difficult and prostrates its victims [6, 20] .", "Ninety-five percent of infected adults are symptomatic after infection, and of these, most become disabled for weeks to months as a result of decreased dexterity, loss of mobility, and delayed reaction. Eighteen months after disease onset, 40% of patients are found to still have anti-CHIKV IgM [6, 18, 23, 24] . The chronic stage of CHIKF is characterized by polyarthralgia that can last from weeks to years beyond the acute stage [6] . CHIKV has been shown to attack fibroblasts, explaining the involvement of muscles, joints, and skin connective tissues. The high number of nociceptive nerve endings found within the joints and muscle connective tissues can explain pain associated with CHIKF [25, 26] .", "More than 50% of patients who suffer from severe CHIKF are over 65 y old, and more than 33% of them die. Most adults who suffer from severe CHIKF have underlying medical conditions [6, 24, 27] . The other group that is disproportionately affected by severe CHIKV is children. Other complications associated with CHIKV, from most common to least common, include respiratory failure, cardiovascular decompensation, meningoencephalitis, severe acute hepatitis, severe cutaneous effects, other central nervous system problems, and kidney failure [6, 18, 20, 23, 24, 26, 27] .", "CHIKV undertakes a complex replication cycle upon host infection (Figure 2 ), which makes its genome susceptible to mutations [28, 29] . For instance, Ae. aegypti, responsible for epidemics in Kenya, Comoros, and Seychelles, carried CHIKV with an alanine in the 226 position of the E1 gene (E1-A226) [4, 18] . However, when the virus struck La Reunion Islands, a decline in population of Ae. aegypti, due to massive dichlorodiphenyltrichloroethane usage and dearth of Ae. albopictus species' www.plosntds.org population, resulted in an ecological pressure, favoring replacement of alanine at position 226 with valine (E1-A226V) [5] . This mutation allowed CHIKV's secondary vector species, Ae. albopictus, to supplement Ae. aegypti as its primary vector [5] .", "Within a year, the E1-A226V mutation was present in La Reunion Island, and Ae. albopictus apparently vectored the large epidemic infecting 34% of La Reunion Island's population [5] . All of the CHIKV strains isolated from Mayotte carried the E1-A226V mutation, and the mutation was also found in Madagascar in 2007 [5] . The E1-A226V mutation was not present at the beginning of the Indian Ocean Islands outbreak (before September 2005). However, more than 90% of later viral strains found there had incorporated the mutation (December-March 2006), indicating a genotype switch during the winter season [5, 18, 20] .", "The E1-A226V mutation also enabled an increase in infectivity of Ae. albopictus when compared to its infectivity of Ae. aegypti [4, 11, 18, 30] , and with several factors taken together, Ae. albopictus has become the new preferred and more lethal vector for CHIKV [4, 5, 11] . In fact, Tsetsarkin et al. found that a Green Fluorescent Protein tagged E1-A226V virus was 100 times more infective to Ae. albopictus than it was to Ae. aegypti [4] . In all the Indian Ocean Islands, Ae. albopictus became the main vector for CHIKV within 1-2 y after CHIKV was introduced to the region [31] .", "Of note is that Ae. aegypti has most likely been established in North America for over 300 y, while Ae. albopictus has been in many areas of the US, since 1985, primarily in Florida [32] and since then has expanded its range in the country. Reiskind et al. set out to determine if Ae. aegypti and Ae. albopictus mosquitoes captured in Florida were susceptible to CHIKV infection by a La Reunion isolate [32] . Each mosquito tested was highly susceptible to infection by a full-length infectious clone of the La Réunion Island isolate, CHIKV LR2006 OPY1 strain. Even though the Ae. albopictus strains were more susceptible to infection, overall ecology and differences in human biting patterns need to be studied further Characteristically, there are two rounds of translation: (+) sense genomic RNA (49S9 = 11.7 kb) acts directly as mRNA and is partially translated (59 end) to produce non-structural proteins (nsp's). These proteins are responsible for replication and formation of a complementary", "(2) strand, the template for further (+) strand synthesis. Subgenomic mRNA (26 S = 4.1 kb) replication occurs through the synthesis of full-length (2) intermediate RNA, which is regulated by nsp4 and p123 precursor in early infection and later by mature nsp's. Translation of the newly synthesized sub-genomic RNA results in production of structural proteins such as Capsid and protein E2-6k-E1 (from 39 end of genome). Assembly occurs at the cell surface, and the envelope is acquired as the virus buds from the cell and release and maturation almost simultaneous occurred. Replication occurs in the cytoplasm and is very rapid (,4 h) [28, 29] . doi:10.1371/journal.pntd.0000623.g002 www.plosntds.org to gain a more accurate understanding of a potential CHIKV epidemic in the US [32] .", "During the 7 d preceding birth, no human mother has been reported to transmit the disease vertically. However, about 50% of newborns delivered while the mother was infected with CHIKV contracted the disease from their mother, despite the method of delivery. Furthermore, there have been instances of CHIKV transmission from mother to fetus causing congenital illness and fetal death [33] .", "During the 2005-2006 La Reunion Island outbreaks, Ramful et al. discovered that mothers could transmit CHIKV to their progeny during the perinatal period (Day 24 to Day +1) [33, 34] , and it is associated with a high degree of morbidity. By mean Day 4 of life, all of the neonates were symptomatic for CHIKV, exhibiting common CHIKF symptoms. Six neonates were confirmed to have contracted CHIKV and developed mengoencephalitis. Of those mothers who, during the La Reunion Island epidemic, were infected long before delivery, only three fetal deaths were reported [12, 33] . Ramful et al. theorized that motherto-child transmission most likely happens transplacentally shortly before delivery [33] . A similar study by Gerardin et al. reported nineteen cases of neonatal infection associated with intrapartum maternal viremia that progressed to develop encephalitis owing to vertical transmission from infected mothers [34] .", "Clinical and epidemiological similarities with dengue fever make CHIKV diagnosis difficult, which may lead physicians to misdiagnose CHIKV as dengue fever; therefore, the incidence of CHIKV may actually be higher than currently believed (Table 1 ) [6, 12, 35] .", "The amount of time elapsed since disease onset is the most critical parameter when choosing a diagnostic test. CHIKV can be detected and isolated by culturing with mosquito cells (C6/36), Vero cells (mammalian), or in mice [26] . However, this method can take at least a week and only achieves a high sensitivity during the viremic phase, which usually only lasts up to 48 h after the bite. Five days post-infection, the viral isolation approach has a low sensitivity but is still the preferred method for detecting the CHIKV strain [12, 26, 31, 35] . RT-PCR on the other hand is a faster and more sensitive method that can be used within the first week of disease onset [26] , and it is currently the most sensitive method for detecting and quantifying viral mRNA [4, 36] .", "Classic serological detection, by assays such as ELISA [37] , immunofluorescence [5, 38] , complement binding, and haemagglutination inhibition [39] , constitutes the second diagnostic tool used for biological diagnosis of CHIKV infection. These proven techniques are useful for detection of Antigen in mosquitoes during epidemiological studies. These assays detect virus-specific IgM and IgG, however the sensitivity and specificity of these assays has been poorly characterized. Viral competence, or the potential of viral infection and transmission, is an important parameter that can be quantified by ELISA, viral culture, and PCR.", "A study by Ng et al. showed biomarkers indicative of severe CHIKV infection [40] . They found decreased levels of RANTES and increased levels of Interleukin-6 (IL-6) and Interleukin-1b (IL-1b) that could be sued for CHIKV detection in patients as indicators of CHIKV-driven cytokine storm. Couderc et al. demonstrate another cytokine, type-I IFN, as a key player in the progression to CHIKV infection [26] . Using an IFN-a/b null mouse model, they demonstrated evidence of muscles, joints, and skin as privileged CHIKV targets, which is consistent with human pathology. Although Ng et al. concluded that RANTES levels were significantly suppressed in severe CHIKF patients [40] , interestingly, an increase in levels of RANTES has been observed in dengue infection [41] . Since the symptoms of CHIKF mimic those of dengue fever, results obtained from this study strongly suggest that RANTES could be a potential distinctive biomarker that differentiates between these two clinically similar", "diseases.", "There are no approved antiviral treatments currently available for CHIKV [1, 3, 12, 42] . Currently, CHIKF is treated symptomatically, usually with non-steroidal anti-inflammatory drugs or steroids, bed rest, and fluids. Movement and mild exercise are thought to decrease stiffness and morning arthralgia, but heavy exercise may exacerbate rheumatic symptoms. Corticosteroids may be used in cases of debilitating chronic CHIKV infection. There is a debate about the appropriateness of chloroquine as treatment for unresolved, non-steroidal anti-inflammatory drugresistant arthritis [43] . A study showed that viral production was www.plosntds.org drastically reduced at 16 h post-infection after treatment with 100 mM dec-RVKR-cmk (Decanoyl-Arg-Val-Lys-Arg-chloromethylketone), a furine inhibitor [42, 44] . Chloroquine acted by raising the pH, blocking low pH-dependent entry of virus into the cell. It is important to note that dec-RVKR-cmk or chloroquine only inhibited viral spreading from cell", "to cell, not CHIKV replication once it had entered the cell [43] . However, most would agree that the best weapon against CHIKV is prevention. A live CHIKV vaccine developed by the United States reached phase II clinical trial encompassing 59 healthy volunteers [45] . Eight percent of the volunteers experienced transient arthralgia, while 98% of the volunteers had seroconversion [45] . However, live CHIKV vaccines are still questionable. One cannot discount the risk of a live vaccine possibly inducing chronic rheumatism. Also, there is the question as to whether widespread use among the public could trigger mosquito transmission or lead to chronic infection or viral reversion [1] .", "An alternative approach would be to produce a chimeric vaccine against CHIKV. Wang et al. developed a chimeric alphavirus vaccine that is uniformly attenuated and does not cause reactogenicity in mice [3] . Three different versions of this vaccine were made using three different backbone vectors: Venezuelan equine encephalitis virus (VEEV) attenuated vaccine strain T-83, naturally attenuated eastern equine encephalitis virus (EEEV), and attenuated Sindbis virus (SINV). In short, CHIKV structural proteins were engineered into the backbones of the aforementioned vaccines to produce the chimeras [3] . These chimeras were found to stimulate a strong humoral immunity, and even at doses of 5.3-5.8 log 10 PFU, they did not trigger reactogenicity. When vaccinated mice were challenged with CHIKV, neither adult nor neonatal mice gained weight, had fever, or displayed signs of neurological illness. Upon comparison of the chimeras with the Army181/25 vaccine, the Army vaccine resulted in higher", "levels of viremia and replication in the joints of neonatal mice. Because the joints are known targets of CHIKV, Wang et al. noted their vaccine might avoid the negative reactogenic side effects of the Army vaccine. After being subcutaneously vaccinated with 5.3-5.8 log 10 PFU of the chimeric vaccines, mice produced strong neutralizing antibody titers. The VEEV and EEEV chimeras yielded higher neutralizing antibody titers than the SINV chimera without being more virulent. On top of this, the VEEV and EEEV CHIKV chimeras seemed to be more immunogenic than the Army vaccine despite the chimeras' lower viremia and replication in the joints of neonatal mice [3] .", "Tiwari et al. [46] adopted a different strategy using formalin inactivated CHIKV in combination with alhydrogel (Aluminum Hydroxide) as an adjuvant. This study clearly suggests that this vaccine elicits both humoral and cell-mediated immune responses in mice, providing its immunogenic potential. A recent study by Couderc et al. [47] showed passive immunization as a potential treatment for CHIKV infection. Using purified immunoglobulin extracted from convalescent CHIKV patients, they demonstrated effective neutralizing activity against CHIKV infection both in vitro and in vivo. This thereby establishes a potential preventive and therapeutic approach to combat CHIKV infection. Pathogenesis studies conducted with related alpha virus, like RRV, have shown the role of macrophages in persistence on infection [48] . They also demonstrated the role of RRV-specific CD8 T cells in clearing viral load in infected patients, thereby warranting similar investigations with CHIKV and the importance", "of investigating a cell-mediated immune response-based vaccine against CHIKV [49] .", "There are always certain risks associated with live attenuated or inactivated viral vaccines [50] . One way to avoid these potential problems is to construct a consensus-based DNA vaccine. DNA based vaccines have an improved safety profile as compared to live or attenuated vaccines [51, 52] . A consequence of CHIKV's rapid evolution is difficulty in constructing a vaccine that will be able to Figure 3 . Levels of CHIKV-specific IgG in mice immunized with CHIKV vaccines. Each group of C57BL/6 mice (n = 5) was immunized with 12.5 mg of pVax1 control vector or CHIKV vaccine plasmids as indicated at 0 and 2 wk. Mice were bled 2 wk after each immunization, and each group's serum pool was diluted to 1:100 and 1:500 for reaction with specific vaccine constructs. Serum was incubated for 1 h at 37uC on 96-well plates coated with 2 mg/ml of respective CHIKV peptides, and antibody was detected using anti-mouse IgG-HRP and OD was measured at 405 nm. doi:10.1371/journal.pntd.0000623.g003", "www.plosntds.org effectively protect large populations from multiple strains of the virus. One of the strengths of DNA consensus vaccines is its ability to induce cross-reactive immune responses against the three distinct phylogenetic groups of CHIKV. Also DNA-based vaccines can be produced more rapidly than protein-based vaccines.", "Recently, Muthumani et al. constructed a vaccine that was shown to induce both humoral and cellular immunity in vivo in 3-4-wk-old female C57/BL6 mice [49] . These mice were immunized using an in vivo electroporation method to deliver the vaccine into the quadriceps muscle. The consensus construct was designed against E1, E2, and the core protein capsid. To design the construct, they aligned 21 sequences of CHIKV isolated between 1952 and 2006, using strains from differing countries, including La Reunion Island. The most common nucleotide among the sequences was chosen at each position to be used in the consensus construct, taking care not to alter the reading frame. They conducted codon and RNA optimization, added a strong Kozak sequence, and substituted signal peptide with an immunoglobulin E leader sequence to improve vaccine efficacy.", "After immunizing the mice, spleens were harvested along with serum and tested to determine antibody titer. After three immunizations, consensus E1, E2, and C vaccines were shown to induce T-cell immune responses leading to strong IFN-c responses and proliferation in C57/BL6 mice. Furthermore, when compared with control mice, immunized mice had higher total IgG levels as well as higher anti-E1 specific, anti-E2 specific, and anti-C specific IgG antibodies, suggesting a strong humoral immune response ( Figure 3 ) and also specificity for the antigens encoded in the vaccine constructs ( Figure 4 ). Because of its promising results and the need for a safer vaccine, this consensus DNA vaccine deserves further investigation. Determining longevity of protective effects of the vaccine and persistence of antibody and IFN-c responses could be the next step of investigation. Challenged studies of immunized mice must also be carried out.", "CHIKV mosquito-borne disease has caused massive outbreaks for at least half a century but is no longer confined to the www.plosntds.org developing nations. It began to encroach into the boundaries of the developing world. As a result, the NIAID has designated CHIKV as a Category C pathogen alongside the influenza and SARS-CoV viruses [3] . Realization of the potential severity of this disease is exigent; for instance, if used as a biological weapon, the world economy could be severely crippled; if enough members of the armed forces were to become infected during a military deployment, military operations could be significantly affected. Efforts to monitor the disease will only provide minimal warning in a global society, and steps to prevent the morbidity and mortality associated with pandemic are imperative [21, 31] . Despite the gravity of its infectious potency and the fear of it being a potential biological weapon, there is currently no vaccine for CHIKV infections. Live", "attenuated vaccine trials were carried out in 2000, but funding for the project was discontinued. Newer approaches such as DNA vaccines appear promising over conventional strategies like live attenuated or inactivated virus and thus call for further investigation. Recent advances such electroporation delivery and incorporation of adjuvants has boosted DNA vaccine efficacy [51, 53] . Despite the low antibody response to DNA vaccines, other numerous advantages have overshadowed these minor drawbacks (Table 2) , the most important one being the ability to induce both humoral and cellular immune responses [51, 54] .", "Judging by recent success, such as the immunogenic construct developed by Muthumani et al., DNA vaccines could play a major role in combating CHIKV [49] . Vaccines are literally a critical component of CHIKV disease control and therefore research in this area is highly encouraged. The dramatic spread of dengue viruses (DENV) throughout tropical America since 1980 via the same vectors and human hosts underscores the risk to public health in the Americas. The adverse events associated with the current live vaccine are well documented [55] . Realizing these drawbacks, earnest efforts should be taken to develop new strategies to forestall further spread and complications." ]	[ 4 ]	3,829	5,688
1,689	What was the finding on the Green Fluorescent tagged E1-A226V?	2,517	[ "E1-A226V virus was 100 times more infective to Ae. albopictus than it was to Ae. aegypti" ]	[ "Chikungunya: A Potentially Emerging Epidemic?\n\nhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC2860491/\n\nSHA: f7c3160bef4169d29e2a8bdd79dd6e9056d4774c\n\nAuthors: Thiboutot, Michelle M.; Kannan, Senthil; Kawalekar, Omkar U.; Shedlock, Devon J.; Khan, Amir S.; Sarangan, Gopalsamy; Srikanth, Padma; Weiner, David B.; Muthumani, Karuppiah\nDate: 2010-04-27\nDOI: 10.1371/journal.pntd.0000623\nLicense: cc-by", "Abstract: Chikungunya virus is a mosquito-borne emerging pathogen that has a major health impact in humans and causes fever disease, headache, rash, nausea, vomiting, myalgia, and arthralgia. Indigenous to tropical Africa, recent large outbreaks have been reported in parts of South East Asia and several of its neighboring islands in 2005–07 and in Europe in 2007. Furthermore, positive cases have been confirmed in the United States in travelers returning from known outbreak areas. Currently, there is no vaccine or antiviral treatment. With the threat of an emerging global pandemic, the peculiar problems associated with the more immediate and seasonal epidemics warrant the development of an effective vaccine. In this review, we summarize the evidence supporting these concepts.", "Text: Chikungunya virus (CHIKV), a mosquito-borne pathogen listed by National Institute of Allergy and Infectious Diseases (NIAID) as a Category C Priority Pathogen that causes Chikungunya fever (CHIKF), has been spreading throughout Asia, Africa, and parts of Europe in recent times [1, 2, 3] . CHIKV is an arthropod-borne virus (arbovirus) and is transmitted to humans primarily by Aedes aegypti, the infamous yellow fever propagator [4, 5] . CHIKV infection is marked by severe joint pain, contorting its victims into unusual postures [6] . The disease gets its name from the Kimakonde vernacular language of Tanzania and Mozambique, and the word chikungunya means ''that which contorts or bends up'' and translates in Swahili to ''the illness of the bended walker'' [7, 8, 9] . In Africa, CHIKV is maintained in a sylvatic cycle among forest-dwelling Aedes spp. mosquitoes, wild primates, squirrels, birds, and rodents ( Figure 1 ) [10] . In Asia, the disease is vectored by Ae. aegypti and Ae.", "albopictus [11] . Transmission in Asia occurs in an urban cycle whereby the mosquito spreads the disease from an infected human to an uninfected human, following an epidemiological pattern similar to dengue fever [12] .", "The 2005-2006 epidemic of CHIKV in La Reunion islands in the Indian Ocean, spurred the discovery of a new vector species, Ae. albopictus [5] . Wrecking over one-third of the island's population, this epidemic peaked its devastation between January and February 2006, when over 46,000 cases came into light every week, including 284 deaths [5, 13] . Ae. albopictus is common in urban areas of the United States and is already flourishing in 36 states, raising grave concerns to the immunologically naive populace of the United States [14] .\n\nAccordingly, this review elaborately details the epidemiology and global expansion of CHIKV, describes its clinical features and pathogenesis and its symptoms and complications, and finally nominates a possible vaccine approach against CHIKV infection.", "CHIKV has been isolated into three genotypes based on phylogenetic studies. These genotypes, based on the gene sequences of an Envelope protein (E1), are Asian, East/Central/ South African, and West African [4, 11, 15] . Using phylogenetic models, Cherian et al. estimate that the Asian genotype of CHIKV emerged between 50 and 310 y ago, and the West and East African genotypes diverged between 100 and 840 y ago [15] . Since then, CHIKV has come a long way, with several mutations incorporated, and has continued to wreak epidemics in several regions. Recent activities of CHIKV include the Indian epidemic in 2005-2006, which was followed by a sudden explosion of cases in 2007. An estimated 1.3 million people across 13 states were reported to be infected in India [12, 16] , and CHIKV was also widespread in Malaysia, Sri Lanka, and Indonesia [17] . In July-August of 2007, CHIKV was reported in Italy, probably brought in by travelers from CHIKV-prone regions of India, Africa, and Indian", "Ocean islands such as Mauritius, Madagascar, and Seychelles. Few of the Italian isolates were found to have evolved from the Kerala isolate, which was associated with a A226V shift in E1 gene that represents a successful evolutionary adaptation in the mosquito vector similar to the ones observed in Reunion Island [2, 18, 19] .", "In recent times, with an increase in global travel, the risk for spreading CHIKV to non-endemic regions has heightened [1] . Several travelers have brought CHIKV home with them after visiting areas with actively infected populations [12, 20] . Such cases have been documented in European countries, Australia, Asia, and the United States [8, 21] . The United States has already reported at least twelve cases of travel-associated CHIKV, while France has reported 850 cases, and the United Kingdom 93 [8, 14] . Beyond this, CHIKV-infected travelers have also been diagnosed in Australia, Belgium, Canada, Czech Republic, French Guiana, Germany, Hong Kong, Italy, Japan, Kenya, Malaysia, Martinique, Norway, Switzerland, and Sri Lanka [21] . Some travelers were viremic, worrying public health officials about the spread of CHIKV to new areas [1, 8] .", "The incubation time for CHIKV is relatively short, requiring only 2-6 d with symptoms usually appearing 4-7 d post-infection [22] . Vazeille et al. detected CHIKV in the salivary glands of Ae. albopictus only 2 d after infection [5] . Upon infection, CHIKF tends to present itself in two phases. The first stage is acute, while the second stage, experienced by most but not all, is persistent, causing disabling polyarthritis. Characteristics of the acute phase include an abrupt onset of fever, arthralgia, and in some cases, maculopapular rash [6, 23] . The acute phase causes such intense joint and muscular pain that makes movement very difficult and prostrates its victims [6, 20] .", "Ninety-five percent of infected adults are symptomatic after infection, and of these, most become disabled for weeks to months as a result of decreased dexterity, loss of mobility, and delayed reaction. Eighteen months after disease onset, 40% of patients are found to still have anti-CHIKV IgM [6, 18, 23, 24] . The chronic stage of CHIKF is characterized by polyarthralgia that can last from weeks to years beyond the acute stage [6] . CHIKV has been shown to attack fibroblasts, explaining the involvement of muscles, joints, and skin connective tissues. The high number of nociceptive nerve endings found within the joints and muscle connective tissues can explain pain associated with CHIKF [25, 26] .", "More than 50% of patients who suffer from severe CHIKF are over 65 y old, and more than 33% of them die. Most adults who suffer from severe CHIKF have underlying medical conditions [6, 24, 27] . The other group that is disproportionately affected by severe CHIKV is children. Other complications associated with CHIKV, from most common to least common, include respiratory failure, cardiovascular decompensation, meningoencephalitis, severe acute hepatitis, severe cutaneous effects, other central nervous system problems, and kidney failure [6, 18, 20, 23, 24, 26, 27] .", "CHIKV undertakes a complex replication cycle upon host infection (Figure 2 ), which makes its genome susceptible to mutations [28, 29] . For instance, Ae. aegypti, responsible for epidemics in Kenya, Comoros, and Seychelles, carried CHIKV with an alanine in the 226 position of the E1 gene (E1-A226) [4, 18] . However, when the virus struck La Reunion Islands, a decline in population of Ae. aegypti, due to massive dichlorodiphenyltrichloroethane usage and dearth of Ae. albopictus species' www.plosntds.org population, resulted in an ecological pressure, favoring replacement of alanine at position 226 with valine (E1-A226V) [5] . This mutation allowed CHIKV's secondary vector species, Ae. albopictus, to supplement Ae. aegypti as its primary vector [5] .", "Within a year, the E1-A226V mutation was present in La Reunion Island, and Ae. albopictus apparently vectored the large epidemic infecting 34% of La Reunion Island's population [5] . All of the CHIKV strains isolated from Mayotte carried the E1-A226V mutation, and the mutation was also found in Madagascar in 2007 [5] . The E1-A226V mutation was not present at the beginning of the Indian Ocean Islands outbreak (before September 2005). However, more than 90% of later viral strains found there had incorporated the mutation (December-March 2006), indicating a genotype switch during the winter season [5, 18, 20] .", "The E1-A226V mutation also enabled an increase in infectivity of Ae. albopictus when compared to its infectivity of Ae. aegypti [4, 11, 18, 30] , and with several factors taken together, Ae. albopictus has become the new preferred and more lethal vector for CHIKV [4, 5, 11] . In fact, Tsetsarkin et al. found that a Green Fluorescent Protein tagged E1-A226V virus was 100 times more infective to Ae. albopictus than it was to Ae. aegypti [4] . In all the Indian Ocean Islands, Ae. albopictus became the main vector for CHIKV within 1-2 y after CHIKV was introduced to the region [31] .", "Of note is that Ae. aegypti has most likely been established in North America for over 300 y, while Ae. albopictus has been in many areas of the US, since 1985, primarily in Florida [32] and since then has expanded its range in the country. Reiskind et al. set out to determine if Ae. aegypti and Ae. albopictus mosquitoes captured in Florida were susceptible to CHIKV infection by a La Reunion isolate [32] . Each mosquito tested was highly susceptible to infection by a full-length infectious clone of the La Réunion Island isolate, CHIKV LR2006 OPY1 strain. Even though the Ae. albopictus strains were more susceptible to infection, overall ecology and differences in human biting patterns need to be studied further Characteristically, there are two rounds of translation: (+) sense genomic RNA (49S9 = 11.7 kb) acts directly as mRNA and is partially translated (59 end) to produce non-structural proteins (nsp's). These proteins are responsible for replication and formation of a complementary", "(2) strand, the template for further (+) strand synthesis. Subgenomic mRNA (26 S = 4.1 kb) replication occurs through the synthesis of full-length (2) intermediate RNA, which is regulated by nsp4 and p123 precursor in early infection and later by mature nsp's. Translation of the newly synthesized sub-genomic RNA results in production of structural proteins such as Capsid and protein E2-6k-E1 (from 39 end of genome). Assembly occurs at the cell surface, and the envelope is acquired as the virus buds from the cell and release and maturation almost simultaneous occurred. Replication occurs in the cytoplasm and is very rapid (,4 h) [28, 29] . doi:10.1371/journal.pntd.0000623.g002 www.plosntds.org to gain a more accurate understanding of a potential CHIKV epidemic in the US [32] .", "During the 7 d preceding birth, no human mother has been reported to transmit the disease vertically. However, about 50% of newborns delivered while the mother was infected with CHIKV contracted the disease from their mother, despite the method of delivery. Furthermore, there have been instances of CHIKV transmission from mother to fetus causing congenital illness and fetal death [33] .", "During the 2005-2006 La Reunion Island outbreaks, Ramful et al. discovered that mothers could transmit CHIKV to their progeny during the perinatal period (Day 24 to Day +1) [33, 34] , and it is associated with a high degree of morbidity. By mean Day 4 of life, all of the neonates were symptomatic for CHIKV, exhibiting common CHIKF symptoms. Six neonates were confirmed to have contracted CHIKV and developed mengoencephalitis. Of those mothers who, during the La Reunion Island epidemic, were infected long before delivery, only three fetal deaths were reported [12, 33] . Ramful et al. theorized that motherto-child transmission most likely happens transplacentally shortly before delivery [33] . A similar study by Gerardin et al. reported nineteen cases of neonatal infection associated with intrapartum maternal viremia that progressed to develop encephalitis owing to vertical transmission from infected mothers [34] .", "Clinical and epidemiological similarities with dengue fever make CHIKV diagnosis difficult, which may lead physicians to misdiagnose CHIKV as dengue fever; therefore, the incidence of CHIKV may actually be higher than currently believed (Table 1 ) [6, 12, 35] .", "The amount of time elapsed since disease onset is the most critical parameter when choosing a diagnostic test. CHIKV can be detected and isolated by culturing with mosquito cells (C6/36), Vero cells (mammalian), or in mice [26] . However, this method can take at least a week and only achieves a high sensitivity during the viremic phase, which usually only lasts up to 48 h after the bite. Five days post-infection, the viral isolation approach has a low sensitivity but is still the preferred method for detecting the CHIKV strain [12, 26, 31, 35] . RT-PCR on the other hand is a faster and more sensitive method that can be used within the first week of disease onset [26] , and it is currently the most sensitive method for detecting and quantifying viral mRNA [4, 36] .", "Classic serological detection, by assays such as ELISA [37] , immunofluorescence [5, 38] , complement binding, and haemagglutination inhibition [39] , constitutes the second diagnostic tool used for biological diagnosis of CHIKV infection. These proven techniques are useful for detection of Antigen in mosquitoes during epidemiological studies. These assays detect virus-specific IgM and IgG, however the sensitivity and specificity of these assays has been poorly characterized. Viral competence, or the potential of viral infection and transmission, is an important parameter that can be quantified by ELISA, viral culture, and PCR.", "A study by Ng et al. showed biomarkers indicative of severe CHIKV infection [40] . They found decreased levels of RANTES and increased levels of Interleukin-6 (IL-6) and Interleukin-1b (IL-1b) that could be sued for CHIKV detection in patients as indicators of CHIKV-driven cytokine storm. Couderc et al. demonstrate another cytokine, type-I IFN, as a key player in the progression to CHIKV infection [26] . Using an IFN-a/b null mouse model, they demonstrated evidence of muscles, joints, and skin as privileged CHIKV targets, which is consistent with human pathology. Although Ng et al. concluded that RANTES levels were significantly suppressed in severe CHIKF patients [40] , interestingly, an increase in levels of RANTES has been observed in dengue infection [41] . Since the symptoms of CHIKF mimic those of dengue fever, results obtained from this study strongly suggest that RANTES could be a potential distinctive biomarker that differentiates between these two clinically similar", "diseases.", "There are no approved antiviral treatments currently available for CHIKV [1, 3, 12, 42] . Currently, CHIKF is treated symptomatically, usually with non-steroidal anti-inflammatory drugs or steroids, bed rest, and fluids. Movement and mild exercise are thought to decrease stiffness and morning arthralgia, but heavy exercise may exacerbate rheumatic symptoms. Corticosteroids may be used in cases of debilitating chronic CHIKV infection. There is a debate about the appropriateness of chloroquine as treatment for unresolved, non-steroidal anti-inflammatory drugresistant arthritis [43] . A study showed that viral production was www.plosntds.org drastically reduced at 16 h post-infection after treatment with 100 mM dec-RVKR-cmk (Decanoyl-Arg-Val-Lys-Arg-chloromethylketone), a furine inhibitor [42, 44] . Chloroquine acted by raising the pH, blocking low pH-dependent entry of virus into the cell. It is important to note that dec-RVKR-cmk or chloroquine only inhibited viral spreading from cell", "to cell, not CHIKV replication once it had entered the cell [43] . However, most would agree that the best weapon against CHIKV is prevention. A live CHIKV vaccine developed by the United States reached phase II clinical trial encompassing 59 healthy volunteers [45] . Eight percent of the volunteers experienced transient arthralgia, while 98% of the volunteers had seroconversion [45] . However, live CHIKV vaccines are still questionable. One cannot discount the risk of a live vaccine possibly inducing chronic rheumatism. Also, there is the question as to whether widespread use among the public could trigger mosquito transmission or lead to chronic infection or viral reversion [1] .", "An alternative approach would be to produce a chimeric vaccine against CHIKV. Wang et al. developed a chimeric alphavirus vaccine that is uniformly attenuated and does not cause reactogenicity in mice [3] . Three different versions of this vaccine were made using three different backbone vectors: Venezuelan equine encephalitis virus (VEEV) attenuated vaccine strain T-83, naturally attenuated eastern equine encephalitis virus (EEEV), and attenuated Sindbis virus (SINV). In short, CHIKV structural proteins were engineered into the backbones of the aforementioned vaccines to produce the chimeras [3] . These chimeras were found to stimulate a strong humoral immunity, and even at doses of 5.3-5.8 log 10 PFU, they did not trigger reactogenicity. When vaccinated mice were challenged with CHIKV, neither adult nor neonatal mice gained weight, had fever, or displayed signs of neurological illness. Upon comparison of the chimeras with the Army181/25 vaccine, the Army vaccine resulted in higher", "levels of viremia and replication in the joints of neonatal mice. Because the joints are known targets of CHIKV, Wang et al. noted their vaccine might avoid the negative reactogenic side effects of the Army vaccine. After being subcutaneously vaccinated with 5.3-5.8 log 10 PFU of the chimeric vaccines, mice produced strong neutralizing antibody titers. The VEEV and EEEV chimeras yielded higher neutralizing antibody titers than the SINV chimera without being more virulent. On top of this, the VEEV and EEEV CHIKV chimeras seemed to be more immunogenic than the Army vaccine despite the chimeras' lower viremia and replication in the joints of neonatal mice [3] .", "Tiwari et al. [46] adopted a different strategy using formalin inactivated CHIKV in combination with alhydrogel (Aluminum Hydroxide) as an adjuvant. This study clearly suggests that this vaccine elicits both humoral and cell-mediated immune responses in mice, providing its immunogenic potential. A recent study by Couderc et al. [47] showed passive immunization as a potential treatment for CHIKV infection. Using purified immunoglobulin extracted from convalescent CHIKV patients, they demonstrated effective neutralizing activity against CHIKV infection both in vitro and in vivo. This thereby establishes a potential preventive and therapeutic approach to combat CHIKV infection. Pathogenesis studies conducted with related alpha virus, like RRV, have shown the role of macrophages in persistence on infection [48] . They also demonstrated the role of RRV-specific CD8 T cells in clearing viral load in infected patients, thereby warranting similar investigations with CHIKV and the importance", "of investigating a cell-mediated immune response-based vaccine against CHIKV [49] .", "There are always certain risks associated with live attenuated or inactivated viral vaccines [50] . One way to avoid these potential problems is to construct a consensus-based DNA vaccine. DNA based vaccines have an improved safety profile as compared to live or attenuated vaccines [51, 52] . A consequence of CHIKV's rapid evolution is difficulty in constructing a vaccine that will be able to Figure 3 . Levels of CHIKV-specific IgG in mice immunized with CHIKV vaccines. Each group of C57BL/6 mice (n = 5) was immunized with 12.5 mg of pVax1 control vector or CHIKV vaccine plasmids as indicated at 0 and 2 wk. Mice were bled 2 wk after each immunization, and each group's serum pool was diluted to 1:100 and 1:500 for reaction with specific vaccine constructs. Serum was incubated for 1 h at 37uC on 96-well plates coated with 2 mg/ml of respective CHIKV peptides, and antibody was detected using anti-mouse IgG-HRP and OD was measured at 405 nm. doi:10.1371/journal.pntd.0000623.g003", "www.plosntds.org effectively protect large populations from multiple strains of the virus. One of the strengths of DNA consensus vaccines is its ability to induce cross-reactive immune responses against the three distinct phylogenetic groups of CHIKV. Also DNA-based vaccines can be produced more rapidly than protein-based vaccines.", "Recently, Muthumani et al. constructed a vaccine that was shown to induce both humoral and cellular immunity in vivo in 3-4-wk-old female C57/BL6 mice [49] . These mice were immunized using an in vivo electroporation method to deliver the vaccine into the quadriceps muscle. The consensus construct was designed against E1, E2, and the core protein capsid. To design the construct, they aligned 21 sequences of CHIKV isolated between 1952 and 2006, using strains from differing countries, including La Reunion Island. The most common nucleotide among the sequences was chosen at each position to be used in the consensus construct, taking care not to alter the reading frame. They conducted codon and RNA optimization, added a strong Kozak sequence, and substituted signal peptide with an immunoglobulin E leader sequence to improve vaccine efficacy.", "After immunizing the mice, spleens were harvested along with serum and tested to determine antibody titer. After three immunizations, consensus E1, E2, and C vaccines were shown to induce T-cell immune responses leading to strong IFN-c responses and proliferation in C57/BL6 mice. Furthermore, when compared with control mice, immunized mice had higher total IgG levels as well as higher anti-E1 specific, anti-E2 specific, and anti-C specific IgG antibodies, suggesting a strong humoral immune response ( Figure 3 ) and also specificity for the antigens encoded in the vaccine constructs ( Figure 4 ). Because of its promising results and the need for a safer vaccine, this consensus DNA vaccine deserves further investigation. Determining longevity of protective effects of the vaccine and persistence of antibody and IFN-c responses could be the next step of investigation. Challenged studies of immunized mice must also be carried out.", "CHIKV mosquito-borne disease has caused massive outbreaks for at least half a century but is no longer confined to the www.plosntds.org developing nations. It began to encroach into the boundaries of the developing world. As a result, the NIAID has designated CHIKV as a Category C pathogen alongside the influenza and SARS-CoV viruses [3] . Realization of the potential severity of this disease is exigent; for instance, if used as a biological weapon, the world economy could be severely crippled; if enough members of the armed forces were to become infected during a military deployment, military operations could be significantly affected. Efforts to monitor the disease will only provide minimal warning in a global society, and steps to prevent the morbidity and mortality associated with pandemic are imperative [21, 31] . Despite the gravity of its infectious potency and the fear of it being a potential biological weapon, there is currently no vaccine for CHIKV infections. Live", "attenuated vaccine trials were carried out in 2000, but funding for the project was discontinued. Newer approaches such as DNA vaccines appear promising over conventional strategies like live attenuated or inactivated virus and thus call for further investigation. Recent advances such electroporation delivery and incorporation of adjuvants has boosted DNA vaccine efficacy [51, 53] . Despite the low antibody response to DNA vaccines, other numerous advantages have overshadowed these minor drawbacks (Table 2) , the most important one being the ability to induce both humoral and cellular immune responses [51, 54] .", "Judging by recent success, such as the immunogenic construct developed by Muthumani et al., DNA vaccines could play a major role in combating CHIKV [49] . Vaccines are literally a critical component of CHIKV disease control and therefore research in this area is highly encouraged. The dramatic spread of dengue viruses (DENV) throughout tropical America since 1980 via the same vectors and human hosts underscores the risk to public health in the Americas. The adverse events associated with the current live vaccine are well documented [55] . Realizing these drawbacks, earnest efforts should be taken to develop new strategies to forestall further spread and complications." ]	[ 13 ]	3,829	5,688
1,689	What became the main vector in the Indian Ocean within 1-2 y after CHIKV was introduced?	2,518	[ "Ae. albopictus" ]	[ "Chikungunya: A Potentially Emerging Epidemic?\n\nhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC2860491/\n\nSHA: f7c3160bef4169d29e2a8bdd79dd6e9056d4774c\n\nAuthors: Thiboutot, Michelle M.; Kannan, Senthil; Kawalekar, Omkar U.; Shedlock, Devon J.; Khan, Amir S.; Sarangan, Gopalsamy; Srikanth, Padma; Weiner, David B.; Muthumani, Karuppiah\nDate: 2010-04-27\nDOI: 10.1371/journal.pntd.0000623\nLicense: cc-by", "Abstract: Chikungunya virus is a mosquito-borne emerging pathogen that has a major health impact in humans and causes fever disease, headache, rash, nausea, vomiting, myalgia, and arthralgia. Indigenous to tropical Africa, recent large outbreaks have been reported in parts of South East Asia and several of its neighboring islands in 2005–07 and in Europe in 2007. Furthermore, positive cases have been confirmed in the United States in travelers returning from known outbreak areas. Currently, there is no vaccine or antiviral treatment. With the threat of an emerging global pandemic, the peculiar problems associated with the more immediate and seasonal epidemics warrant the development of an effective vaccine. In this review, we summarize the evidence supporting these concepts.", "Text: Chikungunya virus (CHIKV), a mosquito-borne pathogen listed by National Institute of Allergy and Infectious Diseases (NIAID) as a Category C Priority Pathogen that causes Chikungunya fever (CHIKF), has been spreading throughout Asia, Africa, and parts of Europe in recent times [1, 2, 3] . CHIKV is an arthropod-borne virus (arbovirus) and is transmitted to humans primarily by Aedes aegypti, the infamous yellow fever propagator [4, 5] . CHIKV infection is marked by severe joint pain, contorting its victims into unusual postures [6] . The disease gets its name from the Kimakonde vernacular language of Tanzania and Mozambique, and the word chikungunya means ''that which contorts or bends up'' and translates in Swahili to ''the illness of the bended walker'' [7, 8, 9] . In Africa, CHIKV is maintained in a sylvatic cycle among forest-dwelling Aedes spp. mosquitoes, wild primates, squirrels, birds, and rodents ( Figure 1 ) [10] . In Asia, the disease is vectored by Ae. aegypti and Ae.", "albopictus [11] . Transmission in Asia occurs in an urban cycle whereby the mosquito spreads the disease from an infected human to an uninfected human, following an epidemiological pattern similar to dengue fever [12] .", "The 2005-2006 epidemic of CHIKV in La Reunion islands in the Indian Ocean, spurred the discovery of a new vector species, Ae. albopictus [5] . Wrecking over one-third of the island's population, this epidemic peaked its devastation between January and February 2006, when over 46,000 cases came into light every week, including 284 deaths [5, 13] . Ae. albopictus is common in urban areas of the United States and is already flourishing in 36 states, raising grave concerns to the immunologically naive populace of the United States [14] .\n\nAccordingly, this review elaborately details the epidemiology and global expansion of CHIKV, describes its clinical features and pathogenesis and its symptoms and complications, and finally nominates a possible vaccine approach against CHIKV infection.", "CHIKV has been isolated into three genotypes based on phylogenetic studies. These genotypes, based on the gene sequences of an Envelope protein (E1), are Asian, East/Central/ South African, and West African [4, 11, 15] . Using phylogenetic models, Cherian et al. estimate that the Asian genotype of CHIKV emerged between 50 and 310 y ago, and the West and East African genotypes diverged between 100 and 840 y ago [15] . Since then, CHIKV has come a long way, with several mutations incorporated, and has continued to wreak epidemics in several regions. Recent activities of CHIKV include the Indian epidemic in 2005-2006, which was followed by a sudden explosion of cases in 2007. An estimated 1.3 million people across 13 states were reported to be infected in India [12, 16] , and CHIKV was also widespread in Malaysia, Sri Lanka, and Indonesia [17] . In July-August of 2007, CHIKV was reported in Italy, probably brought in by travelers from CHIKV-prone regions of India, Africa, and Indian", "Ocean islands such as Mauritius, Madagascar, and Seychelles. Few of the Italian isolates were found to have evolved from the Kerala isolate, which was associated with a A226V shift in E1 gene that represents a successful evolutionary adaptation in the mosquito vector similar to the ones observed in Reunion Island [2, 18, 19] .", "In recent times, with an increase in global travel, the risk for spreading CHIKV to non-endemic regions has heightened [1] . Several travelers have brought CHIKV home with them after visiting areas with actively infected populations [12, 20] . Such cases have been documented in European countries, Australia, Asia, and the United States [8, 21] . The United States has already reported at least twelve cases of travel-associated CHIKV, while France has reported 850 cases, and the United Kingdom 93 [8, 14] . Beyond this, CHIKV-infected travelers have also been diagnosed in Australia, Belgium, Canada, Czech Republic, French Guiana, Germany, Hong Kong, Italy, Japan, Kenya, Malaysia, Martinique, Norway, Switzerland, and Sri Lanka [21] . Some travelers were viremic, worrying public health officials about the spread of CHIKV to new areas [1, 8] .", "The incubation time for CHIKV is relatively short, requiring only 2-6 d with symptoms usually appearing 4-7 d post-infection [22] . Vazeille et al. detected CHIKV in the salivary glands of Ae. albopictus only 2 d after infection [5] . Upon infection, CHIKF tends to present itself in two phases. The first stage is acute, while the second stage, experienced by most but not all, is persistent, causing disabling polyarthritis. Characteristics of the acute phase include an abrupt onset of fever, arthralgia, and in some cases, maculopapular rash [6, 23] . The acute phase causes such intense joint and muscular pain that makes movement very difficult and prostrates its victims [6, 20] .", "Ninety-five percent of infected adults are symptomatic after infection, and of these, most become disabled for weeks to months as a result of decreased dexterity, loss of mobility, and delayed reaction. Eighteen months after disease onset, 40% of patients are found to still have anti-CHIKV IgM [6, 18, 23, 24] . The chronic stage of CHIKF is characterized by polyarthralgia that can last from weeks to years beyond the acute stage [6] . CHIKV has been shown to attack fibroblasts, explaining the involvement of muscles, joints, and skin connective tissues. The high number of nociceptive nerve endings found within the joints and muscle connective tissues can explain pain associated with CHIKF [25, 26] .", "More than 50% of patients who suffer from severe CHIKF are over 65 y old, and more than 33% of them die. Most adults who suffer from severe CHIKF have underlying medical conditions [6, 24, 27] . The other group that is disproportionately affected by severe CHIKV is children. Other complications associated with CHIKV, from most common to least common, include respiratory failure, cardiovascular decompensation, meningoencephalitis, severe acute hepatitis, severe cutaneous effects, other central nervous system problems, and kidney failure [6, 18, 20, 23, 24, 26, 27] .", "CHIKV undertakes a complex replication cycle upon host infection (Figure 2 ), which makes its genome susceptible to mutations [28, 29] . For instance, Ae. aegypti, responsible for epidemics in Kenya, Comoros, and Seychelles, carried CHIKV with an alanine in the 226 position of the E1 gene (E1-A226) [4, 18] . However, when the virus struck La Reunion Islands, a decline in population of Ae. aegypti, due to massive dichlorodiphenyltrichloroethane usage and dearth of Ae. albopictus species' www.plosntds.org population, resulted in an ecological pressure, favoring replacement of alanine at position 226 with valine (E1-A226V) [5] . This mutation allowed CHIKV's secondary vector species, Ae. albopictus, to supplement Ae. aegypti as its primary vector [5] .", "Within a year, the E1-A226V mutation was present in La Reunion Island, and Ae. albopictus apparently vectored the large epidemic infecting 34% of La Reunion Island's population [5] . All of the CHIKV strains isolated from Mayotte carried the E1-A226V mutation, and the mutation was also found in Madagascar in 2007 [5] . The E1-A226V mutation was not present at the beginning of the Indian Ocean Islands outbreak (before September 2005). However, more than 90% of later viral strains found there had incorporated the mutation (December-March 2006), indicating a genotype switch during the winter season [5, 18, 20] .", "The E1-A226V mutation also enabled an increase in infectivity of Ae. albopictus when compared to its infectivity of Ae. aegypti [4, 11, 18, 30] , and with several factors taken together, Ae. albopictus has become the new preferred and more lethal vector for CHIKV [4, 5, 11] . In fact, Tsetsarkin et al. found that a Green Fluorescent Protein tagged E1-A226V virus was 100 times more infective to Ae. albopictus than it was to Ae. aegypti [4] . In all the Indian Ocean Islands, Ae. albopictus became the main vector for CHIKV within 1-2 y after CHIKV was introduced to the region [31] .", "Of note is that Ae. aegypti has most likely been established in North America for over 300 y, while Ae. albopictus has been in many areas of the US, since 1985, primarily in Florida [32] and since then has expanded its range in the country. Reiskind et al. set out to determine if Ae. aegypti and Ae. albopictus mosquitoes captured in Florida were susceptible to CHIKV infection by a La Reunion isolate [32] . Each mosquito tested was highly susceptible to infection by a full-length infectious clone of the La Réunion Island isolate, CHIKV LR2006 OPY1 strain. Even though the Ae. albopictus strains were more susceptible to infection, overall ecology and differences in human biting patterns need to be studied further Characteristically, there are two rounds of translation: (+) sense genomic RNA (49S9 = 11.7 kb) acts directly as mRNA and is partially translated (59 end) to produce non-structural proteins (nsp's). These proteins are responsible for replication and formation of a complementary", "(2) strand, the template for further (+) strand synthesis. Subgenomic mRNA (26 S = 4.1 kb) replication occurs through the synthesis of full-length (2) intermediate RNA, which is regulated by nsp4 and p123 precursor in early infection and later by mature nsp's. Translation of the newly synthesized sub-genomic RNA results in production of structural proteins such as Capsid and protein E2-6k-E1 (from 39 end of genome). Assembly occurs at the cell surface, and the envelope is acquired as the virus buds from the cell and release and maturation almost simultaneous occurred. Replication occurs in the cytoplasm and is very rapid (,4 h) [28, 29] . doi:10.1371/journal.pntd.0000623.g002 www.plosntds.org to gain a more accurate understanding of a potential CHIKV epidemic in the US [32] .", "During the 7 d preceding birth, no human mother has been reported to transmit the disease vertically. However, about 50% of newborns delivered while the mother was infected with CHIKV contracted the disease from their mother, despite the method of delivery. Furthermore, there have been instances of CHIKV transmission from mother to fetus causing congenital illness and fetal death [33] .", "During the 2005-2006 La Reunion Island outbreaks, Ramful et al. discovered that mothers could transmit CHIKV to their progeny during the perinatal period (Day 24 to Day +1) [33, 34] , and it is associated with a high degree of morbidity. By mean Day 4 of life, all of the neonates were symptomatic for CHIKV, exhibiting common CHIKF symptoms. Six neonates were confirmed to have contracted CHIKV and developed mengoencephalitis. Of those mothers who, during the La Reunion Island epidemic, were infected long before delivery, only three fetal deaths were reported [12, 33] . Ramful et al. theorized that motherto-child transmission most likely happens transplacentally shortly before delivery [33] . A similar study by Gerardin et al. reported nineteen cases of neonatal infection associated with intrapartum maternal viremia that progressed to develop encephalitis owing to vertical transmission from infected mothers [34] .", "Clinical and epidemiological similarities with dengue fever make CHIKV diagnosis difficult, which may lead physicians to misdiagnose CHIKV as dengue fever; therefore, the incidence of CHIKV may actually be higher than currently believed (Table 1 ) [6, 12, 35] .", "The amount of time elapsed since disease onset is the most critical parameter when choosing a diagnostic test. CHIKV can be detected and isolated by culturing with mosquito cells (C6/36), Vero cells (mammalian), or in mice [26] . However, this method can take at least a week and only achieves a high sensitivity during the viremic phase, which usually only lasts up to 48 h after the bite. Five days post-infection, the viral isolation approach has a low sensitivity but is still the preferred method for detecting the CHIKV strain [12, 26, 31, 35] . RT-PCR on the other hand is a faster and more sensitive method that can be used within the first week of disease onset [26] , and it is currently the most sensitive method for detecting and quantifying viral mRNA [4, 36] .", "Classic serological detection, by assays such as ELISA [37] , immunofluorescence [5, 38] , complement binding, and haemagglutination inhibition [39] , constitutes the second diagnostic tool used for biological diagnosis of CHIKV infection. These proven techniques are useful for detection of Antigen in mosquitoes during epidemiological studies. These assays detect virus-specific IgM and IgG, however the sensitivity and specificity of these assays has been poorly characterized. Viral competence, or the potential of viral infection and transmission, is an important parameter that can be quantified by ELISA, viral culture, and PCR.", "A study by Ng et al. showed biomarkers indicative of severe CHIKV infection [40] . They found decreased levels of RANTES and increased levels of Interleukin-6 (IL-6) and Interleukin-1b (IL-1b) that could be sued for CHIKV detection in patients as indicators of CHIKV-driven cytokine storm. Couderc et al. demonstrate another cytokine, type-I IFN, as a key player in the progression to CHIKV infection [26] . Using an IFN-a/b null mouse model, they demonstrated evidence of muscles, joints, and skin as privileged CHIKV targets, which is consistent with human pathology. Although Ng et al. concluded that RANTES levels were significantly suppressed in severe CHIKF patients [40] , interestingly, an increase in levels of RANTES has been observed in dengue infection [41] . Since the symptoms of CHIKF mimic those of dengue fever, results obtained from this study strongly suggest that RANTES could be a potential distinctive biomarker that differentiates between these two clinically similar", "diseases.", "There are no approved antiviral treatments currently available for CHIKV [1, 3, 12, 42] . Currently, CHIKF is treated symptomatically, usually with non-steroidal anti-inflammatory drugs or steroids, bed rest, and fluids. Movement and mild exercise are thought to decrease stiffness and morning arthralgia, but heavy exercise may exacerbate rheumatic symptoms. Corticosteroids may be used in cases of debilitating chronic CHIKV infection. There is a debate about the appropriateness of chloroquine as treatment for unresolved, non-steroidal anti-inflammatory drugresistant arthritis [43] . A study showed that viral production was www.plosntds.org drastically reduced at 16 h post-infection after treatment with 100 mM dec-RVKR-cmk (Decanoyl-Arg-Val-Lys-Arg-chloromethylketone), a furine inhibitor [42, 44] . Chloroquine acted by raising the pH, blocking low pH-dependent entry of virus into the cell. It is important to note that dec-RVKR-cmk or chloroquine only inhibited viral spreading from cell", "to cell, not CHIKV replication once it had entered the cell [43] . However, most would agree that the best weapon against CHIKV is prevention. A live CHIKV vaccine developed by the United States reached phase II clinical trial encompassing 59 healthy volunteers [45] . Eight percent of the volunteers experienced transient arthralgia, while 98% of the volunteers had seroconversion [45] . However, live CHIKV vaccines are still questionable. One cannot discount the risk of a live vaccine possibly inducing chronic rheumatism. Also, there is the question as to whether widespread use among the public could trigger mosquito transmission or lead to chronic infection or viral reversion [1] .", "An alternative approach would be to produce a chimeric vaccine against CHIKV. Wang et al. developed a chimeric alphavirus vaccine that is uniformly attenuated and does not cause reactogenicity in mice [3] . Three different versions of this vaccine were made using three different backbone vectors: Venezuelan equine encephalitis virus (VEEV) attenuated vaccine strain T-83, naturally attenuated eastern equine encephalitis virus (EEEV), and attenuated Sindbis virus (SINV). In short, CHIKV structural proteins were engineered into the backbones of the aforementioned vaccines to produce the chimeras [3] . These chimeras were found to stimulate a strong humoral immunity, and even at doses of 5.3-5.8 log 10 PFU, they did not trigger reactogenicity. When vaccinated mice were challenged with CHIKV, neither adult nor neonatal mice gained weight, had fever, or displayed signs of neurological illness. Upon comparison of the chimeras with the Army181/25 vaccine, the Army vaccine resulted in higher", "levels of viremia and replication in the joints of neonatal mice. Because the joints are known targets of CHIKV, Wang et al. noted their vaccine might avoid the negative reactogenic side effects of the Army vaccine. After being subcutaneously vaccinated with 5.3-5.8 log 10 PFU of the chimeric vaccines, mice produced strong neutralizing antibody titers. The VEEV and EEEV chimeras yielded higher neutralizing antibody titers than the SINV chimera without being more virulent. On top of this, the VEEV and EEEV CHIKV chimeras seemed to be more immunogenic than the Army vaccine despite the chimeras' lower viremia and replication in the joints of neonatal mice [3] .", "Tiwari et al. [46] adopted a different strategy using formalin inactivated CHIKV in combination with alhydrogel (Aluminum Hydroxide) as an adjuvant. This study clearly suggests that this vaccine elicits both humoral and cell-mediated immune responses in mice, providing its immunogenic potential. A recent study by Couderc et al. [47] showed passive immunization as a potential treatment for CHIKV infection. Using purified immunoglobulin extracted from convalescent CHIKV patients, they demonstrated effective neutralizing activity against CHIKV infection both in vitro and in vivo. This thereby establishes a potential preventive and therapeutic approach to combat CHIKV infection. Pathogenesis studies conducted with related alpha virus, like RRV, have shown the role of macrophages in persistence on infection [48] . They also demonstrated the role of RRV-specific CD8 T cells in clearing viral load in infected patients, thereby warranting similar investigations with CHIKV and the importance", "of investigating a cell-mediated immune response-based vaccine against CHIKV [49] .", "There are always certain risks associated with live attenuated or inactivated viral vaccines [50] . One way to avoid these potential problems is to construct a consensus-based DNA vaccine. DNA based vaccines have an improved safety profile as compared to live or attenuated vaccines [51, 52] . A consequence of CHIKV's rapid evolution is difficulty in constructing a vaccine that will be able to Figure 3 . Levels of CHIKV-specific IgG in mice immunized with CHIKV vaccines. Each group of C57BL/6 mice (n = 5) was immunized with 12.5 mg of pVax1 control vector or CHIKV vaccine plasmids as indicated at 0 and 2 wk. Mice were bled 2 wk after each immunization, and each group's serum pool was diluted to 1:100 and 1:500 for reaction with specific vaccine constructs. Serum was incubated for 1 h at 37uC on 96-well plates coated with 2 mg/ml of respective CHIKV peptides, and antibody was detected using anti-mouse IgG-HRP and OD was measured at 405 nm. doi:10.1371/journal.pntd.0000623.g003", "www.plosntds.org effectively protect large populations from multiple strains of the virus. One of the strengths of DNA consensus vaccines is its ability to induce cross-reactive immune responses against the three distinct phylogenetic groups of CHIKV. Also DNA-based vaccines can be produced more rapidly than protein-based vaccines.", "Recently, Muthumani et al. constructed a vaccine that was shown to induce both humoral and cellular immunity in vivo in 3-4-wk-old female C57/BL6 mice [49] . These mice were immunized using an in vivo electroporation method to deliver the vaccine into the quadriceps muscle. The consensus construct was designed against E1, E2, and the core protein capsid. To design the construct, they aligned 21 sequences of CHIKV isolated between 1952 and 2006, using strains from differing countries, including La Reunion Island. The most common nucleotide among the sequences was chosen at each position to be used in the consensus construct, taking care not to alter the reading frame. They conducted codon and RNA optimization, added a strong Kozak sequence, and substituted signal peptide with an immunoglobulin E leader sequence to improve vaccine efficacy.", "After immunizing the mice, spleens were harvested along with serum and tested to determine antibody titer. After three immunizations, consensus E1, E2, and C vaccines were shown to induce T-cell immune responses leading to strong IFN-c responses and proliferation in C57/BL6 mice. Furthermore, when compared with control mice, immunized mice had higher total IgG levels as well as higher anti-E1 specific, anti-E2 specific, and anti-C specific IgG antibodies, suggesting a strong humoral immune response ( Figure 3 ) and also specificity for the antigens encoded in the vaccine constructs ( Figure 4 ). Because of its promising results and the need for a safer vaccine, this consensus DNA vaccine deserves further investigation. Determining longevity of protective effects of the vaccine and persistence of antibody and IFN-c responses could be the next step of investigation. Challenged studies of immunized mice must also be carried out.", "CHIKV mosquito-borne disease has caused massive outbreaks for at least half a century but is no longer confined to the www.plosntds.org developing nations. It began to encroach into the boundaries of the developing world. As a result, the NIAID has designated CHIKV as a Category C pathogen alongside the influenza and SARS-CoV viruses [3] . Realization of the potential severity of this disease is exigent; for instance, if used as a biological weapon, the world economy could be severely crippled; if enough members of the armed forces were to become infected during a military deployment, military operations could be significantly affected. Efforts to monitor the disease will only provide minimal warning in a global society, and steps to prevent the morbidity and mortality associated with pandemic are imperative [21, 31] . Despite the gravity of its infectious potency and the fear of it being a potential biological weapon, there is currently no vaccine for CHIKV infections. Live", "attenuated vaccine trials were carried out in 2000, but funding for the project was discontinued. Newer approaches such as DNA vaccines appear promising over conventional strategies like live attenuated or inactivated virus and thus call for further investigation. Recent advances such electroporation delivery and incorporation of adjuvants has boosted DNA vaccine efficacy [51, 53] . Despite the low antibody response to DNA vaccines, other numerous advantages have overshadowed these minor drawbacks (Table 2) , the most important one being the ability to induce both humoral and cellular immune responses [51, 54] .", "Judging by recent success, such as the immunogenic construct developed by Muthumani et al., DNA vaccines could play a major role in combating CHIKV [49] . Vaccines are literally a critical component of CHIKV disease control and therefore research in this area is highly encouraged. The dramatic spread of dengue viruses (DENV) throughout tropical America since 1980 via the same vectors and human hosts underscores the risk to public health in the Americas. The adverse events associated with the current live vaccine are well documented [55] . Realizing these drawbacks, earnest efforts should be taken to develop new strategies to forestall further spread and complications." ]	[ 4 ]	3,829	5,688
1,689	how long Ae. aegypti been established in North America?	2,519	[ "for over 300" ]	[ "Chikungunya: A Potentially Emerging Epidemic?\n\nhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC2860491/\n\nSHA: f7c3160bef4169d29e2a8bdd79dd6e9056d4774c\n\nAuthors: Thiboutot, Michelle M.; Kannan, Senthil; Kawalekar, Omkar U.; Shedlock, Devon J.; Khan, Amir S.; Sarangan, Gopalsamy; Srikanth, Padma; Weiner, David B.; Muthumani, Karuppiah\nDate: 2010-04-27\nDOI: 10.1371/journal.pntd.0000623\nLicense: cc-by", "Abstract: Chikungunya virus is a mosquito-borne emerging pathogen that has a major health impact in humans and causes fever disease, headache, rash, nausea, vomiting, myalgia, and arthralgia. Indigenous to tropical Africa, recent large outbreaks have been reported in parts of South East Asia and several of its neighboring islands in 2005–07 and in Europe in 2007. Furthermore, positive cases have been confirmed in the United States in travelers returning from known outbreak areas. Currently, there is no vaccine or antiviral treatment. With the threat of an emerging global pandemic, the peculiar problems associated with the more immediate and seasonal epidemics warrant the development of an effective vaccine. In this review, we summarize the evidence supporting these concepts.", "Text: Chikungunya virus (CHIKV), a mosquito-borne pathogen listed by National Institute of Allergy and Infectious Diseases (NIAID) as a Category C Priority Pathogen that causes Chikungunya fever (CHIKF), has been spreading throughout Asia, Africa, and parts of Europe in recent times [1, 2, 3] . CHIKV is an arthropod-borne virus (arbovirus) and is transmitted to humans primarily by Aedes aegypti, the infamous yellow fever propagator [4, 5] . CHIKV infection is marked by severe joint pain, contorting its victims into unusual postures [6] . The disease gets its name from the Kimakonde vernacular language of Tanzania and Mozambique, and the word chikungunya means ''that which contorts or bends up'' and translates in Swahili to ''the illness of the bended walker'' [7, 8, 9] . In Africa, CHIKV is maintained in a sylvatic cycle among forest-dwelling Aedes spp. mosquitoes, wild primates, squirrels, birds, and rodents ( Figure 1 ) [10] . In Asia, the disease is vectored by Ae. aegypti and Ae.", "albopictus [11] . Transmission in Asia occurs in an urban cycle whereby the mosquito spreads the disease from an infected human to an uninfected human, following an epidemiological pattern similar to dengue fever [12] .", "The 2005-2006 epidemic of CHIKV in La Reunion islands in the Indian Ocean, spurred the discovery of a new vector species, Ae. albopictus [5] . Wrecking over one-third of the island's population, this epidemic peaked its devastation between January and February 2006, when over 46,000 cases came into light every week, including 284 deaths [5, 13] . Ae. albopictus is common in urban areas of the United States and is already flourishing in 36 states, raising grave concerns to the immunologically naive populace of the United States [14] .\n\nAccordingly, this review elaborately details the epidemiology and global expansion of CHIKV, describes its clinical features and pathogenesis and its symptoms and complications, and finally nominates a possible vaccine approach against CHIKV infection.", "CHIKV has been isolated into three genotypes based on phylogenetic studies. These genotypes, based on the gene sequences of an Envelope protein (E1), are Asian, East/Central/ South African, and West African [4, 11, 15] . Using phylogenetic models, Cherian et al. estimate that the Asian genotype of CHIKV emerged between 50 and 310 y ago, and the West and East African genotypes diverged between 100 and 840 y ago [15] . Since then, CHIKV has come a long way, with several mutations incorporated, and has continued to wreak epidemics in several regions. Recent activities of CHIKV include the Indian epidemic in 2005-2006, which was followed by a sudden explosion of cases in 2007. An estimated 1.3 million people across 13 states were reported to be infected in India [12, 16] , and CHIKV was also widespread in Malaysia, Sri Lanka, and Indonesia [17] . In July-August of 2007, CHIKV was reported in Italy, probably brought in by travelers from CHIKV-prone regions of India, Africa, and Indian", "Ocean islands such as Mauritius, Madagascar, and Seychelles. Few of the Italian isolates were found to have evolved from the Kerala isolate, which was associated with a A226V shift in E1 gene that represents a successful evolutionary adaptation in the mosquito vector similar to the ones observed in Reunion Island [2, 18, 19] .", "In recent times, with an increase in global travel, the risk for spreading CHIKV to non-endemic regions has heightened [1] . Several travelers have brought CHIKV home with them after visiting areas with actively infected populations [12, 20] . Such cases have been documented in European countries, Australia, Asia, and the United States [8, 21] . The United States has already reported at least twelve cases of travel-associated CHIKV, while France has reported 850 cases, and the United Kingdom 93 [8, 14] . Beyond this, CHIKV-infected travelers have also been diagnosed in Australia, Belgium, Canada, Czech Republic, French Guiana, Germany, Hong Kong, Italy, Japan, Kenya, Malaysia, Martinique, Norway, Switzerland, and Sri Lanka [21] . Some travelers were viremic, worrying public health officials about the spread of CHIKV to new areas [1, 8] .", "The incubation time for CHIKV is relatively short, requiring only 2-6 d with symptoms usually appearing 4-7 d post-infection [22] . Vazeille et al. detected CHIKV in the salivary glands of Ae. albopictus only 2 d after infection [5] . Upon infection, CHIKF tends to present itself in two phases. The first stage is acute, while the second stage, experienced by most but not all, is persistent, causing disabling polyarthritis. Characteristics of the acute phase include an abrupt onset of fever, arthralgia, and in some cases, maculopapular rash [6, 23] . The acute phase causes such intense joint and muscular pain that makes movement very difficult and prostrates its victims [6, 20] .", "Ninety-five percent of infected adults are symptomatic after infection, and of these, most become disabled for weeks to months as a result of decreased dexterity, loss of mobility, and delayed reaction. Eighteen months after disease onset, 40% of patients are found to still have anti-CHIKV IgM [6, 18, 23, 24] . The chronic stage of CHIKF is characterized by polyarthralgia that can last from weeks to years beyond the acute stage [6] . CHIKV has been shown to attack fibroblasts, explaining the involvement of muscles, joints, and skin connective tissues. The high number of nociceptive nerve endings found within the joints and muscle connective tissues can explain pain associated with CHIKF [25, 26] .", "More than 50% of patients who suffer from severe CHIKF are over 65 y old, and more than 33% of them die. Most adults who suffer from severe CHIKF have underlying medical conditions [6, 24, 27] . The other group that is disproportionately affected by severe CHIKV is children. Other complications associated with CHIKV, from most common to least common, include respiratory failure, cardiovascular decompensation, meningoencephalitis, severe acute hepatitis, severe cutaneous effects, other central nervous system problems, and kidney failure [6, 18, 20, 23, 24, 26, 27] .", "CHIKV undertakes a complex replication cycle upon host infection (Figure 2 ), which makes its genome susceptible to mutations [28, 29] . For instance, Ae. aegypti, responsible for epidemics in Kenya, Comoros, and Seychelles, carried CHIKV with an alanine in the 226 position of the E1 gene (E1-A226) [4, 18] . However, when the virus struck La Reunion Islands, a decline in population of Ae. aegypti, due to massive dichlorodiphenyltrichloroethane usage and dearth of Ae. albopictus species' www.plosntds.org population, resulted in an ecological pressure, favoring replacement of alanine at position 226 with valine (E1-A226V) [5] . This mutation allowed CHIKV's secondary vector species, Ae. albopictus, to supplement Ae. aegypti as its primary vector [5] .", "Within a year, the E1-A226V mutation was present in La Reunion Island, and Ae. albopictus apparently vectored the large epidemic infecting 34% of La Reunion Island's population [5] . All of the CHIKV strains isolated from Mayotte carried the E1-A226V mutation, and the mutation was also found in Madagascar in 2007 [5] . The E1-A226V mutation was not present at the beginning of the Indian Ocean Islands outbreak (before September 2005). However, more than 90% of later viral strains found there had incorporated the mutation (December-March 2006), indicating a genotype switch during the winter season [5, 18, 20] .", "The E1-A226V mutation also enabled an increase in infectivity of Ae. albopictus when compared to its infectivity of Ae. aegypti [4, 11, 18, 30] , and with several factors taken together, Ae. albopictus has become the new preferred and more lethal vector for CHIKV [4, 5, 11] . In fact, Tsetsarkin et al. found that a Green Fluorescent Protein tagged E1-A226V virus was 100 times more infective to Ae. albopictus than it was to Ae. aegypti [4] . In all the Indian Ocean Islands, Ae. albopictus became the main vector for CHIKV within 1-2 y after CHIKV was introduced to the region [31] .", "Of note is that Ae. aegypti has most likely been established in North America for over 300 y, while Ae. albopictus has been in many areas of the US, since 1985, primarily in Florida [32] and since then has expanded its range in the country. Reiskind et al. set out to determine if Ae. aegypti and Ae. albopictus mosquitoes captured in Florida were susceptible to CHIKV infection by a La Reunion isolate [32] . Each mosquito tested was highly susceptible to infection by a full-length infectious clone of the La Réunion Island isolate, CHIKV LR2006 OPY1 strain. Even though the Ae. albopictus strains were more susceptible to infection, overall ecology and differences in human biting patterns need to be studied further Characteristically, there are two rounds of translation: (+) sense genomic RNA (49S9 = 11.7 kb) acts directly as mRNA and is partially translated (59 end) to produce non-structural proteins (nsp's). These proteins are responsible for replication and formation of a complementary", "(2) strand, the template for further (+) strand synthesis. Subgenomic mRNA (26 S = 4.1 kb) replication occurs through the synthesis of full-length (2) intermediate RNA, which is regulated by nsp4 and p123 precursor in early infection and later by mature nsp's. Translation of the newly synthesized sub-genomic RNA results in production of structural proteins such as Capsid and protein E2-6k-E1 (from 39 end of genome). Assembly occurs at the cell surface, and the envelope is acquired as the virus buds from the cell and release and maturation almost simultaneous occurred. Replication occurs in the cytoplasm and is very rapid (,4 h) [28, 29] . doi:10.1371/journal.pntd.0000623.g002 www.plosntds.org to gain a more accurate understanding of a potential CHIKV epidemic in the US [32] .", "During the 7 d preceding birth, no human mother has been reported to transmit the disease vertically. However, about 50% of newborns delivered while the mother was infected with CHIKV contracted the disease from their mother, despite the method of delivery. Furthermore, there have been instances of CHIKV transmission from mother to fetus causing congenital illness and fetal death [33] .", "During the 2005-2006 La Reunion Island outbreaks, Ramful et al. discovered that mothers could transmit CHIKV to their progeny during the perinatal period (Day 24 to Day +1) [33, 34] , and it is associated with a high degree of morbidity. By mean Day 4 of life, all of the neonates were symptomatic for CHIKV, exhibiting common CHIKF symptoms. Six neonates were confirmed to have contracted CHIKV and developed mengoencephalitis. Of those mothers who, during the La Reunion Island epidemic, were infected long before delivery, only three fetal deaths were reported [12, 33] . Ramful et al. theorized that motherto-child transmission most likely happens transplacentally shortly before delivery [33] . A similar study by Gerardin et al. reported nineteen cases of neonatal infection associated with intrapartum maternal viremia that progressed to develop encephalitis owing to vertical transmission from infected mothers [34] .", "Clinical and epidemiological similarities with dengue fever make CHIKV diagnosis difficult, which may lead physicians to misdiagnose CHIKV as dengue fever; therefore, the incidence of CHIKV may actually be higher than currently believed (Table 1 ) [6, 12, 35] .", "The amount of time elapsed since disease onset is the most critical parameter when choosing a diagnostic test. CHIKV can be detected and isolated by culturing with mosquito cells (C6/36), Vero cells (mammalian), or in mice [26] . However, this method can take at least a week and only achieves a high sensitivity during the viremic phase, which usually only lasts up to 48 h after the bite. Five days post-infection, the viral isolation approach has a low sensitivity but is still the preferred method for detecting the CHIKV strain [12, 26, 31, 35] . RT-PCR on the other hand is a faster and more sensitive method that can be used within the first week of disease onset [26] , and it is currently the most sensitive method for detecting and quantifying viral mRNA [4, 36] .", "Classic serological detection, by assays such as ELISA [37] , immunofluorescence [5, 38] , complement binding, and haemagglutination inhibition [39] , constitutes the second diagnostic tool used for biological diagnosis of CHIKV infection. These proven techniques are useful for detection of Antigen in mosquitoes during epidemiological studies. These assays detect virus-specific IgM and IgG, however the sensitivity and specificity of these assays has been poorly characterized. Viral competence, or the potential of viral infection and transmission, is an important parameter that can be quantified by ELISA, viral culture, and PCR.", "A study by Ng et al. showed biomarkers indicative of severe CHIKV infection [40] . They found decreased levels of RANTES and increased levels of Interleukin-6 (IL-6) and Interleukin-1b (IL-1b) that could be sued for CHIKV detection in patients as indicators of CHIKV-driven cytokine storm. Couderc et al. demonstrate another cytokine, type-I IFN, as a key player in the progression to CHIKV infection [26] . Using an IFN-a/b null mouse model, they demonstrated evidence of muscles, joints, and skin as privileged CHIKV targets, which is consistent with human pathology. Although Ng et al. concluded that RANTES levels were significantly suppressed in severe CHIKF patients [40] , interestingly, an increase in levels of RANTES has been observed in dengue infection [41] . Since the symptoms of CHIKF mimic those of dengue fever, results obtained from this study strongly suggest that RANTES could be a potential distinctive biomarker that differentiates between these two clinically similar", "diseases.", "There are no approved antiviral treatments currently available for CHIKV [1, 3, 12, 42] . Currently, CHIKF is treated symptomatically, usually with non-steroidal anti-inflammatory drugs or steroids, bed rest, and fluids. Movement and mild exercise are thought to decrease stiffness and morning arthralgia, but heavy exercise may exacerbate rheumatic symptoms. Corticosteroids may be used in cases of debilitating chronic CHIKV infection. There is a debate about the appropriateness of chloroquine as treatment for unresolved, non-steroidal anti-inflammatory drugresistant arthritis [43] . A study showed that viral production was www.plosntds.org drastically reduced at 16 h post-infection after treatment with 100 mM dec-RVKR-cmk (Decanoyl-Arg-Val-Lys-Arg-chloromethylketone), a furine inhibitor [42, 44] . Chloroquine acted by raising the pH, blocking low pH-dependent entry of virus into the cell. It is important to note that dec-RVKR-cmk or chloroquine only inhibited viral spreading from cell", "to cell, not CHIKV replication once it had entered the cell [43] . However, most would agree that the best weapon against CHIKV is prevention. A live CHIKV vaccine developed by the United States reached phase II clinical trial encompassing 59 healthy volunteers [45] . Eight percent of the volunteers experienced transient arthralgia, while 98% of the volunteers had seroconversion [45] . However, live CHIKV vaccines are still questionable. One cannot discount the risk of a live vaccine possibly inducing chronic rheumatism. Also, there is the question as to whether widespread use among the public could trigger mosquito transmission or lead to chronic infection or viral reversion [1] .", "An alternative approach would be to produce a chimeric vaccine against CHIKV. Wang et al. developed a chimeric alphavirus vaccine that is uniformly attenuated and does not cause reactogenicity in mice [3] . Three different versions of this vaccine were made using three different backbone vectors: Venezuelan equine encephalitis virus (VEEV) attenuated vaccine strain T-83, naturally attenuated eastern equine encephalitis virus (EEEV), and attenuated Sindbis virus (SINV). In short, CHIKV structural proteins were engineered into the backbones of the aforementioned vaccines to produce the chimeras [3] . These chimeras were found to stimulate a strong humoral immunity, and even at doses of 5.3-5.8 log 10 PFU, they did not trigger reactogenicity. When vaccinated mice were challenged with CHIKV, neither adult nor neonatal mice gained weight, had fever, or displayed signs of neurological illness. Upon comparison of the chimeras with the Army181/25 vaccine, the Army vaccine resulted in higher", "levels of viremia and replication in the joints of neonatal mice. Because the joints are known targets of CHIKV, Wang et al. noted their vaccine might avoid the negative reactogenic side effects of the Army vaccine. After being subcutaneously vaccinated with 5.3-5.8 log 10 PFU of the chimeric vaccines, mice produced strong neutralizing antibody titers. The VEEV and EEEV chimeras yielded higher neutralizing antibody titers than the SINV chimera without being more virulent. On top of this, the VEEV and EEEV CHIKV chimeras seemed to be more immunogenic than the Army vaccine despite the chimeras' lower viremia and replication in the joints of neonatal mice [3] .", "Tiwari et al. [46] adopted a different strategy using formalin inactivated CHIKV in combination with alhydrogel (Aluminum Hydroxide) as an adjuvant. This study clearly suggests that this vaccine elicits both humoral and cell-mediated immune responses in mice, providing its immunogenic potential. A recent study by Couderc et al. [47] showed passive immunization as a potential treatment for CHIKV infection. Using purified immunoglobulin extracted from convalescent CHIKV patients, they demonstrated effective neutralizing activity against CHIKV infection both in vitro and in vivo. This thereby establishes a potential preventive and therapeutic approach to combat CHIKV infection. Pathogenesis studies conducted with related alpha virus, like RRV, have shown the role of macrophages in persistence on infection [48] . They also demonstrated the role of RRV-specific CD8 T cells in clearing viral load in infected patients, thereby warranting similar investigations with CHIKV and the importance", "of investigating a cell-mediated immune response-based vaccine against CHIKV [49] .", "There are always certain risks associated with live attenuated or inactivated viral vaccines [50] . One way to avoid these potential problems is to construct a consensus-based DNA vaccine. DNA based vaccines have an improved safety profile as compared to live or attenuated vaccines [51, 52] . A consequence of CHIKV's rapid evolution is difficulty in constructing a vaccine that will be able to Figure 3 . Levels of CHIKV-specific IgG in mice immunized with CHIKV vaccines. Each group of C57BL/6 mice (n = 5) was immunized with 12.5 mg of pVax1 control vector or CHIKV vaccine plasmids as indicated at 0 and 2 wk. Mice were bled 2 wk after each immunization, and each group's serum pool was diluted to 1:100 and 1:500 for reaction with specific vaccine constructs. Serum was incubated for 1 h at 37uC on 96-well plates coated with 2 mg/ml of respective CHIKV peptides, and antibody was detected using anti-mouse IgG-HRP and OD was measured at 405 nm. doi:10.1371/journal.pntd.0000623.g003", "www.plosntds.org effectively protect large populations from multiple strains of the virus. One of the strengths of DNA consensus vaccines is its ability to induce cross-reactive immune responses against the three distinct phylogenetic groups of CHIKV. Also DNA-based vaccines can be produced more rapidly than protein-based vaccines.", "Recently, Muthumani et al. constructed a vaccine that was shown to induce both humoral and cellular immunity in vivo in 3-4-wk-old female C57/BL6 mice [49] . These mice were immunized using an in vivo electroporation method to deliver the vaccine into the quadriceps muscle. The consensus construct was designed against E1, E2, and the core protein capsid. To design the construct, they aligned 21 sequences of CHIKV isolated between 1952 and 2006, using strains from differing countries, including La Reunion Island. The most common nucleotide among the sequences was chosen at each position to be used in the consensus construct, taking care not to alter the reading frame. They conducted codon and RNA optimization, added a strong Kozak sequence, and substituted signal peptide with an immunoglobulin E leader sequence to improve vaccine efficacy.", "After immunizing the mice, spleens were harvested along with serum and tested to determine antibody titer. After three immunizations, consensus E1, E2, and C vaccines were shown to induce T-cell immune responses leading to strong IFN-c responses and proliferation in C57/BL6 mice. Furthermore, when compared with control mice, immunized mice had higher total IgG levels as well as higher anti-E1 specific, anti-E2 specific, and anti-C specific IgG antibodies, suggesting a strong humoral immune response ( Figure 3 ) and also specificity for the antigens encoded in the vaccine constructs ( Figure 4 ). Because of its promising results and the need for a safer vaccine, this consensus DNA vaccine deserves further investigation. Determining longevity of protective effects of the vaccine and persistence of antibody and IFN-c responses could be the next step of investigation. Challenged studies of immunized mice must also be carried out.", "CHIKV mosquito-borne disease has caused massive outbreaks for at least half a century but is no longer confined to the www.plosntds.org developing nations. It began to encroach into the boundaries of the developing world. As a result, the NIAID has designated CHIKV as a Category C pathogen alongside the influenza and SARS-CoV viruses [3] . Realization of the potential severity of this disease is exigent; for instance, if used as a biological weapon, the world economy could be severely crippled; if enough members of the armed forces were to become infected during a military deployment, military operations could be significantly affected. Efforts to monitor the disease will only provide minimal warning in a global society, and steps to prevent the morbidity and mortality associated with pandemic are imperative [21, 31] . Despite the gravity of its infectious potency and the fear of it being a potential biological weapon, there is currently no vaccine for CHIKV infections. Live", "attenuated vaccine trials were carried out in 2000, but funding for the project was discontinued. Newer approaches such as DNA vaccines appear promising over conventional strategies like live attenuated or inactivated virus and thus call for further investigation. Recent advances such electroporation delivery and incorporation of adjuvants has boosted DNA vaccine efficacy [51, 53] . Despite the low antibody response to DNA vaccines, other numerous advantages have overshadowed these minor drawbacks (Table 2) , the most important one being the ability to induce both humoral and cellular immune responses [51, 54] .", "Judging by recent success, such as the immunogenic construct developed by Muthumani et al., DNA vaccines could play a major role in combating CHIKV [49] . Vaccines are literally a critical component of CHIKV disease control and therefore research in this area is highly encouraged. The dramatic spread of dengue viruses (DENV) throughout tropical America since 1980 via the same vectors and human hosts underscores the risk to public health in the Americas. The adverse events associated with the current live vaccine are well documented [55] . Realizing these drawbacks, earnest efforts should be taken to develop new strategies to forestall further spread and complications." ]	[ 14 ]	3,829	5,688
1,689	What is the presence of Ae.albopictus in North America?	2,520	[ "has been in many areas of the US, since 1985, primarily in Florida [32] and since then has expanded its range in the country." ]	[ "Chikungunya: A Potentially Emerging Epidemic?\n\nhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC2860491/\n\nSHA: f7c3160bef4169d29e2a8bdd79dd6e9056d4774c\n\nAuthors: Thiboutot, Michelle M.; Kannan, Senthil; Kawalekar, Omkar U.; Shedlock, Devon J.; Khan, Amir S.; Sarangan, Gopalsamy; Srikanth, Padma; Weiner, David B.; Muthumani, Karuppiah\nDate: 2010-04-27\nDOI: 10.1371/journal.pntd.0000623\nLicense: cc-by", "Abstract: Chikungunya virus is a mosquito-borne emerging pathogen that has a major health impact in humans and causes fever disease, headache, rash, nausea, vomiting, myalgia, and arthralgia. Indigenous to tropical Africa, recent large outbreaks have been reported in parts of South East Asia and several of its neighboring islands in 2005–07 and in Europe in 2007. Furthermore, positive cases have been confirmed in the United States in travelers returning from known outbreak areas. Currently, there is no vaccine or antiviral treatment. With the threat of an emerging global pandemic, the peculiar problems associated with the more immediate and seasonal epidemics warrant the development of an effective vaccine. In this review, we summarize the evidence supporting these concepts.", "Text: Chikungunya virus (CHIKV), a mosquito-borne pathogen listed by National Institute of Allergy and Infectious Diseases (NIAID) as a Category C Priority Pathogen that causes Chikungunya fever (CHIKF), has been spreading throughout Asia, Africa, and parts of Europe in recent times [1, 2, 3] . CHIKV is an arthropod-borne virus (arbovirus) and is transmitted to humans primarily by Aedes aegypti, the infamous yellow fever propagator [4, 5] . CHIKV infection is marked by severe joint pain, contorting its victims into unusual postures [6] . The disease gets its name from the Kimakonde vernacular language of Tanzania and Mozambique, and the word chikungunya means ''that which contorts or bends up'' and translates in Swahili to ''the illness of the bended walker'' [7, 8, 9] . In Africa, CHIKV is maintained in a sylvatic cycle among forest-dwelling Aedes spp. mosquitoes, wild primates, squirrels, birds, and rodents ( Figure 1 ) [10] . In Asia, the disease is vectored by Ae. aegypti and Ae.", "albopictus [11] . Transmission in Asia occurs in an urban cycle whereby the mosquito spreads the disease from an infected human to an uninfected human, following an epidemiological pattern similar to dengue fever [12] .", "The 2005-2006 epidemic of CHIKV in La Reunion islands in the Indian Ocean, spurred the discovery of a new vector species, Ae. albopictus [5] . Wrecking over one-third of the island's population, this epidemic peaked its devastation between January and February 2006, when over 46,000 cases came into light every week, including 284 deaths [5, 13] . Ae. albopictus is common in urban areas of the United States and is already flourishing in 36 states, raising grave concerns to the immunologically naive populace of the United States [14] .\n\nAccordingly, this review elaborately details the epidemiology and global expansion of CHIKV, describes its clinical features and pathogenesis and its symptoms and complications, and finally nominates a possible vaccine approach against CHIKV infection.", "CHIKV has been isolated into three genotypes based on phylogenetic studies. These genotypes, based on the gene sequences of an Envelope protein (E1), are Asian, East/Central/ South African, and West African [4, 11, 15] . Using phylogenetic models, Cherian et al. estimate that the Asian genotype of CHIKV emerged between 50 and 310 y ago, and the West and East African genotypes diverged between 100 and 840 y ago [15] . Since then, CHIKV has come a long way, with several mutations incorporated, and has continued to wreak epidemics in several regions. Recent activities of CHIKV include the Indian epidemic in 2005-2006, which was followed by a sudden explosion of cases in 2007. An estimated 1.3 million people across 13 states were reported to be infected in India [12, 16] , and CHIKV was also widespread in Malaysia, Sri Lanka, and Indonesia [17] . In July-August of 2007, CHIKV was reported in Italy, probably brought in by travelers from CHIKV-prone regions of India, Africa, and Indian", "Ocean islands such as Mauritius, Madagascar, and Seychelles. Few of the Italian isolates were found to have evolved from the Kerala isolate, which was associated with a A226V shift in E1 gene that represents a successful evolutionary adaptation in the mosquito vector similar to the ones observed in Reunion Island [2, 18, 19] .", "In recent times, with an increase in global travel, the risk for spreading CHIKV to non-endemic regions has heightened [1] . Several travelers have brought CHIKV home with them after visiting areas with actively infected populations [12, 20] . Such cases have been documented in European countries, Australia, Asia, and the United States [8, 21] . The United States has already reported at least twelve cases of travel-associated CHIKV, while France has reported 850 cases, and the United Kingdom 93 [8, 14] . Beyond this, CHIKV-infected travelers have also been diagnosed in Australia, Belgium, Canada, Czech Republic, French Guiana, Germany, Hong Kong, Italy, Japan, Kenya, Malaysia, Martinique, Norway, Switzerland, and Sri Lanka [21] . Some travelers were viremic, worrying public health officials about the spread of CHIKV to new areas [1, 8] .", "The incubation time for CHIKV is relatively short, requiring only 2-6 d with symptoms usually appearing 4-7 d post-infection [22] . Vazeille et al. detected CHIKV in the salivary glands of Ae. albopictus only 2 d after infection [5] . Upon infection, CHIKF tends to present itself in two phases. The first stage is acute, while the second stage, experienced by most but not all, is persistent, causing disabling polyarthritis. Characteristics of the acute phase include an abrupt onset of fever, arthralgia, and in some cases, maculopapular rash [6, 23] . The acute phase causes such intense joint and muscular pain that makes movement very difficult and prostrates its victims [6, 20] .", "Ninety-five percent of infected adults are symptomatic after infection, and of these, most become disabled for weeks to months as a result of decreased dexterity, loss of mobility, and delayed reaction. Eighteen months after disease onset, 40% of patients are found to still have anti-CHIKV IgM [6, 18, 23, 24] . The chronic stage of CHIKF is characterized by polyarthralgia that can last from weeks to years beyond the acute stage [6] . CHIKV has been shown to attack fibroblasts, explaining the involvement of muscles, joints, and skin connective tissues. The high number of nociceptive nerve endings found within the joints and muscle connective tissues can explain pain associated with CHIKF [25, 26] .", "More than 50% of patients who suffer from severe CHIKF are over 65 y old, and more than 33% of them die. Most adults who suffer from severe CHIKF have underlying medical conditions [6, 24, 27] . The other group that is disproportionately affected by severe CHIKV is children. Other complications associated with CHIKV, from most common to least common, include respiratory failure, cardiovascular decompensation, meningoencephalitis, severe acute hepatitis, severe cutaneous effects, other central nervous system problems, and kidney failure [6, 18, 20, 23, 24, 26, 27] .", "CHIKV undertakes a complex replication cycle upon host infection (Figure 2 ), which makes its genome susceptible to mutations [28, 29] . For instance, Ae. aegypti, responsible for epidemics in Kenya, Comoros, and Seychelles, carried CHIKV with an alanine in the 226 position of the E1 gene (E1-A226) [4, 18] . However, when the virus struck La Reunion Islands, a decline in population of Ae. aegypti, due to massive dichlorodiphenyltrichloroethane usage and dearth of Ae. albopictus species' www.plosntds.org population, resulted in an ecological pressure, favoring replacement of alanine at position 226 with valine (E1-A226V) [5] . This mutation allowed CHIKV's secondary vector species, Ae. albopictus, to supplement Ae. aegypti as its primary vector [5] .", "Within a year, the E1-A226V mutation was present in La Reunion Island, and Ae. albopictus apparently vectored the large epidemic infecting 34% of La Reunion Island's population [5] . All of the CHIKV strains isolated from Mayotte carried the E1-A226V mutation, and the mutation was also found in Madagascar in 2007 [5] . The E1-A226V mutation was not present at the beginning of the Indian Ocean Islands outbreak (before September 2005). However, more than 90% of later viral strains found there had incorporated the mutation (December-March 2006), indicating a genotype switch during the winter season [5, 18, 20] .", "The E1-A226V mutation also enabled an increase in infectivity of Ae. albopictus when compared to its infectivity of Ae. aegypti [4, 11, 18, 30] , and with several factors taken together, Ae. albopictus has become the new preferred and more lethal vector for CHIKV [4, 5, 11] . In fact, Tsetsarkin et al. found that a Green Fluorescent Protein tagged E1-A226V virus was 100 times more infective to Ae. albopictus than it was to Ae. aegypti [4] . In all the Indian Ocean Islands, Ae. albopictus became the main vector for CHIKV within 1-2 y after CHIKV was introduced to the region [31] .", "Of note is that Ae. aegypti has most likely been established in North America for over 300 y, while Ae. albopictus has been in many areas of the US, since 1985, primarily in Florida [32] and since then has expanded its range in the country. Reiskind et al. set out to determine if Ae. aegypti and Ae. albopictus mosquitoes captured in Florida were susceptible to CHIKV infection by a La Reunion isolate [32] . Each mosquito tested was highly susceptible to infection by a full-length infectious clone of the La Réunion Island isolate, CHIKV LR2006 OPY1 strain. Even though the Ae. albopictus strains were more susceptible to infection, overall ecology and differences in human biting patterns need to be studied further Characteristically, there are two rounds of translation: (+) sense genomic RNA (49S9 = 11.7 kb) acts directly as mRNA and is partially translated (59 end) to produce non-structural proteins (nsp's). These proteins are responsible for replication and formation of a complementary", "(2) strand, the template for further (+) strand synthesis. Subgenomic mRNA (26 S = 4.1 kb) replication occurs through the synthesis of full-length (2) intermediate RNA, which is regulated by nsp4 and p123 precursor in early infection and later by mature nsp's. Translation of the newly synthesized sub-genomic RNA results in production of structural proteins such as Capsid and protein E2-6k-E1 (from 39 end of genome). Assembly occurs at the cell surface, and the envelope is acquired as the virus buds from the cell and release and maturation almost simultaneous occurred. Replication occurs in the cytoplasm and is very rapid (,4 h) [28, 29] . doi:10.1371/journal.pntd.0000623.g002 www.plosntds.org to gain a more accurate understanding of a potential CHIKV epidemic in the US [32] .", "During the 7 d preceding birth, no human mother has been reported to transmit the disease vertically. However, about 50% of newborns delivered while the mother was infected with CHIKV contracted the disease from their mother, despite the method of delivery. Furthermore, there have been instances of CHIKV transmission from mother to fetus causing congenital illness and fetal death [33] .", "During the 2005-2006 La Reunion Island outbreaks, Ramful et al. discovered that mothers could transmit CHIKV to their progeny during the perinatal period (Day 24 to Day +1) [33, 34] , and it is associated with a high degree of morbidity. By mean Day 4 of life, all of the neonates were symptomatic for CHIKV, exhibiting common CHIKF symptoms. Six neonates were confirmed to have contracted CHIKV and developed mengoencephalitis. Of those mothers who, during the La Reunion Island epidemic, were infected long before delivery, only three fetal deaths were reported [12, 33] . Ramful et al. theorized that motherto-child transmission most likely happens transplacentally shortly before delivery [33] . A similar study by Gerardin et al. reported nineteen cases of neonatal infection associated with intrapartum maternal viremia that progressed to develop encephalitis owing to vertical transmission from infected mothers [34] .", "Clinical and epidemiological similarities with dengue fever make CHIKV diagnosis difficult, which may lead physicians to misdiagnose CHIKV as dengue fever; therefore, the incidence of CHIKV may actually be higher than currently believed (Table 1 ) [6, 12, 35] .", "The amount of time elapsed since disease onset is the most critical parameter when choosing a diagnostic test. CHIKV can be detected and isolated by culturing with mosquito cells (C6/36), Vero cells (mammalian), or in mice [26] . However, this method can take at least a week and only achieves a high sensitivity during the viremic phase, which usually only lasts up to 48 h after the bite. Five days post-infection, the viral isolation approach has a low sensitivity but is still the preferred method for detecting the CHIKV strain [12, 26, 31, 35] . RT-PCR on the other hand is a faster and more sensitive method that can be used within the first week of disease onset [26] , and it is currently the most sensitive method for detecting and quantifying viral mRNA [4, 36] .", "Classic serological detection, by assays such as ELISA [37] , immunofluorescence [5, 38] , complement binding, and haemagglutination inhibition [39] , constitutes the second diagnostic tool used for biological diagnosis of CHIKV infection. These proven techniques are useful for detection of Antigen in mosquitoes during epidemiological studies. These assays detect virus-specific IgM and IgG, however the sensitivity and specificity of these assays has been poorly characterized. Viral competence, or the potential of viral infection and transmission, is an important parameter that can be quantified by ELISA, viral culture, and PCR.", "A study by Ng et al. showed biomarkers indicative of severe CHIKV infection [40] . They found decreased levels of RANTES and increased levels of Interleukin-6 (IL-6) and Interleukin-1b (IL-1b) that could be sued for CHIKV detection in patients as indicators of CHIKV-driven cytokine storm. Couderc et al. demonstrate another cytokine, type-I IFN, as a key player in the progression to CHIKV infection [26] . Using an IFN-a/b null mouse model, they demonstrated evidence of muscles, joints, and skin as privileged CHIKV targets, which is consistent with human pathology. Although Ng et al. concluded that RANTES levels were significantly suppressed in severe CHIKF patients [40] , interestingly, an increase in levels of RANTES has been observed in dengue infection [41] . Since the symptoms of CHIKF mimic those of dengue fever, results obtained from this study strongly suggest that RANTES could be a potential distinctive biomarker that differentiates between these two clinically similar", "diseases.", "There are no approved antiviral treatments currently available for CHIKV [1, 3, 12, 42] . Currently, CHIKF is treated symptomatically, usually with non-steroidal anti-inflammatory drugs or steroids, bed rest, and fluids. Movement and mild exercise are thought to decrease stiffness and morning arthralgia, but heavy exercise may exacerbate rheumatic symptoms. Corticosteroids may be used in cases of debilitating chronic CHIKV infection. There is a debate about the appropriateness of chloroquine as treatment for unresolved, non-steroidal anti-inflammatory drugresistant arthritis [43] . A study showed that viral production was www.plosntds.org drastically reduced at 16 h post-infection after treatment with 100 mM dec-RVKR-cmk (Decanoyl-Arg-Val-Lys-Arg-chloromethylketone), a furine inhibitor [42, 44] . Chloroquine acted by raising the pH, blocking low pH-dependent entry of virus into the cell. It is important to note that dec-RVKR-cmk or chloroquine only inhibited viral spreading from cell", "to cell, not CHIKV replication once it had entered the cell [43] . However, most would agree that the best weapon against CHIKV is prevention. A live CHIKV vaccine developed by the United States reached phase II clinical trial encompassing 59 healthy volunteers [45] . Eight percent of the volunteers experienced transient arthralgia, while 98% of the volunteers had seroconversion [45] . However, live CHIKV vaccines are still questionable. One cannot discount the risk of a live vaccine possibly inducing chronic rheumatism. Also, there is the question as to whether widespread use among the public could trigger mosquito transmission or lead to chronic infection or viral reversion [1] .", "An alternative approach would be to produce a chimeric vaccine against CHIKV. Wang et al. developed a chimeric alphavirus vaccine that is uniformly attenuated and does not cause reactogenicity in mice [3] . Three different versions of this vaccine were made using three different backbone vectors: Venezuelan equine encephalitis virus (VEEV) attenuated vaccine strain T-83, naturally attenuated eastern equine encephalitis virus (EEEV), and attenuated Sindbis virus (SINV). In short, CHIKV structural proteins were engineered into the backbones of the aforementioned vaccines to produce the chimeras [3] . These chimeras were found to stimulate a strong humoral immunity, and even at doses of 5.3-5.8 log 10 PFU, they did not trigger reactogenicity. When vaccinated mice were challenged with CHIKV, neither adult nor neonatal mice gained weight, had fever, or displayed signs of neurological illness. Upon comparison of the chimeras with the Army181/25 vaccine, the Army vaccine resulted in higher", "levels of viremia and replication in the joints of neonatal mice. Because the joints are known targets of CHIKV, Wang et al. noted their vaccine might avoid the negative reactogenic side effects of the Army vaccine. After being subcutaneously vaccinated with 5.3-5.8 log 10 PFU of the chimeric vaccines, mice produced strong neutralizing antibody titers. The VEEV and EEEV chimeras yielded higher neutralizing antibody titers than the SINV chimera without being more virulent. On top of this, the VEEV and EEEV CHIKV chimeras seemed to be more immunogenic than the Army vaccine despite the chimeras' lower viremia and replication in the joints of neonatal mice [3] .", "Tiwari et al. [46] adopted a different strategy using formalin inactivated CHIKV in combination with alhydrogel (Aluminum Hydroxide) as an adjuvant. This study clearly suggests that this vaccine elicits both humoral and cell-mediated immune responses in mice, providing its immunogenic potential. A recent study by Couderc et al. [47] showed passive immunization as a potential treatment for CHIKV infection. Using purified immunoglobulin extracted from convalescent CHIKV patients, they demonstrated effective neutralizing activity against CHIKV infection both in vitro and in vivo. This thereby establishes a potential preventive and therapeutic approach to combat CHIKV infection. Pathogenesis studies conducted with related alpha virus, like RRV, have shown the role of macrophages in persistence on infection [48] . They also demonstrated the role of RRV-specific CD8 T cells in clearing viral load in infected patients, thereby warranting similar investigations with CHIKV and the importance", "of investigating a cell-mediated immune response-based vaccine against CHIKV [49] .", "There are always certain risks associated with live attenuated or inactivated viral vaccines [50] . One way to avoid these potential problems is to construct a consensus-based DNA vaccine. DNA based vaccines have an improved safety profile as compared to live or attenuated vaccines [51, 52] . A consequence of CHIKV's rapid evolution is difficulty in constructing a vaccine that will be able to Figure 3 . Levels of CHIKV-specific IgG in mice immunized with CHIKV vaccines. Each group of C57BL/6 mice (n = 5) was immunized with 12.5 mg of pVax1 control vector or CHIKV vaccine plasmids as indicated at 0 and 2 wk. Mice were bled 2 wk after each immunization, and each group's serum pool was diluted to 1:100 and 1:500 for reaction with specific vaccine constructs. Serum was incubated for 1 h at 37uC on 96-well plates coated with 2 mg/ml of respective CHIKV peptides, and antibody was detected using anti-mouse IgG-HRP and OD was measured at 405 nm. doi:10.1371/journal.pntd.0000623.g003", "www.plosntds.org effectively protect large populations from multiple strains of the virus. One of the strengths of DNA consensus vaccines is its ability to induce cross-reactive immune responses against the three distinct phylogenetic groups of CHIKV. Also DNA-based vaccines can be produced more rapidly than protein-based vaccines.", "Recently, Muthumani et al. constructed a vaccine that was shown to induce both humoral and cellular immunity in vivo in 3-4-wk-old female C57/BL6 mice [49] . These mice were immunized using an in vivo electroporation method to deliver the vaccine into the quadriceps muscle. The consensus construct was designed against E1, E2, and the core protein capsid. To design the construct, they aligned 21 sequences of CHIKV isolated between 1952 and 2006, using strains from differing countries, including La Reunion Island. The most common nucleotide among the sequences was chosen at each position to be used in the consensus construct, taking care not to alter the reading frame. They conducted codon and RNA optimization, added a strong Kozak sequence, and substituted signal peptide with an immunoglobulin E leader sequence to improve vaccine efficacy.", "After immunizing the mice, spleens were harvested along with serum and tested to determine antibody titer. After three immunizations, consensus E1, E2, and C vaccines were shown to induce T-cell immune responses leading to strong IFN-c responses and proliferation in C57/BL6 mice. Furthermore, when compared with control mice, immunized mice had higher total IgG levels as well as higher anti-E1 specific, anti-E2 specific, and anti-C specific IgG antibodies, suggesting a strong humoral immune response ( Figure 3 ) and also specificity for the antigens encoded in the vaccine constructs ( Figure 4 ). Because of its promising results and the need for a safer vaccine, this consensus DNA vaccine deserves further investigation. Determining longevity of protective effects of the vaccine and persistence of antibody and IFN-c responses could be the next step of investigation. Challenged studies of immunized mice must also be carried out.", "CHIKV mosquito-borne disease has caused massive outbreaks for at least half a century but is no longer confined to the www.plosntds.org developing nations. It began to encroach into the boundaries of the developing world. As a result, the NIAID has designated CHIKV as a Category C pathogen alongside the influenza and SARS-CoV viruses [3] . Realization of the potential severity of this disease is exigent; for instance, if used as a biological weapon, the world economy could be severely crippled; if enough members of the armed forces were to become infected during a military deployment, military operations could be significantly affected. Efforts to monitor the disease will only provide minimal warning in a global society, and steps to prevent the morbidity and mortality associated with pandemic are imperative [21, 31] . Despite the gravity of its infectious potency and the fear of it being a potential biological weapon, there is currently no vaccine for CHIKV infections. Live", "attenuated vaccine trials were carried out in 2000, but funding for the project was discontinued. Newer approaches such as DNA vaccines appear promising over conventional strategies like live attenuated or inactivated virus and thus call for further investigation. Recent advances such electroporation delivery and incorporation of adjuvants has boosted DNA vaccine efficacy [51, 53] . Despite the low antibody response to DNA vaccines, other numerous advantages have overshadowed these minor drawbacks (Table 2) , the most important one being the ability to induce both humoral and cellular immune responses [51, 54] .", "Judging by recent success, such as the immunogenic construct developed by Muthumani et al., DNA vaccines could play a major role in combating CHIKV [49] . Vaccines are literally a critical component of CHIKV disease control and therefore research in this area is highly encouraged. The dramatic spread of dengue viruses (DENV) throughout tropical America since 1980 via the same vectors and human hosts underscores the risk to public health in the Americas. The adverse events associated with the current live vaccine are well documented [55] . Realizing these drawbacks, earnest efforts should be taken to develop new strategies to forestall further spread and complications." ]	[ 14 ]	3,829	5,688
1,689	What percentage of newborns were infected from their mother?	2,521	[ "50%" ]	[ "Chikungunya: A Potentially Emerging Epidemic?\n\nhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC2860491/\n\nSHA: f7c3160bef4169d29e2a8bdd79dd6e9056d4774c\n\nAuthors: Thiboutot, Michelle M.; Kannan, Senthil; Kawalekar, Omkar U.; Shedlock, Devon J.; Khan, Amir S.; Sarangan, Gopalsamy; Srikanth, Padma; Weiner, David B.; Muthumani, Karuppiah\nDate: 2010-04-27\nDOI: 10.1371/journal.pntd.0000623\nLicense: cc-by", "Abstract: Chikungunya virus is a mosquito-borne emerging pathogen that has a major health impact in humans and causes fever disease, headache, rash, nausea, vomiting, myalgia, and arthralgia. Indigenous to tropical Africa, recent large outbreaks have been reported in parts of South East Asia and several of its neighboring islands in 2005–07 and in Europe in 2007. Furthermore, positive cases have been confirmed in the United States in travelers returning from known outbreak areas. Currently, there is no vaccine or antiviral treatment. With the threat of an emerging global pandemic, the peculiar problems associated with the more immediate and seasonal epidemics warrant the development of an effective vaccine. In this review, we summarize the evidence supporting these concepts.", "Text: Chikungunya virus (CHIKV), a mosquito-borne pathogen listed by National Institute of Allergy and Infectious Diseases (NIAID) as a Category C Priority Pathogen that causes Chikungunya fever (CHIKF), has been spreading throughout Asia, Africa, and parts of Europe in recent times [1, 2, 3] . CHIKV is an arthropod-borne virus (arbovirus) and is transmitted to humans primarily by Aedes aegypti, the infamous yellow fever propagator [4, 5] . CHIKV infection is marked by severe joint pain, contorting its victims into unusual postures [6] . The disease gets its name from the Kimakonde vernacular language of Tanzania and Mozambique, and the word chikungunya means ''that which contorts or bends up'' and translates in Swahili to ''the illness of the bended walker'' [7, 8, 9] . In Africa, CHIKV is maintained in a sylvatic cycle among forest-dwelling Aedes spp. mosquitoes, wild primates, squirrels, birds, and rodents ( Figure 1 ) [10] . In Asia, the disease is vectored by Ae. aegypti and Ae.", "albopictus [11] . Transmission in Asia occurs in an urban cycle whereby the mosquito spreads the disease from an infected human to an uninfected human, following an epidemiological pattern similar to dengue fever [12] .", "The 2005-2006 epidemic of CHIKV in La Reunion islands in the Indian Ocean, spurred the discovery of a new vector species, Ae. albopictus [5] . Wrecking over one-third of the island's population, this epidemic peaked its devastation between January and February 2006, when over 46,000 cases came into light every week, including 284 deaths [5, 13] . Ae. albopictus is common in urban areas of the United States and is already flourishing in 36 states, raising grave concerns to the immunologically naive populace of the United States [14] .\n\nAccordingly, this review elaborately details the epidemiology and global expansion of CHIKV, describes its clinical features and pathogenesis and its symptoms and complications, and finally nominates a possible vaccine approach against CHIKV infection.", "CHIKV has been isolated into three genotypes based on phylogenetic studies. These genotypes, based on the gene sequences of an Envelope protein (E1), are Asian, East/Central/ South African, and West African [4, 11, 15] . Using phylogenetic models, Cherian et al. estimate that the Asian genotype of CHIKV emerged between 50 and 310 y ago, and the West and East African genotypes diverged between 100 and 840 y ago [15] . Since then, CHIKV has come a long way, with several mutations incorporated, and has continued to wreak epidemics in several regions. Recent activities of CHIKV include the Indian epidemic in 2005-2006, which was followed by a sudden explosion of cases in 2007. An estimated 1.3 million people across 13 states were reported to be infected in India [12, 16] , and CHIKV was also widespread in Malaysia, Sri Lanka, and Indonesia [17] . In July-August of 2007, CHIKV was reported in Italy, probably brought in by travelers from CHIKV-prone regions of India, Africa, and Indian", "Ocean islands such as Mauritius, Madagascar, and Seychelles. Few of the Italian isolates were found to have evolved from the Kerala isolate, which was associated with a A226V shift in E1 gene that represents a successful evolutionary adaptation in the mosquito vector similar to the ones observed in Reunion Island [2, 18, 19] .", "In recent times, with an increase in global travel, the risk for spreading CHIKV to non-endemic regions has heightened [1] . Several travelers have brought CHIKV home with them after visiting areas with actively infected populations [12, 20] . Such cases have been documented in European countries, Australia, Asia, and the United States [8, 21] . The United States has already reported at least twelve cases of travel-associated CHIKV, while France has reported 850 cases, and the United Kingdom 93 [8, 14] . Beyond this, CHIKV-infected travelers have also been diagnosed in Australia, Belgium, Canada, Czech Republic, French Guiana, Germany, Hong Kong, Italy, Japan, Kenya, Malaysia, Martinique, Norway, Switzerland, and Sri Lanka [21] . Some travelers were viremic, worrying public health officials about the spread of CHIKV to new areas [1, 8] .", "The incubation time for CHIKV is relatively short, requiring only 2-6 d with symptoms usually appearing 4-7 d post-infection [22] . Vazeille et al. detected CHIKV in the salivary glands of Ae. albopictus only 2 d after infection [5] . Upon infection, CHIKF tends to present itself in two phases. The first stage is acute, while the second stage, experienced by most but not all, is persistent, causing disabling polyarthritis. Characteristics of the acute phase include an abrupt onset of fever, arthralgia, and in some cases, maculopapular rash [6, 23] . The acute phase causes such intense joint and muscular pain that makes movement very difficult and prostrates its victims [6, 20] .", "Ninety-five percent of infected adults are symptomatic after infection, and of these, most become disabled for weeks to months as a result of decreased dexterity, loss of mobility, and delayed reaction. Eighteen months after disease onset, 40% of patients are found to still have anti-CHIKV IgM [6, 18, 23, 24] . The chronic stage of CHIKF is characterized by polyarthralgia that can last from weeks to years beyond the acute stage [6] . CHIKV has been shown to attack fibroblasts, explaining the involvement of muscles, joints, and skin connective tissues. The high number of nociceptive nerve endings found within the joints and muscle connective tissues can explain pain associated with CHIKF [25, 26] .", "More than 50% of patients who suffer from severe CHIKF are over 65 y old, and more than 33% of them die. Most adults who suffer from severe CHIKF have underlying medical conditions [6, 24, 27] . The other group that is disproportionately affected by severe CHIKV is children. Other complications associated with CHIKV, from most common to least common, include respiratory failure, cardiovascular decompensation, meningoencephalitis, severe acute hepatitis, severe cutaneous effects, other central nervous system problems, and kidney failure [6, 18, 20, 23, 24, 26, 27] .", "CHIKV undertakes a complex replication cycle upon host infection (Figure 2 ), which makes its genome susceptible to mutations [28, 29] . For instance, Ae. aegypti, responsible for epidemics in Kenya, Comoros, and Seychelles, carried CHIKV with an alanine in the 226 position of the E1 gene (E1-A226) [4, 18] . However, when the virus struck La Reunion Islands, a decline in population of Ae. aegypti, due to massive dichlorodiphenyltrichloroethane usage and dearth of Ae. albopictus species' www.plosntds.org population, resulted in an ecological pressure, favoring replacement of alanine at position 226 with valine (E1-A226V) [5] . This mutation allowed CHIKV's secondary vector species, Ae. albopictus, to supplement Ae. aegypti as its primary vector [5] .", "Within a year, the E1-A226V mutation was present in La Reunion Island, and Ae. albopictus apparently vectored the large epidemic infecting 34% of La Reunion Island's population [5] . All of the CHIKV strains isolated from Mayotte carried the E1-A226V mutation, and the mutation was also found in Madagascar in 2007 [5] . The E1-A226V mutation was not present at the beginning of the Indian Ocean Islands outbreak (before September 2005). However, more than 90% of later viral strains found there had incorporated the mutation (December-March 2006), indicating a genotype switch during the winter season [5, 18, 20] .", "The E1-A226V mutation also enabled an increase in infectivity of Ae. albopictus when compared to its infectivity of Ae. aegypti [4, 11, 18, 30] , and with several factors taken together, Ae. albopictus has become the new preferred and more lethal vector for CHIKV [4, 5, 11] . In fact, Tsetsarkin et al. found that a Green Fluorescent Protein tagged E1-A226V virus was 100 times more infective to Ae. albopictus than it was to Ae. aegypti [4] . In all the Indian Ocean Islands, Ae. albopictus became the main vector for CHIKV within 1-2 y after CHIKV was introduced to the region [31] .", "Of note is that Ae. aegypti has most likely been established in North America for over 300 y, while Ae. albopictus has been in many areas of the US, since 1985, primarily in Florida [32] and since then has expanded its range in the country. Reiskind et al. set out to determine if Ae. aegypti and Ae. albopictus mosquitoes captured in Florida were susceptible to CHIKV infection by a La Reunion isolate [32] . Each mosquito tested was highly susceptible to infection by a full-length infectious clone of the La Réunion Island isolate, CHIKV LR2006 OPY1 strain. Even though the Ae. albopictus strains were more susceptible to infection, overall ecology and differences in human biting patterns need to be studied further Characteristically, there are two rounds of translation: (+) sense genomic RNA (49S9 = 11.7 kb) acts directly as mRNA and is partially translated (59 end) to produce non-structural proteins (nsp's). These proteins are responsible for replication and formation of a complementary", "(2) strand, the template for further (+) strand synthesis. Subgenomic mRNA (26 S = 4.1 kb) replication occurs through the synthesis of full-length (2) intermediate RNA, which is regulated by nsp4 and p123 precursor in early infection and later by mature nsp's. Translation of the newly synthesized sub-genomic RNA results in production of structural proteins such as Capsid and protein E2-6k-E1 (from 39 end of genome). Assembly occurs at the cell surface, and the envelope is acquired as the virus buds from the cell and release and maturation almost simultaneous occurred. Replication occurs in the cytoplasm and is very rapid (,4 h) [28, 29] . doi:10.1371/journal.pntd.0000623.g002 www.plosntds.org to gain a more accurate understanding of a potential CHIKV epidemic in the US [32] .", "During the 7 d preceding birth, no human mother has been reported to transmit the disease vertically. However, about 50% of newborns delivered while the mother was infected with CHIKV contracted the disease from their mother, despite the method of delivery. Furthermore, there have been instances of CHIKV transmission from mother to fetus causing congenital illness and fetal death [33] .", "During the 2005-2006 La Reunion Island outbreaks, Ramful et al. discovered that mothers could transmit CHIKV to their progeny during the perinatal period (Day 24 to Day +1) [33, 34] , and it is associated with a high degree of morbidity. By mean Day 4 of life, all of the neonates were symptomatic for CHIKV, exhibiting common CHIKF symptoms. Six neonates were confirmed to have contracted CHIKV and developed mengoencephalitis. Of those mothers who, during the La Reunion Island epidemic, were infected long before delivery, only three fetal deaths were reported [12, 33] . Ramful et al. theorized that motherto-child transmission most likely happens transplacentally shortly before delivery [33] . A similar study by Gerardin et al. reported nineteen cases of neonatal infection associated with intrapartum maternal viremia that progressed to develop encephalitis owing to vertical transmission from infected mothers [34] .", "Clinical and epidemiological similarities with dengue fever make CHIKV diagnosis difficult, which may lead physicians to misdiagnose CHIKV as dengue fever; therefore, the incidence of CHIKV may actually be higher than currently believed (Table 1 ) [6, 12, 35] .", "The amount of time elapsed since disease onset is the most critical parameter when choosing a diagnostic test. CHIKV can be detected and isolated by culturing with mosquito cells (C6/36), Vero cells (mammalian), or in mice [26] . However, this method can take at least a week and only achieves a high sensitivity during the viremic phase, which usually only lasts up to 48 h after the bite. Five days post-infection, the viral isolation approach has a low sensitivity but is still the preferred method for detecting the CHIKV strain [12, 26, 31, 35] . RT-PCR on the other hand is a faster and more sensitive method that can be used within the first week of disease onset [26] , and it is currently the most sensitive method for detecting and quantifying viral mRNA [4, 36] .", "Classic serological detection, by assays such as ELISA [37] , immunofluorescence [5, 38] , complement binding, and haemagglutination inhibition [39] , constitutes the second diagnostic tool used for biological diagnosis of CHIKV infection. These proven techniques are useful for detection of Antigen in mosquitoes during epidemiological studies. These assays detect virus-specific IgM and IgG, however the sensitivity and specificity of these assays has been poorly characterized. Viral competence, or the potential of viral infection and transmission, is an important parameter that can be quantified by ELISA, viral culture, and PCR.", "A study by Ng et al. showed biomarkers indicative of severe CHIKV infection [40] . They found decreased levels of RANTES and increased levels of Interleukin-6 (IL-6) and Interleukin-1b (IL-1b) that could be sued for CHIKV detection in patients as indicators of CHIKV-driven cytokine storm. Couderc et al. demonstrate another cytokine, type-I IFN, as a key player in the progression to CHIKV infection [26] . Using an IFN-a/b null mouse model, they demonstrated evidence of muscles, joints, and skin as privileged CHIKV targets, which is consistent with human pathology. Although Ng et al. concluded that RANTES levels were significantly suppressed in severe CHIKF patients [40] , interestingly, an increase in levels of RANTES has been observed in dengue infection [41] . Since the symptoms of CHIKF mimic those of dengue fever, results obtained from this study strongly suggest that RANTES could be a potential distinctive biomarker that differentiates between these two clinically similar", "diseases.", "There are no approved antiviral treatments currently available for CHIKV [1, 3, 12, 42] . Currently, CHIKF is treated symptomatically, usually with non-steroidal anti-inflammatory drugs or steroids, bed rest, and fluids. Movement and mild exercise are thought to decrease stiffness and morning arthralgia, but heavy exercise may exacerbate rheumatic symptoms. Corticosteroids may be used in cases of debilitating chronic CHIKV infection. There is a debate about the appropriateness of chloroquine as treatment for unresolved, non-steroidal anti-inflammatory drugresistant arthritis [43] . A study showed that viral production was www.plosntds.org drastically reduced at 16 h post-infection after treatment with 100 mM dec-RVKR-cmk (Decanoyl-Arg-Val-Lys-Arg-chloromethylketone), a furine inhibitor [42, 44] . Chloroquine acted by raising the pH, blocking low pH-dependent entry of virus into the cell. It is important to note that dec-RVKR-cmk or chloroquine only inhibited viral spreading from cell", "to cell, not CHIKV replication once it had entered the cell [43] . However, most would agree that the best weapon against CHIKV is prevention. A live CHIKV vaccine developed by the United States reached phase II clinical trial encompassing 59 healthy volunteers [45] . Eight percent of the volunteers experienced transient arthralgia, while 98% of the volunteers had seroconversion [45] . However, live CHIKV vaccines are still questionable. One cannot discount the risk of a live vaccine possibly inducing chronic rheumatism. Also, there is the question as to whether widespread use among the public could trigger mosquito transmission or lead to chronic infection or viral reversion [1] .", "An alternative approach would be to produce a chimeric vaccine against CHIKV. Wang et al. developed a chimeric alphavirus vaccine that is uniformly attenuated and does not cause reactogenicity in mice [3] . Three different versions of this vaccine were made using three different backbone vectors: Venezuelan equine encephalitis virus (VEEV) attenuated vaccine strain T-83, naturally attenuated eastern equine encephalitis virus (EEEV), and attenuated Sindbis virus (SINV). In short, CHIKV structural proteins were engineered into the backbones of the aforementioned vaccines to produce the chimeras [3] . These chimeras were found to stimulate a strong humoral immunity, and even at doses of 5.3-5.8 log 10 PFU, they did not trigger reactogenicity. When vaccinated mice were challenged with CHIKV, neither adult nor neonatal mice gained weight, had fever, or displayed signs of neurological illness. Upon comparison of the chimeras with the Army181/25 vaccine, the Army vaccine resulted in higher", "levels of viremia and replication in the joints of neonatal mice. Because the joints are known targets of CHIKV, Wang et al. noted their vaccine might avoid the negative reactogenic side effects of the Army vaccine. After being subcutaneously vaccinated with 5.3-5.8 log 10 PFU of the chimeric vaccines, mice produced strong neutralizing antibody titers. The VEEV and EEEV chimeras yielded higher neutralizing antibody titers than the SINV chimera without being more virulent. On top of this, the VEEV and EEEV CHIKV chimeras seemed to be more immunogenic than the Army vaccine despite the chimeras' lower viremia and replication in the joints of neonatal mice [3] .", "Tiwari et al. [46] adopted a different strategy using formalin inactivated CHIKV in combination with alhydrogel (Aluminum Hydroxide) as an adjuvant. This study clearly suggests that this vaccine elicits both humoral and cell-mediated immune responses in mice, providing its immunogenic potential. A recent study by Couderc et al. [47] showed passive immunization as a potential treatment for CHIKV infection. Using purified immunoglobulin extracted from convalescent CHIKV patients, they demonstrated effective neutralizing activity against CHIKV infection both in vitro and in vivo. This thereby establishes a potential preventive and therapeutic approach to combat CHIKV infection. Pathogenesis studies conducted with related alpha virus, like RRV, have shown the role of macrophages in persistence on infection [48] . They also demonstrated the role of RRV-specific CD8 T cells in clearing viral load in infected patients, thereby warranting similar investigations with CHIKV and the importance", "of investigating a cell-mediated immune response-based vaccine against CHIKV [49] .", "There are always certain risks associated with live attenuated or inactivated viral vaccines [50] . One way to avoid these potential problems is to construct a consensus-based DNA vaccine. DNA based vaccines have an improved safety profile as compared to live or attenuated vaccines [51, 52] . A consequence of CHIKV's rapid evolution is difficulty in constructing a vaccine that will be able to Figure 3 . Levels of CHIKV-specific IgG in mice immunized with CHIKV vaccines. Each group of C57BL/6 mice (n = 5) was immunized with 12.5 mg of pVax1 control vector or CHIKV vaccine plasmids as indicated at 0 and 2 wk. Mice were bled 2 wk after each immunization, and each group's serum pool was diluted to 1:100 and 1:500 for reaction with specific vaccine constructs. Serum was incubated for 1 h at 37uC on 96-well plates coated with 2 mg/ml of respective CHIKV peptides, and antibody was detected using anti-mouse IgG-HRP and OD was measured at 405 nm. doi:10.1371/journal.pntd.0000623.g003", "www.plosntds.org effectively protect large populations from multiple strains of the virus. One of the strengths of DNA consensus vaccines is its ability to induce cross-reactive immune responses against the three distinct phylogenetic groups of CHIKV. Also DNA-based vaccines can be produced more rapidly than protein-based vaccines.", "Recently, Muthumani et al. constructed a vaccine that was shown to induce both humoral and cellular immunity in vivo in 3-4-wk-old female C57/BL6 mice [49] . These mice were immunized using an in vivo electroporation method to deliver the vaccine into the quadriceps muscle. The consensus construct was designed against E1, E2, and the core protein capsid. To design the construct, they aligned 21 sequences of CHIKV isolated between 1952 and 2006, using strains from differing countries, including La Reunion Island. The most common nucleotide among the sequences was chosen at each position to be used in the consensus construct, taking care not to alter the reading frame. They conducted codon and RNA optimization, added a strong Kozak sequence, and substituted signal peptide with an immunoglobulin E leader sequence to improve vaccine efficacy.", "After immunizing the mice, spleens were harvested along with serum and tested to determine antibody titer. After three immunizations, consensus E1, E2, and C vaccines were shown to induce T-cell immune responses leading to strong IFN-c responses and proliferation in C57/BL6 mice. Furthermore, when compared with control mice, immunized mice had higher total IgG levels as well as higher anti-E1 specific, anti-E2 specific, and anti-C specific IgG antibodies, suggesting a strong humoral immune response ( Figure 3 ) and also specificity for the antigens encoded in the vaccine constructs ( Figure 4 ). Because of its promising results and the need for a safer vaccine, this consensus DNA vaccine deserves further investigation. Determining longevity of protective effects of the vaccine and persistence of antibody and IFN-c responses could be the next step of investigation. Challenged studies of immunized mice must also be carried out.", "CHIKV mosquito-borne disease has caused massive outbreaks for at least half a century but is no longer confined to the www.plosntds.org developing nations. It began to encroach into the boundaries of the developing world. As a result, the NIAID has designated CHIKV as a Category C pathogen alongside the influenza and SARS-CoV viruses [3] . Realization of the potential severity of this disease is exigent; for instance, if used as a biological weapon, the world economy could be severely crippled; if enough members of the armed forces were to become infected during a military deployment, military operations could be significantly affected. Efforts to monitor the disease will only provide minimal warning in a global society, and steps to prevent the morbidity and mortality associated with pandemic are imperative [21, 31] . Despite the gravity of its infectious potency and the fear of it being a potential biological weapon, there is currently no vaccine for CHIKV infections. Live", "attenuated vaccine trials were carried out in 2000, but funding for the project was discontinued. Newer approaches such as DNA vaccines appear promising over conventional strategies like live attenuated or inactivated virus and thus call for further investigation. Recent advances such electroporation delivery and incorporation of adjuvants has boosted DNA vaccine efficacy [51, 53] . Despite the low antibody response to DNA vaccines, other numerous advantages have overshadowed these minor drawbacks (Table 2) , the most important one being the ability to induce both humoral and cellular immune responses [51, 54] .", "Judging by recent success, such as the immunogenic construct developed by Muthumani et al., DNA vaccines could play a major role in combating CHIKV [49] . Vaccines are literally a critical component of CHIKV disease control and therefore research in this area is highly encouraged. The dramatic spread of dengue viruses (DENV) throughout tropical America since 1980 via the same vectors and human hosts underscores the risk to public health in the Americas. The adverse events associated with the current live vaccine are well documented [55] . Realizing these drawbacks, earnest efforts should be taken to develop new strategies to forestall further spread and complications." ]	[ 10 ]	3,829	5,688
1,689	What has been some instances of mother to fetus transmission?	2,522	[ "congenital illness and fetal death" ]	[ "Chikungunya: A Potentially Emerging Epidemic?\n\nhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC2860491/\n\nSHA: f7c3160bef4169d29e2a8bdd79dd6e9056d4774c\n\nAuthors: Thiboutot, Michelle M.; Kannan, Senthil; Kawalekar, Omkar U.; Shedlock, Devon J.; Khan, Amir S.; Sarangan, Gopalsamy; Srikanth, Padma; Weiner, David B.; Muthumani, Karuppiah\nDate: 2010-04-27\nDOI: 10.1371/journal.pntd.0000623\nLicense: cc-by", "Abstract: Chikungunya virus is a mosquito-borne emerging pathogen that has a major health impact in humans and causes fever disease, headache, rash, nausea, vomiting, myalgia, and arthralgia. Indigenous to tropical Africa, recent large outbreaks have been reported in parts of South East Asia and several of its neighboring islands in 2005–07 and in Europe in 2007. Furthermore, positive cases have been confirmed in the United States in travelers returning from known outbreak areas. Currently, there is no vaccine or antiviral treatment. With the threat of an emerging global pandemic, the peculiar problems associated with the more immediate and seasonal epidemics warrant the development of an effective vaccine. In this review, we summarize the evidence supporting these concepts.", "Text: Chikungunya virus (CHIKV), a mosquito-borne pathogen listed by National Institute of Allergy and Infectious Diseases (NIAID) as a Category C Priority Pathogen that causes Chikungunya fever (CHIKF), has been spreading throughout Asia, Africa, and parts of Europe in recent times [1, 2, 3] . CHIKV is an arthropod-borne virus (arbovirus) and is transmitted to humans primarily by Aedes aegypti, the infamous yellow fever propagator [4, 5] . CHIKV infection is marked by severe joint pain, contorting its victims into unusual postures [6] . The disease gets its name from the Kimakonde vernacular language of Tanzania and Mozambique, and the word chikungunya means ''that which contorts or bends up'' and translates in Swahili to ''the illness of the bended walker'' [7, 8, 9] . In Africa, CHIKV is maintained in a sylvatic cycle among forest-dwelling Aedes spp. mosquitoes, wild primates, squirrels, birds, and rodents ( Figure 1 ) [10] . In Asia, the disease is vectored by Ae. aegypti and Ae.", "albopictus [11] . Transmission in Asia occurs in an urban cycle whereby the mosquito spreads the disease from an infected human to an uninfected human, following an epidemiological pattern similar to dengue fever [12] .", "The 2005-2006 epidemic of CHIKV in La Reunion islands in the Indian Ocean, spurred the discovery of a new vector species, Ae. albopictus [5] . Wrecking over one-third of the island's population, this epidemic peaked its devastation between January and February 2006, when over 46,000 cases came into light every week, including 284 deaths [5, 13] . Ae. albopictus is common in urban areas of the United States and is already flourishing in 36 states, raising grave concerns to the immunologically naive populace of the United States [14] .\n\nAccordingly, this review elaborately details the epidemiology and global expansion of CHIKV, describes its clinical features and pathogenesis and its symptoms and complications, and finally nominates a possible vaccine approach against CHIKV infection.", "CHIKV has been isolated into three genotypes based on phylogenetic studies. These genotypes, based on the gene sequences of an Envelope protein (E1), are Asian, East/Central/ South African, and West African [4, 11, 15] . Using phylogenetic models, Cherian et al. estimate that the Asian genotype of CHIKV emerged between 50 and 310 y ago, and the West and East African genotypes diverged between 100 and 840 y ago [15] . Since then, CHIKV has come a long way, with several mutations incorporated, and has continued to wreak epidemics in several regions. Recent activities of CHIKV include the Indian epidemic in 2005-2006, which was followed by a sudden explosion of cases in 2007. An estimated 1.3 million people across 13 states were reported to be infected in India [12, 16] , and CHIKV was also widespread in Malaysia, Sri Lanka, and Indonesia [17] . In July-August of 2007, CHIKV was reported in Italy, probably brought in by travelers from CHIKV-prone regions of India, Africa, and Indian", "Ocean islands such as Mauritius, Madagascar, and Seychelles. Few of the Italian isolates were found to have evolved from the Kerala isolate, which was associated with a A226V shift in E1 gene that represents a successful evolutionary adaptation in the mosquito vector similar to the ones observed in Reunion Island [2, 18, 19] .", "In recent times, with an increase in global travel, the risk for spreading CHIKV to non-endemic regions has heightened [1] . Several travelers have brought CHIKV home with them after visiting areas with actively infected populations [12, 20] . Such cases have been documented in European countries, Australia, Asia, and the United States [8, 21] . The United States has already reported at least twelve cases of travel-associated CHIKV, while France has reported 850 cases, and the United Kingdom 93 [8, 14] . Beyond this, CHIKV-infected travelers have also been diagnosed in Australia, Belgium, Canada, Czech Republic, French Guiana, Germany, Hong Kong, Italy, Japan, Kenya, Malaysia, Martinique, Norway, Switzerland, and Sri Lanka [21] . Some travelers were viremic, worrying public health officials about the spread of CHIKV to new areas [1, 8] .", "The incubation time for CHIKV is relatively short, requiring only 2-6 d with symptoms usually appearing 4-7 d post-infection [22] . Vazeille et al. detected CHIKV in the salivary glands of Ae. albopictus only 2 d after infection [5] . Upon infection, CHIKF tends to present itself in two phases. The first stage is acute, while the second stage, experienced by most but not all, is persistent, causing disabling polyarthritis. Characteristics of the acute phase include an abrupt onset of fever, arthralgia, and in some cases, maculopapular rash [6, 23] . The acute phase causes such intense joint and muscular pain that makes movement very difficult and prostrates its victims [6, 20] .", "Ninety-five percent of infected adults are symptomatic after infection, and of these, most become disabled for weeks to months as a result of decreased dexterity, loss of mobility, and delayed reaction. Eighteen months after disease onset, 40% of patients are found to still have anti-CHIKV IgM [6, 18, 23, 24] . The chronic stage of CHIKF is characterized by polyarthralgia that can last from weeks to years beyond the acute stage [6] . CHIKV has been shown to attack fibroblasts, explaining the involvement of muscles, joints, and skin connective tissues. The high number of nociceptive nerve endings found within the joints and muscle connective tissues can explain pain associated with CHIKF [25, 26] .", "More than 50% of patients who suffer from severe CHIKF are over 65 y old, and more than 33% of them die. Most adults who suffer from severe CHIKF have underlying medical conditions [6, 24, 27] . The other group that is disproportionately affected by severe CHIKV is children. Other complications associated with CHIKV, from most common to least common, include respiratory failure, cardiovascular decompensation, meningoencephalitis, severe acute hepatitis, severe cutaneous effects, other central nervous system problems, and kidney failure [6, 18, 20, 23, 24, 26, 27] .", "CHIKV undertakes a complex replication cycle upon host infection (Figure 2 ), which makes its genome susceptible to mutations [28, 29] . For instance, Ae. aegypti, responsible for epidemics in Kenya, Comoros, and Seychelles, carried CHIKV with an alanine in the 226 position of the E1 gene (E1-A226) [4, 18] . However, when the virus struck La Reunion Islands, a decline in population of Ae. aegypti, due to massive dichlorodiphenyltrichloroethane usage and dearth of Ae. albopictus species' www.plosntds.org population, resulted in an ecological pressure, favoring replacement of alanine at position 226 with valine (E1-A226V) [5] . This mutation allowed CHIKV's secondary vector species, Ae. albopictus, to supplement Ae. aegypti as its primary vector [5] .", "Within a year, the E1-A226V mutation was present in La Reunion Island, and Ae. albopictus apparently vectored the large epidemic infecting 34% of La Reunion Island's population [5] . All of the CHIKV strains isolated from Mayotte carried the E1-A226V mutation, and the mutation was also found in Madagascar in 2007 [5] . The E1-A226V mutation was not present at the beginning of the Indian Ocean Islands outbreak (before September 2005). However, more than 90% of later viral strains found there had incorporated the mutation (December-March 2006), indicating a genotype switch during the winter season [5, 18, 20] .", "The E1-A226V mutation also enabled an increase in infectivity of Ae. albopictus when compared to its infectivity of Ae. aegypti [4, 11, 18, 30] , and with several factors taken together, Ae. albopictus has become the new preferred and more lethal vector for CHIKV [4, 5, 11] . In fact, Tsetsarkin et al. found that a Green Fluorescent Protein tagged E1-A226V virus was 100 times more infective to Ae. albopictus than it was to Ae. aegypti [4] . In all the Indian Ocean Islands, Ae. albopictus became the main vector for CHIKV within 1-2 y after CHIKV was introduced to the region [31] .", "Of note is that Ae. aegypti has most likely been established in North America for over 300 y, while Ae. albopictus has been in many areas of the US, since 1985, primarily in Florida [32] and since then has expanded its range in the country. Reiskind et al. set out to determine if Ae. aegypti and Ae. albopictus mosquitoes captured in Florida were susceptible to CHIKV infection by a La Reunion isolate [32] . Each mosquito tested was highly susceptible to infection by a full-length infectious clone of the La Réunion Island isolate, CHIKV LR2006 OPY1 strain. Even though the Ae. albopictus strains were more susceptible to infection, overall ecology and differences in human biting patterns need to be studied further Characteristically, there are two rounds of translation: (+) sense genomic RNA (49S9 = 11.7 kb) acts directly as mRNA and is partially translated (59 end) to produce non-structural proteins (nsp's). These proteins are responsible for replication and formation of a complementary", "(2) strand, the template for further (+) strand synthesis. Subgenomic mRNA (26 S = 4.1 kb) replication occurs through the synthesis of full-length (2) intermediate RNA, which is regulated by nsp4 and p123 precursor in early infection and later by mature nsp's. Translation of the newly synthesized sub-genomic RNA results in production of structural proteins such as Capsid and protein E2-6k-E1 (from 39 end of genome). Assembly occurs at the cell surface, and the envelope is acquired as the virus buds from the cell and release and maturation almost simultaneous occurred. Replication occurs in the cytoplasm and is very rapid (,4 h) [28, 29] . doi:10.1371/journal.pntd.0000623.g002 www.plosntds.org to gain a more accurate understanding of a potential CHIKV epidemic in the US [32] .", "During the 7 d preceding birth, no human mother has been reported to transmit the disease vertically. However, about 50% of newborns delivered while the mother was infected with CHIKV contracted the disease from their mother, despite the method of delivery. Furthermore, there have been instances of CHIKV transmission from mother to fetus causing congenital illness and fetal death [33] .", "During the 2005-2006 La Reunion Island outbreaks, Ramful et al. discovered that mothers could transmit CHIKV to their progeny during the perinatal period (Day 24 to Day +1) [33, 34] , and it is associated with a high degree of morbidity. By mean Day 4 of life, all of the neonates were symptomatic for CHIKV, exhibiting common CHIKF symptoms. Six neonates were confirmed to have contracted CHIKV and developed mengoencephalitis. Of those mothers who, during the La Reunion Island epidemic, were infected long before delivery, only three fetal deaths were reported [12, 33] . Ramful et al. theorized that motherto-child transmission most likely happens transplacentally shortly before delivery [33] . A similar study by Gerardin et al. reported nineteen cases of neonatal infection associated with intrapartum maternal viremia that progressed to develop encephalitis owing to vertical transmission from infected mothers [34] .", "Clinical and epidemiological similarities with dengue fever make CHIKV diagnosis difficult, which may lead physicians to misdiagnose CHIKV as dengue fever; therefore, the incidence of CHIKV may actually be higher than currently believed (Table 1 ) [6, 12, 35] .", "The amount of time elapsed since disease onset is the most critical parameter when choosing a diagnostic test. CHIKV can be detected and isolated by culturing with mosquito cells (C6/36), Vero cells (mammalian), or in mice [26] . However, this method can take at least a week and only achieves a high sensitivity during the viremic phase, which usually only lasts up to 48 h after the bite. Five days post-infection, the viral isolation approach has a low sensitivity but is still the preferred method for detecting the CHIKV strain [12, 26, 31, 35] . RT-PCR on the other hand is a faster and more sensitive method that can be used within the first week of disease onset [26] , and it is currently the most sensitive method for detecting and quantifying viral mRNA [4, 36] .", "Classic serological detection, by assays such as ELISA [37] , immunofluorescence [5, 38] , complement binding, and haemagglutination inhibition [39] , constitutes the second diagnostic tool used for biological diagnosis of CHIKV infection. These proven techniques are useful for detection of Antigen in mosquitoes during epidemiological studies. These assays detect virus-specific IgM and IgG, however the sensitivity and specificity of these assays has been poorly characterized. Viral competence, or the potential of viral infection and transmission, is an important parameter that can be quantified by ELISA, viral culture, and PCR.", "A study by Ng et al. showed biomarkers indicative of severe CHIKV infection [40] . They found decreased levels of RANTES and increased levels of Interleukin-6 (IL-6) and Interleukin-1b (IL-1b) that could be sued for CHIKV detection in patients as indicators of CHIKV-driven cytokine storm. Couderc et al. demonstrate another cytokine, type-I IFN, as a key player in the progression to CHIKV infection [26] . Using an IFN-a/b null mouse model, they demonstrated evidence of muscles, joints, and skin as privileged CHIKV targets, which is consistent with human pathology. Although Ng et al. concluded that RANTES levels were significantly suppressed in severe CHIKF patients [40] , interestingly, an increase in levels of RANTES has been observed in dengue infection [41] . Since the symptoms of CHIKF mimic those of dengue fever, results obtained from this study strongly suggest that RANTES could be a potential distinctive biomarker that differentiates between these two clinically similar", "diseases.", "There are no approved antiviral treatments currently available for CHIKV [1, 3, 12, 42] . Currently, CHIKF is treated symptomatically, usually with non-steroidal anti-inflammatory drugs or steroids, bed rest, and fluids. Movement and mild exercise are thought to decrease stiffness and morning arthralgia, but heavy exercise may exacerbate rheumatic symptoms. Corticosteroids may be used in cases of debilitating chronic CHIKV infection. There is a debate about the appropriateness of chloroquine as treatment for unresolved, non-steroidal anti-inflammatory drugresistant arthritis [43] . A study showed that viral production was www.plosntds.org drastically reduced at 16 h post-infection after treatment with 100 mM dec-RVKR-cmk (Decanoyl-Arg-Val-Lys-Arg-chloromethylketone), a furine inhibitor [42, 44] . Chloroquine acted by raising the pH, blocking low pH-dependent entry of virus into the cell. It is important to note that dec-RVKR-cmk or chloroquine only inhibited viral spreading from cell", "to cell, not CHIKV replication once it had entered the cell [43] . However, most would agree that the best weapon against CHIKV is prevention. A live CHIKV vaccine developed by the United States reached phase II clinical trial encompassing 59 healthy volunteers [45] . Eight percent of the volunteers experienced transient arthralgia, while 98% of the volunteers had seroconversion [45] . However, live CHIKV vaccines are still questionable. One cannot discount the risk of a live vaccine possibly inducing chronic rheumatism. Also, there is the question as to whether widespread use among the public could trigger mosquito transmission or lead to chronic infection or viral reversion [1] .", "An alternative approach would be to produce a chimeric vaccine against CHIKV. Wang et al. developed a chimeric alphavirus vaccine that is uniformly attenuated and does not cause reactogenicity in mice [3] . Three different versions of this vaccine were made using three different backbone vectors: Venezuelan equine encephalitis virus (VEEV) attenuated vaccine strain T-83, naturally attenuated eastern equine encephalitis virus (EEEV), and attenuated Sindbis virus (SINV). In short, CHIKV structural proteins were engineered into the backbones of the aforementioned vaccines to produce the chimeras [3] . These chimeras were found to stimulate a strong humoral immunity, and even at doses of 5.3-5.8 log 10 PFU, they did not trigger reactogenicity. When vaccinated mice were challenged with CHIKV, neither adult nor neonatal mice gained weight, had fever, or displayed signs of neurological illness. Upon comparison of the chimeras with the Army181/25 vaccine, the Army vaccine resulted in higher", "levels of viremia and replication in the joints of neonatal mice. Because the joints are known targets of CHIKV, Wang et al. noted their vaccine might avoid the negative reactogenic side effects of the Army vaccine. After being subcutaneously vaccinated with 5.3-5.8 log 10 PFU of the chimeric vaccines, mice produced strong neutralizing antibody titers. The VEEV and EEEV chimeras yielded higher neutralizing antibody titers than the SINV chimera without being more virulent. On top of this, the VEEV and EEEV CHIKV chimeras seemed to be more immunogenic than the Army vaccine despite the chimeras' lower viremia and replication in the joints of neonatal mice [3] .", "Tiwari et al. [46] adopted a different strategy using formalin inactivated CHIKV in combination with alhydrogel (Aluminum Hydroxide) as an adjuvant. This study clearly suggests that this vaccine elicits both humoral and cell-mediated immune responses in mice, providing its immunogenic potential. A recent study by Couderc et al. [47] showed passive immunization as a potential treatment for CHIKV infection. Using purified immunoglobulin extracted from convalescent CHIKV patients, they demonstrated effective neutralizing activity against CHIKV infection both in vitro and in vivo. This thereby establishes a potential preventive and therapeutic approach to combat CHIKV infection. Pathogenesis studies conducted with related alpha virus, like RRV, have shown the role of macrophages in persistence on infection [48] . They also demonstrated the role of RRV-specific CD8 T cells in clearing viral load in infected patients, thereby warranting similar investigations with CHIKV and the importance", "of investigating a cell-mediated immune response-based vaccine against CHIKV [49] .", "There are always certain risks associated with live attenuated or inactivated viral vaccines [50] . One way to avoid these potential problems is to construct a consensus-based DNA vaccine. DNA based vaccines have an improved safety profile as compared to live or attenuated vaccines [51, 52] . A consequence of CHIKV's rapid evolution is difficulty in constructing a vaccine that will be able to Figure 3 . Levels of CHIKV-specific IgG in mice immunized with CHIKV vaccines. Each group of C57BL/6 mice (n = 5) was immunized with 12.5 mg of pVax1 control vector or CHIKV vaccine plasmids as indicated at 0 and 2 wk. Mice were bled 2 wk after each immunization, and each group's serum pool was diluted to 1:100 and 1:500 for reaction with specific vaccine constructs. Serum was incubated for 1 h at 37uC on 96-well plates coated with 2 mg/ml of respective CHIKV peptides, and antibody was detected using anti-mouse IgG-HRP and OD was measured at 405 nm. doi:10.1371/journal.pntd.0000623.g003", "www.plosntds.org effectively protect large populations from multiple strains of the virus. One of the strengths of DNA consensus vaccines is its ability to induce cross-reactive immune responses against the three distinct phylogenetic groups of CHIKV. Also DNA-based vaccines can be produced more rapidly than protein-based vaccines.", "Recently, Muthumani et al. constructed a vaccine that was shown to induce both humoral and cellular immunity in vivo in 3-4-wk-old female C57/BL6 mice [49] . These mice were immunized using an in vivo electroporation method to deliver the vaccine into the quadriceps muscle. The consensus construct was designed against E1, E2, and the core protein capsid. To design the construct, they aligned 21 sequences of CHIKV isolated between 1952 and 2006, using strains from differing countries, including La Reunion Island. The most common nucleotide among the sequences was chosen at each position to be used in the consensus construct, taking care not to alter the reading frame. They conducted codon and RNA optimization, added a strong Kozak sequence, and substituted signal peptide with an immunoglobulin E leader sequence to improve vaccine efficacy.", "After immunizing the mice, spleens were harvested along with serum and tested to determine antibody titer. After three immunizations, consensus E1, E2, and C vaccines were shown to induce T-cell immune responses leading to strong IFN-c responses and proliferation in C57/BL6 mice. Furthermore, when compared with control mice, immunized mice had higher total IgG levels as well as higher anti-E1 specific, anti-E2 specific, and anti-C specific IgG antibodies, suggesting a strong humoral immune response ( Figure 3 ) and also specificity for the antigens encoded in the vaccine constructs ( Figure 4 ). Because of its promising results and the need for a safer vaccine, this consensus DNA vaccine deserves further investigation. Determining longevity of protective effects of the vaccine and persistence of antibody and IFN-c responses could be the next step of investigation. Challenged studies of immunized mice must also be carried out.", "CHIKV mosquito-borne disease has caused massive outbreaks for at least half a century but is no longer confined to the www.plosntds.org developing nations. It began to encroach into the boundaries of the developing world. As a result, the NIAID has designated CHIKV as a Category C pathogen alongside the influenza and SARS-CoV viruses [3] . Realization of the potential severity of this disease is exigent; for instance, if used as a biological weapon, the world economy could be severely crippled; if enough members of the armed forces were to become infected during a military deployment, military operations could be significantly affected. Efforts to monitor the disease will only provide minimal warning in a global society, and steps to prevent the morbidity and mortality associated with pandemic are imperative [21, 31] . Despite the gravity of its infectious potency and the fear of it being a potential biological weapon, there is currently no vaccine for CHIKV infections. Live", "attenuated vaccine trials were carried out in 2000, but funding for the project was discontinued. Newer approaches such as DNA vaccines appear promising over conventional strategies like live attenuated or inactivated virus and thus call for further investigation. Recent advances such electroporation delivery and incorporation of adjuvants has boosted DNA vaccine efficacy [51, 53] . Despite the low antibody response to DNA vaccines, other numerous advantages have overshadowed these minor drawbacks (Table 2) , the most important one being the ability to induce both humoral and cellular immune responses [51, 54] .", "Judging by recent success, such as the immunogenic construct developed by Muthumani et al., DNA vaccines could play a major role in combating CHIKV [49] . Vaccines are literally a critical component of CHIKV disease control and therefore research in this area is highly encouraged. The dramatic spread of dengue viruses (DENV) throughout tropical America since 1980 via the same vectors and human hosts underscores the risk to public health in the Americas. The adverse events associated with the current live vaccine are well documented [55] . Realizing these drawbacks, earnest efforts should be taken to develop new strategies to forestall further spread and complications." ]	[ 16 ]	3,829	5,688
1,689	What did the studies reveal regarding transmission from mothers during perinatal period?	2,523	[ "During the 2005-2006 La Reunion Island outbreaks, Ramful et al. discovered that mothers could transmit CHIKV to their progeny during the perinatal period (Day 24 to Day +1) [33, 34] , and it is associated with a high degree of morbidity. By mean Day 4 of life, all of the neonates were symptomatic for CHIKV, exhibiting common CHIKF symptoms." ]	[ "Chikungunya: A Potentially Emerging Epidemic?\n\nhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC2860491/\n\nSHA: f7c3160bef4169d29e2a8bdd79dd6e9056d4774c\n\nAuthors: Thiboutot, Michelle M.; Kannan, Senthil; Kawalekar, Omkar U.; Shedlock, Devon J.; Khan, Amir S.; Sarangan, Gopalsamy; Srikanth, Padma; Weiner, David B.; Muthumani, Karuppiah\nDate: 2010-04-27\nDOI: 10.1371/journal.pntd.0000623\nLicense: cc-by", "Abstract: Chikungunya virus is a mosquito-borne emerging pathogen that has a major health impact in humans and causes fever disease, headache, rash, nausea, vomiting, myalgia, and arthralgia. Indigenous to tropical Africa, recent large outbreaks have been reported in parts of South East Asia and several of its neighboring islands in 2005–07 and in Europe in 2007. Furthermore, positive cases have been confirmed in the United States in travelers returning from known outbreak areas. Currently, there is no vaccine or antiviral treatment. With the threat of an emerging global pandemic, the peculiar problems associated with the more immediate and seasonal epidemics warrant the development of an effective vaccine. In this review, we summarize the evidence supporting these concepts.", "Text: Chikungunya virus (CHIKV), a mosquito-borne pathogen listed by National Institute of Allergy and Infectious Diseases (NIAID) as a Category C Priority Pathogen that causes Chikungunya fever (CHIKF), has been spreading throughout Asia, Africa, and parts of Europe in recent times [1, 2, 3] . CHIKV is an arthropod-borne virus (arbovirus) and is transmitted to humans primarily by Aedes aegypti, the infamous yellow fever propagator [4, 5] . CHIKV infection is marked by severe joint pain, contorting its victims into unusual postures [6] . The disease gets its name from the Kimakonde vernacular language of Tanzania and Mozambique, and the word chikungunya means ''that which contorts or bends up'' and translates in Swahili to ''the illness of the bended walker'' [7, 8, 9] . In Africa, CHIKV is maintained in a sylvatic cycle among forest-dwelling Aedes spp. mosquitoes, wild primates, squirrels, birds, and rodents ( Figure 1 ) [10] . In Asia, the disease is vectored by Ae. aegypti and Ae.", "albopictus [11] . Transmission in Asia occurs in an urban cycle whereby the mosquito spreads the disease from an infected human to an uninfected human, following an epidemiological pattern similar to dengue fever [12] .", "The 2005-2006 epidemic of CHIKV in La Reunion islands in the Indian Ocean, spurred the discovery of a new vector species, Ae. albopictus [5] . Wrecking over one-third of the island's population, this epidemic peaked its devastation between January and February 2006, when over 46,000 cases came into light every week, including 284 deaths [5, 13] . Ae. albopictus is common in urban areas of the United States and is already flourishing in 36 states, raising grave concerns to the immunologically naive populace of the United States [14] .\n\nAccordingly, this review elaborately details the epidemiology and global expansion of CHIKV, describes its clinical features and pathogenesis and its symptoms and complications, and finally nominates a possible vaccine approach against CHIKV infection.", "CHIKV has been isolated into three genotypes based on phylogenetic studies. These genotypes, based on the gene sequences of an Envelope protein (E1), are Asian, East/Central/ South African, and West African [4, 11, 15] . Using phylogenetic models, Cherian et al. estimate that the Asian genotype of CHIKV emerged between 50 and 310 y ago, and the West and East African genotypes diverged between 100 and 840 y ago [15] . Since then, CHIKV has come a long way, with several mutations incorporated, and has continued to wreak epidemics in several regions. Recent activities of CHIKV include the Indian epidemic in 2005-2006, which was followed by a sudden explosion of cases in 2007. An estimated 1.3 million people across 13 states were reported to be infected in India [12, 16] , and CHIKV was also widespread in Malaysia, Sri Lanka, and Indonesia [17] . In July-August of 2007, CHIKV was reported in Italy, probably brought in by travelers from CHIKV-prone regions of India, Africa, and Indian", "Ocean islands such as Mauritius, Madagascar, and Seychelles. Few of the Italian isolates were found to have evolved from the Kerala isolate, which was associated with a A226V shift in E1 gene that represents a successful evolutionary adaptation in the mosquito vector similar to the ones observed in Reunion Island [2, 18, 19] .", "In recent times, with an increase in global travel, the risk for spreading CHIKV to non-endemic regions has heightened [1] . Several travelers have brought CHIKV home with them after visiting areas with actively infected populations [12, 20] . Such cases have been documented in European countries, Australia, Asia, and the United States [8, 21] . The United States has already reported at least twelve cases of travel-associated CHIKV, while France has reported 850 cases, and the United Kingdom 93 [8, 14] . Beyond this, CHIKV-infected travelers have also been diagnosed in Australia, Belgium, Canada, Czech Republic, French Guiana, Germany, Hong Kong, Italy, Japan, Kenya, Malaysia, Martinique, Norway, Switzerland, and Sri Lanka [21] . Some travelers were viremic, worrying public health officials about the spread of CHIKV to new areas [1, 8] .", "The incubation time for CHIKV is relatively short, requiring only 2-6 d with symptoms usually appearing 4-7 d post-infection [22] . Vazeille et al. detected CHIKV in the salivary glands of Ae. albopictus only 2 d after infection [5] . Upon infection, CHIKF tends to present itself in two phases. The first stage is acute, while the second stage, experienced by most but not all, is persistent, causing disabling polyarthritis. Characteristics of the acute phase include an abrupt onset of fever, arthralgia, and in some cases, maculopapular rash [6, 23] . The acute phase causes such intense joint and muscular pain that makes movement very difficult and prostrates its victims [6, 20] .", "Ninety-five percent of infected adults are symptomatic after infection, and of these, most become disabled for weeks to months as a result of decreased dexterity, loss of mobility, and delayed reaction. Eighteen months after disease onset, 40% of patients are found to still have anti-CHIKV IgM [6, 18, 23, 24] . The chronic stage of CHIKF is characterized by polyarthralgia that can last from weeks to years beyond the acute stage [6] . CHIKV has been shown to attack fibroblasts, explaining the involvement of muscles, joints, and skin connective tissues. The high number of nociceptive nerve endings found within the joints and muscle connective tissues can explain pain associated with CHIKF [25, 26] .", "More than 50% of patients who suffer from severe CHIKF are over 65 y old, and more than 33% of them die. Most adults who suffer from severe CHIKF have underlying medical conditions [6, 24, 27] . The other group that is disproportionately affected by severe CHIKV is children. Other complications associated with CHIKV, from most common to least common, include respiratory failure, cardiovascular decompensation, meningoencephalitis, severe acute hepatitis, severe cutaneous effects, other central nervous system problems, and kidney failure [6, 18, 20, 23, 24, 26, 27] .", "CHIKV undertakes a complex replication cycle upon host infection (Figure 2 ), which makes its genome susceptible to mutations [28, 29] . For instance, Ae. aegypti, responsible for epidemics in Kenya, Comoros, and Seychelles, carried CHIKV with an alanine in the 226 position of the E1 gene (E1-A226) [4, 18] . However, when the virus struck La Reunion Islands, a decline in population of Ae. aegypti, due to massive dichlorodiphenyltrichloroethane usage and dearth of Ae. albopictus species' www.plosntds.org population, resulted in an ecological pressure, favoring replacement of alanine at position 226 with valine (E1-A226V) [5] . This mutation allowed CHIKV's secondary vector species, Ae. albopictus, to supplement Ae. aegypti as its primary vector [5] .", "Within a year, the E1-A226V mutation was present in La Reunion Island, and Ae. albopictus apparently vectored the large epidemic infecting 34% of La Reunion Island's population [5] . All of the CHIKV strains isolated from Mayotte carried the E1-A226V mutation, and the mutation was also found in Madagascar in 2007 [5] . The E1-A226V mutation was not present at the beginning of the Indian Ocean Islands outbreak (before September 2005). However, more than 90% of later viral strains found there had incorporated the mutation (December-March 2006), indicating a genotype switch during the winter season [5, 18, 20] .", "The E1-A226V mutation also enabled an increase in infectivity of Ae. albopictus when compared to its infectivity of Ae. aegypti [4, 11, 18, 30] , and with several factors taken together, Ae. albopictus has become the new preferred and more lethal vector for CHIKV [4, 5, 11] . In fact, Tsetsarkin et al. found that a Green Fluorescent Protein tagged E1-A226V virus was 100 times more infective to Ae. albopictus than it was to Ae. aegypti [4] . In all the Indian Ocean Islands, Ae. albopictus became the main vector for CHIKV within 1-2 y after CHIKV was introduced to the region [31] .", "Of note is that Ae. aegypti has most likely been established in North America for over 300 y, while Ae. albopictus has been in many areas of the US, since 1985, primarily in Florida [32] and since then has expanded its range in the country. Reiskind et al. set out to determine if Ae. aegypti and Ae. albopictus mosquitoes captured in Florida were susceptible to CHIKV infection by a La Reunion isolate [32] . Each mosquito tested was highly susceptible to infection by a full-length infectious clone of the La Réunion Island isolate, CHIKV LR2006 OPY1 strain. Even though the Ae. albopictus strains were more susceptible to infection, overall ecology and differences in human biting patterns need to be studied further Characteristically, there are two rounds of translation: (+) sense genomic RNA (49S9 = 11.7 kb) acts directly as mRNA and is partially translated (59 end) to produce non-structural proteins (nsp's). These proteins are responsible for replication and formation of a complementary", "(2) strand, the template for further (+) strand synthesis. Subgenomic mRNA (26 S = 4.1 kb) replication occurs through the synthesis of full-length (2) intermediate RNA, which is regulated by nsp4 and p123 precursor in early infection and later by mature nsp's. Translation of the newly synthesized sub-genomic RNA results in production of structural proteins such as Capsid and protein E2-6k-E1 (from 39 end of genome). Assembly occurs at the cell surface, and the envelope is acquired as the virus buds from the cell and release and maturation almost simultaneous occurred. Replication occurs in the cytoplasm and is very rapid (,4 h) [28, 29] . doi:10.1371/journal.pntd.0000623.g002 www.plosntds.org to gain a more accurate understanding of a potential CHIKV epidemic in the US [32] .", "During the 7 d preceding birth, no human mother has been reported to transmit the disease vertically. However, about 50% of newborns delivered while the mother was infected with CHIKV contracted the disease from their mother, despite the method of delivery. Furthermore, there have been instances of CHIKV transmission from mother to fetus causing congenital illness and fetal death [33] .", "During the 2005-2006 La Reunion Island outbreaks, Ramful et al. discovered that mothers could transmit CHIKV to their progeny during the perinatal period (Day 24 to Day +1) [33, 34] , and it is associated with a high degree of morbidity. By mean Day 4 of life, all of the neonates were symptomatic for CHIKV, exhibiting common CHIKF symptoms. Six neonates were confirmed to have contracted CHIKV and developed mengoencephalitis. Of those mothers who, during the La Reunion Island epidemic, were infected long before delivery, only three fetal deaths were reported [12, 33] . Ramful et al. theorized that motherto-child transmission most likely happens transplacentally shortly before delivery [33] . A similar study by Gerardin et al. reported nineteen cases of neonatal infection associated with intrapartum maternal viremia that progressed to develop encephalitis owing to vertical transmission from infected mothers [34] .", "Clinical and epidemiological similarities with dengue fever make CHIKV diagnosis difficult, which may lead physicians to misdiagnose CHIKV as dengue fever; therefore, the incidence of CHIKV may actually be higher than currently believed (Table 1 ) [6, 12, 35] .", "The amount of time elapsed since disease onset is the most critical parameter when choosing a diagnostic test. CHIKV can be detected and isolated by culturing with mosquito cells (C6/36), Vero cells (mammalian), or in mice [26] . However, this method can take at least a week and only achieves a high sensitivity during the viremic phase, which usually only lasts up to 48 h after the bite. Five days post-infection, the viral isolation approach has a low sensitivity but is still the preferred method for detecting the CHIKV strain [12, 26, 31, 35] . RT-PCR on the other hand is a faster and more sensitive method that can be used within the first week of disease onset [26] , and it is currently the most sensitive method for detecting and quantifying viral mRNA [4, 36] .", "Classic serological detection, by assays such as ELISA [37] , immunofluorescence [5, 38] , complement binding, and haemagglutination inhibition [39] , constitutes the second diagnostic tool used for biological diagnosis of CHIKV infection. These proven techniques are useful for detection of Antigen in mosquitoes during epidemiological studies. These assays detect virus-specific IgM and IgG, however the sensitivity and specificity of these assays has been poorly characterized. Viral competence, or the potential of viral infection and transmission, is an important parameter that can be quantified by ELISA, viral culture, and PCR.", "A study by Ng et al. showed biomarkers indicative of severe CHIKV infection [40] . They found decreased levels of RANTES and increased levels of Interleukin-6 (IL-6) and Interleukin-1b (IL-1b) that could be sued for CHIKV detection in patients as indicators of CHIKV-driven cytokine storm. Couderc et al. demonstrate another cytokine, type-I IFN, as a key player in the progression to CHIKV infection [26] . Using an IFN-a/b null mouse model, they demonstrated evidence of muscles, joints, and skin as privileged CHIKV targets, which is consistent with human pathology. Although Ng et al. concluded that RANTES levels were significantly suppressed in severe CHIKF patients [40] , interestingly, an increase in levels of RANTES has been observed in dengue infection [41] . Since the symptoms of CHIKF mimic those of dengue fever, results obtained from this study strongly suggest that RANTES could be a potential distinctive biomarker that differentiates between these two clinically similar", "diseases.", "There are no approved antiviral treatments currently available for CHIKV [1, 3, 12, 42] . Currently, CHIKF is treated symptomatically, usually with non-steroidal anti-inflammatory drugs or steroids, bed rest, and fluids. Movement and mild exercise are thought to decrease stiffness and morning arthralgia, but heavy exercise may exacerbate rheumatic symptoms. Corticosteroids may be used in cases of debilitating chronic CHIKV infection. There is a debate about the appropriateness of chloroquine as treatment for unresolved, non-steroidal anti-inflammatory drugresistant arthritis [43] . A study showed that viral production was www.plosntds.org drastically reduced at 16 h post-infection after treatment with 100 mM dec-RVKR-cmk (Decanoyl-Arg-Val-Lys-Arg-chloromethylketone), a furine inhibitor [42, 44] . Chloroquine acted by raising the pH, blocking low pH-dependent entry of virus into the cell. It is important to note that dec-RVKR-cmk or chloroquine only inhibited viral spreading from cell", "to cell, not CHIKV replication once it had entered the cell [43] . However, most would agree that the best weapon against CHIKV is prevention. A live CHIKV vaccine developed by the United States reached phase II clinical trial encompassing 59 healthy volunteers [45] . Eight percent of the volunteers experienced transient arthralgia, while 98% of the volunteers had seroconversion [45] . However, live CHIKV vaccines are still questionable. One cannot discount the risk of a live vaccine possibly inducing chronic rheumatism. Also, there is the question as to whether widespread use among the public could trigger mosquito transmission or lead to chronic infection or viral reversion [1] .", "An alternative approach would be to produce a chimeric vaccine against CHIKV. Wang et al. developed a chimeric alphavirus vaccine that is uniformly attenuated and does not cause reactogenicity in mice [3] . Three different versions of this vaccine were made using three different backbone vectors: Venezuelan equine encephalitis virus (VEEV) attenuated vaccine strain T-83, naturally attenuated eastern equine encephalitis virus (EEEV), and attenuated Sindbis virus (SINV). In short, CHIKV structural proteins were engineered into the backbones of the aforementioned vaccines to produce the chimeras [3] . These chimeras were found to stimulate a strong humoral immunity, and even at doses of 5.3-5.8 log 10 PFU, they did not trigger reactogenicity. When vaccinated mice were challenged with CHIKV, neither adult nor neonatal mice gained weight, had fever, or displayed signs of neurological illness. Upon comparison of the chimeras with the Army181/25 vaccine, the Army vaccine resulted in higher", "levels of viremia and replication in the joints of neonatal mice. Because the joints are known targets of CHIKV, Wang et al. noted their vaccine might avoid the negative reactogenic side effects of the Army vaccine. After being subcutaneously vaccinated with 5.3-5.8 log 10 PFU of the chimeric vaccines, mice produced strong neutralizing antibody titers. The VEEV and EEEV chimeras yielded higher neutralizing antibody titers than the SINV chimera without being more virulent. On top of this, the VEEV and EEEV CHIKV chimeras seemed to be more immunogenic than the Army vaccine despite the chimeras' lower viremia and replication in the joints of neonatal mice [3] .", "Tiwari et al. [46] adopted a different strategy using formalin inactivated CHIKV in combination with alhydrogel (Aluminum Hydroxide) as an adjuvant. This study clearly suggests that this vaccine elicits both humoral and cell-mediated immune responses in mice, providing its immunogenic potential. A recent study by Couderc et al. [47] showed passive immunization as a potential treatment for CHIKV infection. Using purified immunoglobulin extracted from convalescent CHIKV patients, they demonstrated effective neutralizing activity against CHIKV infection both in vitro and in vivo. This thereby establishes a potential preventive and therapeutic approach to combat CHIKV infection. Pathogenesis studies conducted with related alpha virus, like RRV, have shown the role of macrophages in persistence on infection [48] . They also demonstrated the role of RRV-specific CD8 T cells in clearing viral load in infected patients, thereby warranting similar investigations with CHIKV and the importance", "of investigating a cell-mediated immune response-based vaccine against CHIKV [49] .", "There are always certain risks associated with live attenuated or inactivated viral vaccines [50] . One way to avoid these potential problems is to construct a consensus-based DNA vaccine. DNA based vaccines have an improved safety profile as compared to live or attenuated vaccines [51, 52] . A consequence of CHIKV's rapid evolution is difficulty in constructing a vaccine that will be able to Figure 3 . Levels of CHIKV-specific IgG in mice immunized with CHIKV vaccines. Each group of C57BL/6 mice (n = 5) was immunized with 12.5 mg of pVax1 control vector or CHIKV vaccine plasmids as indicated at 0 and 2 wk. Mice were bled 2 wk after each immunization, and each group's serum pool was diluted to 1:100 and 1:500 for reaction with specific vaccine constructs. Serum was incubated for 1 h at 37uC on 96-well plates coated with 2 mg/ml of respective CHIKV peptides, and antibody was detected using anti-mouse IgG-HRP and OD was measured at 405 nm. doi:10.1371/journal.pntd.0000623.g003", "www.plosntds.org effectively protect large populations from multiple strains of the virus. One of the strengths of DNA consensus vaccines is its ability to induce cross-reactive immune responses against the three distinct phylogenetic groups of CHIKV. Also DNA-based vaccines can be produced more rapidly than protein-based vaccines.", "Recently, Muthumani et al. constructed a vaccine that was shown to induce both humoral and cellular immunity in vivo in 3-4-wk-old female C57/BL6 mice [49] . These mice were immunized using an in vivo electroporation method to deliver the vaccine into the quadriceps muscle. The consensus construct was designed against E1, E2, and the core protein capsid. To design the construct, they aligned 21 sequences of CHIKV isolated between 1952 and 2006, using strains from differing countries, including La Reunion Island. The most common nucleotide among the sequences was chosen at each position to be used in the consensus construct, taking care not to alter the reading frame. They conducted codon and RNA optimization, added a strong Kozak sequence, and substituted signal peptide with an immunoglobulin E leader sequence to improve vaccine efficacy.", "After immunizing the mice, spleens were harvested along with serum and tested to determine antibody titer. After three immunizations, consensus E1, E2, and C vaccines were shown to induce T-cell immune responses leading to strong IFN-c responses and proliferation in C57/BL6 mice. Furthermore, when compared with control mice, immunized mice had higher total IgG levels as well as higher anti-E1 specific, anti-E2 specific, and anti-C specific IgG antibodies, suggesting a strong humoral immune response ( Figure 3 ) and also specificity for the antigens encoded in the vaccine constructs ( Figure 4 ). Because of its promising results and the need for a safer vaccine, this consensus DNA vaccine deserves further investigation. Determining longevity of protective effects of the vaccine and persistence of antibody and IFN-c responses could be the next step of investigation. Challenged studies of immunized mice must also be carried out.", "CHIKV mosquito-borne disease has caused massive outbreaks for at least half a century but is no longer confined to the www.plosntds.org developing nations. It began to encroach into the boundaries of the developing world. As a result, the NIAID has designated CHIKV as a Category C pathogen alongside the influenza and SARS-CoV viruses [3] . Realization of the potential severity of this disease is exigent; for instance, if used as a biological weapon, the world economy could be severely crippled; if enough members of the armed forces were to become infected during a military deployment, military operations could be significantly affected. Efforts to monitor the disease will only provide minimal warning in a global society, and steps to prevent the morbidity and mortality associated with pandemic are imperative [21, 31] . Despite the gravity of its infectious potency and the fear of it being a potential biological weapon, there is currently no vaccine for CHIKV infections. Live", "attenuated vaccine trials were carried out in 2000, but funding for the project was discontinued. Newer approaches such as DNA vaccines appear promising over conventional strategies like live attenuated or inactivated virus and thus call for further investigation. Recent advances such electroporation delivery and incorporation of adjuvants has boosted DNA vaccine efficacy [51, 53] . Despite the low antibody response to DNA vaccines, other numerous advantages have overshadowed these minor drawbacks (Table 2) , the most important one being the ability to induce both humoral and cellular immune responses [51, 54] .", "Judging by recent success, such as the immunogenic construct developed by Muthumani et al., DNA vaccines could play a major role in combating CHIKV [49] . Vaccines are literally a critical component of CHIKV disease control and therefore research in this area is highly encouraged. The dramatic spread of dengue viruses (DENV) throughout tropical America since 1980 via the same vectors and human hosts underscores the risk to public health in the Americas. The adverse events associated with the current live vaccine are well documented [55] . Realizing these drawbacks, earnest efforts should be taken to develop new strategies to forestall further spread and complications." ]	[ 17 ]	3,829	5,688
1,689	What is theorized regarding transmission?	2,524	[ "motherto-child transmission most likely happens transplacentally shortly before delivery" ]	[ "Chikungunya: A Potentially Emerging Epidemic?\n\nhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC2860491/\n\nSHA: f7c3160bef4169d29e2a8bdd79dd6e9056d4774c\n\nAuthors: Thiboutot, Michelle M.; Kannan, Senthil; Kawalekar, Omkar U.; Shedlock, Devon J.; Khan, Amir S.; Sarangan, Gopalsamy; Srikanth, Padma; Weiner, David B.; Muthumani, Karuppiah\nDate: 2010-04-27\nDOI: 10.1371/journal.pntd.0000623\nLicense: cc-by", "Abstract: Chikungunya virus is a mosquito-borne emerging pathogen that has a major health impact in humans and causes fever disease, headache, rash, nausea, vomiting, myalgia, and arthralgia. Indigenous to tropical Africa, recent large outbreaks have been reported in parts of South East Asia and several of its neighboring islands in 2005–07 and in Europe in 2007. Furthermore, positive cases have been confirmed in the United States in travelers returning from known outbreak areas. Currently, there is no vaccine or antiviral treatment. With the threat of an emerging global pandemic, the peculiar problems associated with the more immediate and seasonal epidemics warrant the development of an effective vaccine. In this review, we summarize the evidence supporting these concepts.", "Text: Chikungunya virus (CHIKV), a mosquito-borne pathogen listed by National Institute of Allergy and Infectious Diseases (NIAID) as a Category C Priority Pathogen that causes Chikungunya fever (CHIKF), has been spreading throughout Asia, Africa, and parts of Europe in recent times [1, 2, 3] . CHIKV is an arthropod-borne virus (arbovirus) and is transmitted to humans primarily by Aedes aegypti, the infamous yellow fever propagator [4, 5] . CHIKV infection is marked by severe joint pain, contorting its victims into unusual postures [6] . The disease gets its name from the Kimakonde vernacular language of Tanzania and Mozambique, and the word chikungunya means ''that which contorts or bends up'' and translates in Swahili to ''the illness of the bended walker'' [7, 8, 9] . In Africa, CHIKV is maintained in a sylvatic cycle among forest-dwelling Aedes spp. mosquitoes, wild primates, squirrels, birds, and rodents ( Figure 1 ) [10] . In Asia, the disease is vectored by Ae. aegypti and Ae.", "albopictus [11] . Transmission in Asia occurs in an urban cycle whereby the mosquito spreads the disease from an infected human to an uninfected human, following an epidemiological pattern similar to dengue fever [12] .", "The 2005-2006 epidemic of CHIKV in La Reunion islands in the Indian Ocean, spurred the discovery of a new vector species, Ae. albopictus [5] . Wrecking over one-third of the island's population, this epidemic peaked its devastation between January and February 2006, when over 46,000 cases came into light every week, including 284 deaths [5, 13] . Ae. albopictus is common in urban areas of the United States and is already flourishing in 36 states, raising grave concerns to the immunologically naive populace of the United States [14] .\n\nAccordingly, this review elaborately details the epidemiology and global expansion of CHIKV, describes its clinical features and pathogenesis and its symptoms and complications, and finally nominates a possible vaccine approach against CHIKV infection.", "CHIKV has been isolated into three genotypes based on phylogenetic studies. These genotypes, based on the gene sequences of an Envelope protein (E1), are Asian, East/Central/ South African, and West African [4, 11, 15] . Using phylogenetic models, Cherian et al. estimate that the Asian genotype of CHIKV emerged between 50 and 310 y ago, and the West and East African genotypes diverged between 100 and 840 y ago [15] . Since then, CHIKV has come a long way, with several mutations incorporated, and has continued to wreak epidemics in several regions. Recent activities of CHIKV include the Indian epidemic in 2005-2006, which was followed by a sudden explosion of cases in 2007. An estimated 1.3 million people across 13 states were reported to be infected in India [12, 16] , and CHIKV was also widespread in Malaysia, Sri Lanka, and Indonesia [17] . In July-August of 2007, CHIKV was reported in Italy, probably brought in by travelers from CHIKV-prone regions of India, Africa, and Indian", "Ocean islands such as Mauritius, Madagascar, and Seychelles. Few of the Italian isolates were found to have evolved from the Kerala isolate, which was associated with a A226V shift in E1 gene that represents a successful evolutionary adaptation in the mosquito vector similar to the ones observed in Reunion Island [2, 18, 19] .", "In recent times, with an increase in global travel, the risk for spreading CHIKV to non-endemic regions has heightened [1] . Several travelers have brought CHIKV home with them after visiting areas with actively infected populations [12, 20] . Such cases have been documented in European countries, Australia, Asia, and the United States [8, 21] . The United States has already reported at least twelve cases of travel-associated CHIKV, while France has reported 850 cases, and the United Kingdom 93 [8, 14] . Beyond this, CHIKV-infected travelers have also been diagnosed in Australia, Belgium, Canada, Czech Republic, French Guiana, Germany, Hong Kong, Italy, Japan, Kenya, Malaysia, Martinique, Norway, Switzerland, and Sri Lanka [21] . Some travelers were viremic, worrying public health officials about the spread of CHIKV to new areas [1, 8] .", "The incubation time for CHIKV is relatively short, requiring only 2-6 d with symptoms usually appearing 4-7 d post-infection [22] . Vazeille et al. detected CHIKV in the salivary glands of Ae. albopictus only 2 d after infection [5] . Upon infection, CHIKF tends to present itself in two phases. The first stage is acute, while the second stage, experienced by most but not all, is persistent, causing disabling polyarthritis. Characteristics of the acute phase include an abrupt onset of fever, arthralgia, and in some cases, maculopapular rash [6, 23] . The acute phase causes such intense joint and muscular pain that makes movement very difficult and prostrates its victims [6, 20] .", "Ninety-five percent of infected adults are symptomatic after infection, and of these, most become disabled for weeks to months as a result of decreased dexterity, loss of mobility, and delayed reaction. Eighteen months after disease onset, 40% of patients are found to still have anti-CHIKV IgM [6, 18, 23, 24] . The chronic stage of CHIKF is characterized by polyarthralgia that can last from weeks to years beyond the acute stage [6] . CHIKV has been shown to attack fibroblasts, explaining the involvement of muscles, joints, and skin connective tissues. The high number of nociceptive nerve endings found within the joints and muscle connective tissues can explain pain associated with CHIKF [25, 26] .", "More than 50% of patients who suffer from severe CHIKF are over 65 y old, and more than 33% of them die. Most adults who suffer from severe CHIKF have underlying medical conditions [6, 24, 27] . The other group that is disproportionately affected by severe CHIKV is children. Other complications associated with CHIKV, from most common to least common, include respiratory failure, cardiovascular decompensation, meningoencephalitis, severe acute hepatitis, severe cutaneous effects, other central nervous system problems, and kidney failure [6, 18, 20, 23, 24, 26, 27] .", "CHIKV undertakes a complex replication cycle upon host infection (Figure 2 ), which makes its genome susceptible to mutations [28, 29] . For instance, Ae. aegypti, responsible for epidemics in Kenya, Comoros, and Seychelles, carried CHIKV with an alanine in the 226 position of the E1 gene (E1-A226) [4, 18] . However, when the virus struck La Reunion Islands, a decline in population of Ae. aegypti, due to massive dichlorodiphenyltrichloroethane usage and dearth of Ae. albopictus species' www.plosntds.org population, resulted in an ecological pressure, favoring replacement of alanine at position 226 with valine (E1-A226V) [5] . This mutation allowed CHIKV's secondary vector species, Ae. albopictus, to supplement Ae. aegypti as its primary vector [5] .", "Within a year, the E1-A226V mutation was present in La Reunion Island, and Ae. albopictus apparently vectored the large epidemic infecting 34% of La Reunion Island's population [5] . All of the CHIKV strains isolated from Mayotte carried the E1-A226V mutation, and the mutation was also found in Madagascar in 2007 [5] . The E1-A226V mutation was not present at the beginning of the Indian Ocean Islands outbreak (before September 2005). However, more than 90% of later viral strains found there had incorporated the mutation (December-March 2006), indicating a genotype switch during the winter season [5, 18, 20] .", "The E1-A226V mutation also enabled an increase in infectivity of Ae. albopictus when compared to its infectivity of Ae. aegypti [4, 11, 18, 30] , and with several factors taken together, Ae. albopictus has become the new preferred and more lethal vector for CHIKV [4, 5, 11] . In fact, Tsetsarkin et al. found that a Green Fluorescent Protein tagged E1-A226V virus was 100 times more infective to Ae. albopictus than it was to Ae. aegypti [4] . In all the Indian Ocean Islands, Ae. albopictus became the main vector for CHIKV within 1-2 y after CHIKV was introduced to the region [31] .", "Of note is that Ae. aegypti has most likely been established in North America for over 300 y, while Ae. albopictus has been in many areas of the US, since 1985, primarily in Florida [32] and since then has expanded its range in the country. Reiskind et al. set out to determine if Ae. aegypti and Ae. albopictus mosquitoes captured in Florida were susceptible to CHIKV infection by a La Reunion isolate [32] . Each mosquito tested was highly susceptible to infection by a full-length infectious clone of the La Réunion Island isolate, CHIKV LR2006 OPY1 strain. Even though the Ae. albopictus strains were more susceptible to infection, overall ecology and differences in human biting patterns need to be studied further Characteristically, there are two rounds of translation: (+) sense genomic RNA (49S9 = 11.7 kb) acts directly as mRNA and is partially translated (59 end) to produce non-structural proteins (nsp's). These proteins are responsible for replication and formation of a complementary", "(2) strand, the template for further (+) strand synthesis. Subgenomic mRNA (26 S = 4.1 kb) replication occurs through the synthesis of full-length (2) intermediate RNA, which is regulated by nsp4 and p123 precursor in early infection and later by mature nsp's. Translation of the newly synthesized sub-genomic RNA results in production of structural proteins such as Capsid and protein E2-6k-E1 (from 39 end of genome). Assembly occurs at the cell surface, and the envelope is acquired as the virus buds from the cell and release and maturation almost simultaneous occurred. Replication occurs in the cytoplasm and is very rapid (,4 h) [28, 29] . doi:10.1371/journal.pntd.0000623.g002 www.plosntds.org to gain a more accurate understanding of a potential CHIKV epidemic in the US [32] .", "During the 7 d preceding birth, no human mother has been reported to transmit the disease vertically. However, about 50% of newborns delivered while the mother was infected with CHIKV contracted the disease from their mother, despite the method of delivery. Furthermore, there have been instances of CHIKV transmission from mother to fetus causing congenital illness and fetal death [33] .", "During the 2005-2006 La Reunion Island outbreaks, Ramful et al. discovered that mothers could transmit CHIKV to their progeny during the perinatal period (Day 24 to Day +1) [33, 34] , and it is associated with a high degree of morbidity. By mean Day 4 of life, all of the neonates were symptomatic for CHIKV, exhibiting common CHIKF symptoms. Six neonates were confirmed to have contracted CHIKV and developed mengoencephalitis. Of those mothers who, during the La Reunion Island epidemic, were infected long before delivery, only three fetal deaths were reported [12, 33] . Ramful et al. theorized that motherto-child transmission most likely happens transplacentally shortly before delivery [33] . A similar study by Gerardin et al. reported nineteen cases of neonatal infection associated with intrapartum maternal viremia that progressed to develop encephalitis owing to vertical transmission from infected mothers [34] .", "Clinical and epidemiological similarities with dengue fever make CHIKV diagnosis difficult, which may lead physicians to misdiagnose CHIKV as dengue fever; therefore, the incidence of CHIKV may actually be higher than currently believed (Table 1 ) [6, 12, 35] .", "The amount of time elapsed since disease onset is the most critical parameter when choosing a diagnostic test. CHIKV can be detected and isolated by culturing with mosquito cells (C6/36), Vero cells (mammalian), or in mice [26] . However, this method can take at least a week and only achieves a high sensitivity during the viremic phase, which usually only lasts up to 48 h after the bite. Five days post-infection, the viral isolation approach has a low sensitivity but is still the preferred method for detecting the CHIKV strain [12, 26, 31, 35] . RT-PCR on the other hand is a faster and more sensitive method that can be used within the first week of disease onset [26] , and it is currently the most sensitive method for detecting and quantifying viral mRNA [4, 36] .", "Classic serological detection, by assays such as ELISA [37] , immunofluorescence [5, 38] , complement binding, and haemagglutination inhibition [39] , constitutes the second diagnostic tool used for biological diagnosis of CHIKV infection. These proven techniques are useful for detection of Antigen in mosquitoes during epidemiological studies. These assays detect virus-specific IgM and IgG, however the sensitivity and specificity of these assays has been poorly characterized. Viral competence, or the potential of viral infection and transmission, is an important parameter that can be quantified by ELISA, viral culture, and PCR.", "A study by Ng et al. showed biomarkers indicative of severe CHIKV infection [40] . They found decreased levels of RANTES and increased levels of Interleukin-6 (IL-6) and Interleukin-1b (IL-1b) that could be sued for CHIKV detection in patients as indicators of CHIKV-driven cytokine storm. Couderc et al. demonstrate another cytokine, type-I IFN, as a key player in the progression to CHIKV infection [26] . Using an IFN-a/b null mouse model, they demonstrated evidence of muscles, joints, and skin as privileged CHIKV targets, which is consistent with human pathology. Although Ng et al. concluded that RANTES levels were significantly suppressed in severe CHIKF patients [40] , interestingly, an increase in levels of RANTES has been observed in dengue infection [41] . Since the symptoms of CHIKF mimic those of dengue fever, results obtained from this study strongly suggest that RANTES could be a potential distinctive biomarker that differentiates between these two clinically similar", "diseases.", "There are no approved antiviral treatments currently available for CHIKV [1, 3, 12, 42] . Currently, CHIKF is treated symptomatically, usually with non-steroidal anti-inflammatory drugs or steroids, bed rest, and fluids. Movement and mild exercise are thought to decrease stiffness and morning arthralgia, but heavy exercise may exacerbate rheumatic symptoms. Corticosteroids may be used in cases of debilitating chronic CHIKV infection. There is a debate about the appropriateness of chloroquine as treatment for unresolved, non-steroidal anti-inflammatory drugresistant arthritis [43] . A study showed that viral production was www.plosntds.org drastically reduced at 16 h post-infection after treatment with 100 mM dec-RVKR-cmk (Decanoyl-Arg-Val-Lys-Arg-chloromethylketone), a furine inhibitor [42, 44] . Chloroquine acted by raising the pH, blocking low pH-dependent entry of virus into the cell. It is important to note that dec-RVKR-cmk or chloroquine only inhibited viral spreading from cell", "to cell, not CHIKV replication once it had entered the cell [43] . However, most would agree that the best weapon against CHIKV is prevention. A live CHIKV vaccine developed by the United States reached phase II clinical trial encompassing 59 healthy volunteers [45] . Eight percent of the volunteers experienced transient arthralgia, while 98% of the volunteers had seroconversion [45] . However, live CHIKV vaccines are still questionable. One cannot discount the risk of a live vaccine possibly inducing chronic rheumatism. Also, there is the question as to whether widespread use among the public could trigger mosquito transmission or lead to chronic infection or viral reversion [1] .", "An alternative approach would be to produce a chimeric vaccine against CHIKV. Wang et al. developed a chimeric alphavirus vaccine that is uniformly attenuated and does not cause reactogenicity in mice [3] . Three different versions of this vaccine were made using three different backbone vectors: Venezuelan equine encephalitis virus (VEEV) attenuated vaccine strain T-83, naturally attenuated eastern equine encephalitis virus (EEEV), and attenuated Sindbis virus (SINV). In short, CHIKV structural proteins were engineered into the backbones of the aforementioned vaccines to produce the chimeras [3] . These chimeras were found to stimulate a strong humoral immunity, and even at doses of 5.3-5.8 log 10 PFU, they did not trigger reactogenicity. When vaccinated mice were challenged with CHIKV, neither adult nor neonatal mice gained weight, had fever, or displayed signs of neurological illness. Upon comparison of the chimeras with the Army181/25 vaccine, the Army vaccine resulted in higher", "levels of viremia and replication in the joints of neonatal mice. Because the joints are known targets of CHIKV, Wang et al. noted their vaccine might avoid the negative reactogenic side effects of the Army vaccine. After being subcutaneously vaccinated with 5.3-5.8 log 10 PFU of the chimeric vaccines, mice produced strong neutralizing antibody titers. The VEEV and EEEV chimeras yielded higher neutralizing antibody titers than the SINV chimera without being more virulent. On top of this, the VEEV and EEEV CHIKV chimeras seemed to be more immunogenic than the Army vaccine despite the chimeras' lower viremia and replication in the joints of neonatal mice [3] .", "Tiwari et al. [46] adopted a different strategy using formalin inactivated CHIKV in combination with alhydrogel (Aluminum Hydroxide) as an adjuvant. This study clearly suggests that this vaccine elicits both humoral and cell-mediated immune responses in mice, providing its immunogenic potential. A recent study by Couderc et al. [47] showed passive immunization as a potential treatment for CHIKV infection. Using purified immunoglobulin extracted from convalescent CHIKV patients, they demonstrated effective neutralizing activity against CHIKV infection both in vitro and in vivo. This thereby establishes a potential preventive and therapeutic approach to combat CHIKV infection. Pathogenesis studies conducted with related alpha virus, like RRV, have shown the role of macrophages in persistence on infection [48] . They also demonstrated the role of RRV-specific CD8 T cells in clearing viral load in infected patients, thereby warranting similar investigations with CHIKV and the importance", "of investigating a cell-mediated immune response-based vaccine against CHIKV [49] .", "There are always certain risks associated with live attenuated or inactivated viral vaccines [50] . One way to avoid these potential problems is to construct a consensus-based DNA vaccine. DNA based vaccines have an improved safety profile as compared to live or attenuated vaccines [51, 52] . A consequence of CHIKV's rapid evolution is difficulty in constructing a vaccine that will be able to Figure 3 . Levels of CHIKV-specific IgG in mice immunized with CHIKV vaccines. Each group of C57BL/6 mice (n = 5) was immunized with 12.5 mg of pVax1 control vector or CHIKV vaccine plasmids as indicated at 0 and 2 wk. Mice were bled 2 wk after each immunization, and each group's serum pool was diluted to 1:100 and 1:500 for reaction with specific vaccine constructs. Serum was incubated for 1 h at 37uC on 96-well plates coated with 2 mg/ml of respective CHIKV peptides, and antibody was detected using anti-mouse IgG-HRP and OD was measured at 405 nm. doi:10.1371/journal.pntd.0000623.g003", "www.plosntds.org effectively protect large populations from multiple strains of the virus. One of the strengths of DNA consensus vaccines is its ability to induce cross-reactive immune responses against the three distinct phylogenetic groups of CHIKV. Also DNA-based vaccines can be produced more rapidly than protein-based vaccines.", "Recently, Muthumani et al. constructed a vaccine that was shown to induce both humoral and cellular immunity in vivo in 3-4-wk-old female C57/BL6 mice [49] . These mice were immunized using an in vivo electroporation method to deliver the vaccine into the quadriceps muscle. The consensus construct was designed against E1, E2, and the core protein capsid. To design the construct, they aligned 21 sequences of CHIKV isolated between 1952 and 2006, using strains from differing countries, including La Reunion Island. The most common nucleotide among the sequences was chosen at each position to be used in the consensus construct, taking care not to alter the reading frame. They conducted codon and RNA optimization, added a strong Kozak sequence, and substituted signal peptide with an immunoglobulin E leader sequence to improve vaccine efficacy.", "After immunizing the mice, spleens were harvested along with serum and tested to determine antibody titer. After three immunizations, consensus E1, E2, and C vaccines were shown to induce T-cell immune responses leading to strong IFN-c responses and proliferation in C57/BL6 mice. Furthermore, when compared with control mice, immunized mice had higher total IgG levels as well as higher anti-E1 specific, anti-E2 specific, and anti-C specific IgG antibodies, suggesting a strong humoral immune response ( Figure 3 ) and also specificity for the antigens encoded in the vaccine constructs ( Figure 4 ). Because of its promising results and the need for a safer vaccine, this consensus DNA vaccine deserves further investigation. Determining longevity of protective effects of the vaccine and persistence of antibody and IFN-c responses could be the next step of investigation. Challenged studies of immunized mice must also be carried out.", "CHIKV mosquito-borne disease has caused massive outbreaks for at least half a century but is no longer confined to the www.plosntds.org developing nations. It began to encroach into the boundaries of the developing world. As a result, the NIAID has designated CHIKV as a Category C pathogen alongside the influenza and SARS-CoV viruses [3] . Realization of the potential severity of this disease is exigent; for instance, if used as a biological weapon, the world economy could be severely crippled; if enough members of the armed forces were to become infected during a military deployment, military operations could be significantly affected. Efforts to monitor the disease will only provide minimal warning in a global society, and steps to prevent the morbidity and mortality associated with pandemic are imperative [21, 31] . Despite the gravity of its infectious potency and the fear of it being a potential biological weapon, there is currently no vaccine for CHIKV infections. Live", "attenuated vaccine trials were carried out in 2000, but funding for the project was discontinued. Newer approaches such as DNA vaccines appear promising over conventional strategies like live attenuated or inactivated virus and thus call for further investigation. Recent advances such electroporation delivery and incorporation of adjuvants has boosted DNA vaccine efficacy [51, 53] . Despite the low antibody response to DNA vaccines, other numerous advantages have overshadowed these minor drawbacks (Table 2) , the most important one being the ability to induce both humoral and cellular immune responses [51, 54] .", "Judging by recent success, such as the immunogenic construct developed by Muthumani et al., DNA vaccines could play a major role in combating CHIKV [49] . Vaccines are literally a critical component of CHIKV disease control and therefore research in this area is highly encouraged. The dramatic spread of dengue viruses (DENV) throughout tropical America since 1980 via the same vectors and human hosts underscores the risk to public health in the Americas. The adverse events associated with the current live vaccine are well documented [55] . Realizing these drawbacks, earnest efforts should be taken to develop new strategies to forestall further spread and complications." ]	[ 17 ]	3,829	5,688
1,689	What did the study report?	2,525	[ "neonatal infection associated with intrapartum maternal viremia that progressed to develop encephalitis owing to vertical transmission from infected mothers" ]	[ "Chikungunya: A Potentially Emerging Epidemic?\n\nhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC2860491/\n\nSHA: f7c3160bef4169d29e2a8bdd79dd6e9056d4774c\n\nAuthors: Thiboutot, Michelle M.; Kannan, Senthil; Kawalekar, Omkar U.; Shedlock, Devon J.; Khan, Amir S.; Sarangan, Gopalsamy; Srikanth, Padma; Weiner, David B.; Muthumani, Karuppiah\nDate: 2010-04-27\nDOI: 10.1371/journal.pntd.0000623\nLicense: cc-by", "Abstract: Chikungunya virus is a mosquito-borne emerging pathogen that has a major health impact in humans and causes fever disease, headache, rash, nausea, vomiting, myalgia, and arthralgia. Indigenous to tropical Africa, recent large outbreaks have been reported in parts of South East Asia and several of its neighboring islands in 2005–07 and in Europe in 2007. Furthermore, positive cases have been confirmed in the United States in travelers returning from known outbreak areas. Currently, there is no vaccine or antiviral treatment. With the threat of an emerging global pandemic, the peculiar problems associated with the more immediate and seasonal epidemics warrant the development of an effective vaccine. In this review, we summarize the evidence supporting these concepts.", "Text: Chikungunya virus (CHIKV), a mosquito-borne pathogen listed by National Institute of Allergy and Infectious Diseases (NIAID) as a Category C Priority Pathogen that causes Chikungunya fever (CHIKF), has been spreading throughout Asia, Africa, and parts of Europe in recent times [1, 2, 3] . CHIKV is an arthropod-borne virus (arbovirus) and is transmitted to humans primarily by Aedes aegypti, the infamous yellow fever propagator [4, 5] . CHIKV infection is marked by severe joint pain, contorting its victims into unusual postures [6] . The disease gets its name from the Kimakonde vernacular language of Tanzania and Mozambique, and the word chikungunya means ''that which contorts or bends up'' and translates in Swahili to ''the illness of the bended walker'' [7, 8, 9] . In Africa, CHIKV is maintained in a sylvatic cycle among forest-dwelling Aedes spp. mosquitoes, wild primates, squirrels, birds, and rodents ( Figure 1 ) [10] . In Asia, the disease is vectored by Ae. aegypti and Ae.", "albopictus [11] . Transmission in Asia occurs in an urban cycle whereby the mosquito spreads the disease from an infected human to an uninfected human, following an epidemiological pattern similar to dengue fever [12] .", "The 2005-2006 epidemic of CHIKV in La Reunion islands in the Indian Ocean, spurred the discovery of a new vector species, Ae. albopictus [5] . Wrecking over one-third of the island's population, this epidemic peaked its devastation between January and February 2006, when over 46,000 cases came into light every week, including 284 deaths [5, 13] . Ae. albopictus is common in urban areas of the United States and is already flourishing in 36 states, raising grave concerns to the immunologically naive populace of the United States [14] .\n\nAccordingly, this review elaborately details the epidemiology and global expansion of CHIKV, describes its clinical features and pathogenesis and its symptoms and complications, and finally nominates a possible vaccine approach against CHIKV infection.", "CHIKV has been isolated into three genotypes based on phylogenetic studies. These genotypes, based on the gene sequences of an Envelope protein (E1), are Asian, East/Central/ South African, and West African [4, 11, 15] . Using phylogenetic models, Cherian et al. estimate that the Asian genotype of CHIKV emerged between 50 and 310 y ago, and the West and East African genotypes diverged between 100 and 840 y ago [15] . Since then, CHIKV has come a long way, with several mutations incorporated, and has continued to wreak epidemics in several regions. Recent activities of CHIKV include the Indian epidemic in 2005-2006, which was followed by a sudden explosion of cases in 2007. An estimated 1.3 million people across 13 states were reported to be infected in India [12, 16] , and CHIKV was also widespread in Malaysia, Sri Lanka, and Indonesia [17] . In July-August of 2007, CHIKV was reported in Italy, probably brought in by travelers from CHIKV-prone regions of India, Africa, and Indian", "Ocean islands such as Mauritius, Madagascar, and Seychelles. Few of the Italian isolates were found to have evolved from the Kerala isolate, which was associated with a A226V shift in E1 gene that represents a successful evolutionary adaptation in the mosquito vector similar to the ones observed in Reunion Island [2, 18, 19] .", "In recent times, with an increase in global travel, the risk for spreading CHIKV to non-endemic regions has heightened [1] . Several travelers have brought CHIKV home with them after visiting areas with actively infected populations [12, 20] . Such cases have been documented in European countries, Australia, Asia, and the United States [8, 21] . The United States has already reported at least twelve cases of travel-associated CHIKV, while France has reported 850 cases, and the United Kingdom 93 [8, 14] . Beyond this, CHIKV-infected travelers have also been diagnosed in Australia, Belgium, Canada, Czech Republic, French Guiana, Germany, Hong Kong, Italy, Japan, Kenya, Malaysia, Martinique, Norway, Switzerland, and Sri Lanka [21] . Some travelers were viremic, worrying public health officials about the spread of CHIKV to new areas [1, 8] .", "The incubation time for CHIKV is relatively short, requiring only 2-6 d with symptoms usually appearing 4-7 d post-infection [22] . Vazeille et al. detected CHIKV in the salivary glands of Ae. albopictus only 2 d after infection [5] . Upon infection, CHIKF tends to present itself in two phases. The first stage is acute, while the second stage, experienced by most but not all, is persistent, causing disabling polyarthritis. Characteristics of the acute phase include an abrupt onset of fever, arthralgia, and in some cases, maculopapular rash [6, 23] . The acute phase causes such intense joint and muscular pain that makes movement very difficult and prostrates its victims [6, 20] .", "Ninety-five percent of infected adults are symptomatic after infection, and of these, most become disabled for weeks to months as a result of decreased dexterity, loss of mobility, and delayed reaction. Eighteen months after disease onset, 40% of patients are found to still have anti-CHIKV IgM [6, 18, 23, 24] . The chronic stage of CHIKF is characterized by polyarthralgia that can last from weeks to years beyond the acute stage [6] . CHIKV has been shown to attack fibroblasts, explaining the involvement of muscles, joints, and skin connective tissues. The high number of nociceptive nerve endings found within the joints and muscle connective tissues can explain pain associated with CHIKF [25, 26] .", "More than 50% of patients who suffer from severe CHIKF are over 65 y old, and more than 33% of them die. Most adults who suffer from severe CHIKF have underlying medical conditions [6, 24, 27] . The other group that is disproportionately affected by severe CHIKV is children. Other complications associated with CHIKV, from most common to least common, include respiratory failure, cardiovascular decompensation, meningoencephalitis, severe acute hepatitis, severe cutaneous effects, other central nervous system problems, and kidney failure [6, 18, 20, 23, 24, 26, 27] .", "CHIKV undertakes a complex replication cycle upon host infection (Figure 2 ), which makes its genome susceptible to mutations [28, 29] . For instance, Ae. aegypti, responsible for epidemics in Kenya, Comoros, and Seychelles, carried CHIKV with an alanine in the 226 position of the E1 gene (E1-A226) [4, 18] . However, when the virus struck La Reunion Islands, a decline in population of Ae. aegypti, due to massive dichlorodiphenyltrichloroethane usage and dearth of Ae. albopictus species' www.plosntds.org population, resulted in an ecological pressure, favoring replacement of alanine at position 226 with valine (E1-A226V) [5] . This mutation allowed CHIKV's secondary vector species, Ae. albopictus, to supplement Ae. aegypti as its primary vector [5] .", "Within a year, the E1-A226V mutation was present in La Reunion Island, and Ae. albopictus apparently vectored the large epidemic infecting 34% of La Reunion Island's population [5] . All of the CHIKV strains isolated from Mayotte carried the E1-A226V mutation, and the mutation was also found in Madagascar in 2007 [5] . The E1-A226V mutation was not present at the beginning of the Indian Ocean Islands outbreak (before September 2005). However, more than 90% of later viral strains found there had incorporated the mutation (December-March 2006), indicating a genotype switch during the winter season [5, 18, 20] .", "The E1-A226V mutation also enabled an increase in infectivity of Ae. albopictus when compared to its infectivity of Ae. aegypti [4, 11, 18, 30] , and with several factors taken together, Ae. albopictus has become the new preferred and more lethal vector for CHIKV [4, 5, 11] . In fact, Tsetsarkin et al. found that a Green Fluorescent Protein tagged E1-A226V virus was 100 times more infective to Ae. albopictus than it was to Ae. aegypti [4] . In all the Indian Ocean Islands, Ae. albopictus became the main vector for CHIKV within 1-2 y after CHIKV was introduced to the region [31] .", "Of note is that Ae. aegypti has most likely been established in North America for over 300 y, while Ae. albopictus has been in many areas of the US, since 1985, primarily in Florida [32] and since then has expanded its range in the country. Reiskind et al. set out to determine if Ae. aegypti and Ae. albopictus mosquitoes captured in Florida were susceptible to CHIKV infection by a La Reunion isolate [32] . Each mosquito tested was highly susceptible to infection by a full-length infectious clone of the La Réunion Island isolate, CHIKV LR2006 OPY1 strain. Even though the Ae. albopictus strains were more susceptible to infection, overall ecology and differences in human biting patterns need to be studied further Characteristically, there are two rounds of translation: (+) sense genomic RNA (49S9 = 11.7 kb) acts directly as mRNA and is partially translated (59 end) to produce non-structural proteins (nsp's). These proteins are responsible for replication and formation of a complementary", "(2) strand, the template for further (+) strand synthesis. Subgenomic mRNA (26 S = 4.1 kb) replication occurs through the synthesis of full-length (2) intermediate RNA, which is regulated by nsp4 and p123 precursor in early infection and later by mature nsp's. Translation of the newly synthesized sub-genomic RNA results in production of structural proteins such as Capsid and protein E2-6k-E1 (from 39 end of genome). Assembly occurs at the cell surface, and the envelope is acquired as the virus buds from the cell and release and maturation almost simultaneous occurred. Replication occurs in the cytoplasm and is very rapid (,4 h) [28, 29] . doi:10.1371/journal.pntd.0000623.g002 www.plosntds.org to gain a more accurate understanding of a potential CHIKV epidemic in the US [32] .", "During the 7 d preceding birth, no human mother has been reported to transmit the disease vertically. However, about 50% of newborns delivered while the mother was infected with CHIKV contracted the disease from their mother, despite the method of delivery. Furthermore, there have been instances of CHIKV transmission from mother to fetus causing congenital illness and fetal death [33] .", "During the 2005-2006 La Reunion Island outbreaks, Ramful et al. discovered that mothers could transmit CHIKV to their progeny during the perinatal period (Day 24 to Day +1) [33, 34] , and it is associated with a high degree of morbidity. By mean Day 4 of life, all of the neonates were symptomatic for CHIKV, exhibiting common CHIKF symptoms. Six neonates were confirmed to have contracted CHIKV and developed mengoencephalitis. Of those mothers who, during the La Reunion Island epidemic, were infected long before delivery, only three fetal deaths were reported [12, 33] . Ramful et al. theorized that motherto-child transmission most likely happens transplacentally shortly before delivery [33] . A similar study by Gerardin et al. reported nineteen cases of neonatal infection associated with intrapartum maternal viremia that progressed to develop encephalitis owing to vertical transmission from infected mothers [34] .", "Clinical and epidemiological similarities with dengue fever make CHIKV diagnosis difficult, which may lead physicians to misdiagnose CHIKV as dengue fever; therefore, the incidence of CHIKV may actually be higher than currently believed (Table 1 ) [6, 12, 35] .", "The amount of time elapsed since disease onset is the most critical parameter when choosing a diagnostic test. CHIKV can be detected and isolated by culturing with mosquito cells (C6/36), Vero cells (mammalian), or in mice [26] . However, this method can take at least a week and only achieves a high sensitivity during the viremic phase, which usually only lasts up to 48 h after the bite. Five days post-infection, the viral isolation approach has a low sensitivity but is still the preferred method for detecting the CHIKV strain [12, 26, 31, 35] . RT-PCR on the other hand is a faster and more sensitive method that can be used within the first week of disease onset [26] , and it is currently the most sensitive method for detecting and quantifying viral mRNA [4, 36] .", "Classic serological detection, by assays such as ELISA [37] , immunofluorescence [5, 38] , complement binding, and haemagglutination inhibition [39] , constitutes the second diagnostic tool used for biological diagnosis of CHIKV infection. These proven techniques are useful for detection of Antigen in mosquitoes during epidemiological studies. These assays detect virus-specific IgM and IgG, however the sensitivity and specificity of these assays has been poorly characterized. Viral competence, or the potential of viral infection and transmission, is an important parameter that can be quantified by ELISA, viral culture, and PCR.", "A study by Ng et al. showed biomarkers indicative of severe CHIKV infection [40] . They found decreased levels of RANTES and increased levels of Interleukin-6 (IL-6) and Interleukin-1b (IL-1b) that could be sued for CHIKV detection in patients as indicators of CHIKV-driven cytokine storm. Couderc et al. demonstrate another cytokine, type-I IFN, as a key player in the progression to CHIKV infection [26] . Using an IFN-a/b null mouse model, they demonstrated evidence of muscles, joints, and skin as privileged CHIKV targets, which is consistent with human pathology. Although Ng et al. concluded that RANTES levels were significantly suppressed in severe CHIKF patients [40] , interestingly, an increase in levels of RANTES has been observed in dengue infection [41] . Since the symptoms of CHIKF mimic those of dengue fever, results obtained from this study strongly suggest that RANTES could be a potential distinctive biomarker that differentiates between these two clinically similar", "diseases.", "There are no approved antiviral treatments currently available for CHIKV [1, 3, 12, 42] . Currently, CHIKF is treated symptomatically, usually with non-steroidal anti-inflammatory drugs or steroids, bed rest, and fluids. Movement and mild exercise are thought to decrease stiffness and morning arthralgia, but heavy exercise may exacerbate rheumatic symptoms. Corticosteroids may be used in cases of debilitating chronic CHIKV infection. There is a debate about the appropriateness of chloroquine as treatment for unresolved, non-steroidal anti-inflammatory drugresistant arthritis [43] . A study showed that viral production was www.plosntds.org drastically reduced at 16 h post-infection after treatment with 100 mM dec-RVKR-cmk (Decanoyl-Arg-Val-Lys-Arg-chloromethylketone), a furine inhibitor [42, 44] . Chloroquine acted by raising the pH, blocking low pH-dependent entry of virus into the cell. It is important to note that dec-RVKR-cmk or chloroquine only inhibited viral spreading from cell", "to cell, not CHIKV replication once it had entered the cell [43] . However, most would agree that the best weapon against CHIKV is prevention. A live CHIKV vaccine developed by the United States reached phase II clinical trial encompassing 59 healthy volunteers [45] . Eight percent of the volunteers experienced transient arthralgia, while 98% of the volunteers had seroconversion [45] . However, live CHIKV vaccines are still questionable. One cannot discount the risk of a live vaccine possibly inducing chronic rheumatism. Also, there is the question as to whether widespread use among the public could trigger mosquito transmission or lead to chronic infection or viral reversion [1] .", "An alternative approach would be to produce a chimeric vaccine against CHIKV. Wang et al. developed a chimeric alphavirus vaccine that is uniformly attenuated and does not cause reactogenicity in mice [3] . Three different versions of this vaccine were made using three different backbone vectors: Venezuelan equine encephalitis virus (VEEV) attenuated vaccine strain T-83, naturally attenuated eastern equine encephalitis virus (EEEV), and attenuated Sindbis virus (SINV). In short, CHIKV structural proteins were engineered into the backbones of the aforementioned vaccines to produce the chimeras [3] . These chimeras were found to stimulate a strong humoral immunity, and even at doses of 5.3-5.8 log 10 PFU, they did not trigger reactogenicity. When vaccinated mice were challenged with CHIKV, neither adult nor neonatal mice gained weight, had fever, or displayed signs of neurological illness. Upon comparison of the chimeras with the Army181/25 vaccine, the Army vaccine resulted in higher", "levels of viremia and replication in the joints of neonatal mice. Because the joints are known targets of CHIKV, Wang et al. noted their vaccine might avoid the negative reactogenic side effects of the Army vaccine. After being subcutaneously vaccinated with 5.3-5.8 log 10 PFU of the chimeric vaccines, mice produced strong neutralizing antibody titers. The VEEV and EEEV chimeras yielded higher neutralizing antibody titers than the SINV chimera without being more virulent. On top of this, the VEEV and EEEV CHIKV chimeras seemed to be more immunogenic than the Army vaccine despite the chimeras' lower viremia and replication in the joints of neonatal mice [3] .", "Tiwari et al. [46] adopted a different strategy using formalin inactivated CHIKV in combination with alhydrogel (Aluminum Hydroxide) as an adjuvant. This study clearly suggests that this vaccine elicits both humoral and cell-mediated immune responses in mice, providing its immunogenic potential. A recent study by Couderc et al. [47] showed passive immunization as a potential treatment for CHIKV infection. Using purified immunoglobulin extracted from convalescent CHIKV patients, they demonstrated effective neutralizing activity against CHIKV infection both in vitro and in vivo. This thereby establishes a potential preventive and therapeutic approach to combat CHIKV infection. Pathogenesis studies conducted with related alpha virus, like RRV, have shown the role of macrophages in persistence on infection [48] . They also demonstrated the role of RRV-specific CD8 T cells in clearing viral load in infected patients, thereby warranting similar investigations with CHIKV and the importance", "of investigating a cell-mediated immune response-based vaccine against CHIKV [49] .", "There are always certain risks associated with live attenuated or inactivated viral vaccines [50] . One way to avoid these potential problems is to construct a consensus-based DNA vaccine. DNA based vaccines have an improved safety profile as compared to live or attenuated vaccines [51, 52] . A consequence of CHIKV's rapid evolution is difficulty in constructing a vaccine that will be able to Figure 3 . Levels of CHIKV-specific IgG in mice immunized with CHIKV vaccines. Each group of C57BL/6 mice (n = 5) was immunized with 12.5 mg of pVax1 control vector or CHIKV vaccine plasmids as indicated at 0 and 2 wk. Mice were bled 2 wk after each immunization, and each group's serum pool was diluted to 1:100 and 1:500 for reaction with specific vaccine constructs. Serum was incubated for 1 h at 37uC on 96-well plates coated with 2 mg/ml of respective CHIKV peptides, and antibody was detected using anti-mouse IgG-HRP and OD was measured at 405 nm. doi:10.1371/journal.pntd.0000623.g003", "www.plosntds.org effectively protect large populations from multiple strains of the virus. One of the strengths of DNA consensus vaccines is its ability to induce cross-reactive immune responses against the three distinct phylogenetic groups of CHIKV. Also DNA-based vaccines can be produced more rapidly than protein-based vaccines.", "Recently, Muthumani et al. constructed a vaccine that was shown to induce both humoral and cellular immunity in vivo in 3-4-wk-old female C57/BL6 mice [49] . These mice were immunized using an in vivo electroporation method to deliver the vaccine into the quadriceps muscle. The consensus construct was designed against E1, E2, and the core protein capsid. To design the construct, they aligned 21 sequences of CHIKV isolated between 1952 and 2006, using strains from differing countries, including La Reunion Island. The most common nucleotide among the sequences was chosen at each position to be used in the consensus construct, taking care not to alter the reading frame. They conducted codon and RNA optimization, added a strong Kozak sequence, and substituted signal peptide with an immunoglobulin E leader sequence to improve vaccine efficacy.", "After immunizing the mice, spleens were harvested along with serum and tested to determine antibody titer. After three immunizations, consensus E1, E2, and C vaccines were shown to induce T-cell immune responses leading to strong IFN-c responses and proliferation in C57/BL6 mice. Furthermore, when compared with control mice, immunized mice had higher total IgG levels as well as higher anti-E1 specific, anti-E2 specific, and anti-C specific IgG antibodies, suggesting a strong humoral immune response ( Figure 3 ) and also specificity for the antigens encoded in the vaccine constructs ( Figure 4 ). Because of its promising results and the need for a safer vaccine, this consensus DNA vaccine deserves further investigation. Determining longevity of protective effects of the vaccine and persistence of antibody and IFN-c responses could be the next step of investigation. Challenged studies of immunized mice must also be carried out.", "CHIKV mosquito-borne disease has caused massive outbreaks for at least half a century but is no longer confined to the www.plosntds.org developing nations. It began to encroach into the boundaries of the developing world. As a result, the NIAID has designated CHIKV as a Category C pathogen alongside the influenza and SARS-CoV viruses [3] . Realization of the potential severity of this disease is exigent; for instance, if used as a biological weapon, the world economy could be severely crippled; if enough members of the armed forces were to become infected during a military deployment, military operations could be significantly affected. Efforts to monitor the disease will only provide minimal warning in a global society, and steps to prevent the morbidity and mortality associated with pandemic are imperative [21, 31] . Despite the gravity of its infectious potency and the fear of it being a potential biological weapon, there is currently no vaccine for CHIKV infections. Live", "attenuated vaccine trials were carried out in 2000, but funding for the project was discontinued. Newer approaches such as DNA vaccines appear promising over conventional strategies like live attenuated or inactivated virus and thus call for further investigation. Recent advances such electroporation delivery and incorporation of adjuvants has boosted DNA vaccine efficacy [51, 53] . Despite the low antibody response to DNA vaccines, other numerous advantages have overshadowed these minor drawbacks (Table 2) , the most important one being the ability to induce both humoral and cellular immune responses [51, 54] .", "Judging by recent success, such as the immunogenic construct developed by Muthumani et al., DNA vaccines could play a major role in combating CHIKV [49] . Vaccines are literally a critical component of CHIKV disease control and therefore research in this area is highly encouraged. The dramatic spread of dengue viruses (DENV) throughout tropical America since 1980 via the same vectors and human hosts underscores the risk to public health in the Americas. The adverse events associated with the current live vaccine are well documented [55] . Realizing these drawbacks, earnest efforts should be taken to develop new strategies to forestall further spread and complications." ]	[ 17 ]	3,829	5,688
1,689	What is a conclusion of this report?	2,526	[ "DNA vaccines could play a major role in combating CHIKV" ]	[ "Chikungunya: A Potentially Emerging Epidemic?\n\nhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC2860491/\n\nSHA: f7c3160bef4169d29e2a8bdd79dd6e9056d4774c\n\nAuthors: Thiboutot, Michelle M.; Kannan, Senthil; Kawalekar, Omkar U.; Shedlock, Devon J.; Khan, Amir S.; Sarangan, Gopalsamy; Srikanth, Padma; Weiner, David B.; Muthumani, Karuppiah\nDate: 2010-04-27\nDOI: 10.1371/journal.pntd.0000623\nLicense: cc-by", "Abstract: Chikungunya virus is a mosquito-borne emerging pathogen that has a major health impact in humans and causes fever disease, headache, rash, nausea, vomiting, myalgia, and arthralgia. Indigenous to tropical Africa, recent large outbreaks have been reported in parts of South East Asia and several of its neighboring islands in 2005–07 and in Europe in 2007. Furthermore, positive cases have been confirmed in the United States in travelers returning from known outbreak areas. Currently, there is no vaccine or antiviral treatment. With the threat of an emerging global pandemic, the peculiar problems associated with the more immediate and seasonal epidemics warrant the development of an effective vaccine. In this review, we summarize the evidence supporting these concepts.", "Text: Chikungunya virus (CHIKV), a mosquito-borne pathogen listed by National Institute of Allergy and Infectious Diseases (NIAID) as a Category C Priority Pathogen that causes Chikungunya fever (CHIKF), has been spreading throughout Asia, Africa, and parts of Europe in recent times [1, 2, 3] . CHIKV is an arthropod-borne virus (arbovirus) and is transmitted to humans primarily by Aedes aegypti, the infamous yellow fever propagator [4, 5] . CHIKV infection is marked by severe joint pain, contorting its victims into unusual postures [6] . The disease gets its name from the Kimakonde vernacular language of Tanzania and Mozambique, and the word chikungunya means ''that which contorts or bends up'' and translates in Swahili to ''the illness of the bended walker'' [7, 8, 9] . In Africa, CHIKV is maintained in a sylvatic cycle among forest-dwelling Aedes spp. mosquitoes, wild primates, squirrels, birds, and rodents ( Figure 1 ) [10] . In Asia, the disease is vectored by Ae. aegypti and Ae.", "albopictus [11] . Transmission in Asia occurs in an urban cycle whereby the mosquito spreads the disease from an infected human to an uninfected human, following an epidemiological pattern similar to dengue fever [12] .", "The 2005-2006 epidemic of CHIKV in La Reunion islands in the Indian Ocean, spurred the discovery of a new vector species, Ae. albopictus [5] . Wrecking over one-third of the island's population, this epidemic peaked its devastation between January and February 2006, when over 46,000 cases came into light every week, including 284 deaths [5, 13] . Ae. albopictus is common in urban areas of the United States and is already flourishing in 36 states, raising grave concerns to the immunologically naive populace of the United States [14] .\n\nAccordingly, this review elaborately details the epidemiology and global expansion of CHIKV, describes its clinical features and pathogenesis and its symptoms and complications, and finally nominates a possible vaccine approach against CHIKV infection.", "CHIKV has been isolated into three genotypes based on phylogenetic studies. These genotypes, based on the gene sequences of an Envelope protein (E1), are Asian, East/Central/ South African, and West African [4, 11, 15] . Using phylogenetic models, Cherian et al. estimate that the Asian genotype of CHIKV emerged between 50 and 310 y ago, and the West and East African genotypes diverged between 100 and 840 y ago [15] . Since then, CHIKV has come a long way, with several mutations incorporated, and has continued to wreak epidemics in several regions. Recent activities of CHIKV include the Indian epidemic in 2005-2006, which was followed by a sudden explosion of cases in 2007. An estimated 1.3 million people across 13 states were reported to be infected in India [12, 16] , and CHIKV was also widespread in Malaysia, Sri Lanka, and Indonesia [17] . In July-August of 2007, CHIKV was reported in Italy, probably brought in by travelers from CHIKV-prone regions of India, Africa, and Indian", "Ocean islands such as Mauritius, Madagascar, and Seychelles. Few of the Italian isolates were found to have evolved from the Kerala isolate, which was associated with a A226V shift in E1 gene that represents a successful evolutionary adaptation in the mosquito vector similar to the ones observed in Reunion Island [2, 18, 19] .", "In recent times, with an increase in global travel, the risk for spreading CHIKV to non-endemic regions has heightened [1] . Several travelers have brought CHIKV home with them after visiting areas with actively infected populations [12, 20] . Such cases have been documented in European countries, Australia, Asia, and the United States [8, 21] . The United States has already reported at least twelve cases of travel-associated CHIKV, while France has reported 850 cases, and the United Kingdom 93 [8, 14] . Beyond this, CHIKV-infected travelers have also been diagnosed in Australia, Belgium, Canada, Czech Republic, French Guiana, Germany, Hong Kong, Italy, Japan, Kenya, Malaysia, Martinique, Norway, Switzerland, and Sri Lanka [21] . Some travelers were viremic, worrying public health officials about the spread of CHIKV to new areas [1, 8] .", "The incubation time for CHIKV is relatively short, requiring only 2-6 d with symptoms usually appearing 4-7 d post-infection [22] . Vazeille et al. detected CHIKV in the salivary glands of Ae. albopictus only 2 d after infection [5] . Upon infection, CHIKF tends to present itself in two phases. The first stage is acute, while the second stage, experienced by most but not all, is persistent, causing disabling polyarthritis. Characteristics of the acute phase include an abrupt onset of fever, arthralgia, and in some cases, maculopapular rash [6, 23] . The acute phase causes such intense joint and muscular pain that makes movement very difficult and prostrates its victims [6, 20] .", "Ninety-five percent of infected adults are symptomatic after infection, and of these, most become disabled for weeks to months as a result of decreased dexterity, loss of mobility, and delayed reaction. Eighteen months after disease onset, 40% of patients are found to still have anti-CHIKV IgM [6, 18, 23, 24] . The chronic stage of CHIKF is characterized by polyarthralgia that can last from weeks to years beyond the acute stage [6] . CHIKV has been shown to attack fibroblasts, explaining the involvement of muscles, joints, and skin connective tissues. The high number of nociceptive nerve endings found within the joints and muscle connective tissues can explain pain associated with CHIKF [25, 26] .", "More than 50% of patients who suffer from severe CHIKF are over 65 y old, and more than 33% of them die. Most adults who suffer from severe CHIKF have underlying medical conditions [6, 24, 27] . The other group that is disproportionately affected by severe CHIKV is children. Other complications associated with CHIKV, from most common to least common, include respiratory failure, cardiovascular decompensation, meningoencephalitis, severe acute hepatitis, severe cutaneous effects, other central nervous system problems, and kidney failure [6, 18, 20, 23, 24, 26, 27] .", "CHIKV undertakes a complex replication cycle upon host infection (Figure 2 ), which makes its genome susceptible to mutations [28, 29] . For instance, Ae. aegypti, responsible for epidemics in Kenya, Comoros, and Seychelles, carried CHIKV with an alanine in the 226 position of the E1 gene (E1-A226) [4, 18] . However, when the virus struck La Reunion Islands, a decline in population of Ae. aegypti, due to massive dichlorodiphenyltrichloroethane usage and dearth of Ae. albopictus species' www.plosntds.org population, resulted in an ecological pressure, favoring replacement of alanine at position 226 with valine (E1-A226V) [5] . This mutation allowed CHIKV's secondary vector species, Ae. albopictus, to supplement Ae. aegypti as its primary vector [5] .", "Within a year, the E1-A226V mutation was present in La Reunion Island, and Ae. albopictus apparently vectored the large epidemic infecting 34% of La Reunion Island's population [5] . All of the CHIKV strains isolated from Mayotte carried the E1-A226V mutation, and the mutation was also found in Madagascar in 2007 [5] . The E1-A226V mutation was not present at the beginning of the Indian Ocean Islands outbreak (before September 2005). However, more than 90% of later viral strains found there had incorporated the mutation (December-March 2006), indicating a genotype switch during the winter season [5, 18, 20] .", "The E1-A226V mutation also enabled an increase in infectivity of Ae. albopictus when compared to its infectivity of Ae. aegypti [4, 11, 18, 30] , and with several factors taken together, Ae. albopictus has become the new preferred and more lethal vector for CHIKV [4, 5, 11] . In fact, Tsetsarkin et al. found that a Green Fluorescent Protein tagged E1-A226V virus was 100 times more infective to Ae. albopictus than it was to Ae. aegypti [4] . In all the Indian Ocean Islands, Ae. albopictus became the main vector for CHIKV within 1-2 y after CHIKV was introduced to the region [31] .", "Of note is that Ae. aegypti has most likely been established in North America for over 300 y, while Ae. albopictus has been in many areas of the US, since 1985, primarily in Florida [32] and since then has expanded its range in the country. Reiskind et al. set out to determine if Ae. aegypti and Ae. albopictus mosquitoes captured in Florida were susceptible to CHIKV infection by a La Reunion isolate [32] . Each mosquito tested was highly susceptible to infection by a full-length infectious clone of the La Réunion Island isolate, CHIKV LR2006 OPY1 strain. Even though the Ae. albopictus strains were more susceptible to infection, overall ecology and differences in human biting patterns need to be studied further Characteristically, there are two rounds of translation: (+) sense genomic RNA (49S9 = 11.7 kb) acts directly as mRNA and is partially translated (59 end) to produce non-structural proteins (nsp's). These proteins are responsible for replication and formation of a complementary", "(2) strand, the template for further (+) strand synthesis. Subgenomic mRNA (26 S = 4.1 kb) replication occurs through the synthesis of full-length (2) intermediate RNA, which is regulated by nsp4 and p123 precursor in early infection and later by mature nsp's. Translation of the newly synthesized sub-genomic RNA results in production of structural proteins such as Capsid and protein E2-6k-E1 (from 39 end of genome). Assembly occurs at the cell surface, and the envelope is acquired as the virus buds from the cell and release and maturation almost simultaneous occurred. Replication occurs in the cytoplasm and is very rapid (,4 h) [28, 29] . doi:10.1371/journal.pntd.0000623.g002 www.plosntds.org to gain a more accurate understanding of a potential CHIKV epidemic in the US [32] .", "During the 7 d preceding birth, no human mother has been reported to transmit the disease vertically. However, about 50% of newborns delivered while the mother was infected with CHIKV contracted the disease from their mother, despite the method of delivery. Furthermore, there have been instances of CHIKV transmission from mother to fetus causing congenital illness and fetal death [33] .", "During the 2005-2006 La Reunion Island outbreaks, Ramful et al. discovered that mothers could transmit CHIKV to their progeny during the perinatal period (Day 24 to Day +1) [33, 34] , and it is associated with a high degree of morbidity. By mean Day 4 of life, all of the neonates were symptomatic for CHIKV, exhibiting common CHIKF symptoms. Six neonates were confirmed to have contracted CHIKV and developed mengoencephalitis. Of those mothers who, during the La Reunion Island epidemic, were infected long before delivery, only three fetal deaths were reported [12, 33] . Ramful et al. theorized that motherto-child transmission most likely happens transplacentally shortly before delivery [33] . A similar study by Gerardin et al. reported nineteen cases of neonatal infection associated with intrapartum maternal viremia that progressed to develop encephalitis owing to vertical transmission from infected mothers [34] .", "Clinical and epidemiological similarities with dengue fever make CHIKV diagnosis difficult, which may lead physicians to misdiagnose CHIKV as dengue fever; therefore, the incidence of CHIKV may actually be higher than currently believed (Table 1 ) [6, 12, 35] .", "The amount of time elapsed since disease onset is the most critical parameter when choosing a diagnostic test. CHIKV can be detected and isolated by culturing with mosquito cells (C6/36), Vero cells (mammalian), or in mice [26] . However, this method can take at least a week and only achieves a high sensitivity during the viremic phase, which usually only lasts up to 48 h after the bite. Five days post-infection, the viral isolation approach has a low sensitivity but is still the preferred method for detecting the CHIKV strain [12, 26, 31, 35] . RT-PCR on the other hand is a faster and more sensitive method that can be used within the first week of disease onset [26] , and it is currently the most sensitive method for detecting and quantifying viral mRNA [4, 36] .", "Classic serological detection, by assays such as ELISA [37] , immunofluorescence [5, 38] , complement binding, and haemagglutination inhibition [39] , constitutes the second diagnostic tool used for biological diagnosis of CHIKV infection. These proven techniques are useful for detection of Antigen in mosquitoes during epidemiological studies. These assays detect virus-specific IgM and IgG, however the sensitivity and specificity of these assays has been poorly characterized. Viral competence, or the potential of viral infection and transmission, is an important parameter that can be quantified by ELISA, viral culture, and PCR.", "A study by Ng et al. showed biomarkers indicative of severe CHIKV infection [40] . They found decreased levels of RANTES and increased levels of Interleukin-6 (IL-6) and Interleukin-1b (IL-1b) that could be sued for CHIKV detection in patients as indicators of CHIKV-driven cytokine storm. Couderc et al. demonstrate another cytokine, type-I IFN, as a key player in the progression to CHIKV infection [26] . Using an IFN-a/b null mouse model, they demonstrated evidence of muscles, joints, and skin as privileged CHIKV targets, which is consistent with human pathology. Although Ng et al. concluded that RANTES levels were significantly suppressed in severe CHIKF patients [40] , interestingly, an increase in levels of RANTES has been observed in dengue infection [41] . Since the symptoms of CHIKF mimic those of dengue fever, results obtained from this study strongly suggest that RANTES could be a potential distinctive biomarker that differentiates between these two clinically similar", "diseases.", "There are no approved antiviral treatments currently available for CHIKV [1, 3, 12, 42] . Currently, CHIKF is treated symptomatically, usually with non-steroidal anti-inflammatory drugs or steroids, bed rest, and fluids. Movement and mild exercise are thought to decrease stiffness and morning arthralgia, but heavy exercise may exacerbate rheumatic symptoms. Corticosteroids may be used in cases of debilitating chronic CHIKV infection. There is a debate about the appropriateness of chloroquine as treatment for unresolved, non-steroidal anti-inflammatory drugresistant arthritis [43] . A study showed that viral production was www.plosntds.org drastically reduced at 16 h post-infection after treatment with 100 mM dec-RVKR-cmk (Decanoyl-Arg-Val-Lys-Arg-chloromethylketone), a furine inhibitor [42, 44] . Chloroquine acted by raising the pH, blocking low pH-dependent entry of virus into the cell. It is important to note that dec-RVKR-cmk or chloroquine only inhibited viral spreading from cell", "to cell, not CHIKV replication once it had entered the cell [43] . However, most would agree that the best weapon against CHIKV is prevention. A live CHIKV vaccine developed by the United States reached phase II clinical trial encompassing 59 healthy volunteers [45] . Eight percent of the volunteers experienced transient arthralgia, while 98% of the volunteers had seroconversion [45] . However, live CHIKV vaccines are still questionable. One cannot discount the risk of a live vaccine possibly inducing chronic rheumatism. Also, there is the question as to whether widespread use among the public could trigger mosquito transmission or lead to chronic infection or viral reversion [1] .", "An alternative approach would be to produce a chimeric vaccine against CHIKV. Wang et al. developed a chimeric alphavirus vaccine that is uniformly attenuated and does not cause reactogenicity in mice [3] . Three different versions of this vaccine were made using three different backbone vectors: Venezuelan equine encephalitis virus (VEEV) attenuated vaccine strain T-83, naturally attenuated eastern equine encephalitis virus (EEEV), and attenuated Sindbis virus (SINV). In short, CHIKV structural proteins were engineered into the backbones of the aforementioned vaccines to produce the chimeras [3] . These chimeras were found to stimulate a strong humoral immunity, and even at doses of 5.3-5.8 log 10 PFU, they did not trigger reactogenicity. When vaccinated mice were challenged with CHIKV, neither adult nor neonatal mice gained weight, had fever, or displayed signs of neurological illness. Upon comparison of the chimeras with the Army181/25 vaccine, the Army vaccine resulted in higher", "levels of viremia and replication in the joints of neonatal mice. Because the joints are known targets of CHIKV, Wang et al. noted their vaccine might avoid the negative reactogenic side effects of the Army vaccine. After being subcutaneously vaccinated with 5.3-5.8 log 10 PFU of the chimeric vaccines, mice produced strong neutralizing antibody titers. The VEEV and EEEV chimeras yielded higher neutralizing antibody titers than the SINV chimera without being more virulent. On top of this, the VEEV and EEEV CHIKV chimeras seemed to be more immunogenic than the Army vaccine despite the chimeras' lower viremia and replication in the joints of neonatal mice [3] .", "Tiwari et al. [46] adopted a different strategy using formalin inactivated CHIKV in combination with alhydrogel (Aluminum Hydroxide) as an adjuvant. This study clearly suggests that this vaccine elicits both humoral and cell-mediated immune responses in mice, providing its immunogenic potential. A recent study by Couderc et al. [47] showed passive immunization as a potential treatment for CHIKV infection. Using purified immunoglobulin extracted from convalescent CHIKV patients, they demonstrated effective neutralizing activity against CHIKV infection both in vitro and in vivo. This thereby establishes a potential preventive and therapeutic approach to combat CHIKV infection. Pathogenesis studies conducted with related alpha virus, like RRV, have shown the role of macrophages in persistence on infection [48] . They also demonstrated the role of RRV-specific CD8 T cells in clearing viral load in infected patients, thereby warranting similar investigations with CHIKV and the importance", "of investigating a cell-mediated immune response-based vaccine against CHIKV [49] .", "There are always certain risks associated with live attenuated or inactivated viral vaccines [50] . One way to avoid these potential problems is to construct a consensus-based DNA vaccine. DNA based vaccines have an improved safety profile as compared to live or attenuated vaccines [51, 52] . A consequence of CHIKV's rapid evolution is difficulty in constructing a vaccine that will be able to Figure 3 . Levels of CHIKV-specific IgG in mice immunized with CHIKV vaccines. Each group of C57BL/6 mice (n = 5) was immunized with 12.5 mg of pVax1 control vector or CHIKV vaccine plasmids as indicated at 0 and 2 wk. Mice were bled 2 wk after each immunization, and each group's serum pool was diluted to 1:100 and 1:500 for reaction with specific vaccine constructs. Serum was incubated for 1 h at 37uC on 96-well plates coated with 2 mg/ml of respective CHIKV peptides, and antibody was detected using anti-mouse IgG-HRP and OD was measured at 405 nm. doi:10.1371/journal.pntd.0000623.g003", "www.plosntds.org effectively protect large populations from multiple strains of the virus. One of the strengths of DNA consensus vaccines is its ability to induce cross-reactive immune responses against the three distinct phylogenetic groups of CHIKV. Also DNA-based vaccines can be produced more rapidly than protein-based vaccines.", "Recently, Muthumani et al. constructed a vaccine that was shown to induce both humoral and cellular immunity in vivo in 3-4-wk-old female C57/BL6 mice [49] . These mice were immunized using an in vivo electroporation method to deliver the vaccine into the quadriceps muscle. The consensus construct was designed against E1, E2, and the core protein capsid. To design the construct, they aligned 21 sequences of CHIKV isolated between 1952 and 2006, using strains from differing countries, including La Reunion Island. The most common nucleotide among the sequences was chosen at each position to be used in the consensus construct, taking care not to alter the reading frame. They conducted codon and RNA optimization, added a strong Kozak sequence, and substituted signal peptide with an immunoglobulin E leader sequence to improve vaccine efficacy.", "After immunizing the mice, spleens were harvested along with serum and tested to determine antibody titer. After three immunizations, consensus E1, E2, and C vaccines were shown to induce T-cell immune responses leading to strong IFN-c responses and proliferation in C57/BL6 mice. Furthermore, when compared with control mice, immunized mice had higher total IgG levels as well as higher anti-E1 specific, anti-E2 specific, and anti-C specific IgG antibodies, suggesting a strong humoral immune response ( Figure 3 ) and also specificity for the antigens encoded in the vaccine constructs ( Figure 4 ). Because of its promising results and the need for a safer vaccine, this consensus DNA vaccine deserves further investigation. Determining longevity of protective effects of the vaccine and persistence of antibody and IFN-c responses could be the next step of investigation. Challenged studies of immunized mice must also be carried out.", "CHIKV mosquito-borne disease has caused massive outbreaks for at least half a century but is no longer confined to the www.plosntds.org developing nations. It began to encroach into the boundaries of the developing world. As a result, the NIAID has designated CHIKV as a Category C pathogen alongside the influenza and SARS-CoV viruses [3] . Realization of the potential severity of this disease is exigent; for instance, if used as a biological weapon, the world economy could be severely crippled; if enough members of the armed forces were to become infected during a military deployment, military operations could be significantly affected. Efforts to monitor the disease will only provide minimal warning in a global society, and steps to prevent the morbidity and mortality associated with pandemic are imperative [21, 31] . Despite the gravity of its infectious potency and the fear of it being a potential biological weapon, there is currently no vaccine for CHIKV infections. Live", "attenuated vaccine trials were carried out in 2000, but funding for the project was discontinued. Newer approaches such as DNA vaccines appear promising over conventional strategies like live attenuated or inactivated virus and thus call for further investigation. Recent advances such electroporation delivery and incorporation of adjuvants has boosted DNA vaccine efficacy [51, 53] . Despite the low antibody response to DNA vaccines, other numerous advantages have overshadowed these minor drawbacks (Table 2) , the most important one being the ability to induce both humoral and cellular immune responses [51, 54] .", "Judging by recent success, such as the immunogenic construct developed by Muthumani et al., DNA vaccines could play a major role in combating CHIKV [49] . Vaccines are literally a critical component of CHIKV disease control and therefore research in this area is highly encouraged. The dramatic spread of dengue viruses (DENV) throughout tropical America since 1980 via the same vectors and human hosts underscores the risk to public health in the Americas. The adverse events associated with the current live vaccine are well documented [55] . Realizing these drawbacks, earnest efforts should be taken to develop new strategies to forestall further spread and complications." ]	[ 35 ]	3,829	5,688
1,689	What is a conclusion of this report?	2,527	[ "Vaccines are literally a critical component of CHIKV disease control and therefore research in this area is highly encouraged." ]	[ "Chikungunya: A Potentially Emerging Epidemic?\n\nhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC2860491/\n\nSHA: f7c3160bef4169d29e2a8bdd79dd6e9056d4774c\n\nAuthors: Thiboutot, Michelle M.; Kannan, Senthil; Kawalekar, Omkar U.; Shedlock, Devon J.; Khan, Amir S.; Sarangan, Gopalsamy; Srikanth, Padma; Weiner, David B.; Muthumani, Karuppiah\nDate: 2010-04-27\nDOI: 10.1371/journal.pntd.0000623\nLicense: cc-by", "Abstract: Chikungunya virus is a mosquito-borne emerging pathogen that has a major health impact in humans and causes fever disease, headache, rash, nausea, vomiting, myalgia, and arthralgia. Indigenous to tropical Africa, recent large outbreaks have been reported in parts of South East Asia and several of its neighboring islands in 2005–07 and in Europe in 2007. Furthermore, positive cases have been confirmed in the United States in travelers returning from known outbreak areas. Currently, there is no vaccine or antiviral treatment. With the threat of an emerging global pandemic, the peculiar problems associated with the more immediate and seasonal epidemics warrant the development of an effective vaccine. In this review, we summarize the evidence supporting these concepts.", "Text: Chikungunya virus (CHIKV), a mosquito-borne pathogen listed by National Institute of Allergy and Infectious Diseases (NIAID) as a Category C Priority Pathogen that causes Chikungunya fever (CHIKF), has been spreading throughout Asia, Africa, and parts of Europe in recent times [1, 2, 3] . CHIKV is an arthropod-borne virus (arbovirus) and is transmitted to humans primarily by Aedes aegypti, the infamous yellow fever propagator [4, 5] . CHIKV infection is marked by severe joint pain, contorting its victims into unusual postures [6] . The disease gets its name from the Kimakonde vernacular language of Tanzania and Mozambique, and the word chikungunya means ''that which contorts or bends up'' and translates in Swahili to ''the illness of the bended walker'' [7, 8, 9] . In Africa, CHIKV is maintained in a sylvatic cycle among forest-dwelling Aedes spp. mosquitoes, wild primates, squirrels, birds, and rodents ( Figure 1 ) [10] . In Asia, the disease is vectored by Ae. aegypti and Ae.", "albopictus [11] . Transmission in Asia occurs in an urban cycle whereby the mosquito spreads the disease from an infected human to an uninfected human, following an epidemiological pattern similar to dengue fever [12] .", "The 2005-2006 epidemic of CHIKV in La Reunion islands in the Indian Ocean, spurred the discovery of a new vector species, Ae. albopictus [5] . Wrecking over one-third of the island's population, this epidemic peaked its devastation between January and February 2006, when over 46,000 cases came into light every week, including 284 deaths [5, 13] . Ae. albopictus is common in urban areas of the United States and is already flourishing in 36 states, raising grave concerns to the immunologically naive populace of the United States [14] .\n\nAccordingly, this review elaborately details the epidemiology and global expansion of CHIKV, describes its clinical features and pathogenesis and its symptoms and complications, and finally nominates a possible vaccine approach against CHIKV infection.", "CHIKV has been isolated into three genotypes based on phylogenetic studies. These genotypes, based on the gene sequences of an Envelope protein (E1), are Asian, East/Central/ South African, and West African [4, 11, 15] . Using phylogenetic models, Cherian et al. estimate that the Asian genotype of CHIKV emerged between 50 and 310 y ago, and the West and East African genotypes diverged between 100 and 840 y ago [15] . Since then, CHIKV has come a long way, with several mutations incorporated, and has continued to wreak epidemics in several regions. Recent activities of CHIKV include the Indian epidemic in 2005-2006, which was followed by a sudden explosion of cases in 2007. An estimated 1.3 million people across 13 states were reported to be infected in India [12, 16] , and CHIKV was also widespread in Malaysia, Sri Lanka, and Indonesia [17] . In July-August of 2007, CHIKV was reported in Italy, probably brought in by travelers from CHIKV-prone regions of India, Africa, and Indian", "Ocean islands such as Mauritius, Madagascar, and Seychelles. Few of the Italian isolates were found to have evolved from the Kerala isolate, which was associated with a A226V shift in E1 gene that represents a successful evolutionary adaptation in the mosquito vector similar to the ones observed in Reunion Island [2, 18, 19] .", "In recent times, with an increase in global travel, the risk for spreading CHIKV to non-endemic regions has heightened [1] . Several travelers have brought CHIKV home with them after visiting areas with actively infected populations [12, 20] . Such cases have been documented in European countries, Australia, Asia, and the United States [8, 21] . The United States has already reported at least twelve cases of travel-associated CHIKV, while France has reported 850 cases, and the United Kingdom 93 [8, 14] . Beyond this, CHIKV-infected travelers have also been diagnosed in Australia, Belgium, Canada, Czech Republic, French Guiana, Germany, Hong Kong, Italy, Japan, Kenya, Malaysia, Martinique, Norway, Switzerland, and Sri Lanka [21] . Some travelers were viremic, worrying public health officials about the spread of CHIKV to new areas [1, 8] .", "The incubation time for CHIKV is relatively short, requiring only 2-6 d with symptoms usually appearing 4-7 d post-infection [22] . Vazeille et al. detected CHIKV in the salivary glands of Ae. albopictus only 2 d after infection [5] . Upon infection, CHIKF tends to present itself in two phases. The first stage is acute, while the second stage, experienced by most but not all, is persistent, causing disabling polyarthritis. Characteristics of the acute phase include an abrupt onset of fever, arthralgia, and in some cases, maculopapular rash [6, 23] . The acute phase causes such intense joint and muscular pain that makes movement very difficult and prostrates its victims [6, 20] .", "Ninety-five percent of infected adults are symptomatic after infection, and of these, most become disabled for weeks to months as a result of decreased dexterity, loss of mobility, and delayed reaction. Eighteen months after disease onset, 40% of patients are found to still have anti-CHIKV IgM [6, 18, 23, 24] . The chronic stage of CHIKF is characterized by polyarthralgia that can last from weeks to years beyond the acute stage [6] . CHIKV has been shown to attack fibroblasts, explaining the involvement of muscles, joints, and skin connective tissues. The high number of nociceptive nerve endings found within the joints and muscle connective tissues can explain pain associated with CHIKF [25, 26] .", "More than 50% of patients who suffer from severe CHIKF are over 65 y old, and more than 33% of them die. Most adults who suffer from severe CHIKF have underlying medical conditions [6, 24, 27] . The other group that is disproportionately affected by severe CHIKV is children. Other complications associated with CHIKV, from most common to least common, include respiratory failure, cardiovascular decompensation, meningoencephalitis, severe acute hepatitis, severe cutaneous effects, other central nervous system problems, and kidney failure [6, 18, 20, 23, 24, 26, 27] .", "CHIKV undertakes a complex replication cycle upon host infection (Figure 2 ), which makes its genome susceptible to mutations [28, 29] . For instance, Ae. aegypti, responsible for epidemics in Kenya, Comoros, and Seychelles, carried CHIKV with an alanine in the 226 position of the E1 gene (E1-A226) [4, 18] . However, when the virus struck La Reunion Islands, a decline in population of Ae. aegypti, due to massive dichlorodiphenyltrichloroethane usage and dearth of Ae. albopictus species' www.plosntds.org population, resulted in an ecological pressure, favoring replacement of alanine at position 226 with valine (E1-A226V) [5] . This mutation allowed CHIKV's secondary vector species, Ae. albopictus, to supplement Ae. aegypti as its primary vector [5] .", "Within a year, the E1-A226V mutation was present in La Reunion Island, and Ae. albopictus apparently vectored the large epidemic infecting 34% of La Reunion Island's population [5] . All of the CHIKV strains isolated from Mayotte carried the E1-A226V mutation, and the mutation was also found in Madagascar in 2007 [5] . The E1-A226V mutation was not present at the beginning of the Indian Ocean Islands outbreak (before September 2005). However, more than 90% of later viral strains found there had incorporated the mutation (December-March 2006), indicating a genotype switch during the winter season [5, 18, 20] .", "The E1-A226V mutation also enabled an increase in infectivity of Ae. albopictus when compared to its infectivity of Ae. aegypti [4, 11, 18, 30] , and with several factors taken together, Ae. albopictus has become the new preferred and more lethal vector for CHIKV [4, 5, 11] . In fact, Tsetsarkin et al. found that a Green Fluorescent Protein tagged E1-A226V virus was 100 times more infective to Ae. albopictus than it was to Ae. aegypti [4] . In all the Indian Ocean Islands, Ae. albopictus became the main vector for CHIKV within 1-2 y after CHIKV was introduced to the region [31] .", "Of note is that Ae. aegypti has most likely been established in North America for over 300 y, while Ae. albopictus has been in many areas of the US, since 1985, primarily in Florida [32] and since then has expanded its range in the country. Reiskind et al. set out to determine if Ae. aegypti and Ae. albopictus mosquitoes captured in Florida were susceptible to CHIKV infection by a La Reunion isolate [32] . Each mosquito tested was highly susceptible to infection by a full-length infectious clone of the La Réunion Island isolate, CHIKV LR2006 OPY1 strain. Even though the Ae. albopictus strains were more susceptible to infection, overall ecology and differences in human biting patterns need to be studied further Characteristically, there are two rounds of translation: (+) sense genomic RNA (49S9 = 11.7 kb) acts directly as mRNA and is partially translated (59 end) to produce non-structural proteins (nsp's). These proteins are responsible for replication and formation of a complementary", "(2) strand, the template for further (+) strand synthesis. Subgenomic mRNA (26 S = 4.1 kb) replication occurs through the synthesis of full-length (2) intermediate RNA, which is regulated by nsp4 and p123 precursor in early infection and later by mature nsp's. Translation of the newly synthesized sub-genomic RNA results in production of structural proteins such as Capsid and protein E2-6k-E1 (from 39 end of genome). Assembly occurs at the cell surface, and the envelope is acquired as the virus buds from the cell and release and maturation almost simultaneous occurred. Replication occurs in the cytoplasm and is very rapid (,4 h) [28, 29] . doi:10.1371/journal.pntd.0000623.g002 www.plosntds.org to gain a more accurate understanding of a potential CHIKV epidemic in the US [32] .", "During the 7 d preceding birth, no human mother has been reported to transmit the disease vertically. However, about 50% of newborns delivered while the mother was infected with CHIKV contracted the disease from their mother, despite the method of delivery. Furthermore, there have been instances of CHIKV transmission from mother to fetus causing congenital illness and fetal death [33] .", "During the 2005-2006 La Reunion Island outbreaks, Ramful et al. discovered that mothers could transmit CHIKV to their progeny during the perinatal period (Day 24 to Day +1) [33, 34] , and it is associated with a high degree of morbidity. By mean Day 4 of life, all of the neonates were symptomatic for CHIKV, exhibiting common CHIKF symptoms. Six neonates were confirmed to have contracted CHIKV and developed mengoencephalitis. Of those mothers who, during the La Reunion Island epidemic, were infected long before delivery, only three fetal deaths were reported [12, 33] . Ramful et al. theorized that motherto-child transmission most likely happens transplacentally shortly before delivery [33] . A similar study by Gerardin et al. reported nineteen cases of neonatal infection associated with intrapartum maternal viremia that progressed to develop encephalitis owing to vertical transmission from infected mothers [34] .", "Clinical and epidemiological similarities with dengue fever make CHIKV diagnosis difficult, which may lead physicians to misdiagnose CHIKV as dengue fever; therefore, the incidence of CHIKV may actually be higher than currently believed (Table 1 ) [6, 12, 35] .", "The amount of time elapsed since disease onset is the most critical parameter when choosing a diagnostic test. CHIKV can be detected and isolated by culturing with mosquito cells (C6/36), Vero cells (mammalian), or in mice [26] . However, this method can take at least a week and only achieves a high sensitivity during the viremic phase, which usually only lasts up to 48 h after the bite. Five days post-infection, the viral isolation approach has a low sensitivity but is still the preferred method for detecting the CHIKV strain [12, 26, 31, 35] . RT-PCR on the other hand is a faster and more sensitive method that can be used within the first week of disease onset [26] , and it is currently the most sensitive method for detecting and quantifying viral mRNA [4, 36] .", "Classic serological detection, by assays such as ELISA [37] , immunofluorescence [5, 38] , complement binding, and haemagglutination inhibition [39] , constitutes the second diagnostic tool used for biological diagnosis of CHIKV infection. These proven techniques are useful for detection of Antigen in mosquitoes during epidemiological studies. These assays detect virus-specific IgM and IgG, however the sensitivity and specificity of these assays has been poorly characterized. Viral competence, or the potential of viral infection and transmission, is an important parameter that can be quantified by ELISA, viral culture, and PCR.", "A study by Ng et al. showed biomarkers indicative of severe CHIKV infection [40] . They found decreased levels of RANTES and increased levels of Interleukin-6 (IL-6) and Interleukin-1b (IL-1b) that could be sued for CHIKV detection in patients as indicators of CHIKV-driven cytokine storm. Couderc et al. demonstrate another cytokine, type-I IFN, as a key player in the progression to CHIKV infection [26] . Using an IFN-a/b null mouse model, they demonstrated evidence of muscles, joints, and skin as privileged CHIKV targets, which is consistent with human pathology. Although Ng et al. concluded that RANTES levels were significantly suppressed in severe CHIKF patients [40] , interestingly, an increase in levels of RANTES has been observed in dengue infection [41] . Since the symptoms of CHIKF mimic those of dengue fever, results obtained from this study strongly suggest that RANTES could be a potential distinctive biomarker that differentiates between these two clinically similar", "diseases.", "There are no approved antiviral treatments currently available for CHIKV [1, 3, 12, 42] . Currently, CHIKF is treated symptomatically, usually with non-steroidal anti-inflammatory drugs or steroids, bed rest, and fluids. Movement and mild exercise are thought to decrease stiffness and morning arthralgia, but heavy exercise may exacerbate rheumatic symptoms. Corticosteroids may be used in cases of debilitating chronic CHIKV infection. There is a debate about the appropriateness of chloroquine as treatment for unresolved, non-steroidal anti-inflammatory drugresistant arthritis [43] . A study showed that viral production was www.plosntds.org drastically reduced at 16 h post-infection after treatment with 100 mM dec-RVKR-cmk (Decanoyl-Arg-Val-Lys-Arg-chloromethylketone), a furine inhibitor [42, 44] . Chloroquine acted by raising the pH, blocking low pH-dependent entry of virus into the cell. It is important to note that dec-RVKR-cmk or chloroquine only inhibited viral spreading from cell", "to cell, not CHIKV replication once it had entered the cell [43] . However, most would agree that the best weapon against CHIKV is prevention. A live CHIKV vaccine developed by the United States reached phase II clinical trial encompassing 59 healthy volunteers [45] . Eight percent of the volunteers experienced transient arthralgia, while 98% of the volunteers had seroconversion [45] . However, live CHIKV vaccines are still questionable. One cannot discount the risk of a live vaccine possibly inducing chronic rheumatism. Also, there is the question as to whether widespread use among the public could trigger mosquito transmission or lead to chronic infection or viral reversion [1] .", "An alternative approach would be to produce a chimeric vaccine against CHIKV. Wang et al. developed a chimeric alphavirus vaccine that is uniformly attenuated and does not cause reactogenicity in mice [3] . Three different versions of this vaccine were made using three different backbone vectors: Venezuelan equine encephalitis virus (VEEV) attenuated vaccine strain T-83, naturally attenuated eastern equine encephalitis virus (EEEV), and attenuated Sindbis virus (SINV). In short, CHIKV structural proteins were engineered into the backbones of the aforementioned vaccines to produce the chimeras [3] . These chimeras were found to stimulate a strong humoral immunity, and even at doses of 5.3-5.8 log 10 PFU, they did not trigger reactogenicity. When vaccinated mice were challenged with CHIKV, neither adult nor neonatal mice gained weight, had fever, or displayed signs of neurological illness. Upon comparison of the chimeras with the Army181/25 vaccine, the Army vaccine resulted in higher", "levels of viremia and replication in the joints of neonatal mice. Because the joints are known targets of CHIKV, Wang et al. noted their vaccine might avoid the negative reactogenic side effects of the Army vaccine. After being subcutaneously vaccinated with 5.3-5.8 log 10 PFU of the chimeric vaccines, mice produced strong neutralizing antibody titers. The VEEV and EEEV chimeras yielded higher neutralizing antibody titers than the SINV chimera without being more virulent. On top of this, the VEEV and EEEV CHIKV chimeras seemed to be more immunogenic than the Army vaccine despite the chimeras' lower viremia and replication in the joints of neonatal mice [3] .", "Tiwari et al. [46] adopted a different strategy using formalin inactivated CHIKV in combination with alhydrogel (Aluminum Hydroxide) as an adjuvant. This study clearly suggests that this vaccine elicits both humoral and cell-mediated immune responses in mice, providing its immunogenic potential. A recent study by Couderc et al. [47] showed passive immunization as a potential treatment for CHIKV infection. Using purified immunoglobulin extracted from convalescent CHIKV patients, they demonstrated effective neutralizing activity against CHIKV infection both in vitro and in vivo. This thereby establishes a potential preventive and therapeutic approach to combat CHIKV infection. Pathogenesis studies conducted with related alpha virus, like RRV, have shown the role of macrophages in persistence on infection [48] . They also demonstrated the role of RRV-specific CD8 T cells in clearing viral load in infected patients, thereby warranting similar investigations with CHIKV and the importance", "of investigating a cell-mediated immune response-based vaccine against CHIKV [49] .", "There are always certain risks associated with live attenuated or inactivated viral vaccines [50] . One way to avoid these potential problems is to construct a consensus-based DNA vaccine. DNA based vaccines have an improved safety profile as compared to live or attenuated vaccines [51, 52] . A consequence of CHIKV's rapid evolution is difficulty in constructing a vaccine that will be able to Figure 3 . Levels of CHIKV-specific IgG in mice immunized with CHIKV vaccines. Each group of C57BL/6 mice (n = 5) was immunized with 12.5 mg of pVax1 control vector or CHIKV vaccine plasmids as indicated at 0 and 2 wk. Mice were bled 2 wk after each immunization, and each group's serum pool was diluted to 1:100 and 1:500 for reaction with specific vaccine constructs. Serum was incubated for 1 h at 37uC on 96-well plates coated with 2 mg/ml of respective CHIKV peptides, and antibody was detected using anti-mouse IgG-HRP and OD was measured at 405 nm. doi:10.1371/journal.pntd.0000623.g003", "www.plosntds.org effectively protect large populations from multiple strains of the virus. One of the strengths of DNA consensus vaccines is its ability to induce cross-reactive immune responses against the three distinct phylogenetic groups of CHIKV. Also DNA-based vaccines can be produced more rapidly than protein-based vaccines.", "Recently, Muthumani et al. constructed a vaccine that was shown to induce both humoral and cellular immunity in vivo in 3-4-wk-old female C57/BL6 mice [49] . These mice were immunized using an in vivo electroporation method to deliver the vaccine into the quadriceps muscle. The consensus construct was designed against E1, E2, and the core protein capsid. To design the construct, they aligned 21 sequences of CHIKV isolated between 1952 and 2006, using strains from differing countries, including La Reunion Island. The most common nucleotide among the sequences was chosen at each position to be used in the consensus construct, taking care not to alter the reading frame. They conducted codon and RNA optimization, added a strong Kozak sequence, and substituted signal peptide with an immunoglobulin E leader sequence to improve vaccine efficacy.", "After immunizing the mice, spleens were harvested along with serum and tested to determine antibody titer. After three immunizations, consensus E1, E2, and C vaccines were shown to induce T-cell immune responses leading to strong IFN-c responses and proliferation in C57/BL6 mice. Furthermore, when compared with control mice, immunized mice had higher total IgG levels as well as higher anti-E1 specific, anti-E2 specific, and anti-C specific IgG antibodies, suggesting a strong humoral immune response ( Figure 3 ) and also specificity for the antigens encoded in the vaccine constructs ( Figure 4 ). Because of its promising results and the need for a safer vaccine, this consensus DNA vaccine deserves further investigation. Determining longevity of protective effects of the vaccine and persistence of antibody and IFN-c responses could be the next step of investigation. Challenged studies of immunized mice must also be carried out.", "CHIKV mosquito-borne disease has caused massive outbreaks for at least half a century but is no longer confined to the www.plosntds.org developing nations. It began to encroach into the boundaries of the developing world. As a result, the NIAID has designated CHIKV as a Category C pathogen alongside the influenza and SARS-CoV viruses [3] . Realization of the potential severity of this disease is exigent; for instance, if used as a biological weapon, the world economy could be severely crippled; if enough members of the armed forces were to become infected during a military deployment, military operations could be significantly affected. Efforts to monitor the disease will only provide minimal warning in a global society, and steps to prevent the morbidity and mortality associated with pandemic are imperative [21, 31] . Despite the gravity of its infectious potency and the fear of it being a potential biological weapon, there is currently no vaccine for CHIKV infections. Live", "attenuated vaccine trials were carried out in 2000, but funding for the project was discontinued. Newer approaches such as DNA vaccines appear promising over conventional strategies like live attenuated or inactivated virus and thus call for further investigation. Recent advances such electroporation delivery and incorporation of adjuvants has boosted DNA vaccine efficacy [51, 53] . Despite the low antibody response to DNA vaccines, other numerous advantages have overshadowed these minor drawbacks (Table 2) , the most important one being the ability to induce both humoral and cellular immune responses [51, 54] .", "Judging by recent success, such as the immunogenic construct developed by Muthumani et al., DNA vaccines could play a major role in combating CHIKV [49] . Vaccines are literally a critical component of CHIKV disease control and therefore research in this area is highly encouraged. The dramatic spread of dengue viruses (DENV) throughout tropical America since 1980 via the same vectors and human hosts underscores the risk to public health in the Americas. The adverse events associated with the current live vaccine are well documented [55] . Realizing these drawbacks, earnest efforts should be taken to develop new strategies to forestall further spread and complications." ]	[ 35 ]	3,829	5,688
1,689	What is the NIAID designation of CHIKV?	2,528	[ "as a Category C pathogen alongside the influenza and SARS-CoV viruses" ]	[ "Chikungunya: A Potentially Emerging Epidemic?\n\nhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC2860491/\n\nSHA: f7c3160bef4169d29e2a8bdd79dd6e9056d4774c\n\nAuthors: Thiboutot, Michelle M.; Kannan, Senthil; Kawalekar, Omkar U.; Shedlock, Devon J.; Khan, Amir S.; Sarangan, Gopalsamy; Srikanth, Padma; Weiner, David B.; Muthumani, Karuppiah\nDate: 2010-04-27\nDOI: 10.1371/journal.pntd.0000623\nLicense: cc-by", "Abstract: Chikungunya virus is a mosquito-borne emerging pathogen that has a major health impact in humans and causes fever disease, headache, rash, nausea, vomiting, myalgia, and arthralgia. Indigenous to tropical Africa, recent large outbreaks have been reported in parts of South East Asia and several of its neighboring islands in 2005–07 and in Europe in 2007. Furthermore, positive cases have been confirmed in the United States in travelers returning from known outbreak areas. Currently, there is no vaccine or antiviral treatment. With the threat of an emerging global pandemic, the peculiar problems associated with the more immediate and seasonal epidemics warrant the development of an effective vaccine. In this review, we summarize the evidence supporting these concepts.", "Text: Chikungunya virus (CHIKV), a mosquito-borne pathogen listed by National Institute of Allergy and Infectious Diseases (NIAID) as a Category C Priority Pathogen that causes Chikungunya fever (CHIKF), has been spreading throughout Asia, Africa, and parts of Europe in recent times [1, 2, 3] . CHIKV is an arthropod-borne virus (arbovirus) and is transmitted to humans primarily by Aedes aegypti, the infamous yellow fever propagator [4, 5] . CHIKV infection is marked by severe joint pain, contorting its victims into unusual postures [6] . The disease gets its name from the Kimakonde vernacular language of Tanzania and Mozambique, and the word chikungunya means ''that which contorts or bends up'' and translates in Swahili to ''the illness of the bended walker'' [7, 8, 9] . In Africa, CHIKV is maintained in a sylvatic cycle among forest-dwelling Aedes spp. mosquitoes, wild primates, squirrels, birds, and rodents ( Figure 1 ) [10] . In Asia, the disease is vectored by Ae. aegypti and Ae.", "albopictus [11] . Transmission in Asia occurs in an urban cycle whereby the mosquito spreads the disease from an infected human to an uninfected human, following an epidemiological pattern similar to dengue fever [12] .", "The 2005-2006 epidemic of CHIKV in La Reunion islands in the Indian Ocean, spurred the discovery of a new vector species, Ae. albopictus [5] . Wrecking over one-third of the island's population, this epidemic peaked its devastation between January and February 2006, when over 46,000 cases came into light every week, including 284 deaths [5, 13] . Ae. albopictus is common in urban areas of the United States and is already flourishing in 36 states, raising grave concerns to the immunologically naive populace of the United States [14] .\n\nAccordingly, this review elaborately details the epidemiology and global expansion of CHIKV, describes its clinical features and pathogenesis and its symptoms and complications, and finally nominates a possible vaccine approach against CHIKV infection.", "CHIKV has been isolated into three genotypes based on phylogenetic studies. These genotypes, based on the gene sequences of an Envelope protein (E1), are Asian, East/Central/ South African, and West African [4, 11, 15] . Using phylogenetic models, Cherian et al. estimate that the Asian genotype of CHIKV emerged between 50 and 310 y ago, and the West and East African genotypes diverged between 100 and 840 y ago [15] . Since then, CHIKV has come a long way, with several mutations incorporated, and has continued to wreak epidemics in several regions. Recent activities of CHIKV include the Indian epidemic in 2005-2006, which was followed by a sudden explosion of cases in 2007. An estimated 1.3 million people across 13 states were reported to be infected in India [12, 16] , and CHIKV was also widespread in Malaysia, Sri Lanka, and Indonesia [17] . In July-August of 2007, CHIKV was reported in Italy, probably brought in by travelers from CHIKV-prone regions of India, Africa, and Indian", "Ocean islands such as Mauritius, Madagascar, and Seychelles. Few of the Italian isolates were found to have evolved from the Kerala isolate, which was associated with a A226V shift in E1 gene that represents a successful evolutionary adaptation in the mosquito vector similar to the ones observed in Reunion Island [2, 18, 19] .", "In recent times, with an increase in global travel, the risk for spreading CHIKV to non-endemic regions has heightened [1] . Several travelers have brought CHIKV home with them after visiting areas with actively infected populations [12, 20] . Such cases have been documented in European countries, Australia, Asia, and the United States [8, 21] . The United States has already reported at least twelve cases of travel-associated CHIKV, while France has reported 850 cases, and the United Kingdom 93 [8, 14] . Beyond this, CHIKV-infected travelers have also been diagnosed in Australia, Belgium, Canada, Czech Republic, French Guiana, Germany, Hong Kong, Italy, Japan, Kenya, Malaysia, Martinique, Norway, Switzerland, and Sri Lanka [21] . Some travelers were viremic, worrying public health officials about the spread of CHIKV to new areas [1, 8] .", "The incubation time for CHIKV is relatively short, requiring only 2-6 d with symptoms usually appearing 4-7 d post-infection [22] . Vazeille et al. detected CHIKV in the salivary glands of Ae. albopictus only 2 d after infection [5] . Upon infection, CHIKF tends to present itself in two phases. The first stage is acute, while the second stage, experienced by most but not all, is persistent, causing disabling polyarthritis. Characteristics of the acute phase include an abrupt onset of fever, arthralgia, and in some cases, maculopapular rash [6, 23] . The acute phase causes such intense joint and muscular pain that makes movement very difficult and prostrates its victims [6, 20] .", "Ninety-five percent of infected adults are symptomatic after infection, and of these, most become disabled for weeks to months as a result of decreased dexterity, loss of mobility, and delayed reaction. Eighteen months after disease onset, 40% of patients are found to still have anti-CHIKV IgM [6, 18, 23, 24] . The chronic stage of CHIKF is characterized by polyarthralgia that can last from weeks to years beyond the acute stage [6] . CHIKV has been shown to attack fibroblasts, explaining the involvement of muscles, joints, and skin connective tissues. The high number of nociceptive nerve endings found within the joints and muscle connective tissues can explain pain associated with CHIKF [25, 26] .", "More than 50% of patients who suffer from severe CHIKF are over 65 y old, and more than 33% of them die. Most adults who suffer from severe CHIKF have underlying medical conditions [6, 24, 27] . The other group that is disproportionately affected by severe CHIKV is children. Other complications associated with CHIKV, from most common to least common, include respiratory failure, cardiovascular decompensation, meningoencephalitis, severe acute hepatitis, severe cutaneous effects, other central nervous system problems, and kidney failure [6, 18, 20, 23, 24, 26, 27] .", "CHIKV undertakes a complex replication cycle upon host infection (Figure 2 ), which makes its genome susceptible to mutations [28, 29] . For instance, Ae. aegypti, responsible for epidemics in Kenya, Comoros, and Seychelles, carried CHIKV with an alanine in the 226 position of the E1 gene (E1-A226) [4, 18] . However, when the virus struck La Reunion Islands, a decline in population of Ae. aegypti, due to massive dichlorodiphenyltrichloroethane usage and dearth of Ae. albopictus species' www.plosntds.org population, resulted in an ecological pressure, favoring replacement of alanine at position 226 with valine (E1-A226V) [5] . This mutation allowed CHIKV's secondary vector species, Ae. albopictus, to supplement Ae. aegypti as its primary vector [5] .", "Within a year, the E1-A226V mutation was present in La Reunion Island, and Ae. albopictus apparently vectored the large epidemic infecting 34% of La Reunion Island's population [5] . All of the CHIKV strains isolated from Mayotte carried the E1-A226V mutation, and the mutation was also found in Madagascar in 2007 [5] . The E1-A226V mutation was not present at the beginning of the Indian Ocean Islands outbreak (before September 2005). However, more than 90% of later viral strains found there had incorporated the mutation (December-March 2006), indicating a genotype switch during the winter season [5, 18, 20] .", "The E1-A226V mutation also enabled an increase in infectivity of Ae. albopictus when compared to its infectivity of Ae. aegypti [4, 11, 18, 30] , and with several factors taken together, Ae. albopictus has become the new preferred and more lethal vector for CHIKV [4, 5, 11] . In fact, Tsetsarkin et al. found that a Green Fluorescent Protein tagged E1-A226V virus was 100 times more infective to Ae. albopictus than it was to Ae. aegypti [4] . In all the Indian Ocean Islands, Ae. albopictus became the main vector for CHIKV within 1-2 y after CHIKV was introduced to the region [31] .", "Of note is that Ae. aegypti has most likely been established in North America for over 300 y, while Ae. albopictus has been in many areas of the US, since 1985, primarily in Florida [32] and since then has expanded its range in the country. Reiskind et al. set out to determine if Ae. aegypti and Ae. albopictus mosquitoes captured in Florida were susceptible to CHIKV infection by a La Reunion isolate [32] . Each mosquito tested was highly susceptible to infection by a full-length infectious clone of the La Réunion Island isolate, CHIKV LR2006 OPY1 strain. Even though the Ae. albopictus strains were more susceptible to infection, overall ecology and differences in human biting patterns need to be studied further Characteristically, there are two rounds of translation: (+) sense genomic RNA (49S9 = 11.7 kb) acts directly as mRNA and is partially translated (59 end) to produce non-structural proteins (nsp's). These proteins are responsible for replication and formation of a complementary", "(2) strand, the template for further (+) strand synthesis. Subgenomic mRNA (26 S = 4.1 kb) replication occurs through the synthesis of full-length (2) intermediate RNA, which is regulated by nsp4 and p123 precursor in early infection and later by mature nsp's. Translation of the newly synthesized sub-genomic RNA results in production of structural proteins such as Capsid and protein E2-6k-E1 (from 39 end of genome). Assembly occurs at the cell surface, and the envelope is acquired as the virus buds from the cell and release and maturation almost simultaneous occurred. Replication occurs in the cytoplasm and is very rapid (,4 h) [28, 29] . doi:10.1371/journal.pntd.0000623.g002 www.plosntds.org to gain a more accurate understanding of a potential CHIKV epidemic in the US [32] .", "During the 7 d preceding birth, no human mother has been reported to transmit the disease vertically. However, about 50% of newborns delivered while the mother was infected with CHIKV contracted the disease from their mother, despite the method of delivery. Furthermore, there have been instances of CHIKV transmission from mother to fetus causing congenital illness and fetal death [33] .", "During the 2005-2006 La Reunion Island outbreaks, Ramful et al. discovered that mothers could transmit CHIKV to their progeny during the perinatal period (Day 24 to Day +1) [33, 34] , and it is associated with a high degree of morbidity. By mean Day 4 of life, all of the neonates were symptomatic for CHIKV, exhibiting common CHIKF symptoms. Six neonates were confirmed to have contracted CHIKV and developed mengoencephalitis. Of those mothers who, during the La Reunion Island epidemic, were infected long before delivery, only three fetal deaths were reported [12, 33] . Ramful et al. theorized that motherto-child transmission most likely happens transplacentally shortly before delivery [33] . A similar study by Gerardin et al. reported nineteen cases of neonatal infection associated with intrapartum maternal viremia that progressed to develop encephalitis owing to vertical transmission from infected mothers [34] .", "Clinical and epidemiological similarities with dengue fever make CHIKV diagnosis difficult, which may lead physicians to misdiagnose CHIKV as dengue fever; therefore, the incidence of CHIKV may actually be higher than currently believed (Table 1 ) [6, 12, 35] .", "The amount of time elapsed since disease onset is the most critical parameter when choosing a diagnostic test. CHIKV can be detected and isolated by culturing with mosquito cells (C6/36), Vero cells (mammalian), or in mice [26] . However, this method can take at least a week and only achieves a high sensitivity during the viremic phase, which usually only lasts up to 48 h after the bite. Five days post-infection, the viral isolation approach has a low sensitivity but is still the preferred method for detecting the CHIKV strain [12, 26, 31, 35] . RT-PCR on the other hand is a faster and more sensitive method that can be used within the first week of disease onset [26] , and it is currently the most sensitive method for detecting and quantifying viral mRNA [4, 36] .", "Classic serological detection, by assays such as ELISA [37] , immunofluorescence [5, 38] , complement binding, and haemagglutination inhibition [39] , constitutes the second diagnostic tool used for biological diagnosis of CHIKV infection. These proven techniques are useful for detection of Antigen in mosquitoes during epidemiological studies. These assays detect virus-specific IgM and IgG, however the sensitivity and specificity of these assays has been poorly characterized. Viral competence, or the potential of viral infection and transmission, is an important parameter that can be quantified by ELISA, viral culture, and PCR.", "A study by Ng et al. showed biomarkers indicative of severe CHIKV infection [40] . They found decreased levels of RANTES and increased levels of Interleukin-6 (IL-6) and Interleukin-1b (IL-1b) that could be sued for CHIKV detection in patients as indicators of CHIKV-driven cytokine storm. Couderc et al. demonstrate another cytokine, type-I IFN, as a key player in the progression to CHIKV infection [26] . Using an IFN-a/b null mouse model, they demonstrated evidence of muscles, joints, and skin as privileged CHIKV targets, which is consistent with human pathology. Although Ng et al. concluded that RANTES levels were significantly suppressed in severe CHIKF patients [40] , interestingly, an increase in levels of RANTES has been observed in dengue infection [41] . Since the symptoms of CHIKF mimic those of dengue fever, results obtained from this study strongly suggest that RANTES could be a potential distinctive biomarker that differentiates between these two clinically similar", "diseases.", "There are no approved antiviral treatments currently available for CHIKV [1, 3, 12, 42] . Currently, CHIKF is treated symptomatically, usually with non-steroidal anti-inflammatory drugs or steroids, bed rest, and fluids. Movement and mild exercise are thought to decrease stiffness and morning arthralgia, but heavy exercise may exacerbate rheumatic symptoms. Corticosteroids may be used in cases of debilitating chronic CHIKV infection. There is a debate about the appropriateness of chloroquine as treatment for unresolved, non-steroidal anti-inflammatory drugresistant arthritis [43] . A study showed that viral production was www.plosntds.org drastically reduced at 16 h post-infection after treatment with 100 mM dec-RVKR-cmk (Decanoyl-Arg-Val-Lys-Arg-chloromethylketone), a furine inhibitor [42, 44] . Chloroquine acted by raising the pH, blocking low pH-dependent entry of virus into the cell. It is important to note that dec-RVKR-cmk or chloroquine only inhibited viral spreading from cell", "to cell, not CHIKV replication once it had entered the cell [43] . However, most would agree that the best weapon against CHIKV is prevention. A live CHIKV vaccine developed by the United States reached phase II clinical trial encompassing 59 healthy volunteers [45] . Eight percent of the volunteers experienced transient arthralgia, while 98% of the volunteers had seroconversion [45] . However, live CHIKV vaccines are still questionable. One cannot discount the risk of a live vaccine possibly inducing chronic rheumatism. Also, there is the question as to whether widespread use among the public could trigger mosquito transmission or lead to chronic infection or viral reversion [1] .", "An alternative approach would be to produce a chimeric vaccine against CHIKV. Wang et al. developed a chimeric alphavirus vaccine that is uniformly attenuated and does not cause reactogenicity in mice [3] . Three different versions of this vaccine were made using three different backbone vectors: Venezuelan equine encephalitis virus (VEEV) attenuated vaccine strain T-83, naturally attenuated eastern equine encephalitis virus (EEEV), and attenuated Sindbis virus (SINV). In short, CHIKV structural proteins were engineered into the backbones of the aforementioned vaccines to produce the chimeras [3] . These chimeras were found to stimulate a strong humoral immunity, and even at doses of 5.3-5.8 log 10 PFU, they did not trigger reactogenicity. When vaccinated mice were challenged with CHIKV, neither adult nor neonatal mice gained weight, had fever, or displayed signs of neurological illness. Upon comparison of the chimeras with the Army181/25 vaccine, the Army vaccine resulted in higher", "levels of viremia and replication in the joints of neonatal mice. Because the joints are known targets of CHIKV, Wang et al. noted their vaccine might avoid the negative reactogenic side effects of the Army vaccine. After being subcutaneously vaccinated with 5.3-5.8 log 10 PFU of the chimeric vaccines, mice produced strong neutralizing antibody titers. The VEEV and EEEV chimeras yielded higher neutralizing antibody titers than the SINV chimera without being more virulent. On top of this, the VEEV and EEEV CHIKV chimeras seemed to be more immunogenic than the Army vaccine despite the chimeras' lower viremia and replication in the joints of neonatal mice [3] .", "Tiwari et al. [46] adopted a different strategy using formalin inactivated CHIKV in combination with alhydrogel (Aluminum Hydroxide) as an adjuvant. This study clearly suggests that this vaccine elicits both humoral and cell-mediated immune responses in mice, providing its immunogenic potential. A recent study by Couderc et al. [47] showed passive immunization as a potential treatment for CHIKV infection. Using purified immunoglobulin extracted from convalescent CHIKV patients, they demonstrated effective neutralizing activity against CHIKV infection both in vitro and in vivo. This thereby establishes a potential preventive and therapeutic approach to combat CHIKV infection. Pathogenesis studies conducted with related alpha virus, like RRV, have shown the role of macrophages in persistence on infection [48] . They also demonstrated the role of RRV-specific CD8 T cells in clearing viral load in infected patients, thereby warranting similar investigations with CHIKV and the importance", "of investigating a cell-mediated immune response-based vaccine against CHIKV [49] .", "There are always certain risks associated with live attenuated or inactivated viral vaccines [50] . One way to avoid these potential problems is to construct a consensus-based DNA vaccine. DNA based vaccines have an improved safety profile as compared to live or attenuated vaccines [51, 52] . A consequence of CHIKV's rapid evolution is difficulty in constructing a vaccine that will be able to Figure 3 . Levels of CHIKV-specific IgG in mice immunized with CHIKV vaccines. Each group of C57BL/6 mice (n = 5) was immunized with 12.5 mg of pVax1 control vector or CHIKV vaccine plasmids as indicated at 0 and 2 wk. Mice were bled 2 wk after each immunization, and each group's serum pool was diluted to 1:100 and 1:500 for reaction with specific vaccine constructs. Serum was incubated for 1 h at 37uC on 96-well plates coated with 2 mg/ml of respective CHIKV peptides, and antibody was detected using anti-mouse IgG-HRP and OD was measured at 405 nm. doi:10.1371/journal.pntd.0000623.g003", "www.plosntds.org effectively protect large populations from multiple strains of the virus. One of the strengths of DNA consensus vaccines is its ability to induce cross-reactive immune responses against the three distinct phylogenetic groups of CHIKV. Also DNA-based vaccines can be produced more rapidly than protein-based vaccines.", "Recently, Muthumani et al. constructed a vaccine that was shown to induce both humoral and cellular immunity in vivo in 3-4-wk-old female C57/BL6 mice [49] . These mice were immunized using an in vivo electroporation method to deliver the vaccine into the quadriceps muscle. The consensus construct was designed against E1, E2, and the core protein capsid. To design the construct, they aligned 21 sequences of CHIKV isolated between 1952 and 2006, using strains from differing countries, including La Reunion Island. The most common nucleotide among the sequences was chosen at each position to be used in the consensus construct, taking care not to alter the reading frame. They conducted codon and RNA optimization, added a strong Kozak sequence, and substituted signal peptide with an immunoglobulin E leader sequence to improve vaccine efficacy.", "After immunizing the mice, spleens were harvested along with serum and tested to determine antibody titer. After three immunizations, consensus E1, E2, and C vaccines were shown to induce T-cell immune responses leading to strong IFN-c responses and proliferation in C57/BL6 mice. Furthermore, when compared with control mice, immunized mice had higher total IgG levels as well as higher anti-E1 specific, anti-E2 specific, and anti-C specific IgG antibodies, suggesting a strong humoral immune response ( Figure 3 ) and also specificity for the antigens encoded in the vaccine constructs ( Figure 4 ). Because of its promising results and the need for a safer vaccine, this consensus DNA vaccine deserves further investigation. Determining longevity of protective effects of the vaccine and persistence of antibody and IFN-c responses could be the next step of investigation. Challenged studies of immunized mice must also be carried out.", "CHIKV mosquito-borne disease has caused massive outbreaks for at least half a century but is no longer confined to the www.plosntds.org developing nations. It began to encroach into the boundaries of the developing world. As a result, the NIAID has designated CHIKV as a Category C pathogen alongside the influenza and SARS-CoV viruses [3] . Realization of the potential severity of this disease is exigent; for instance, if used as a biological weapon, the world economy could be severely crippled; if enough members of the armed forces were to become infected during a military deployment, military operations could be significantly affected. Efforts to monitor the disease will only provide minimal warning in a global society, and steps to prevent the morbidity and mortality associated with pandemic are imperative [21, 31] . Despite the gravity of its infectious potency and the fear of it being a potential biological weapon, there is currently no vaccine for CHIKV infections. Live", "attenuated vaccine trials were carried out in 2000, but funding for the project was discontinued. Newer approaches such as DNA vaccines appear promising over conventional strategies like live attenuated or inactivated virus and thus call for further investigation. Recent advances such electroporation delivery and incorporation of adjuvants has boosted DNA vaccine efficacy [51, 53] . Despite the low antibody response to DNA vaccines, other numerous advantages have overshadowed these minor drawbacks (Table 2) , the most important one being the ability to induce both humoral and cellular immune responses [51, 54] .", "Judging by recent success, such as the immunogenic construct developed by Muthumani et al., DNA vaccines could play a major role in combating CHIKV [49] . Vaccines are literally a critical component of CHIKV disease control and therefore research in this area is highly encouraged. The dramatic spread of dengue viruses (DENV) throughout tropical America since 1980 via the same vectors and human hosts underscores the risk to public health in the Americas. The adverse events associated with the current live vaccine are well documented [55] . Realizing these drawbacks, earnest efforts should be taken to develop new strategies to forestall further spread and complications." ]	[ 33 ]	3,829	5,688
1,689	What are the strengths and advantages of DNA based vaccine?	2,529	[ "its ability to induce cross-reactive immune responses against the three distinct phylogenetic groups of CHIKV. Also DNA-based vaccines can be produced more rapidly than protein-based vaccines." ]	[ "Chikungunya: A Potentially Emerging Epidemic?\n\nhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC2860491/\n\nSHA: f7c3160bef4169d29e2a8bdd79dd6e9056d4774c\n\nAuthors: Thiboutot, Michelle M.; Kannan, Senthil; Kawalekar, Omkar U.; Shedlock, Devon J.; Khan, Amir S.; Sarangan, Gopalsamy; Srikanth, Padma; Weiner, David B.; Muthumani, Karuppiah\nDate: 2010-04-27\nDOI: 10.1371/journal.pntd.0000623\nLicense: cc-by", "Abstract: Chikungunya virus is a mosquito-borne emerging pathogen that has a major health impact in humans and causes fever disease, headache, rash, nausea, vomiting, myalgia, and arthralgia. Indigenous to tropical Africa, recent large outbreaks have been reported in parts of South East Asia and several of its neighboring islands in 2005–07 and in Europe in 2007. Furthermore, positive cases have been confirmed in the United States in travelers returning from known outbreak areas. Currently, there is no vaccine or antiviral treatment. With the threat of an emerging global pandemic, the peculiar problems associated with the more immediate and seasonal epidemics warrant the development of an effective vaccine. In this review, we summarize the evidence supporting these concepts.", "Text: Chikungunya virus (CHIKV), a mosquito-borne pathogen listed by National Institute of Allergy and Infectious Diseases (NIAID) as a Category C Priority Pathogen that causes Chikungunya fever (CHIKF), has been spreading throughout Asia, Africa, and parts of Europe in recent times [1, 2, 3] . CHIKV is an arthropod-borne virus (arbovirus) and is transmitted to humans primarily by Aedes aegypti, the infamous yellow fever propagator [4, 5] . CHIKV infection is marked by severe joint pain, contorting its victims into unusual postures [6] . The disease gets its name from the Kimakonde vernacular language of Tanzania and Mozambique, and the word chikungunya means ''that which contorts or bends up'' and translates in Swahili to ''the illness of the bended walker'' [7, 8, 9] . In Africa, CHIKV is maintained in a sylvatic cycle among forest-dwelling Aedes spp. mosquitoes, wild primates, squirrels, birds, and rodents ( Figure 1 ) [10] . In Asia, the disease is vectored by Ae. aegypti and Ae.", "albopictus [11] . Transmission in Asia occurs in an urban cycle whereby the mosquito spreads the disease from an infected human to an uninfected human, following an epidemiological pattern similar to dengue fever [12] .", "The 2005-2006 epidemic of CHIKV in La Reunion islands in the Indian Ocean, spurred the discovery of a new vector species, Ae. albopictus [5] . Wrecking over one-third of the island's population, this epidemic peaked its devastation between January and February 2006, when over 46,000 cases came into light every week, including 284 deaths [5, 13] . Ae. albopictus is common in urban areas of the United States and is already flourishing in 36 states, raising grave concerns to the immunologically naive populace of the United States [14] .\n\nAccordingly, this review elaborately details the epidemiology and global expansion of CHIKV, describes its clinical features and pathogenesis and its symptoms and complications, and finally nominates a possible vaccine approach against CHIKV infection.", "CHIKV has been isolated into three genotypes based on phylogenetic studies. These genotypes, based on the gene sequences of an Envelope protein (E1), are Asian, East/Central/ South African, and West African [4, 11, 15] . Using phylogenetic models, Cherian et al. estimate that the Asian genotype of CHIKV emerged between 50 and 310 y ago, and the West and East African genotypes diverged between 100 and 840 y ago [15] . Since then, CHIKV has come a long way, with several mutations incorporated, and has continued to wreak epidemics in several regions. Recent activities of CHIKV include the Indian epidemic in 2005-2006, which was followed by a sudden explosion of cases in 2007. An estimated 1.3 million people across 13 states were reported to be infected in India [12, 16] , and CHIKV was also widespread in Malaysia, Sri Lanka, and Indonesia [17] . In July-August of 2007, CHIKV was reported in Italy, probably brought in by travelers from CHIKV-prone regions of India, Africa, and Indian", "Ocean islands such as Mauritius, Madagascar, and Seychelles. Few of the Italian isolates were found to have evolved from the Kerala isolate, which was associated with a A226V shift in E1 gene that represents a successful evolutionary adaptation in the mosquito vector similar to the ones observed in Reunion Island [2, 18, 19] .", "In recent times, with an increase in global travel, the risk for spreading CHIKV to non-endemic regions has heightened [1] . Several travelers have brought CHIKV home with them after visiting areas with actively infected populations [12, 20] . Such cases have been documented in European countries, Australia, Asia, and the United States [8, 21] . The United States has already reported at least twelve cases of travel-associated CHIKV, while France has reported 850 cases, and the United Kingdom 93 [8, 14] . Beyond this, CHIKV-infected travelers have also been diagnosed in Australia, Belgium, Canada, Czech Republic, French Guiana, Germany, Hong Kong, Italy, Japan, Kenya, Malaysia, Martinique, Norway, Switzerland, and Sri Lanka [21] . Some travelers were viremic, worrying public health officials about the spread of CHIKV to new areas [1, 8] .", "The incubation time for CHIKV is relatively short, requiring only 2-6 d with symptoms usually appearing 4-7 d post-infection [22] . Vazeille et al. detected CHIKV in the salivary glands of Ae. albopictus only 2 d after infection [5] . Upon infection, CHIKF tends to present itself in two phases. The first stage is acute, while the second stage, experienced by most but not all, is persistent, causing disabling polyarthritis. Characteristics of the acute phase include an abrupt onset of fever, arthralgia, and in some cases, maculopapular rash [6, 23] . The acute phase causes such intense joint and muscular pain that makes movement very difficult and prostrates its victims [6, 20] .", "Ninety-five percent of infected adults are symptomatic after infection, and of these, most become disabled for weeks to months as a result of decreased dexterity, loss of mobility, and delayed reaction. Eighteen months after disease onset, 40% of patients are found to still have anti-CHIKV IgM [6, 18, 23, 24] . The chronic stage of CHIKF is characterized by polyarthralgia that can last from weeks to years beyond the acute stage [6] . CHIKV has been shown to attack fibroblasts, explaining the involvement of muscles, joints, and skin connective tissues. The high number of nociceptive nerve endings found within the joints and muscle connective tissues can explain pain associated with CHIKF [25, 26] .", "More than 50% of patients who suffer from severe CHIKF are over 65 y old, and more than 33% of them die. Most adults who suffer from severe CHIKF have underlying medical conditions [6, 24, 27] . The other group that is disproportionately affected by severe CHIKV is children. Other complications associated with CHIKV, from most common to least common, include respiratory failure, cardiovascular decompensation, meningoencephalitis, severe acute hepatitis, severe cutaneous effects, other central nervous system problems, and kidney failure [6, 18, 20, 23, 24, 26, 27] .", "CHIKV undertakes a complex replication cycle upon host infection (Figure 2 ), which makes its genome susceptible to mutations [28, 29] . For instance, Ae. aegypti, responsible for epidemics in Kenya, Comoros, and Seychelles, carried CHIKV with an alanine in the 226 position of the E1 gene (E1-A226) [4, 18] . However, when the virus struck La Reunion Islands, a decline in population of Ae. aegypti, due to massive dichlorodiphenyltrichloroethane usage and dearth of Ae. albopictus species' www.plosntds.org population, resulted in an ecological pressure, favoring replacement of alanine at position 226 with valine (E1-A226V) [5] . This mutation allowed CHIKV's secondary vector species, Ae. albopictus, to supplement Ae. aegypti as its primary vector [5] .", "Within a year, the E1-A226V mutation was present in La Reunion Island, and Ae. albopictus apparently vectored the large epidemic infecting 34% of La Reunion Island's population [5] . All of the CHIKV strains isolated from Mayotte carried the E1-A226V mutation, and the mutation was also found in Madagascar in 2007 [5] . The E1-A226V mutation was not present at the beginning of the Indian Ocean Islands outbreak (before September 2005). However, more than 90% of later viral strains found there had incorporated the mutation (December-March 2006), indicating a genotype switch during the winter season [5, 18, 20] .", "The E1-A226V mutation also enabled an increase in infectivity of Ae. albopictus when compared to its infectivity of Ae. aegypti [4, 11, 18, 30] , and with several factors taken together, Ae. albopictus has become the new preferred and more lethal vector for CHIKV [4, 5, 11] . In fact, Tsetsarkin et al. found that a Green Fluorescent Protein tagged E1-A226V virus was 100 times more infective to Ae. albopictus than it was to Ae. aegypti [4] . In all the Indian Ocean Islands, Ae. albopictus became the main vector for CHIKV within 1-2 y after CHIKV was introduced to the region [31] .", "Of note is that Ae. aegypti has most likely been established in North America for over 300 y, while Ae. albopictus has been in many areas of the US, since 1985, primarily in Florida [32] and since then has expanded its range in the country. Reiskind et al. set out to determine if Ae. aegypti and Ae. albopictus mosquitoes captured in Florida were susceptible to CHIKV infection by a La Reunion isolate [32] . Each mosquito tested was highly susceptible to infection by a full-length infectious clone of the La Réunion Island isolate, CHIKV LR2006 OPY1 strain. Even though the Ae. albopictus strains were more susceptible to infection, overall ecology and differences in human biting patterns need to be studied further Characteristically, there are two rounds of translation: (+) sense genomic RNA (49S9 = 11.7 kb) acts directly as mRNA and is partially translated (59 end) to produce non-structural proteins (nsp's). These proteins are responsible for replication and formation of a complementary", "(2) strand, the template for further (+) strand synthesis. Subgenomic mRNA (26 S = 4.1 kb) replication occurs through the synthesis of full-length (2) intermediate RNA, which is regulated by nsp4 and p123 precursor in early infection and later by mature nsp's. Translation of the newly synthesized sub-genomic RNA results in production of structural proteins such as Capsid and protein E2-6k-E1 (from 39 end of genome). Assembly occurs at the cell surface, and the envelope is acquired as the virus buds from the cell and release and maturation almost simultaneous occurred. Replication occurs in the cytoplasm and is very rapid (,4 h) [28, 29] . doi:10.1371/journal.pntd.0000623.g002 www.plosntds.org to gain a more accurate understanding of a potential CHIKV epidemic in the US [32] .", "During the 7 d preceding birth, no human mother has been reported to transmit the disease vertically. However, about 50% of newborns delivered while the mother was infected with CHIKV contracted the disease from their mother, despite the method of delivery. Furthermore, there have been instances of CHIKV transmission from mother to fetus causing congenital illness and fetal death [33] .", "During the 2005-2006 La Reunion Island outbreaks, Ramful et al. discovered that mothers could transmit CHIKV to their progeny during the perinatal period (Day 24 to Day +1) [33, 34] , and it is associated with a high degree of morbidity. By mean Day 4 of life, all of the neonates were symptomatic for CHIKV, exhibiting common CHIKF symptoms. Six neonates were confirmed to have contracted CHIKV and developed mengoencephalitis. Of those mothers who, during the La Reunion Island epidemic, were infected long before delivery, only three fetal deaths were reported [12, 33] . Ramful et al. theorized that motherto-child transmission most likely happens transplacentally shortly before delivery [33] . A similar study by Gerardin et al. reported nineteen cases of neonatal infection associated with intrapartum maternal viremia that progressed to develop encephalitis owing to vertical transmission from infected mothers [34] .", "Clinical and epidemiological similarities with dengue fever make CHIKV diagnosis difficult, which may lead physicians to misdiagnose CHIKV as dengue fever; therefore, the incidence of CHIKV may actually be higher than currently believed (Table 1 ) [6, 12, 35] .", "The amount of time elapsed since disease onset is the most critical parameter when choosing a diagnostic test. CHIKV can be detected and isolated by culturing with mosquito cells (C6/36), Vero cells (mammalian), or in mice [26] . However, this method can take at least a week and only achieves a high sensitivity during the viremic phase, which usually only lasts up to 48 h after the bite. Five days post-infection, the viral isolation approach has a low sensitivity but is still the preferred method for detecting the CHIKV strain [12, 26, 31, 35] . RT-PCR on the other hand is a faster and more sensitive method that can be used within the first week of disease onset [26] , and it is currently the most sensitive method for detecting and quantifying viral mRNA [4, 36] .", "Classic serological detection, by assays such as ELISA [37] , immunofluorescence [5, 38] , complement binding, and haemagglutination inhibition [39] , constitutes the second diagnostic tool used for biological diagnosis of CHIKV infection. These proven techniques are useful for detection of Antigen in mosquitoes during epidemiological studies. These assays detect virus-specific IgM and IgG, however the sensitivity and specificity of these assays has been poorly characterized. Viral competence, or the potential of viral infection and transmission, is an important parameter that can be quantified by ELISA, viral culture, and PCR.", "A study by Ng et al. showed biomarkers indicative of severe CHIKV infection [40] . They found decreased levels of RANTES and increased levels of Interleukin-6 (IL-6) and Interleukin-1b (IL-1b) that could be sued for CHIKV detection in patients as indicators of CHIKV-driven cytokine storm. Couderc et al. demonstrate another cytokine, type-I IFN, as a key player in the progression to CHIKV infection [26] . Using an IFN-a/b null mouse model, they demonstrated evidence of muscles, joints, and skin as privileged CHIKV targets, which is consistent with human pathology. Although Ng et al. concluded that RANTES levels were significantly suppressed in severe CHIKF patients [40] , interestingly, an increase in levels of RANTES has been observed in dengue infection [41] . Since the symptoms of CHIKF mimic those of dengue fever, results obtained from this study strongly suggest that RANTES could be a potential distinctive biomarker that differentiates between these two clinically similar", "diseases.", "There are no approved antiviral treatments currently available for CHIKV [1, 3, 12, 42] . Currently, CHIKF is treated symptomatically, usually with non-steroidal anti-inflammatory drugs or steroids, bed rest, and fluids. Movement and mild exercise are thought to decrease stiffness and morning arthralgia, but heavy exercise may exacerbate rheumatic symptoms. Corticosteroids may be used in cases of debilitating chronic CHIKV infection. There is a debate about the appropriateness of chloroquine as treatment for unresolved, non-steroidal anti-inflammatory drugresistant arthritis [43] . A study showed that viral production was www.plosntds.org drastically reduced at 16 h post-infection after treatment with 100 mM dec-RVKR-cmk (Decanoyl-Arg-Val-Lys-Arg-chloromethylketone), a furine inhibitor [42, 44] . Chloroquine acted by raising the pH, blocking low pH-dependent entry of virus into the cell. It is important to note that dec-RVKR-cmk or chloroquine only inhibited viral spreading from cell", "to cell, not CHIKV replication once it had entered the cell [43] . However, most would agree that the best weapon against CHIKV is prevention. A live CHIKV vaccine developed by the United States reached phase II clinical trial encompassing 59 healthy volunteers [45] . Eight percent of the volunteers experienced transient arthralgia, while 98% of the volunteers had seroconversion [45] . However, live CHIKV vaccines are still questionable. One cannot discount the risk of a live vaccine possibly inducing chronic rheumatism. Also, there is the question as to whether widespread use among the public could trigger mosquito transmission or lead to chronic infection or viral reversion [1] .", "An alternative approach would be to produce a chimeric vaccine against CHIKV. Wang et al. developed a chimeric alphavirus vaccine that is uniformly attenuated and does not cause reactogenicity in mice [3] . Three different versions of this vaccine were made using three different backbone vectors: Venezuelan equine encephalitis virus (VEEV) attenuated vaccine strain T-83, naturally attenuated eastern equine encephalitis virus (EEEV), and attenuated Sindbis virus (SINV). In short, CHIKV structural proteins were engineered into the backbones of the aforementioned vaccines to produce the chimeras [3] . These chimeras were found to stimulate a strong humoral immunity, and even at doses of 5.3-5.8 log 10 PFU, they did not trigger reactogenicity. When vaccinated mice were challenged with CHIKV, neither adult nor neonatal mice gained weight, had fever, or displayed signs of neurological illness. Upon comparison of the chimeras with the Army181/25 vaccine, the Army vaccine resulted in higher", "levels of viremia and replication in the joints of neonatal mice. Because the joints are known targets of CHIKV, Wang et al. noted their vaccine might avoid the negative reactogenic side effects of the Army vaccine. After being subcutaneously vaccinated with 5.3-5.8 log 10 PFU of the chimeric vaccines, mice produced strong neutralizing antibody titers. The VEEV and EEEV chimeras yielded higher neutralizing antibody titers than the SINV chimera without being more virulent. On top of this, the VEEV and EEEV CHIKV chimeras seemed to be more immunogenic than the Army vaccine despite the chimeras' lower viremia and replication in the joints of neonatal mice [3] .", "Tiwari et al. [46] adopted a different strategy using formalin inactivated CHIKV in combination with alhydrogel (Aluminum Hydroxide) as an adjuvant. This study clearly suggests that this vaccine elicits both humoral and cell-mediated immune responses in mice, providing its immunogenic potential. A recent study by Couderc et al. [47] showed passive immunization as a potential treatment for CHIKV infection. Using purified immunoglobulin extracted from convalescent CHIKV patients, they demonstrated effective neutralizing activity against CHIKV infection both in vitro and in vivo. This thereby establishes a potential preventive and therapeutic approach to combat CHIKV infection. Pathogenesis studies conducted with related alpha virus, like RRV, have shown the role of macrophages in persistence on infection [48] . They also demonstrated the role of RRV-specific CD8 T cells in clearing viral load in infected patients, thereby warranting similar investigations with CHIKV and the importance", "of investigating a cell-mediated immune response-based vaccine against CHIKV [49] .", "There are always certain risks associated with live attenuated or inactivated viral vaccines [50] . One way to avoid these potential problems is to construct a consensus-based DNA vaccine. DNA based vaccines have an improved safety profile as compared to live or attenuated vaccines [51, 52] . A consequence of CHIKV's rapid evolution is difficulty in constructing a vaccine that will be able to Figure 3 . Levels of CHIKV-specific IgG in mice immunized with CHIKV vaccines. Each group of C57BL/6 mice (n = 5) was immunized with 12.5 mg of pVax1 control vector or CHIKV vaccine plasmids as indicated at 0 and 2 wk. Mice were bled 2 wk after each immunization, and each group's serum pool was diluted to 1:100 and 1:500 for reaction with specific vaccine constructs. Serum was incubated for 1 h at 37uC on 96-well plates coated with 2 mg/ml of respective CHIKV peptides, and antibody was detected using anti-mouse IgG-HRP and OD was measured at 405 nm. doi:10.1371/journal.pntd.0000623.g003", "www.plosntds.org effectively protect large populations from multiple strains of the virus. One of the strengths of DNA consensus vaccines is its ability to induce cross-reactive immune responses against the three distinct phylogenetic groups of CHIKV. Also DNA-based vaccines can be produced more rapidly than protein-based vaccines.", "Recently, Muthumani et al. constructed a vaccine that was shown to induce both humoral and cellular immunity in vivo in 3-4-wk-old female C57/BL6 mice [49] . These mice were immunized using an in vivo electroporation method to deliver the vaccine into the quadriceps muscle. The consensus construct was designed against E1, E2, and the core protein capsid. To design the construct, they aligned 21 sequences of CHIKV isolated between 1952 and 2006, using strains from differing countries, including La Reunion Island. The most common nucleotide among the sequences was chosen at each position to be used in the consensus construct, taking care not to alter the reading frame. They conducted codon and RNA optimization, added a strong Kozak sequence, and substituted signal peptide with an immunoglobulin E leader sequence to improve vaccine efficacy.", "After immunizing the mice, spleens were harvested along with serum and tested to determine antibody titer. After three immunizations, consensus E1, E2, and C vaccines were shown to induce T-cell immune responses leading to strong IFN-c responses and proliferation in C57/BL6 mice. Furthermore, when compared with control mice, immunized mice had higher total IgG levels as well as higher anti-E1 specific, anti-E2 specific, and anti-C specific IgG antibodies, suggesting a strong humoral immune response ( Figure 3 ) and also specificity for the antigens encoded in the vaccine constructs ( Figure 4 ). Because of its promising results and the need for a safer vaccine, this consensus DNA vaccine deserves further investigation. Determining longevity of protective effects of the vaccine and persistence of antibody and IFN-c responses could be the next step of investigation. Challenged studies of immunized mice must also be carried out.", "CHIKV mosquito-borne disease has caused massive outbreaks for at least half a century but is no longer confined to the www.plosntds.org developing nations. It began to encroach into the boundaries of the developing world. As a result, the NIAID has designated CHIKV as a Category C pathogen alongside the influenza and SARS-CoV viruses [3] . Realization of the potential severity of this disease is exigent; for instance, if used as a biological weapon, the world economy could be severely crippled; if enough members of the armed forces were to become infected during a military deployment, military operations could be significantly affected. Efforts to monitor the disease will only provide minimal warning in a global society, and steps to prevent the morbidity and mortality associated with pandemic are imperative [21, 31] . Despite the gravity of its infectious potency and the fear of it being a potential biological weapon, there is currently no vaccine for CHIKV infections. Live", "attenuated vaccine trials were carried out in 2000, but funding for the project was discontinued. Newer approaches such as DNA vaccines appear promising over conventional strategies like live attenuated or inactivated virus and thus call for further investigation. Recent advances such electroporation delivery and incorporation of adjuvants has boosted DNA vaccine efficacy [51, 53] . Despite the low antibody response to DNA vaccines, other numerous advantages have overshadowed these minor drawbacks (Table 2) , the most important one being the ability to induce both humoral and cellular immune responses [51, 54] .", "Judging by recent success, such as the immunogenic construct developed by Muthumani et al., DNA vaccines could play a major role in combating CHIKV [49] . Vaccines are literally a critical component of CHIKV disease control and therefore research in this area is highly encouraged. The dramatic spread of dengue viruses (DENV) throughout tropical America since 1980 via the same vectors and human hosts underscores the risk to public health in the Americas. The adverse events associated with the current live vaccine are well documented [55] . Realizing these drawbacks, earnest efforts should be taken to develop new strategies to forestall further spread and complications." ]	[ 30 ]	3,829	5,688
1,688	How many facilities were monitored in this study?	4,250	[ "two" ]	[ "Health care workers indicate ill preparedness for Ebola Virus Disease outbreak in Ashanti Region of Ghana\n\nhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC5461762/\n\nSHA: f8efe7295a7cf875c8a695df3e87a42e651ce60d\n\nAuthors: Annan, Augustina Angelina; Yar, Denis Dekugmen; Owusu, Michael; Biney, Eno Akua; Forson, Paa Kobina; Okyere, Portia Boakye; Gyimah, Akosua Adumea; Owusu-Dabo, Ellis\nDate: 2017-06-06\nDOI: 10.1186/s12889-017-4474-6\nLicense: cc-by", "Abstract: BACKGROUND: The recent Ebola Virus Disease (EVD) epidemic that hit some countries in West Africa underscores the need to train front line high-risk health workers on disease prevention skills. Although Ghana did not record (and is yet to) any case, and several health workers have received numerous training schemes, there is no record of any study that assessed preparedness of healthcare workers (HCWS) regarding EVD and any emergency prone disease in Ghana. We therefore conducted a hospital based cross sectional study involving 101 HCWs from two facilities in Kumasi, Ghana to assess the level of preparedness of HCWs to respond to any possible EVD. METHODS: We administered a face-to-face questionnaire using an adapted WHO (2015) and CDC (2014) Checklist for Ebola Preparedness and assessed overall knowledge gaps, and preparedness of the Ghanaian HCWs in selected health facilities of the Ashanti Region of Ghana from October to December 2015. RESULTS: A total 92 (91.09%) HCWs", "indicated they were not adequately trained to handle an EVD suspected case. Only 25.74% (n = 26) considered their facilities sufficiently equipped to handle and manage EVD patients. When asked which disinfectant to use after attending to and caring for a suspected patient with EVD, only 8.91% (n = 9) could correctly identify the right disinfectant (χ(2) = 28.52, p = 0.001). CONCLUSION: Our study demonstrates poor knowledge and ill preparedness and unwillingness of many HCWs to attend to EVD. Beyond knowledge acquisition, there is the need for more training from time to time to fully prepare HCWs to handle any possible EVD case.", "Text: During the last outbreak of Ebola Virus Disease (EVD) and its consequential massive epidemic with very high mortality [1] , many health systems and services in West Africa were overwhelmed and disrupted. This was partly due to the poor and weak health systems coupled with unprepared and unskilled frontline healthcare workers (HCWs) compounded by poor understanding of the disease dynamics tied to lack of requisite resources. During the early part of 2014, the emergence of EVD [1] in Guinea, jolted the health care systems of West African sub-region claiming over 9800 lives [2] including more than 491 (58.7%) deaths of HCWs from 839 infections [2] . This epidemic therefore reinforced the fact that HCWs are at high-risk of being infected with the disease in line with their core duties. Empirical data generated during and after the epidemic indicated how unprepared most HCWs were in the face of the crisis. Studies in Nigeria, Guinea and India indicate the low level of knowledge,", "negative attitude and sub-standard practices that can be eliminated through continued training of HCWs as well as provision of needed and adequate resources in their line of duties [3] [4] [5] [6] .", "The countries worst hit were Liberia, Sierra Leone, Guinea and several other countries with imported cases [7] . Like most West African nations, Ghana was on high alert and was number one on the list of countries deemed to be at high risk of EVD. Thus, the country tried to make some preparations in the wake of the epidemic [8] . The government with support from donor organizations such as the World Health Organization (WHO), Médecins sans frontières (MSF) put in place resources for training of health professionals and some level of retooling of hospitals and preparedness of health workers in the face of any possible emergency scenarios. Various HCWs received both theoretical and practical training on how to manage infected and affected persons. These training sessions took the form of onsite and off site coaching as well as workshops. Simulation exercises were also conducted to bring to bear how HCWs would react during EVD emergency scenarios. For example, the German government", "through the Kumasi Centre for Collaborative Research in Tropical Medicine organized hands on training for several West African nationals on sample taking, sample testing and donning and doffing personal protective equipment (http://kccr.org). More importantly, there was the construction of three treatment centres and as well, a standby ambulance service for transportation of confirmed cases to the treatment centres. Incidentally, Ghana did not record any case in the wake of the epidemic and has so far not recorded any case of EVD. However, the response of HCWs to the scenarios identified several gaps. Following a series of training for HCWs, one could easily assume that health care workers are adequately prepared and equipped with the requisite knowledge and skills to deal with any possible EVD outbreak. It is unclear for example to what extent these exercises were practiced and for how long they were made a part of routine hospital activities. One therefore wonders how well prepared", "HCWs within Ghana are to responding not only to EVD but other epidemic prone diseases (EPDs) requiring a concerted approach to preparedness and management.", "Even though some resources have been invested in response to the EVD scare in Ghana, there has not been any assessment on the preparedness of health workers in the face of any possible emergency scenarios. Simply providing the tools such as medications, personnel protective equipment (PPE) and other logistics is no panacea for adequately and appropriately responding to EPDs. Consequently, if healthcare staff lack the basic knowledge, practical and organizational skills to plan and respond to such emergency situations, it would not only spell doom for themselves but also for the general population as was the case of the recent epidemic in West Africa. It is important for example to understand the dynamics of what will propel a HCW to be willing to put his or her life in the line of duty for a case of EVD. It is therefore critical to understand current preparedness of the healthcare worker in Ghana in order to make recommendations for future training and planning for any epidemics", "situation. The need for Ghana to therefore have empirical data on general emergency preparedness to determine and understand knowledge gaps, and to assess knowledge versus practice in a bid to provide direction for policy cannot be overemphasized. In view of this, we therefore assessed the level of preparedness, readiness and knowledge of EVD emergency response among a population of healthcare workers (HCWs) in the Kumasi Metropolis of Ashanti Region, Ghana.", "We conducted a hospital based cross-sectional study among healthcare workers at the Kumasi South and Suntreso Government Hospitals designated as \"advanced Ebola holding unit\" and \"Ebola standing team\" respectively, in the Kumasi Metropolis. The Kumasi South and Suntreso hospitals have an average monthly Out Patient Department (OPD) attendance of about 20,603 and 11,712 patients respectively and health staff of approximately 450 each. Similar to most facilities, there are more females nurses than males.\n\nWe organized a day's training for our research assistants on how to use Personal Digital Assistant device (PDAs) Samsung Galaxy note 8 GT-N5100 (Samsung Electronics Co. Ltd., Seoul, Korea) in capturing data.", "The original version of the questionnaire was pretested, with five healthcare workers who were similar in their characteristics to the members of the study population but outside the area of jurisdiction and study to ensure validity and measurement bias. The questionnaire was revised based on the suggestions and comments (mainly on how the questions had been constructed) obtained from the pilot. This was the final and validated data capturing tool used during the study.", "At both facilities, we contacted the Medical Superintendents to obtain permission to attend their morning meetings to explain the aims and objectives of the work to HCWs. During this time, HCWs were given the opportunity to ask questions. Two field assistants were stationed at each of the study sites for data capture. Some of the questions asked included the organism responsible for EVD, the mode of transmission of the disease, HCW preparedness to handle any EVD case and among other things early clinical features of the infection.", "In estimating the sample size for this study, previous data from the hospital indicates that there are approximately 900 HCWs at the two facilities. Assuming a 95% confidence interval and if 70% of these HCWs would come into contact with an EVD suspected case, allowing an error rate of 10%, approximately 87 HCWs would provide a default study power of 80% and an alpha of 5%. With approximately a non-response rate of 15% allowing us to sample 101 HCWs from the two facilities providing emergency services within the Ashanti Region of Ghana.", "Any healthcare worker attending directly to patients in emergency situation was therefore eligible for inclusion in the study. Our sampling frame consisted of a list of a total of 200. From this list, we then took a systematic random sample of all eligible health workers to represent the sample size. After obtaining written informed consent indicated by signature and or thumbprint of participants, we then administered the questionnaires within the two facilities.", "We used the WHO (2015) and CDC (2014) Checklist for Ebola Preparedness that provides practical and specific suggestions to ensure that health facilities are able to help their personnel detect possible Ebola cases, protect personnel, and respond appropriately [9, 10] . This checklist included facility evaluation, knowledge and preparedness of HCWs. Based on these checklists we developed a questionnaire to ascertain the overall knowledge and preparedness of Ghanaian HCWs on EVD outbreak. Our questionnaire was administered from a PDA and recorded each participant's demographics, preparedness, form of compensation HCWs think would be appropriate when taking care of EVD case, and knowledge of EVD during the period October to December 2015. Answers to these questions were needed from HCWs to determine information access on EVD among HCWs, their knowledge about EVD and the form of compensation HCWs think would be appropriate when taking care of EVD case among others.", "Data were collected electronically using tablets for cloud storage through CommCare ODK version 2.27.2, aggregated into Microsoft Excel file, exported into STATA version 14 and analyzed. Descriptive statistics was used to summarize the distribution of various variables into tables and figures. Categorical variables were analyzed using chisquare tests and logistic regression for associations.", "Background of the study participants Table 1 shows the background characteristics of the study participants. A total of 101 study participants were interviewed, of which 85 (84.16%) were females. Respondents were categorized into three main groups by occupation: Nurses (76.24%), Medical Doctors (19.80%) and Physician Assistants (PA) (3.96%). Majority (54.46%) of the respondents were married. A total 52.48% (53) had been practicing their profession for less than 5 years (SD = 9.22 ± 10.52 years). At both facilities, 75.25% (76) of the respondents had been working in the facility for less than 5 years (SD = 4.04 ± 4.07 years). Table 2 shows the participants knowledge and awareness of EVD. Of the 101 HCWs interviewed, 83.17% (n = 84) correctly identified the cause of EVD, 13.86% (n = 14) did not know the cause, while 2.97% (n = 3) incorrectly labeled the cause to be a bacterium. Even though one (0.99%) Doctor and 16 (15.84%) Nurses were unable to correctly identify the cause; no group", "was significantly likely to incorrectly label the cause of EVD (χ 2 = 5.41, p = 0.247).", "A total of 72 (71.29%) HCWs indicated media especially radio as the main source of information when asked where they first heard of EVD. This was significantly more than other sources (χ 2 = 45.44, p < 0.05). When asked which biosafety level laboratory (BSL) is required to test sample from suspected patient with EVD, a total 19 (18.81%) indicated BSL-3 of which 11 (10.89%) were Medical Doctors, while 8 (7.92) and 1 (0.99%) were Nurses and Physician Assistants, respectively. A further 76 (75.25%), of which 9 (8.91%) were doctors, 62 (61.39%) Nurses When asked which disinfectant to use after attending to and caring for a suspected patient with EVD, only 8.91% (n = 9) could correctly identify bleach (0.5% Sodium Hypochlorite) which disinfectant to use (χ 2 = 28.52, p = 0.001).", "Preparedness for an EVD outbreak by HCW category Table 3 shows the levels of preparedness of HCWs to handle and manage EVD outbreak. When HCWs were asked if they considered their facilities sufficiently equipped to handle and manage EVD patients, 25.74% (n = 26) responded in the affirmative, while 54.46% (55) indicated otherwise. Of this, 14 (13.86%) were Medical Doctors, 39 (38.61%) Nurses and 2 (1.98%) were PA (χ 2 = 2.66, p = 0.62). If they became accidentally infected with EVD after attending to a patient with EVD, 98 (97.03%) of those surveyed indicated they would accept to be isolated (χ 2 = 4.69, p = 0.321). Meanwhile, 44.55% (n = 45) of HCWs would willingly attend to an EVD suspected patient (χ 2 = 8.03, p = 0.09).", "A total of 92 (91.09%) HCWs surveyed indicated they were not adequately trained to handle an EVD suspected case. When asked to rate their competence in handling an EVD suspected patient, 18.81% (n = 19) indicated they had little confidence and competence, while 6.93% (n = 7) indicated they were extremely confident to handle a suspected case of EVD (χ 2 = 13.09, p = 0.11).", "Beyond EVD, we asked our survey population to name other epidemic prone diseases. Of the total number of HCWs interviewed, 56.43% (57/101) mentioned epidemic diseases of bacteria origin such as tuberculosis and cholera. A further 33.70% (34/101) named diseases of viral origin such as SARS, Flu, HIV, Lassa fever and dengue, while 9.90% (10) mentioned others referring to malaria. When asked the form of compensation HCWs thought would be appropriate when taking care of an Ebola suspected patient, responses given included personal insurance (32/101), family compensation in case of death (31/101), money (30/101) and awards (8/101) while others also suggested job promotion (7/101), and others (18/101).\n\nOur survey population recommended the provision of logistics and training as two key issues in the way forward in adequately preparing HCWs towards any epidemic prone diseases.", "Many issues surrounding the preparedness of HCWs have been extensively discussed globally especially in the aftermath of the Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV) and the Middle East Respiratory Syndrome (MERS)-CoV epidemic. While it is on record that the recent EVD outbreak recorded very high mortality among HCWs, to the best of our knowledge, only few studies have addressed these issues in anticipation of an EVD outbreak particularly in countries not hit by the EVD epidemic and especially in sub Saharan Africa, such a study is almost non-existent. Our study therefore assessed how prepared HCWs are in the face of a possible EVD epidemic.", "The results of this survey showed that more than half (54.46%) HCWs indicated that their facilities were not ready to handle EVD cases. Nearly 92% indicated they were not adequately trained to handle an EVD suspected case and it is not surprising that less than 50% indicated they would willingly attend to a suspected patient. Moreover, nearly a third of HCWs would also want insurance for themselves and their families in case they were infected with EVD.", "These results are clearly indicative of how ill-prepared the HCWs surveyed are in the face a potentially life threatening epidemic prone diseases, such as EVD in Ghana. In this study, only 25.7% of HCWs said their facility was sufficiently equipped to handle an EVD outbreak. Such low ratings of the hospitals by majority of HCWs is a mark of lack of confidence in their facilities preparedness and this may actually indicate a real lack of preparedness and readiness of the hospitals to handle not only EVD cases but potentially other epidemic prone diseases. Alternatively, it could also mean that HCWs were probably unaware of preparatory work and retooling of their facilities to handle EVD outbreak situation.", "Willingness to work during outbreaks and emergencies is deemed a sense of duty even in the face of risk. In this study, less than 50% of HCWs indicated their willingness to work in the event of an EVD outbreak. Additionally, over one third indicated various forms of compensation for themselves or families in case of death or while taking care of an EVD case. This implies that if HCWs are assured or guaranteed that they and or their families would be taken care of in case of death or while taking care of an EVD case, they will willingly work in the face of any emergency scenario. The assumption is that HCWs would willingly work in the face of an infectious diseases emergency and respond appropriately; however, there are evidences of HCWs avoiding this \"sacred duty\" in caring for patients and would leave patients vulnerable in times of crisis [11] . In order to prevent HCWs from being infected while obliged to work even in the face of personal risk as required by their codes of ethics", "and professionalism, it is imperative to ensure that appropriate conventional standards, guarantees and effective public health practices are met to enable HCWs respond to such outbreaks so that they are not infected and or affected despite the risks they might face and continue to face [12] . Thus, appropriate training of HCWs as indicated by those surveyed during the study, coupled with retooling of some health facilities preparation is very critical in ensuring that they are equipped with the needed knowledge and tools needed to work with in the face of any epidemic.", "General knowledge of EVD is crucial to adequately respond to and care for patients. Nearly 17% of our study population could not identify that EVD as caused by a virus. Arguably, infection control measures would be difficult and problematic for such HCWs. Less than 10% could correctly identify 0.5% Sodium Hypochlorite as the best disinfectant out of the many options provided. This strongly contradicts a similar study in Conakry conducted during the peak of the epidemic where 68% of HCWs knew the correct concentration of disinfectant [5] . While not trying to compare these two scenarios, this information may be vital in the realization that knowledge of HCWs in infection prevention and control measures is critical in their line of duty.", "This study showed that most HCWs first heard of EVD through the media especially radio. This establishes the crucial role media plays in informing the general populace in such disease outbreaks. In Ghana, there are over 350 media outlets (radio and television put together) and majority of households either own a radio, television or have access to internet. Notwithstanding the media pluralism, it is still incumbent upon health institutions and facilities to organize special training on any emerging infectious disease that occurs globally to update the knowledge of HCWs.", "Isolation is a key public health measure to prevent the spread of infectious diseases. In this study, over 97% of HCW indicated their willingness to comply and accept to be isolated in case they became infected after attending to suspected EVD patient. However, a small proportion of HCWs surveyed stated that they would be very unhappy, and this could ultimately affect compliance. Isolation is one of the oldest methods of controlling communicable disease outbreaks for patients [13] . However, it is worthy of note that less that 50% said they would be willing to attend to an EVD suspected patient and we suspected that this could be related to fear of personal safety [14] . Emergency response from an epidemic prone disease from an exotic virulent virus or pathogen will naturally spark some level of fear and skepticism among any group of individuals especially when their knowledge about the dynamics of the disease outbreak is low. There are stories of HCWs who have avoided the", "responsibility of treating patients [15] and this was apparent in the HIV/AIDS and Severe Acute Respiratory Syndrome-Coronavirus (SARS-CoV) during the 1980s and 2003, respectively where the fear of contact with suspected and infected patients gripped some HCWs [16, 17] . In the long run, this fear would likely affect their confidence and commitment to professionalism.", "The results of this study point to the fact that knowledge and the provision of tools such as personnel protective equipment (PPE) and other logistics alone is not good enough strategy. There might be the need to as well address issues related to myth, and culture as well as assurances of upkeep should one be infected. The general outlook one's country's devotion to their health staff might be a contributory factor in all of this and cannot be ignored. However, getting HCWs inspired and feel safe in caring for such highly infectious disease outbreaks is critical. During our study, HCWs indicated various forms of compensation to be paid to them should they be affected in the case of EVD attack.", "This study had some inherent limitations. This was an exploratory study and our sample size was limited. Therefore, while not trying to generalize the results, we are of the opinion that this may be a reflection of HCWs in general. Additionally, since our study focused mainly on two health facilities, we are again careful in extrapolating these to other to reflect other facilities. Moreover, since this has not been a real experience, and a questionnaire-based survey, responses may not accurately reflect real-life experiences in the event of an EVD epidemic. Despite these limitations, the need for training was strong among HCWs. The results further demonstrate the ill-preparedness of health facilities, and the large proportion of HCWs unwillingness to attend to a suspected case of EVD. This thus calls for concerted efforts of health institutions and facilities to fully equip and prepare HCWs with the requisite tools and knowledge and ensuring competency to handle any epidemic prone", "disease." ]	[ 1 ]	3,596	4,831
1,688	What percentage of facilities believed they were adequately equipped to handle Ebola virus disease?	4,251	[ "25.74%" ]	[ "Health care workers indicate ill preparedness for Ebola Virus Disease outbreak in Ashanti Region of Ghana\n\nhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC5461762/\n\nSHA: f8efe7295a7cf875c8a695df3e87a42e651ce60d\n\nAuthors: Annan, Augustina Angelina; Yar, Denis Dekugmen; Owusu, Michael; Biney, Eno Akua; Forson, Paa Kobina; Okyere, Portia Boakye; Gyimah, Akosua Adumea; Owusu-Dabo, Ellis\nDate: 2017-06-06\nDOI: 10.1186/s12889-017-4474-6\nLicense: cc-by", "Abstract: BACKGROUND: The recent Ebola Virus Disease (EVD) epidemic that hit some countries in West Africa underscores the need to train front line high-risk health workers on disease prevention skills. Although Ghana did not record (and is yet to) any case, and several health workers have received numerous training schemes, there is no record of any study that assessed preparedness of healthcare workers (HCWS) regarding EVD and any emergency prone disease in Ghana. We therefore conducted a hospital based cross sectional study involving 101 HCWs from two facilities in Kumasi, Ghana to assess the level of preparedness of HCWs to respond to any possible EVD. METHODS: We administered a face-to-face questionnaire using an adapted WHO (2015) and CDC (2014) Checklist for Ebola Preparedness and assessed overall knowledge gaps, and preparedness of the Ghanaian HCWs in selected health facilities of the Ashanti Region of Ghana from October to December 2015. RESULTS: A total 92 (91.09%) HCWs", "indicated they were not adequately trained to handle an EVD suspected case. Only 25.74% (n = 26) considered their facilities sufficiently equipped to handle and manage EVD patients. When asked which disinfectant to use after attending to and caring for a suspected patient with EVD, only 8.91% (n = 9) could correctly identify the right disinfectant (χ(2) = 28.52, p = 0.001). CONCLUSION: Our study demonstrates poor knowledge and ill preparedness and unwillingness of many HCWs to attend to EVD. Beyond knowledge acquisition, there is the need for more training from time to time to fully prepare HCWs to handle any possible EVD case.", "Text: During the last outbreak of Ebola Virus Disease (EVD) and its consequential massive epidemic with very high mortality [1] , many health systems and services in West Africa were overwhelmed and disrupted. This was partly due to the poor and weak health systems coupled with unprepared and unskilled frontline healthcare workers (HCWs) compounded by poor understanding of the disease dynamics tied to lack of requisite resources. During the early part of 2014, the emergence of EVD [1] in Guinea, jolted the health care systems of West African sub-region claiming over 9800 lives [2] including more than 491 (58.7%) deaths of HCWs from 839 infections [2] . This epidemic therefore reinforced the fact that HCWs are at high-risk of being infected with the disease in line with their core duties. Empirical data generated during and after the epidemic indicated how unprepared most HCWs were in the face of the crisis. Studies in Nigeria, Guinea and India indicate the low level of knowledge,", "negative attitude and sub-standard practices that can be eliminated through continued training of HCWs as well as provision of needed and adequate resources in their line of duties [3] [4] [5] [6] .", "The countries worst hit were Liberia, Sierra Leone, Guinea and several other countries with imported cases [7] . Like most West African nations, Ghana was on high alert and was number one on the list of countries deemed to be at high risk of EVD. Thus, the country tried to make some preparations in the wake of the epidemic [8] . The government with support from donor organizations such as the World Health Organization (WHO), Médecins sans frontières (MSF) put in place resources for training of health professionals and some level of retooling of hospitals and preparedness of health workers in the face of any possible emergency scenarios. Various HCWs received both theoretical and practical training on how to manage infected and affected persons. These training sessions took the form of onsite and off site coaching as well as workshops. Simulation exercises were also conducted to bring to bear how HCWs would react during EVD emergency scenarios. For example, the German government", "through the Kumasi Centre for Collaborative Research in Tropical Medicine organized hands on training for several West African nationals on sample taking, sample testing and donning and doffing personal protective equipment (http://kccr.org). More importantly, there was the construction of three treatment centres and as well, a standby ambulance service for transportation of confirmed cases to the treatment centres. Incidentally, Ghana did not record any case in the wake of the epidemic and has so far not recorded any case of EVD. However, the response of HCWs to the scenarios identified several gaps. Following a series of training for HCWs, one could easily assume that health care workers are adequately prepared and equipped with the requisite knowledge and skills to deal with any possible EVD outbreak. It is unclear for example to what extent these exercises were practiced and for how long they were made a part of routine hospital activities. One therefore wonders how well prepared", "HCWs within Ghana are to responding not only to EVD but other epidemic prone diseases (EPDs) requiring a concerted approach to preparedness and management.", "Even though some resources have been invested in response to the EVD scare in Ghana, there has not been any assessment on the preparedness of health workers in the face of any possible emergency scenarios. Simply providing the tools such as medications, personnel protective equipment (PPE) and other logistics is no panacea for adequately and appropriately responding to EPDs. Consequently, if healthcare staff lack the basic knowledge, practical and organizational skills to plan and respond to such emergency situations, it would not only spell doom for themselves but also for the general population as was the case of the recent epidemic in West Africa. It is important for example to understand the dynamics of what will propel a HCW to be willing to put his or her life in the line of duty for a case of EVD. It is therefore critical to understand current preparedness of the healthcare worker in Ghana in order to make recommendations for future training and planning for any epidemics", "situation. The need for Ghana to therefore have empirical data on general emergency preparedness to determine and understand knowledge gaps, and to assess knowledge versus practice in a bid to provide direction for policy cannot be overemphasized. In view of this, we therefore assessed the level of preparedness, readiness and knowledge of EVD emergency response among a population of healthcare workers (HCWs) in the Kumasi Metropolis of Ashanti Region, Ghana.", "We conducted a hospital based cross-sectional study among healthcare workers at the Kumasi South and Suntreso Government Hospitals designated as \"advanced Ebola holding unit\" and \"Ebola standing team\" respectively, in the Kumasi Metropolis. The Kumasi South and Suntreso hospitals have an average monthly Out Patient Department (OPD) attendance of about 20,603 and 11,712 patients respectively and health staff of approximately 450 each. Similar to most facilities, there are more females nurses than males.\n\nWe organized a day's training for our research assistants on how to use Personal Digital Assistant device (PDAs) Samsung Galaxy note 8 GT-N5100 (Samsung Electronics Co. Ltd., Seoul, Korea) in capturing data.", "The original version of the questionnaire was pretested, with five healthcare workers who were similar in their characteristics to the members of the study population but outside the area of jurisdiction and study to ensure validity and measurement bias. The questionnaire was revised based on the suggestions and comments (mainly on how the questions had been constructed) obtained from the pilot. This was the final and validated data capturing tool used during the study.", "At both facilities, we contacted the Medical Superintendents to obtain permission to attend their morning meetings to explain the aims and objectives of the work to HCWs. During this time, HCWs were given the opportunity to ask questions. Two field assistants were stationed at each of the study sites for data capture. Some of the questions asked included the organism responsible for EVD, the mode of transmission of the disease, HCW preparedness to handle any EVD case and among other things early clinical features of the infection.", "In estimating the sample size for this study, previous data from the hospital indicates that there are approximately 900 HCWs at the two facilities. Assuming a 95% confidence interval and if 70% of these HCWs would come into contact with an EVD suspected case, allowing an error rate of 10%, approximately 87 HCWs would provide a default study power of 80% and an alpha of 5%. With approximately a non-response rate of 15% allowing us to sample 101 HCWs from the two facilities providing emergency services within the Ashanti Region of Ghana.", "Any healthcare worker attending directly to patients in emergency situation was therefore eligible for inclusion in the study. Our sampling frame consisted of a list of a total of 200. From this list, we then took a systematic random sample of all eligible health workers to represent the sample size. After obtaining written informed consent indicated by signature and or thumbprint of participants, we then administered the questionnaires within the two facilities.", "We used the WHO (2015) and CDC (2014) Checklist for Ebola Preparedness that provides practical and specific suggestions to ensure that health facilities are able to help their personnel detect possible Ebola cases, protect personnel, and respond appropriately [9, 10] . This checklist included facility evaluation, knowledge and preparedness of HCWs. Based on these checklists we developed a questionnaire to ascertain the overall knowledge and preparedness of Ghanaian HCWs on EVD outbreak. Our questionnaire was administered from a PDA and recorded each participant's demographics, preparedness, form of compensation HCWs think would be appropriate when taking care of EVD case, and knowledge of EVD during the period October to December 2015. Answers to these questions were needed from HCWs to determine information access on EVD among HCWs, their knowledge about EVD and the form of compensation HCWs think would be appropriate when taking care of EVD case among others.", "Data were collected electronically using tablets for cloud storage through CommCare ODK version 2.27.2, aggregated into Microsoft Excel file, exported into STATA version 14 and analyzed. Descriptive statistics was used to summarize the distribution of various variables into tables and figures. Categorical variables were analyzed using chisquare tests and logistic regression for associations.", "Background of the study participants Table 1 shows the background characteristics of the study participants. A total of 101 study participants were interviewed, of which 85 (84.16%) were females. Respondents were categorized into three main groups by occupation: Nurses (76.24%), Medical Doctors (19.80%) and Physician Assistants (PA) (3.96%). Majority (54.46%) of the respondents were married. A total 52.48% (53) had been practicing their profession for less than 5 years (SD = 9.22 ± 10.52 years). At both facilities, 75.25% (76) of the respondents had been working in the facility for less than 5 years (SD = 4.04 ± 4.07 years). Table 2 shows the participants knowledge and awareness of EVD. Of the 101 HCWs interviewed, 83.17% (n = 84) correctly identified the cause of EVD, 13.86% (n = 14) did not know the cause, while 2.97% (n = 3) incorrectly labeled the cause to be a bacterium. Even though one (0.99%) Doctor and 16 (15.84%) Nurses were unable to correctly identify the cause; no group", "was significantly likely to incorrectly label the cause of EVD (χ 2 = 5.41, p = 0.247).", "A total of 72 (71.29%) HCWs indicated media especially radio as the main source of information when asked where they first heard of EVD. This was significantly more than other sources (χ 2 = 45.44, p < 0.05). When asked which biosafety level laboratory (BSL) is required to test sample from suspected patient with EVD, a total 19 (18.81%) indicated BSL-3 of which 11 (10.89%) were Medical Doctors, while 8 (7.92) and 1 (0.99%) were Nurses and Physician Assistants, respectively. A further 76 (75.25%), of which 9 (8.91%) were doctors, 62 (61.39%) Nurses When asked which disinfectant to use after attending to and caring for a suspected patient with EVD, only 8.91% (n = 9) could correctly identify bleach (0.5% Sodium Hypochlorite) which disinfectant to use (χ 2 = 28.52, p = 0.001).", "Preparedness for an EVD outbreak by HCW category Table 3 shows the levels of preparedness of HCWs to handle and manage EVD outbreak. When HCWs were asked if they considered their facilities sufficiently equipped to handle and manage EVD patients, 25.74% (n = 26) responded in the affirmative, while 54.46% (55) indicated otherwise. Of this, 14 (13.86%) were Medical Doctors, 39 (38.61%) Nurses and 2 (1.98%) were PA (χ 2 = 2.66, p = 0.62). If they became accidentally infected with EVD after attending to a patient with EVD, 98 (97.03%) of those surveyed indicated they would accept to be isolated (χ 2 = 4.69, p = 0.321). Meanwhile, 44.55% (n = 45) of HCWs would willingly attend to an EVD suspected patient (χ 2 = 8.03, p = 0.09).", "A total of 92 (91.09%) HCWs surveyed indicated they were not adequately trained to handle an EVD suspected case. When asked to rate their competence in handling an EVD suspected patient, 18.81% (n = 19) indicated they had little confidence and competence, while 6.93% (n = 7) indicated they were extremely confident to handle a suspected case of EVD (χ 2 = 13.09, p = 0.11).", "Beyond EVD, we asked our survey population to name other epidemic prone diseases. Of the total number of HCWs interviewed, 56.43% (57/101) mentioned epidemic diseases of bacteria origin such as tuberculosis and cholera. A further 33.70% (34/101) named diseases of viral origin such as SARS, Flu, HIV, Lassa fever and dengue, while 9.90% (10) mentioned others referring to malaria. When asked the form of compensation HCWs thought would be appropriate when taking care of an Ebola suspected patient, responses given included personal insurance (32/101), family compensation in case of death (31/101), money (30/101) and awards (8/101) while others also suggested job promotion (7/101), and others (18/101).\n\nOur survey population recommended the provision of logistics and training as two key issues in the way forward in adequately preparing HCWs towards any epidemic prone diseases.", "Many issues surrounding the preparedness of HCWs have been extensively discussed globally especially in the aftermath of the Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV) and the Middle East Respiratory Syndrome (MERS)-CoV epidemic. While it is on record that the recent EVD outbreak recorded very high mortality among HCWs, to the best of our knowledge, only few studies have addressed these issues in anticipation of an EVD outbreak particularly in countries not hit by the EVD epidemic and especially in sub Saharan Africa, such a study is almost non-existent. Our study therefore assessed how prepared HCWs are in the face of a possible EVD epidemic.", "The results of this survey showed that more than half (54.46%) HCWs indicated that their facilities were not ready to handle EVD cases. Nearly 92% indicated they were not adequately trained to handle an EVD suspected case and it is not surprising that less than 50% indicated they would willingly attend to a suspected patient. Moreover, nearly a third of HCWs would also want insurance for themselves and their families in case they were infected with EVD.", "These results are clearly indicative of how ill-prepared the HCWs surveyed are in the face a potentially life threatening epidemic prone diseases, such as EVD in Ghana. In this study, only 25.7% of HCWs said their facility was sufficiently equipped to handle an EVD outbreak. Such low ratings of the hospitals by majority of HCWs is a mark of lack of confidence in their facilities preparedness and this may actually indicate a real lack of preparedness and readiness of the hospitals to handle not only EVD cases but potentially other epidemic prone diseases. Alternatively, it could also mean that HCWs were probably unaware of preparatory work and retooling of their facilities to handle EVD outbreak situation.", "Willingness to work during outbreaks and emergencies is deemed a sense of duty even in the face of risk. In this study, less than 50% of HCWs indicated their willingness to work in the event of an EVD outbreak. Additionally, over one third indicated various forms of compensation for themselves or families in case of death or while taking care of an EVD case. This implies that if HCWs are assured or guaranteed that they and or their families would be taken care of in case of death or while taking care of an EVD case, they will willingly work in the face of any emergency scenario. The assumption is that HCWs would willingly work in the face of an infectious diseases emergency and respond appropriately; however, there are evidences of HCWs avoiding this \"sacred duty\" in caring for patients and would leave patients vulnerable in times of crisis [11] . In order to prevent HCWs from being infected while obliged to work even in the face of personal risk as required by their codes of ethics", "and professionalism, it is imperative to ensure that appropriate conventional standards, guarantees and effective public health practices are met to enable HCWs respond to such outbreaks so that they are not infected and or affected despite the risks they might face and continue to face [12] . Thus, appropriate training of HCWs as indicated by those surveyed during the study, coupled with retooling of some health facilities preparation is very critical in ensuring that they are equipped with the needed knowledge and tools needed to work with in the face of any epidemic.", "General knowledge of EVD is crucial to adequately respond to and care for patients. Nearly 17% of our study population could not identify that EVD as caused by a virus. Arguably, infection control measures would be difficult and problematic for such HCWs. Less than 10% could correctly identify 0.5% Sodium Hypochlorite as the best disinfectant out of the many options provided. This strongly contradicts a similar study in Conakry conducted during the peak of the epidemic where 68% of HCWs knew the correct concentration of disinfectant [5] . While not trying to compare these two scenarios, this information may be vital in the realization that knowledge of HCWs in infection prevention and control measures is critical in their line of duty.", "This study showed that most HCWs first heard of EVD through the media especially radio. This establishes the crucial role media plays in informing the general populace in such disease outbreaks. In Ghana, there are over 350 media outlets (radio and television put together) and majority of households either own a radio, television or have access to internet. Notwithstanding the media pluralism, it is still incumbent upon health institutions and facilities to organize special training on any emerging infectious disease that occurs globally to update the knowledge of HCWs.", "Isolation is a key public health measure to prevent the spread of infectious diseases. In this study, over 97% of HCW indicated their willingness to comply and accept to be isolated in case they became infected after attending to suspected EVD patient. However, a small proportion of HCWs surveyed stated that they would be very unhappy, and this could ultimately affect compliance. Isolation is one of the oldest methods of controlling communicable disease outbreaks for patients [13] . However, it is worthy of note that less that 50% said they would be willing to attend to an EVD suspected patient and we suspected that this could be related to fear of personal safety [14] . Emergency response from an epidemic prone disease from an exotic virulent virus or pathogen will naturally spark some level of fear and skepticism among any group of individuals especially when their knowledge about the dynamics of the disease outbreak is low. There are stories of HCWs who have avoided the", "responsibility of treating patients [15] and this was apparent in the HIV/AIDS and Severe Acute Respiratory Syndrome-Coronavirus (SARS-CoV) during the 1980s and 2003, respectively where the fear of contact with suspected and infected patients gripped some HCWs [16, 17] . In the long run, this fear would likely affect their confidence and commitment to professionalism.", "The results of this study point to the fact that knowledge and the provision of tools such as personnel protective equipment (PPE) and other logistics alone is not good enough strategy. There might be the need to as well address issues related to myth, and culture as well as assurances of upkeep should one be infected. The general outlook one's country's devotion to their health staff might be a contributory factor in all of this and cannot be ignored. However, getting HCWs inspired and feel safe in caring for such highly infectious disease outbreaks is critical. During our study, HCWs indicated various forms of compensation to be paid to them should they be affected in the case of EVD attack.", "This study had some inherent limitations. This was an exploratory study and our sample size was limited. Therefore, while not trying to generalize the results, we are of the opinion that this may be a reflection of HCWs in general. Additionally, since our study focused mainly on two health facilities, we are again careful in extrapolating these to other to reflect other facilities. Moreover, since this has not been a real experience, and a questionnaire-based survey, responses may not accurately reflect real-life experiences in the event of an EVD epidemic. Despite these limitations, the need for training was strong among HCWs. The results further demonstrate the ill-preparedness of health facilities, and the large proportion of HCWs unwillingness to attend to a suspected case of EVD. This thus calls for concerted efforts of health institutions and facilities to fully equip and prepare HCWs with the requisite tools and knowledge and ensuring competency to handle any epidemic prone", "disease." ]	[ 2 ]	3,596	4,831
1,688	How many facilities believed they were adequately equipped to handle Ebla virus disease?	4,252	[ "26" ]	[ "Health care workers indicate ill preparedness for Ebola Virus Disease outbreak in Ashanti Region of Ghana\n\nhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC5461762/\n\nSHA: f8efe7295a7cf875c8a695df3e87a42e651ce60d\n\nAuthors: Annan, Augustina Angelina; Yar, Denis Dekugmen; Owusu, Michael; Biney, Eno Akua; Forson, Paa Kobina; Okyere, Portia Boakye; Gyimah, Akosua Adumea; Owusu-Dabo, Ellis\nDate: 2017-06-06\nDOI: 10.1186/s12889-017-4474-6\nLicense: cc-by", "Abstract: BACKGROUND: The recent Ebola Virus Disease (EVD) epidemic that hit some countries in West Africa underscores the need to train front line high-risk health workers on disease prevention skills. Although Ghana did not record (and is yet to) any case, and several health workers have received numerous training schemes, there is no record of any study that assessed preparedness of healthcare workers (HCWS) regarding EVD and any emergency prone disease in Ghana. We therefore conducted a hospital based cross sectional study involving 101 HCWs from two facilities in Kumasi, Ghana to assess the level of preparedness of HCWs to respond to any possible EVD. METHODS: We administered a face-to-face questionnaire using an adapted WHO (2015) and CDC (2014) Checklist for Ebola Preparedness and assessed overall knowledge gaps, and preparedness of the Ghanaian HCWs in selected health facilities of the Ashanti Region of Ghana from October to December 2015. RESULTS: A total 92 (91.09%) HCWs", "indicated they were not adequately trained to handle an EVD suspected case. Only 25.74% (n = 26) considered their facilities sufficiently equipped to handle and manage EVD patients. When asked which disinfectant to use after attending to and caring for a suspected patient with EVD, only 8.91% (n = 9) could correctly identify the right disinfectant (χ(2) = 28.52, p = 0.001). CONCLUSION: Our study demonstrates poor knowledge and ill preparedness and unwillingness of many HCWs to attend to EVD. Beyond knowledge acquisition, there is the need for more training from time to time to fully prepare HCWs to handle any possible EVD case.", "Text: During the last outbreak of Ebola Virus Disease (EVD) and its consequential massive epidemic with very high mortality [1] , many health systems and services in West Africa were overwhelmed and disrupted. This was partly due to the poor and weak health systems coupled with unprepared and unskilled frontline healthcare workers (HCWs) compounded by poor understanding of the disease dynamics tied to lack of requisite resources. During the early part of 2014, the emergence of EVD [1] in Guinea, jolted the health care systems of West African sub-region claiming over 9800 lives [2] including more than 491 (58.7%) deaths of HCWs from 839 infections [2] . This epidemic therefore reinforced the fact that HCWs are at high-risk of being infected with the disease in line with their core duties. Empirical data generated during and after the epidemic indicated how unprepared most HCWs were in the face of the crisis. Studies in Nigeria, Guinea and India indicate the low level of knowledge,", "negative attitude and sub-standard practices that can be eliminated through continued training of HCWs as well as provision of needed and adequate resources in their line of duties [3] [4] [5] [6] .", "The countries worst hit were Liberia, Sierra Leone, Guinea and several other countries with imported cases [7] . Like most West African nations, Ghana was on high alert and was number one on the list of countries deemed to be at high risk of EVD. Thus, the country tried to make some preparations in the wake of the epidemic [8] . The government with support from donor organizations such as the World Health Organization (WHO), Médecins sans frontières (MSF) put in place resources for training of health professionals and some level of retooling of hospitals and preparedness of health workers in the face of any possible emergency scenarios. Various HCWs received both theoretical and practical training on how to manage infected and affected persons. These training sessions took the form of onsite and off site coaching as well as workshops. Simulation exercises were also conducted to bring to bear how HCWs would react during EVD emergency scenarios. For example, the German government", "through the Kumasi Centre for Collaborative Research in Tropical Medicine organized hands on training for several West African nationals on sample taking, sample testing and donning and doffing personal protective equipment (http://kccr.org). More importantly, there was the construction of three treatment centres and as well, a standby ambulance service for transportation of confirmed cases to the treatment centres. Incidentally, Ghana did not record any case in the wake of the epidemic and has so far not recorded any case of EVD. However, the response of HCWs to the scenarios identified several gaps. Following a series of training for HCWs, one could easily assume that health care workers are adequately prepared and equipped with the requisite knowledge and skills to deal with any possible EVD outbreak. It is unclear for example to what extent these exercises were practiced and for how long they were made a part of routine hospital activities. One therefore wonders how well prepared", "HCWs within Ghana are to responding not only to EVD but other epidemic prone diseases (EPDs) requiring a concerted approach to preparedness and management.", "Even though some resources have been invested in response to the EVD scare in Ghana, there has not been any assessment on the preparedness of health workers in the face of any possible emergency scenarios. Simply providing the tools such as medications, personnel protective equipment (PPE) and other logistics is no panacea for adequately and appropriately responding to EPDs. Consequently, if healthcare staff lack the basic knowledge, practical and organizational skills to plan and respond to such emergency situations, it would not only spell doom for themselves but also for the general population as was the case of the recent epidemic in West Africa. It is important for example to understand the dynamics of what will propel a HCW to be willing to put his or her life in the line of duty for a case of EVD. It is therefore critical to understand current preparedness of the healthcare worker in Ghana in order to make recommendations for future training and planning for any epidemics", "situation. The need for Ghana to therefore have empirical data on general emergency preparedness to determine and understand knowledge gaps, and to assess knowledge versus practice in a bid to provide direction for policy cannot be overemphasized. In view of this, we therefore assessed the level of preparedness, readiness and knowledge of EVD emergency response among a population of healthcare workers (HCWs) in the Kumasi Metropolis of Ashanti Region, Ghana.", "We conducted a hospital based cross-sectional study among healthcare workers at the Kumasi South and Suntreso Government Hospitals designated as \"advanced Ebola holding unit\" and \"Ebola standing team\" respectively, in the Kumasi Metropolis. The Kumasi South and Suntreso hospitals have an average monthly Out Patient Department (OPD) attendance of about 20,603 and 11,712 patients respectively and health staff of approximately 450 each. Similar to most facilities, there are more females nurses than males.\n\nWe organized a day's training for our research assistants on how to use Personal Digital Assistant device (PDAs) Samsung Galaxy note 8 GT-N5100 (Samsung Electronics Co. Ltd., Seoul, Korea) in capturing data.", "The original version of the questionnaire was pretested, with five healthcare workers who were similar in their characteristics to the members of the study population but outside the area of jurisdiction and study to ensure validity and measurement bias. The questionnaire was revised based on the suggestions and comments (mainly on how the questions had been constructed) obtained from the pilot. This was the final and validated data capturing tool used during the study.", "At both facilities, we contacted the Medical Superintendents to obtain permission to attend their morning meetings to explain the aims and objectives of the work to HCWs. During this time, HCWs were given the opportunity to ask questions. Two field assistants were stationed at each of the study sites for data capture. Some of the questions asked included the organism responsible for EVD, the mode of transmission of the disease, HCW preparedness to handle any EVD case and among other things early clinical features of the infection.", "In estimating the sample size for this study, previous data from the hospital indicates that there are approximately 900 HCWs at the two facilities. Assuming a 95% confidence interval and if 70% of these HCWs would come into contact with an EVD suspected case, allowing an error rate of 10%, approximately 87 HCWs would provide a default study power of 80% and an alpha of 5%. With approximately a non-response rate of 15% allowing us to sample 101 HCWs from the two facilities providing emergency services within the Ashanti Region of Ghana.", "Any healthcare worker attending directly to patients in emergency situation was therefore eligible for inclusion in the study. Our sampling frame consisted of a list of a total of 200. From this list, we then took a systematic random sample of all eligible health workers to represent the sample size. After obtaining written informed consent indicated by signature and or thumbprint of participants, we then administered the questionnaires within the two facilities.", "We used the WHO (2015) and CDC (2014) Checklist for Ebola Preparedness that provides practical and specific suggestions to ensure that health facilities are able to help their personnel detect possible Ebola cases, protect personnel, and respond appropriately [9, 10] . This checklist included facility evaluation, knowledge and preparedness of HCWs. Based on these checklists we developed a questionnaire to ascertain the overall knowledge and preparedness of Ghanaian HCWs on EVD outbreak. Our questionnaire was administered from a PDA and recorded each participant's demographics, preparedness, form of compensation HCWs think would be appropriate when taking care of EVD case, and knowledge of EVD during the period October to December 2015. Answers to these questions were needed from HCWs to determine information access on EVD among HCWs, their knowledge about EVD and the form of compensation HCWs think would be appropriate when taking care of EVD case among others.", "Data were collected electronically using tablets for cloud storage through CommCare ODK version 2.27.2, aggregated into Microsoft Excel file, exported into STATA version 14 and analyzed. Descriptive statistics was used to summarize the distribution of various variables into tables and figures. Categorical variables were analyzed using chisquare tests and logistic regression for associations.", "Background of the study participants Table 1 shows the background characteristics of the study participants. A total of 101 study participants were interviewed, of which 85 (84.16%) were females. Respondents were categorized into three main groups by occupation: Nurses (76.24%), Medical Doctors (19.80%) and Physician Assistants (PA) (3.96%). Majority (54.46%) of the respondents were married. A total 52.48% (53) had been practicing their profession for less than 5 years (SD = 9.22 ± 10.52 years). At both facilities, 75.25% (76) of the respondents had been working in the facility for less than 5 years (SD = 4.04 ± 4.07 years). Table 2 shows the participants knowledge and awareness of EVD. Of the 101 HCWs interviewed, 83.17% (n = 84) correctly identified the cause of EVD, 13.86% (n = 14) did not know the cause, while 2.97% (n = 3) incorrectly labeled the cause to be a bacterium. Even though one (0.99%) Doctor and 16 (15.84%) Nurses were unable to correctly identify the cause; no group", "was significantly likely to incorrectly label the cause of EVD (χ 2 = 5.41, p = 0.247).", "A total of 72 (71.29%) HCWs indicated media especially radio as the main source of information when asked where they first heard of EVD. This was significantly more than other sources (χ 2 = 45.44, p < 0.05). When asked which biosafety level laboratory (BSL) is required to test sample from suspected patient with EVD, a total 19 (18.81%) indicated BSL-3 of which 11 (10.89%) were Medical Doctors, while 8 (7.92) and 1 (0.99%) were Nurses and Physician Assistants, respectively. A further 76 (75.25%), of which 9 (8.91%) were doctors, 62 (61.39%) Nurses When asked which disinfectant to use after attending to and caring for a suspected patient with EVD, only 8.91% (n = 9) could correctly identify bleach (0.5% Sodium Hypochlorite) which disinfectant to use (χ 2 = 28.52, p = 0.001).", "Preparedness for an EVD outbreak by HCW category Table 3 shows the levels of preparedness of HCWs to handle and manage EVD outbreak. When HCWs were asked if they considered their facilities sufficiently equipped to handle and manage EVD patients, 25.74% (n = 26) responded in the affirmative, while 54.46% (55) indicated otherwise. Of this, 14 (13.86%) were Medical Doctors, 39 (38.61%) Nurses and 2 (1.98%) were PA (χ 2 = 2.66, p = 0.62). If they became accidentally infected with EVD after attending to a patient with EVD, 98 (97.03%) of those surveyed indicated they would accept to be isolated (χ 2 = 4.69, p = 0.321). Meanwhile, 44.55% (n = 45) of HCWs would willingly attend to an EVD suspected patient (χ 2 = 8.03, p = 0.09).", "A total of 92 (91.09%) HCWs surveyed indicated they were not adequately trained to handle an EVD suspected case. When asked to rate their competence in handling an EVD suspected patient, 18.81% (n = 19) indicated they had little confidence and competence, while 6.93% (n = 7) indicated they were extremely confident to handle a suspected case of EVD (χ 2 = 13.09, p = 0.11).", "Beyond EVD, we asked our survey population to name other epidemic prone diseases. Of the total number of HCWs interviewed, 56.43% (57/101) mentioned epidemic diseases of bacteria origin such as tuberculosis and cholera. A further 33.70% (34/101) named diseases of viral origin such as SARS, Flu, HIV, Lassa fever and dengue, while 9.90% (10) mentioned others referring to malaria. When asked the form of compensation HCWs thought would be appropriate when taking care of an Ebola suspected patient, responses given included personal insurance (32/101), family compensation in case of death (31/101), money (30/101) and awards (8/101) while others also suggested job promotion (7/101), and others (18/101).\n\nOur survey population recommended the provision of logistics and training as two key issues in the way forward in adequately preparing HCWs towards any epidemic prone diseases.", "Many issues surrounding the preparedness of HCWs have been extensively discussed globally especially in the aftermath of the Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV) and the Middle East Respiratory Syndrome (MERS)-CoV epidemic. While it is on record that the recent EVD outbreak recorded very high mortality among HCWs, to the best of our knowledge, only few studies have addressed these issues in anticipation of an EVD outbreak particularly in countries not hit by the EVD epidemic and especially in sub Saharan Africa, such a study is almost non-existent. Our study therefore assessed how prepared HCWs are in the face of a possible EVD epidemic.", "The results of this survey showed that more than half (54.46%) HCWs indicated that their facilities were not ready to handle EVD cases. Nearly 92% indicated they were not adequately trained to handle an EVD suspected case and it is not surprising that less than 50% indicated they would willingly attend to a suspected patient. Moreover, nearly a third of HCWs would also want insurance for themselves and their families in case they were infected with EVD.", "These results are clearly indicative of how ill-prepared the HCWs surveyed are in the face a potentially life threatening epidemic prone diseases, such as EVD in Ghana. In this study, only 25.7% of HCWs said their facility was sufficiently equipped to handle an EVD outbreak. Such low ratings of the hospitals by majority of HCWs is a mark of lack of confidence in their facilities preparedness and this may actually indicate a real lack of preparedness and readiness of the hospitals to handle not only EVD cases but potentially other epidemic prone diseases. Alternatively, it could also mean that HCWs were probably unaware of preparatory work and retooling of their facilities to handle EVD outbreak situation.", "Willingness to work during outbreaks and emergencies is deemed a sense of duty even in the face of risk. In this study, less than 50% of HCWs indicated their willingness to work in the event of an EVD outbreak. Additionally, over one third indicated various forms of compensation for themselves or families in case of death or while taking care of an EVD case. This implies that if HCWs are assured or guaranteed that they and or their families would be taken care of in case of death or while taking care of an EVD case, they will willingly work in the face of any emergency scenario. The assumption is that HCWs would willingly work in the face of an infectious diseases emergency and respond appropriately; however, there are evidences of HCWs avoiding this \"sacred duty\" in caring for patients and would leave patients vulnerable in times of crisis [11] . In order to prevent HCWs from being infected while obliged to work even in the face of personal risk as required by their codes of ethics", "and professionalism, it is imperative to ensure that appropriate conventional standards, guarantees and effective public health practices are met to enable HCWs respond to such outbreaks so that they are not infected and or affected despite the risks they might face and continue to face [12] . Thus, appropriate training of HCWs as indicated by those surveyed during the study, coupled with retooling of some health facilities preparation is very critical in ensuring that they are equipped with the needed knowledge and tools needed to work with in the face of any epidemic.", "General knowledge of EVD is crucial to adequately respond to and care for patients. Nearly 17% of our study population could not identify that EVD as caused by a virus. Arguably, infection control measures would be difficult and problematic for such HCWs. Less than 10% could correctly identify 0.5% Sodium Hypochlorite as the best disinfectant out of the many options provided. This strongly contradicts a similar study in Conakry conducted during the peak of the epidemic where 68% of HCWs knew the correct concentration of disinfectant [5] . While not trying to compare these two scenarios, this information may be vital in the realization that knowledge of HCWs in infection prevention and control measures is critical in their line of duty.", "This study showed that most HCWs first heard of EVD through the media especially radio. This establishes the crucial role media plays in informing the general populace in such disease outbreaks. In Ghana, there are over 350 media outlets (radio and television put together) and majority of households either own a radio, television or have access to internet. Notwithstanding the media pluralism, it is still incumbent upon health institutions and facilities to organize special training on any emerging infectious disease that occurs globally to update the knowledge of HCWs.", "Isolation is a key public health measure to prevent the spread of infectious diseases. In this study, over 97% of HCW indicated their willingness to comply and accept to be isolated in case they became infected after attending to suspected EVD patient. However, a small proportion of HCWs surveyed stated that they would be very unhappy, and this could ultimately affect compliance. Isolation is one of the oldest methods of controlling communicable disease outbreaks for patients [13] . However, it is worthy of note that less that 50% said they would be willing to attend to an EVD suspected patient and we suspected that this could be related to fear of personal safety [14] . Emergency response from an epidemic prone disease from an exotic virulent virus or pathogen will naturally spark some level of fear and skepticism among any group of individuals especially when their knowledge about the dynamics of the disease outbreak is low. There are stories of HCWs who have avoided the", "responsibility of treating patients [15] and this was apparent in the HIV/AIDS and Severe Acute Respiratory Syndrome-Coronavirus (SARS-CoV) during the 1980s and 2003, respectively where the fear of contact with suspected and infected patients gripped some HCWs [16, 17] . In the long run, this fear would likely affect their confidence and commitment to professionalism.", "The results of this study point to the fact that knowledge and the provision of tools such as personnel protective equipment (PPE) and other logistics alone is not good enough strategy. There might be the need to as well address issues related to myth, and culture as well as assurances of upkeep should one be infected. The general outlook one's country's devotion to their health staff might be a contributory factor in all of this and cannot be ignored. However, getting HCWs inspired and feel safe in caring for such highly infectious disease outbreaks is critical. During our study, HCWs indicated various forms of compensation to be paid to them should they be affected in the case of EVD attack.", "This study had some inherent limitations. This was an exploratory study and our sample size was limited. Therefore, while not trying to generalize the results, we are of the opinion that this may be a reflection of HCWs in general. Additionally, since our study focused mainly on two health facilities, we are again careful in extrapolating these to other to reflect other facilities. Moreover, since this has not been a real experience, and a questionnaire-based survey, responses may not accurately reflect real-life experiences in the event of an EVD epidemic. Despite these limitations, the need for training was strong among HCWs. The results further demonstrate the ill-preparedness of health facilities, and the large proportion of HCWs unwillingness to attend to a suspected case of EVD. This thus calls for concerted efforts of health institutions and facilities to fully equip and prepare HCWs with the requisite tools and knowledge and ensuring competency to handle any epidemic prone", "disease." ]	[ 2 ]	3,596	4,831
1,688	How many healthcare workers would be willing to continue working during the Ebola virus outbreak?	4,253	[ "less than 50%" ]	[ "Health care workers indicate ill preparedness for Ebola Virus Disease outbreak in Ashanti Region of Ghana\n\nhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC5461762/\n\nSHA: f8efe7295a7cf875c8a695df3e87a42e651ce60d\n\nAuthors: Annan, Augustina Angelina; Yar, Denis Dekugmen; Owusu, Michael; Biney, Eno Akua; Forson, Paa Kobina; Okyere, Portia Boakye; Gyimah, Akosua Adumea; Owusu-Dabo, Ellis\nDate: 2017-06-06\nDOI: 10.1186/s12889-017-4474-6\nLicense: cc-by", "Abstract: BACKGROUND: The recent Ebola Virus Disease (EVD) epidemic that hit some countries in West Africa underscores the need to train front line high-risk health workers on disease prevention skills. Although Ghana did not record (and is yet to) any case, and several health workers have received numerous training schemes, there is no record of any study that assessed preparedness of healthcare workers (HCWS) regarding EVD and any emergency prone disease in Ghana. We therefore conducted a hospital based cross sectional study involving 101 HCWs from two facilities in Kumasi, Ghana to assess the level of preparedness of HCWs to respond to any possible EVD. METHODS: We administered a face-to-face questionnaire using an adapted WHO (2015) and CDC (2014) Checklist for Ebola Preparedness and assessed overall knowledge gaps, and preparedness of the Ghanaian HCWs in selected health facilities of the Ashanti Region of Ghana from October to December 2015. RESULTS: A total 92 (91.09%) HCWs", "indicated they were not adequately trained to handle an EVD suspected case. Only 25.74% (n = 26) considered their facilities sufficiently equipped to handle and manage EVD patients. When asked which disinfectant to use after attending to and caring for a suspected patient with EVD, only 8.91% (n = 9) could correctly identify the right disinfectant (χ(2) = 28.52, p = 0.001). CONCLUSION: Our study demonstrates poor knowledge and ill preparedness and unwillingness of many HCWs to attend to EVD. Beyond knowledge acquisition, there is the need for more training from time to time to fully prepare HCWs to handle any possible EVD case.", "Text: During the last outbreak of Ebola Virus Disease (EVD) and its consequential massive epidemic with very high mortality [1] , many health systems and services in West Africa were overwhelmed and disrupted. This was partly due to the poor and weak health systems coupled with unprepared and unskilled frontline healthcare workers (HCWs) compounded by poor understanding of the disease dynamics tied to lack of requisite resources. During the early part of 2014, the emergence of EVD [1] in Guinea, jolted the health care systems of West African sub-region claiming over 9800 lives [2] including more than 491 (58.7%) deaths of HCWs from 839 infections [2] . This epidemic therefore reinforced the fact that HCWs are at high-risk of being infected with the disease in line with their core duties. Empirical data generated during and after the epidemic indicated how unprepared most HCWs were in the face of the crisis. Studies in Nigeria, Guinea and India indicate the low level of knowledge,", "negative attitude and sub-standard practices that can be eliminated through continued training of HCWs as well as provision of needed and adequate resources in their line of duties [3] [4] [5] [6] .", "The countries worst hit were Liberia, Sierra Leone, Guinea and several other countries with imported cases [7] . Like most West African nations, Ghana was on high alert and was number one on the list of countries deemed to be at high risk of EVD. Thus, the country tried to make some preparations in the wake of the epidemic [8] . The government with support from donor organizations such as the World Health Organization (WHO), Médecins sans frontières (MSF) put in place resources for training of health professionals and some level of retooling of hospitals and preparedness of health workers in the face of any possible emergency scenarios. Various HCWs received both theoretical and practical training on how to manage infected and affected persons. These training sessions took the form of onsite and off site coaching as well as workshops. Simulation exercises were also conducted to bring to bear how HCWs would react during EVD emergency scenarios. For example, the German government", "through the Kumasi Centre for Collaborative Research in Tropical Medicine organized hands on training for several West African nationals on sample taking, sample testing and donning and doffing personal protective equipment (http://kccr.org). More importantly, there was the construction of three treatment centres and as well, a standby ambulance service for transportation of confirmed cases to the treatment centres. Incidentally, Ghana did not record any case in the wake of the epidemic and has so far not recorded any case of EVD. However, the response of HCWs to the scenarios identified several gaps. Following a series of training for HCWs, one could easily assume that health care workers are adequately prepared and equipped with the requisite knowledge and skills to deal with any possible EVD outbreak. It is unclear for example to what extent these exercises were practiced and for how long they were made a part of routine hospital activities. One therefore wonders how well prepared", "HCWs within Ghana are to responding not only to EVD but other epidemic prone diseases (EPDs) requiring a concerted approach to preparedness and management.", "Even though some resources have been invested in response to the EVD scare in Ghana, there has not been any assessment on the preparedness of health workers in the face of any possible emergency scenarios. Simply providing the tools such as medications, personnel protective equipment (PPE) and other logistics is no panacea for adequately and appropriately responding to EPDs. Consequently, if healthcare staff lack the basic knowledge, practical and organizational skills to plan and respond to such emergency situations, it would not only spell doom for themselves but also for the general population as was the case of the recent epidemic in West Africa. It is important for example to understand the dynamics of what will propel a HCW to be willing to put his or her life in the line of duty for a case of EVD. It is therefore critical to understand current preparedness of the healthcare worker in Ghana in order to make recommendations for future training and planning for any epidemics", "situation. The need for Ghana to therefore have empirical data on general emergency preparedness to determine and understand knowledge gaps, and to assess knowledge versus practice in a bid to provide direction for policy cannot be overemphasized. In view of this, we therefore assessed the level of preparedness, readiness and knowledge of EVD emergency response among a population of healthcare workers (HCWs) in the Kumasi Metropolis of Ashanti Region, Ghana.", "We conducted a hospital based cross-sectional study among healthcare workers at the Kumasi South and Suntreso Government Hospitals designated as \"advanced Ebola holding unit\" and \"Ebola standing team\" respectively, in the Kumasi Metropolis. The Kumasi South and Suntreso hospitals have an average monthly Out Patient Department (OPD) attendance of about 20,603 and 11,712 patients respectively and health staff of approximately 450 each. Similar to most facilities, there are more females nurses than males.\n\nWe organized a day's training for our research assistants on how to use Personal Digital Assistant device (PDAs) Samsung Galaxy note 8 GT-N5100 (Samsung Electronics Co. Ltd., Seoul, Korea) in capturing data.", "The original version of the questionnaire was pretested, with five healthcare workers who were similar in their characteristics to the members of the study population but outside the area of jurisdiction and study to ensure validity and measurement bias. The questionnaire was revised based on the suggestions and comments (mainly on how the questions had been constructed) obtained from the pilot. This was the final and validated data capturing tool used during the study.", "At both facilities, we contacted the Medical Superintendents to obtain permission to attend their morning meetings to explain the aims and objectives of the work to HCWs. During this time, HCWs were given the opportunity to ask questions. Two field assistants were stationed at each of the study sites for data capture. Some of the questions asked included the organism responsible for EVD, the mode of transmission of the disease, HCW preparedness to handle any EVD case and among other things early clinical features of the infection.", "In estimating the sample size for this study, previous data from the hospital indicates that there are approximately 900 HCWs at the two facilities. Assuming a 95% confidence interval and if 70% of these HCWs would come into contact with an EVD suspected case, allowing an error rate of 10%, approximately 87 HCWs would provide a default study power of 80% and an alpha of 5%. With approximately a non-response rate of 15% allowing us to sample 101 HCWs from the two facilities providing emergency services within the Ashanti Region of Ghana.", "Any healthcare worker attending directly to patients in emergency situation was therefore eligible for inclusion in the study. Our sampling frame consisted of a list of a total of 200. From this list, we then took a systematic random sample of all eligible health workers to represent the sample size. After obtaining written informed consent indicated by signature and or thumbprint of participants, we then administered the questionnaires within the two facilities.", "We used the WHO (2015) and CDC (2014) Checklist for Ebola Preparedness that provides practical and specific suggestions to ensure that health facilities are able to help their personnel detect possible Ebola cases, protect personnel, and respond appropriately [9, 10] . This checklist included facility evaluation, knowledge and preparedness of HCWs. Based on these checklists we developed a questionnaire to ascertain the overall knowledge and preparedness of Ghanaian HCWs on EVD outbreak. Our questionnaire was administered from a PDA and recorded each participant's demographics, preparedness, form of compensation HCWs think would be appropriate when taking care of EVD case, and knowledge of EVD during the period October to December 2015. Answers to these questions were needed from HCWs to determine information access on EVD among HCWs, their knowledge about EVD and the form of compensation HCWs think would be appropriate when taking care of EVD case among others.", "Data were collected electronically using tablets for cloud storage through CommCare ODK version 2.27.2, aggregated into Microsoft Excel file, exported into STATA version 14 and analyzed. Descriptive statistics was used to summarize the distribution of various variables into tables and figures. Categorical variables were analyzed using chisquare tests and logistic regression for associations.", "Background of the study participants Table 1 shows the background characteristics of the study participants. A total of 101 study participants were interviewed, of which 85 (84.16%) were females. Respondents were categorized into three main groups by occupation: Nurses (76.24%), Medical Doctors (19.80%) and Physician Assistants (PA) (3.96%). Majority (54.46%) of the respondents were married. A total 52.48% (53) had been practicing their profession for less than 5 years (SD = 9.22 ± 10.52 years). At both facilities, 75.25% (76) of the respondents had been working in the facility for less than 5 years (SD = 4.04 ± 4.07 years). Table 2 shows the participants knowledge and awareness of EVD. Of the 101 HCWs interviewed, 83.17% (n = 84) correctly identified the cause of EVD, 13.86% (n = 14) did not know the cause, while 2.97% (n = 3) incorrectly labeled the cause to be a bacterium. Even though one (0.99%) Doctor and 16 (15.84%) Nurses were unable to correctly identify the cause; no group", "was significantly likely to incorrectly label the cause of EVD (χ 2 = 5.41, p = 0.247).", "A total of 72 (71.29%) HCWs indicated media especially radio as the main source of information when asked where they first heard of EVD. This was significantly more than other sources (χ 2 = 45.44, p < 0.05). When asked which biosafety level laboratory (BSL) is required to test sample from suspected patient with EVD, a total 19 (18.81%) indicated BSL-3 of which 11 (10.89%) were Medical Doctors, while 8 (7.92) and 1 (0.99%) were Nurses and Physician Assistants, respectively. A further 76 (75.25%), of which 9 (8.91%) were doctors, 62 (61.39%) Nurses When asked which disinfectant to use after attending to and caring for a suspected patient with EVD, only 8.91% (n = 9) could correctly identify bleach (0.5% Sodium Hypochlorite) which disinfectant to use (χ 2 = 28.52, p = 0.001).", "Preparedness for an EVD outbreak by HCW category Table 3 shows the levels of preparedness of HCWs to handle and manage EVD outbreak. When HCWs were asked if they considered their facilities sufficiently equipped to handle and manage EVD patients, 25.74% (n = 26) responded in the affirmative, while 54.46% (55) indicated otherwise. Of this, 14 (13.86%) were Medical Doctors, 39 (38.61%) Nurses and 2 (1.98%) were PA (χ 2 = 2.66, p = 0.62). If they became accidentally infected with EVD after attending to a patient with EVD, 98 (97.03%) of those surveyed indicated they would accept to be isolated (χ 2 = 4.69, p = 0.321). Meanwhile, 44.55% (n = 45) of HCWs would willingly attend to an EVD suspected patient (χ 2 = 8.03, p = 0.09).", "A total of 92 (91.09%) HCWs surveyed indicated they were not adequately trained to handle an EVD suspected case. When asked to rate their competence in handling an EVD suspected patient, 18.81% (n = 19) indicated they had little confidence and competence, while 6.93% (n = 7) indicated they were extremely confident to handle a suspected case of EVD (χ 2 = 13.09, p = 0.11).", "Beyond EVD, we asked our survey population to name other epidemic prone diseases. Of the total number of HCWs interviewed, 56.43% (57/101) mentioned epidemic diseases of bacteria origin such as tuberculosis and cholera. A further 33.70% (34/101) named diseases of viral origin such as SARS, Flu, HIV, Lassa fever and dengue, while 9.90% (10) mentioned others referring to malaria. When asked the form of compensation HCWs thought would be appropriate when taking care of an Ebola suspected patient, responses given included personal insurance (32/101), family compensation in case of death (31/101), money (30/101) and awards (8/101) while others also suggested job promotion (7/101), and others (18/101).\n\nOur survey population recommended the provision of logistics and training as two key issues in the way forward in adequately preparing HCWs towards any epidemic prone diseases.", "Many issues surrounding the preparedness of HCWs have been extensively discussed globally especially in the aftermath of the Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV) and the Middle East Respiratory Syndrome (MERS)-CoV epidemic. While it is on record that the recent EVD outbreak recorded very high mortality among HCWs, to the best of our knowledge, only few studies have addressed these issues in anticipation of an EVD outbreak particularly in countries not hit by the EVD epidemic and especially in sub Saharan Africa, such a study is almost non-existent. Our study therefore assessed how prepared HCWs are in the face of a possible EVD epidemic.", "The results of this survey showed that more than half (54.46%) HCWs indicated that their facilities were not ready to handle EVD cases. Nearly 92% indicated they were not adequately trained to handle an EVD suspected case and it is not surprising that less than 50% indicated they would willingly attend to a suspected patient. Moreover, nearly a third of HCWs would also want insurance for themselves and their families in case they were infected with EVD.", "These results are clearly indicative of how ill-prepared the HCWs surveyed are in the face a potentially life threatening epidemic prone diseases, such as EVD in Ghana. In this study, only 25.7% of HCWs said their facility was sufficiently equipped to handle an EVD outbreak. Such low ratings of the hospitals by majority of HCWs is a mark of lack of confidence in their facilities preparedness and this may actually indicate a real lack of preparedness and readiness of the hospitals to handle not only EVD cases but potentially other epidemic prone diseases. Alternatively, it could also mean that HCWs were probably unaware of preparatory work and retooling of their facilities to handle EVD outbreak situation.", "Willingness to work during outbreaks and emergencies is deemed a sense of duty even in the face of risk. In this study, less than 50% of HCWs indicated their willingness to work in the event of an EVD outbreak. Additionally, over one third indicated various forms of compensation for themselves or families in case of death or while taking care of an EVD case. This implies that if HCWs are assured or guaranteed that they and or their families would be taken care of in case of death or while taking care of an EVD case, they will willingly work in the face of any emergency scenario. The assumption is that HCWs would willingly work in the face of an infectious diseases emergency and respond appropriately; however, there are evidences of HCWs avoiding this \"sacred duty\" in caring for patients and would leave patients vulnerable in times of crisis [11] . In order to prevent HCWs from being infected while obliged to work even in the face of personal risk as required by their codes of ethics", "and professionalism, it is imperative to ensure that appropriate conventional standards, guarantees and effective public health practices are met to enable HCWs respond to such outbreaks so that they are not infected and or affected despite the risks they might face and continue to face [12] . Thus, appropriate training of HCWs as indicated by those surveyed during the study, coupled with retooling of some health facilities preparation is very critical in ensuring that they are equipped with the needed knowledge and tools needed to work with in the face of any epidemic.", "General knowledge of EVD is crucial to adequately respond to and care for patients. Nearly 17% of our study population could not identify that EVD as caused by a virus. Arguably, infection control measures would be difficult and problematic for such HCWs. Less than 10% could correctly identify 0.5% Sodium Hypochlorite as the best disinfectant out of the many options provided. This strongly contradicts a similar study in Conakry conducted during the peak of the epidemic where 68% of HCWs knew the correct concentration of disinfectant [5] . While not trying to compare these two scenarios, this information may be vital in the realization that knowledge of HCWs in infection prevention and control measures is critical in their line of duty.", "This study showed that most HCWs first heard of EVD through the media especially radio. This establishes the crucial role media plays in informing the general populace in such disease outbreaks. In Ghana, there are over 350 media outlets (radio and television put together) and majority of households either own a radio, television or have access to internet. Notwithstanding the media pluralism, it is still incumbent upon health institutions and facilities to organize special training on any emerging infectious disease that occurs globally to update the knowledge of HCWs.", "Isolation is a key public health measure to prevent the spread of infectious diseases. In this study, over 97% of HCW indicated their willingness to comply and accept to be isolated in case they became infected after attending to suspected EVD patient. However, a small proportion of HCWs surveyed stated that they would be very unhappy, and this could ultimately affect compliance. Isolation is one of the oldest methods of controlling communicable disease outbreaks for patients [13] . However, it is worthy of note that less that 50% said they would be willing to attend to an EVD suspected patient and we suspected that this could be related to fear of personal safety [14] . Emergency response from an epidemic prone disease from an exotic virulent virus or pathogen will naturally spark some level of fear and skepticism among any group of individuals especially when their knowledge about the dynamics of the disease outbreak is low. There are stories of HCWs who have avoided the", "responsibility of treating patients [15] and this was apparent in the HIV/AIDS and Severe Acute Respiratory Syndrome-Coronavirus (SARS-CoV) during the 1980s and 2003, respectively where the fear of contact with suspected and infected patients gripped some HCWs [16, 17] . In the long run, this fear would likely affect their confidence and commitment to professionalism.", "The results of this study point to the fact that knowledge and the provision of tools such as personnel protective equipment (PPE) and other logistics alone is not good enough strategy. There might be the need to as well address issues related to myth, and culture as well as assurances of upkeep should one be infected. The general outlook one's country's devotion to their health staff might be a contributory factor in all of this and cannot be ignored. However, getting HCWs inspired and feel safe in caring for such highly infectious disease outbreaks is critical. During our study, HCWs indicated various forms of compensation to be paid to them should they be affected in the case of EVD attack.", "This study had some inherent limitations. This was an exploratory study and our sample size was limited. Therefore, while not trying to generalize the results, we are of the opinion that this may be a reflection of HCWs in general. Additionally, since our study focused mainly on two health facilities, we are again careful in extrapolating these to other to reflect other facilities. Moreover, since this has not been a real experience, and a questionnaire-based survey, responses may not accurately reflect real-life experiences in the event of an EVD epidemic. Despite these limitations, the need for training was strong among HCWs. The results further demonstrate the ill-preparedness of health facilities, and the large proportion of HCWs unwillingness to attend to a suspected case of EVD. This thus calls for concerted efforts of health institutions and facilities to fully equip and prepare HCWs with the requisite tools and knowledge and ensuring competency to handle any epidemic prone", "disease." ]	[ 24 ]	3,596	4,831
1,688	What does the study suggest would make healthcare workers more willing to care for patients during an Ebola virus outbreak?	4,254	[ "if HCWs are assured or guaranteed that they and or their families would be taken care of in case of death or while taking care of an EVD case," ]	[ "Health care workers indicate ill preparedness for Ebola Virus Disease outbreak in Ashanti Region of Ghana\n\nhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC5461762/\n\nSHA: f8efe7295a7cf875c8a695df3e87a42e651ce60d\n\nAuthors: Annan, Augustina Angelina; Yar, Denis Dekugmen; Owusu, Michael; Biney, Eno Akua; Forson, Paa Kobina; Okyere, Portia Boakye; Gyimah, Akosua Adumea; Owusu-Dabo, Ellis\nDate: 2017-06-06\nDOI: 10.1186/s12889-017-4474-6\nLicense: cc-by", "Abstract: BACKGROUND: The recent Ebola Virus Disease (EVD) epidemic that hit some countries in West Africa underscores the need to train front line high-risk health workers on disease prevention skills. Although Ghana did not record (and is yet to) any case, and several health workers have received numerous training schemes, there is no record of any study that assessed preparedness of healthcare workers (HCWS) regarding EVD and any emergency prone disease in Ghana. We therefore conducted a hospital based cross sectional study involving 101 HCWs from two facilities in Kumasi, Ghana to assess the level of preparedness of HCWs to respond to any possible EVD. METHODS: We administered a face-to-face questionnaire using an adapted WHO (2015) and CDC (2014) Checklist for Ebola Preparedness and assessed overall knowledge gaps, and preparedness of the Ghanaian HCWs in selected health facilities of the Ashanti Region of Ghana from October to December 2015. RESULTS: A total 92 (91.09%) HCWs", "indicated they were not adequately trained to handle an EVD suspected case. Only 25.74% (n = 26) considered their facilities sufficiently equipped to handle and manage EVD patients. When asked which disinfectant to use after attending to and caring for a suspected patient with EVD, only 8.91% (n = 9) could correctly identify the right disinfectant (χ(2) = 28.52, p = 0.001). CONCLUSION: Our study demonstrates poor knowledge and ill preparedness and unwillingness of many HCWs to attend to EVD. Beyond knowledge acquisition, there is the need for more training from time to time to fully prepare HCWs to handle any possible EVD case.", "Text: During the last outbreak of Ebola Virus Disease (EVD) and its consequential massive epidemic with very high mortality [1] , many health systems and services in West Africa were overwhelmed and disrupted. This was partly due to the poor and weak health systems coupled with unprepared and unskilled frontline healthcare workers (HCWs) compounded by poor understanding of the disease dynamics tied to lack of requisite resources. During the early part of 2014, the emergence of EVD [1] in Guinea, jolted the health care systems of West African sub-region claiming over 9800 lives [2] including more than 491 (58.7%) deaths of HCWs from 839 infections [2] . This epidemic therefore reinforced the fact that HCWs are at high-risk of being infected with the disease in line with their core duties. Empirical data generated during and after the epidemic indicated how unprepared most HCWs were in the face of the crisis. Studies in Nigeria, Guinea and India indicate the low level of knowledge,", "negative attitude and sub-standard practices that can be eliminated through continued training of HCWs as well as provision of needed and adequate resources in their line of duties [3] [4] [5] [6] .", "The countries worst hit were Liberia, Sierra Leone, Guinea and several other countries with imported cases [7] . Like most West African nations, Ghana was on high alert and was number one on the list of countries deemed to be at high risk of EVD. Thus, the country tried to make some preparations in the wake of the epidemic [8] . The government with support from donor organizations such as the World Health Organization (WHO), Médecins sans frontières (MSF) put in place resources for training of health professionals and some level of retooling of hospitals and preparedness of health workers in the face of any possible emergency scenarios. Various HCWs received both theoretical and practical training on how to manage infected and affected persons. These training sessions took the form of onsite and off site coaching as well as workshops. Simulation exercises were also conducted to bring to bear how HCWs would react during EVD emergency scenarios. For example, the German government", "through the Kumasi Centre for Collaborative Research in Tropical Medicine organized hands on training for several West African nationals on sample taking, sample testing and donning and doffing personal protective equipment (http://kccr.org). More importantly, there was the construction of three treatment centres and as well, a standby ambulance service for transportation of confirmed cases to the treatment centres. Incidentally, Ghana did not record any case in the wake of the epidemic and has so far not recorded any case of EVD. However, the response of HCWs to the scenarios identified several gaps. Following a series of training for HCWs, one could easily assume that health care workers are adequately prepared and equipped with the requisite knowledge and skills to deal with any possible EVD outbreak. It is unclear for example to what extent these exercises were practiced and for how long they were made a part of routine hospital activities. One therefore wonders how well prepared", "HCWs within Ghana are to responding not only to EVD but other epidemic prone diseases (EPDs) requiring a concerted approach to preparedness and management.", "Even though some resources have been invested in response to the EVD scare in Ghana, there has not been any assessment on the preparedness of health workers in the face of any possible emergency scenarios. Simply providing the tools such as medications, personnel protective equipment (PPE) and other logistics is no panacea for adequately and appropriately responding to EPDs. Consequently, if healthcare staff lack the basic knowledge, practical and organizational skills to plan and respond to such emergency situations, it would not only spell doom for themselves but also for the general population as was the case of the recent epidemic in West Africa. It is important for example to understand the dynamics of what will propel a HCW to be willing to put his or her life in the line of duty for a case of EVD. It is therefore critical to understand current preparedness of the healthcare worker in Ghana in order to make recommendations for future training and planning for any epidemics", "situation. The need for Ghana to therefore have empirical data on general emergency preparedness to determine and understand knowledge gaps, and to assess knowledge versus practice in a bid to provide direction for policy cannot be overemphasized. In view of this, we therefore assessed the level of preparedness, readiness and knowledge of EVD emergency response among a population of healthcare workers (HCWs) in the Kumasi Metropolis of Ashanti Region, Ghana.", "We conducted a hospital based cross-sectional study among healthcare workers at the Kumasi South and Suntreso Government Hospitals designated as \"advanced Ebola holding unit\" and \"Ebola standing team\" respectively, in the Kumasi Metropolis. The Kumasi South and Suntreso hospitals have an average monthly Out Patient Department (OPD) attendance of about 20,603 and 11,712 patients respectively and health staff of approximately 450 each. Similar to most facilities, there are more females nurses than males.\n\nWe organized a day's training for our research assistants on how to use Personal Digital Assistant device (PDAs) Samsung Galaxy note 8 GT-N5100 (Samsung Electronics Co. Ltd., Seoul, Korea) in capturing data.", "The original version of the questionnaire was pretested, with five healthcare workers who were similar in their characteristics to the members of the study population but outside the area of jurisdiction and study to ensure validity and measurement bias. The questionnaire was revised based on the suggestions and comments (mainly on how the questions had been constructed) obtained from the pilot. This was the final and validated data capturing tool used during the study.", "At both facilities, we contacted the Medical Superintendents to obtain permission to attend their morning meetings to explain the aims and objectives of the work to HCWs. During this time, HCWs were given the opportunity to ask questions. Two field assistants were stationed at each of the study sites for data capture. Some of the questions asked included the organism responsible for EVD, the mode of transmission of the disease, HCW preparedness to handle any EVD case and among other things early clinical features of the infection.", "In estimating the sample size for this study, previous data from the hospital indicates that there are approximately 900 HCWs at the two facilities. Assuming a 95% confidence interval and if 70% of these HCWs would come into contact with an EVD suspected case, allowing an error rate of 10%, approximately 87 HCWs would provide a default study power of 80% and an alpha of 5%. With approximately a non-response rate of 15% allowing us to sample 101 HCWs from the two facilities providing emergency services within the Ashanti Region of Ghana.", "Any healthcare worker attending directly to patients in emergency situation was therefore eligible for inclusion in the study. Our sampling frame consisted of a list of a total of 200. From this list, we then took a systematic random sample of all eligible health workers to represent the sample size. After obtaining written informed consent indicated by signature and or thumbprint of participants, we then administered the questionnaires within the two facilities.", "We used the WHO (2015) and CDC (2014) Checklist for Ebola Preparedness that provides practical and specific suggestions to ensure that health facilities are able to help their personnel detect possible Ebola cases, protect personnel, and respond appropriately [9, 10] . This checklist included facility evaluation, knowledge and preparedness of HCWs. Based on these checklists we developed a questionnaire to ascertain the overall knowledge and preparedness of Ghanaian HCWs on EVD outbreak. Our questionnaire was administered from a PDA and recorded each participant's demographics, preparedness, form of compensation HCWs think would be appropriate when taking care of EVD case, and knowledge of EVD during the period October to December 2015. Answers to these questions were needed from HCWs to determine information access on EVD among HCWs, their knowledge about EVD and the form of compensation HCWs think would be appropriate when taking care of EVD case among others.", "Data were collected electronically using tablets for cloud storage through CommCare ODK version 2.27.2, aggregated into Microsoft Excel file, exported into STATA version 14 and analyzed. Descriptive statistics was used to summarize the distribution of various variables into tables and figures. Categorical variables were analyzed using chisquare tests and logistic regression for associations.", "Background of the study participants Table 1 shows the background characteristics of the study participants. A total of 101 study participants were interviewed, of which 85 (84.16%) were females. Respondents were categorized into three main groups by occupation: Nurses (76.24%), Medical Doctors (19.80%) and Physician Assistants (PA) (3.96%). Majority (54.46%) of the respondents were married. A total 52.48% (53) had been practicing their profession for less than 5 years (SD = 9.22 ± 10.52 years). At both facilities, 75.25% (76) of the respondents had been working in the facility for less than 5 years (SD = 4.04 ± 4.07 years). Table 2 shows the participants knowledge and awareness of EVD. Of the 101 HCWs interviewed, 83.17% (n = 84) correctly identified the cause of EVD, 13.86% (n = 14) did not know the cause, while 2.97% (n = 3) incorrectly labeled the cause to be a bacterium. Even though one (0.99%) Doctor and 16 (15.84%) Nurses were unable to correctly identify the cause; no group", "was significantly likely to incorrectly label the cause of EVD (χ 2 = 5.41, p = 0.247).", "A total of 72 (71.29%) HCWs indicated media especially radio as the main source of information when asked where they first heard of EVD. This was significantly more than other sources (χ 2 = 45.44, p < 0.05). When asked which biosafety level laboratory (BSL) is required to test sample from suspected patient with EVD, a total 19 (18.81%) indicated BSL-3 of which 11 (10.89%) were Medical Doctors, while 8 (7.92) and 1 (0.99%) were Nurses and Physician Assistants, respectively. A further 76 (75.25%), of which 9 (8.91%) were doctors, 62 (61.39%) Nurses When asked which disinfectant to use after attending to and caring for a suspected patient with EVD, only 8.91% (n = 9) could correctly identify bleach (0.5% Sodium Hypochlorite) which disinfectant to use (χ 2 = 28.52, p = 0.001).", "Preparedness for an EVD outbreak by HCW category Table 3 shows the levels of preparedness of HCWs to handle and manage EVD outbreak. When HCWs were asked if they considered their facilities sufficiently equipped to handle and manage EVD patients, 25.74% (n = 26) responded in the affirmative, while 54.46% (55) indicated otherwise. Of this, 14 (13.86%) were Medical Doctors, 39 (38.61%) Nurses and 2 (1.98%) were PA (χ 2 = 2.66, p = 0.62). If they became accidentally infected with EVD after attending to a patient with EVD, 98 (97.03%) of those surveyed indicated they would accept to be isolated (χ 2 = 4.69, p = 0.321). Meanwhile, 44.55% (n = 45) of HCWs would willingly attend to an EVD suspected patient (χ 2 = 8.03, p = 0.09).", "A total of 92 (91.09%) HCWs surveyed indicated they were not adequately trained to handle an EVD suspected case. When asked to rate their competence in handling an EVD suspected patient, 18.81% (n = 19) indicated they had little confidence and competence, while 6.93% (n = 7) indicated they were extremely confident to handle a suspected case of EVD (χ 2 = 13.09, p = 0.11).", "Beyond EVD, we asked our survey population to name other epidemic prone diseases. Of the total number of HCWs interviewed, 56.43% (57/101) mentioned epidemic diseases of bacteria origin such as tuberculosis and cholera. A further 33.70% (34/101) named diseases of viral origin such as SARS, Flu, HIV, Lassa fever and dengue, while 9.90% (10) mentioned others referring to malaria. When asked the form of compensation HCWs thought would be appropriate when taking care of an Ebola suspected patient, responses given included personal insurance (32/101), family compensation in case of death (31/101), money (30/101) and awards (8/101) while others also suggested job promotion (7/101), and others (18/101).\n\nOur survey population recommended the provision of logistics and training as two key issues in the way forward in adequately preparing HCWs towards any epidemic prone diseases.", "Many issues surrounding the preparedness of HCWs have been extensively discussed globally especially in the aftermath of the Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV) and the Middle East Respiratory Syndrome (MERS)-CoV epidemic. While it is on record that the recent EVD outbreak recorded very high mortality among HCWs, to the best of our knowledge, only few studies have addressed these issues in anticipation of an EVD outbreak particularly in countries not hit by the EVD epidemic and especially in sub Saharan Africa, such a study is almost non-existent. Our study therefore assessed how prepared HCWs are in the face of a possible EVD epidemic.", "The results of this survey showed that more than half (54.46%) HCWs indicated that their facilities were not ready to handle EVD cases. Nearly 92% indicated they were not adequately trained to handle an EVD suspected case and it is not surprising that less than 50% indicated they would willingly attend to a suspected patient. Moreover, nearly a third of HCWs would also want insurance for themselves and their families in case they were infected with EVD.", "These results are clearly indicative of how ill-prepared the HCWs surveyed are in the face a potentially life threatening epidemic prone diseases, such as EVD in Ghana. In this study, only 25.7% of HCWs said their facility was sufficiently equipped to handle an EVD outbreak. Such low ratings of the hospitals by majority of HCWs is a mark of lack of confidence in their facilities preparedness and this may actually indicate a real lack of preparedness and readiness of the hospitals to handle not only EVD cases but potentially other epidemic prone diseases. Alternatively, it could also mean that HCWs were probably unaware of preparatory work and retooling of their facilities to handle EVD outbreak situation.", "Willingness to work during outbreaks and emergencies is deemed a sense of duty even in the face of risk. In this study, less than 50% of HCWs indicated their willingness to work in the event of an EVD outbreak. Additionally, over one third indicated various forms of compensation for themselves or families in case of death or while taking care of an EVD case. This implies that if HCWs are assured or guaranteed that they and or their families would be taken care of in case of death or while taking care of an EVD case, they will willingly work in the face of any emergency scenario. The assumption is that HCWs would willingly work in the face of an infectious diseases emergency and respond appropriately; however, there are evidences of HCWs avoiding this \"sacred duty\" in caring for patients and would leave patients vulnerable in times of crisis [11] . In order to prevent HCWs from being infected while obliged to work even in the face of personal risk as required by their codes of ethics", "and professionalism, it is imperative to ensure that appropriate conventional standards, guarantees and effective public health practices are met to enable HCWs respond to such outbreaks so that they are not infected and or affected despite the risks they might face and continue to face [12] . Thus, appropriate training of HCWs as indicated by those surveyed during the study, coupled with retooling of some health facilities preparation is very critical in ensuring that they are equipped with the needed knowledge and tools needed to work with in the face of any epidemic.", "General knowledge of EVD is crucial to adequately respond to and care for patients. Nearly 17% of our study population could not identify that EVD as caused by a virus. Arguably, infection control measures would be difficult and problematic for such HCWs. Less than 10% could correctly identify 0.5% Sodium Hypochlorite as the best disinfectant out of the many options provided. This strongly contradicts a similar study in Conakry conducted during the peak of the epidemic where 68% of HCWs knew the correct concentration of disinfectant [5] . While not trying to compare these two scenarios, this information may be vital in the realization that knowledge of HCWs in infection prevention and control measures is critical in their line of duty.", "This study showed that most HCWs first heard of EVD through the media especially radio. This establishes the crucial role media plays in informing the general populace in such disease outbreaks. In Ghana, there are over 350 media outlets (radio and television put together) and majority of households either own a radio, television or have access to internet. Notwithstanding the media pluralism, it is still incumbent upon health institutions and facilities to organize special training on any emerging infectious disease that occurs globally to update the knowledge of HCWs.", "Isolation is a key public health measure to prevent the spread of infectious diseases. In this study, over 97% of HCW indicated their willingness to comply and accept to be isolated in case they became infected after attending to suspected EVD patient. However, a small proportion of HCWs surveyed stated that they would be very unhappy, and this could ultimately affect compliance. Isolation is one of the oldest methods of controlling communicable disease outbreaks for patients [13] . However, it is worthy of note that less that 50% said they would be willing to attend to an EVD suspected patient and we suspected that this could be related to fear of personal safety [14] . Emergency response from an epidemic prone disease from an exotic virulent virus or pathogen will naturally spark some level of fear and skepticism among any group of individuals especially when their knowledge about the dynamics of the disease outbreak is low. There are stories of HCWs who have avoided the", "responsibility of treating patients [15] and this was apparent in the HIV/AIDS and Severe Acute Respiratory Syndrome-Coronavirus (SARS-CoV) during the 1980s and 2003, respectively where the fear of contact with suspected and infected patients gripped some HCWs [16, 17] . In the long run, this fear would likely affect their confidence and commitment to professionalism.", "The results of this study point to the fact that knowledge and the provision of tools such as personnel protective equipment (PPE) and other logistics alone is not good enough strategy. There might be the need to as well address issues related to myth, and culture as well as assurances of upkeep should one be infected. The general outlook one's country's devotion to their health staff might be a contributory factor in all of this and cannot be ignored. However, getting HCWs inspired and feel safe in caring for such highly infectious disease outbreaks is critical. During our study, HCWs indicated various forms of compensation to be paid to them should they be affected in the case of EVD attack.", "This study had some inherent limitations. This was an exploratory study and our sample size was limited. Therefore, while not trying to generalize the results, we are of the opinion that this may be a reflection of HCWs in general. Additionally, since our study focused mainly on two health facilities, we are again careful in extrapolating these to other to reflect other facilities. Moreover, since this has not been a real experience, and a questionnaire-based survey, responses may not accurately reflect real-life experiences in the event of an EVD epidemic. Despite these limitations, the need for training was strong among HCWs. The results further demonstrate the ill-preparedness of health facilities, and the large proportion of HCWs unwillingness to attend to a suspected case of EVD. This thus calls for concerted efforts of health institutions and facilities to fully equip and prepare HCWs with the requisite tools and knowledge and ensuring competency to handle any epidemic prone", "disease." ]	[ 26 ]	3,596	4,831
185	What age group has the highest rate of severe outcomes?	236	[ "people 85 years and older" ]	[ "CDC Summary 21 MAR 2020,\nhttps://www.cdc.gov/coronavirus/2019-ncov/cases-updates/summary.html\n\nThis is a rapidly evolving situation and CDC will provide updated information and guidance as it becomes available.\n\nUpdated March 21, 2020\n\nCDC is responding to a pandemic of respiratory disease spreading from person-to-person caused by a novel (new) coronavirus. The disease has been named “coronavirus disease 2019” (abbreviated “COVID-19”). This situation poses a serious public health risk. The federal government is working closely with state, local, tribal, and territorial partners, as well as public health partners, to respond to this situation. COVID-19 can cause mild to severe illness; most severe illness occurs in older adults.", "Situation in U.S.\nDifferent parts of the country are seeing different levels of COVID-19 activity. The United States nationally is in the initiation phase of the pandemic. States in which community spread is occurring are in the acceleration phase. The duration and severity of each pandemic phase can vary depending on the characteristics of the virus and the public health response.\n\nCDC and state and local public health laboratories are testing for the virus that causes COVID-19. View CDC’s Public Health Laboratory Testing map.\nAll 50 states have reported cases of COVID-19 to CDC.\nU.S. COVID-19 cases include:\nImported cases in travelers\nCases among close contacts of a known case\nCommunity-acquired cases where the source of the infection is unknown.\nTwenty-seven U.S. states are reporting some community spread of COVID-19.\nView latest case counts, deaths, and a map of states with reported cases.", "CDC Recommends\nEveryone can do their part to help us respond to this emerging public health threat:\nOn March 16, the White House announced a program called “15 Days to Slow the Spread,”pdf iconexternal icon which is a nationwide effort to slow the spread of COVID-19 through the implementation of social distancing at all levels of society.\nOlder people and people with severe chronic conditions should take special precautions because they are at higher risk of developing serious COVID-19 illness.\nIf you are a healthcare provider, use your judgment to determine if a patient has signs and symptoms compatible with COVID-19 and whether the patient should be tested. Factors to consider in addition to clinical symptoms may include:\nDoes the patient have recent travel from an affected area?\nHas the patient been in close contact with someone with COVID-19 or with patients with pneumonia of unknown cause?\nDoes the patient reside in an area where there has been community spread of COVID-19?", "If you are a healthcare provider or a public health responder caring for a COVID-19 patient, please take care of yourself and follow recommended infection control procedures.\nPeople who get a fever or cough should consider whether they might have COVID-19, depending on where they live, their travel history or other exposures. More than half of the U.S. is seeing some level of community spread of COVID-19. Testing for COVID-19 may be accessed through medical providers or public health departments, but there is no treatment for this virus. Most people have mild illness and are able to recover at home without medical care.\nFor people who are ill with COVID-19, but are not sick enough to be hospitalized, please follow CDC guidance on how to reduce the risk of spreading your illness to others. People who are mildly ill with COVID-19 are able to isolate at home during their illness.", "If you have been in China or another affected area or have been exposed to someone sick with COVID-19 in the last 14 days, you will face some limitations on your movement and activity. Please follow instructions during this time. Your cooperation is integral to the ongoing public health response to try to slow spread of this virus.\nCOVID-19 Emergence\nCOVID-19 is caused by a coronavirus. Coronaviruses are a large family of viruses that are common in people and many different species of animals, including camels, cattle, cats, and bats. Rarely, animal coronaviruses can infect people and then spread between people such as with MERS-CoV, SARS-CoV, and now with this new virus (named SARS-CoV-2).", "The SARS-CoV-2 virus is a betacoronavirus, like MERS-CoV and SARS-CoV. All three of these viruses have their origins in bats. The sequences from U.S. patients are similar to the one that China initially posted, suggesting a likely single, recent emergence of this virus from an animal reservoir.", "Early on, many of the patients at the epicenter of the outbreak in Wuhan, Hubei Province, China had some link to a large seafood and live animal market, suggesting animal-to-person spread. Later, a growing number of patients reportedly did not have exposure to animal markets, indicating person-to-person spread. Person-to-person spread was subsequently reported outside Hubei and in countries outside China, including in the United States. Some international destinations now have ongoing community spread with the virus that causes COVID-19, as do some parts of the United States. Community spread means some people have been infected and it is not known how or where they became exposed. Learn more about the spread of this newly emerged coronavirus.", "Severity\nThe complete clinical picture with regard to COVID-19 is not fully known. Reported illnesses have ranged from very mild (including some with no reported symptoms) to severe, including illness resulting in death. While information so far suggests that most COVID-19 illness is mild, a reportexternal icon out of China suggests serious illness occurs in 16% of cases. Older people and people of all ages with severe chronic medical conditions — like heart disease, lung disease and diabetes, for example — seem to be at higher risk of developing serious COVID-19 illness. A CDC Morbidity & Mortality Weekly Report that looked at severity of disease among COVID-19 cases in the United States by age group found that 80% of deaths were among adults 65 years and older with the highest percentage of severe outcomes occurring in people 85 years and older.\n\nLearn more about the symptoms associated with COVID-19.", "COVID-19 Pandemic\nA pandemic is a global outbreak of disease. Pandemics happen when a new virus emerges to infect people and can spread between people sustainably. Because there is little to no pre-existing immunity against the new virus, it spreads worldwide.\n\nThe virus that causes COVID-19 is infecting people and spreading easily from person-to-person. Cases have been detected in most countries worldwide and community spread is being detected in a growing number of countries. On March 11, the COVID-19 outbreak was characterized as a pandemic by the WHOexternal icon.", "This is the first pandemic known to be caused by the emergence of a new coronavirus. In the past century, there have been four pandemics caused by the emergence of novel influenza viruses. As a result, most research and guidance around pandemics is specific to influenza, but the same premises can be applied to the current COVID-19 pandemic. Pandemics of respiratory disease follow a certain progression outlined in a “Pandemic Intervals Framework.” Pandemics begin with an investigation phase, followed by recognition, initiation, and acceleration phases. The peak of illnesses occurs at the end of the acceleration phase, which is followed by a deceleration phase, during which there is a decrease in illnesses. Different countries can be in different phases of the pandemic at any point in time and different parts of the same country can also be in different phases of a pandemic.", "There are ongoing investigations to learn more. This is a rapidly evolving situation and information will be updated as it becomes available.\n\nRisk Assessment\nRisk depends on characteristics of the virus, including how well it spreads between people; the severity of resulting illness; and the medical or other measures available to control the impact of the virus (for example, vaccines or medications that can treat the illness) and the relative success of these. In the absence of vaccine or treatment medications, nonpharmaceutical interventions become the most important response strategy. These are community interventions that can reduce the impact of disease.\n\nThe risk from COVID-19 to Americans can be broken down into risk of exposure versus risk of serious illness and death.\n\nRisk of exposure:", "The immediate risk of being exposed to this virus is still low for most Americans, but as the outbreak expands, that risk will increase. Cases of COVID-19 and instances of community spread are being reported in a growing number of states.\nPeople in places where ongoing community spread of the virus that causes COVID-19 has been reported are at elevated risk of exposure, with the level of risk dependent on the location.\nHealthcare workers caring for patients with COVID-19 are at elevated risk of exposure.\nClose contacts of persons with COVID-19 also are at elevated risk of exposure.\nTravelers returning from affected international locations where community spread is occurring also are at elevated risk of exposure, with level of risk dependent on where they traveled.\nRisk of Severe Illness:\n\nEarly information out of China, where COVID-19 first started, shows that some people are at higher risk of getting very sick from this illness. This includes:", "Older adults, with risk increasing by age.\nPeople who have serious chronic medical conditions like:\nHeart disease\nDiabetes\nLung disease\nCDC has developed guidance to help in the risk assessment and management of people with potential exposures to COVID-19.\n\nWhat May Happen\nMore cases of COVID-19 are likely to be identified in the United States in the coming days, including more instances of community spread. CDC expects that widespread transmission of COVID-19 in the United States will occur. In the coming months, most of the U.S. population will be exposed to this virus.", "Widespread transmission of COVID-19 could translate into large numbers of people needing medical care at the same time. Schools, childcare centers, and workplaces, may experience more absenteeism. Mass gatherings may be sparsely attended or postponed. Public health and healthcare systems may become overloaded, with elevated rates of hospitalizations and deaths. Other critical infrastructure, such as law enforcement, emergency medical services, and sectors of the transportation industry may also be affected. Healthcare providers and hospitals may be overwhelmed. At this time, there is no vaccine to protect against COVID-19 and no medications approved to treat it. Nonpharmaceutical interventions will be the most important response strategy to try to delay the spread of the virus and reduce the impact of disease.", "CDC Response\nGlobal efforts at this time are focused concurrently on lessening the spread and impact of this virus. The federal government is working closely with state, local, tribal, and territorial partners, as well as public health partners, to respond to this public health threat.", "Highlights of CDC’s Response\nCDC established a COVID-19 Incident Management System on January 7, 2020. On January 21, CDC activated its Emergency Operations Center to better provide ongoing support to the COVID-19 response.\nThe U.S. government has taken unprecedented steps with respect to travel in response to the growing public health threat posed by this new coronavirus:\nForeign nationals who have been in China, Iran, the United Kingdom, Ireland and any one of the 26 European countries in the Schengen Area within the past 14 days cannot enter the United States.\nU.S. citizens, residents, and their immediate family members who have been any one of those countries within in the past 14 days can enter the United States, but they are subject to health monitoring and possible quarantine for up to 14 days.\nPeople at higher risk of serious COVID-19 illness avoid cruise travel and non-essential air travel.\nCDC has issued additional specific travel guidance related to COVID-19.", "CDC has issued clinical guidance, including:\nClinical Guidance for Management of Patients with Confirmed Coronavirus Disease (COVID-19).\nInfection Prevention and Control Recommendations for Patients, including guidance on the use of personal protective equipment (PPE) during a shortage.\nCDC also has issued guidance for other settings, including:\nPreparing for COVID-19: Long-term Care Facilities, Nursing Homes\nDiscontinuation of Home Isolation for Persons with COVID-19\nCDC has deployed multidisciplinary teams to support state health departments in case identification, contact tracing, clinical management, and public communications.\nCDC has worked with federal partners to support the safe return of Americans overseas who have been affected by COVID-19.", "An important part of CDC’s role during a public health emergency is to develop a test for the pathogen and equip state and local public health labs with testing capacity.\nCDC developed an rRT-PCR test to diagnose COVID-19.\nAs of the evening of March 17, 89 state and local public health labs in 50 states, the District of Columbia, Guam, and Puerto Rico have successfully verified and are currently using CDC COVID-19 diagnostic tests.\nCommercial manufacturers are now producing their own tests.\nCDC has grown the COVID-19 virus in cell culture, which is necessary for further studies, including for additional genetic characterization. The cell-grown virus was sent to NIH’s BEI Resources Repositoryexternal icon for use by the broad scientific community.\nCDC also is developing a serology test for COVID-19.\nOther Available Resources\nThe following resources are available with information on COVID-19\n\nWorld Health Organization, Coronavirusexternal icon" ]	[ 7 ]	2,073	2,836
185	How is COVID-19 spread?	225	[ "person-to-person" ]	[ "CDC Summary 21 MAR 2020,\nhttps://www.cdc.gov/coronavirus/2019-ncov/cases-updates/summary.html\n\nThis is a rapidly evolving situation and CDC will provide updated information and guidance as it becomes available.\n\nUpdated March 21, 2020\n\nCDC is responding to a pandemic of respiratory disease spreading from person-to-person caused by a novel (new) coronavirus. The disease has been named “coronavirus disease 2019” (abbreviated “COVID-19”). This situation poses a serious public health risk. The federal government is working closely with state, local, tribal, and territorial partners, as well as public health partners, to respond to this situation. COVID-19 can cause mild to severe illness; most severe illness occurs in older adults.", "Situation in U.S.\nDifferent parts of the country are seeing different levels of COVID-19 activity. The United States nationally is in the initiation phase of the pandemic. States in which community spread is occurring are in the acceleration phase. The duration and severity of each pandemic phase can vary depending on the characteristics of the virus and the public health response.\n\nCDC and state and local public health laboratories are testing for the virus that causes COVID-19. View CDC’s Public Health Laboratory Testing map.\nAll 50 states have reported cases of COVID-19 to CDC.\nU.S. COVID-19 cases include:\nImported cases in travelers\nCases among close contacts of a known case\nCommunity-acquired cases where the source of the infection is unknown.\nTwenty-seven U.S. states are reporting some community spread of COVID-19.\nView latest case counts, deaths, and a map of states with reported cases.", "CDC Recommends\nEveryone can do their part to help us respond to this emerging public health threat:\nOn March 16, the White House announced a program called “15 Days to Slow the Spread,”pdf iconexternal icon which is a nationwide effort to slow the spread of COVID-19 through the implementation of social distancing at all levels of society.\nOlder people and people with severe chronic conditions should take special precautions because they are at higher risk of developing serious COVID-19 illness.\nIf you are a healthcare provider, use your judgment to determine if a patient has signs and symptoms compatible with COVID-19 and whether the patient should be tested. Factors to consider in addition to clinical symptoms may include:\nDoes the patient have recent travel from an affected area?\nHas the patient been in close contact with someone with COVID-19 or with patients with pneumonia of unknown cause?\nDoes the patient reside in an area where there has been community spread of COVID-19?", "If you are a healthcare provider or a public health responder caring for a COVID-19 patient, please take care of yourself and follow recommended infection control procedures.\nPeople who get a fever or cough should consider whether they might have COVID-19, depending on where they live, their travel history or other exposures. More than half of the U.S. is seeing some level of community spread of COVID-19. Testing for COVID-19 may be accessed through medical providers or public health departments, but there is no treatment for this virus. Most people have mild illness and are able to recover at home without medical care.\nFor people who are ill with COVID-19, but are not sick enough to be hospitalized, please follow CDC guidance on how to reduce the risk of spreading your illness to others. People who are mildly ill with COVID-19 are able to isolate at home during their illness.", "If you have been in China or another affected area or have been exposed to someone sick with COVID-19 in the last 14 days, you will face some limitations on your movement and activity. Please follow instructions during this time. Your cooperation is integral to the ongoing public health response to try to slow spread of this virus.\nCOVID-19 Emergence\nCOVID-19 is caused by a coronavirus. Coronaviruses are a large family of viruses that are common in people and many different species of animals, including camels, cattle, cats, and bats. Rarely, animal coronaviruses can infect people and then spread between people such as with MERS-CoV, SARS-CoV, and now with this new virus (named SARS-CoV-2).", "The SARS-CoV-2 virus is a betacoronavirus, like MERS-CoV and SARS-CoV. All three of these viruses have their origins in bats. The sequences from U.S. patients are similar to the one that China initially posted, suggesting a likely single, recent emergence of this virus from an animal reservoir.", "Early on, many of the patients at the epicenter of the outbreak in Wuhan, Hubei Province, China had some link to a large seafood and live animal market, suggesting animal-to-person spread. Later, a growing number of patients reportedly did not have exposure to animal markets, indicating person-to-person spread. Person-to-person spread was subsequently reported outside Hubei and in countries outside China, including in the United States. Some international destinations now have ongoing community spread with the virus that causes COVID-19, as do some parts of the United States. Community spread means some people have been infected and it is not known how or where they became exposed. Learn more about the spread of this newly emerged coronavirus.", "Severity\nThe complete clinical picture with regard to COVID-19 is not fully known. Reported illnesses have ranged from very mild (including some with no reported symptoms) to severe, including illness resulting in death. While information so far suggests that most COVID-19 illness is mild, a reportexternal icon out of China suggests serious illness occurs in 16% of cases. Older people and people of all ages with severe chronic medical conditions — like heart disease, lung disease and diabetes, for example — seem to be at higher risk of developing serious COVID-19 illness. A CDC Morbidity & Mortality Weekly Report that looked at severity of disease among COVID-19 cases in the United States by age group found that 80% of deaths were among adults 65 years and older with the highest percentage of severe outcomes occurring in people 85 years and older.\n\nLearn more about the symptoms associated with COVID-19.", "COVID-19 Pandemic\nA pandemic is a global outbreak of disease. Pandemics happen when a new virus emerges to infect people and can spread between people sustainably. Because there is little to no pre-existing immunity against the new virus, it spreads worldwide.\n\nThe virus that causes COVID-19 is infecting people and spreading easily from person-to-person. Cases have been detected in most countries worldwide and community spread is being detected in a growing number of countries. On March 11, the COVID-19 outbreak was characterized as a pandemic by the WHOexternal icon.", "This is the first pandemic known to be caused by the emergence of a new coronavirus. In the past century, there have been four pandemics caused by the emergence of novel influenza viruses. As a result, most research and guidance around pandemics is specific to influenza, but the same premises can be applied to the current COVID-19 pandemic. Pandemics of respiratory disease follow a certain progression outlined in a “Pandemic Intervals Framework.” Pandemics begin with an investigation phase, followed by recognition, initiation, and acceleration phases. The peak of illnesses occurs at the end of the acceleration phase, which is followed by a deceleration phase, during which there is a decrease in illnesses. Different countries can be in different phases of the pandemic at any point in time and different parts of the same country can also be in different phases of a pandemic.", "There are ongoing investigations to learn more. This is a rapidly evolving situation and information will be updated as it becomes available.\n\nRisk Assessment\nRisk depends on characteristics of the virus, including how well it spreads between people; the severity of resulting illness; and the medical or other measures available to control the impact of the virus (for example, vaccines or medications that can treat the illness) and the relative success of these. In the absence of vaccine or treatment medications, nonpharmaceutical interventions become the most important response strategy. These are community interventions that can reduce the impact of disease.\n\nThe risk from COVID-19 to Americans can be broken down into risk of exposure versus risk of serious illness and death.\n\nRisk of exposure:", "The immediate risk of being exposed to this virus is still low for most Americans, but as the outbreak expands, that risk will increase. Cases of COVID-19 and instances of community spread are being reported in a growing number of states.\nPeople in places where ongoing community spread of the virus that causes COVID-19 has been reported are at elevated risk of exposure, with the level of risk dependent on the location.\nHealthcare workers caring for patients with COVID-19 are at elevated risk of exposure.\nClose contacts of persons with COVID-19 also are at elevated risk of exposure.\nTravelers returning from affected international locations where community spread is occurring also are at elevated risk of exposure, with level of risk dependent on where they traveled.\nRisk of Severe Illness:\n\nEarly information out of China, where COVID-19 first started, shows that some people are at higher risk of getting very sick from this illness. This includes:", "Older adults, with risk increasing by age.\nPeople who have serious chronic medical conditions like:\nHeart disease\nDiabetes\nLung disease\nCDC has developed guidance to help in the risk assessment and management of people with potential exposures to COVID-19.\n\nWhat May Happen\nMore cases of COVID-19 are likely to be identified in the United States in the coming days, including more instances of community spread. CDC expects that widespread transmission of COVID-19 in the United States will occur. In the coming months, most of the U.S. population will be exposed to this virus.", "Widespread transmission of COVID-19 could translate into large numbers of people needing medical care at the same time. Schools, childcare centers, and workplaces, may experience more absenteeism. Mass gatherings may be sparsely attended or postponed. Public health and healthcare systems may become overloaded, with elevated rates of hospitalizations and deaths. Other critical infrastructure, such as law enforcement, emergency medical services, and sectors of the transportation industry may also be affected. Healthcare providers and hospitals may be overwhelmed. At this time, there is no vaccine to protect against COVID-19 and no medications approved to treat it. Nonpharmaceutical interventions will be the most important response strategy to try to delay the spread of the virus and reduce the impact of disease.", "CDC Response\nGlobal efforts at this time are focused concurrently on lessening the spread and impact of this virus. The federal government is working closely with state, local, tribal, and territorial partners, as well as public health partners, to respond to this public health threat.", "Highlights of CDC’s Response\nCDC established a COVID-19 Incident Management System on January 7, 2020. On January 21, CDC activated its Emergency Operations Center to better provide ongoing support to the COVID-19 response.\nThe U.S. government has taken unprecedented steps with respect to travel in response to the growing public health threat posed by this new coronavirus:\nForeign nationals who have been in China, Iran, the United Kingdom, Ireland and any one of the 26 European countries in the Schengen Area within the past 14 days cannot enter the United States.\nU.S. citizens, residents, and their immediate family members who have been any one of those countries within in the past 14 days can enter the United States, but they are subject to health monitoring and possible quarantine for up to 14 days.\nPeople at higher risk of serious COVID-19 illness avoid cruise travel and non-essential air travel.\nCDC has issued additional specific travel guidance related to COVID-19.", "CDC has issued clinical guidance, including:\nClinical Guidance for Management of Patients with Confirmed Coronavirus Disease (COVID-19).\nInfection Prevention and Control Recommendations for Patients, including guidance on the use of personal protective equipment (PPE) during a shortage.\nCDC also has issued guidance for other settings, including:\nPreparing for COVID-19: Long-term Care Facilities, Nursing Homes\nDiscontinuation of Home Isolation for Persons with COVID-19\nCDC has deployed multidisciplinary teams to support state health departments in case identification, contact tracing, clinical management, and public communications.\nCDC has worked with federal partners to support the safe return of Americans overseas who have been affected by COVID-19.", "An important part of CDC’s role during a public health emergency is to develop a test for the pathogen and equip state and local public health labs with testing capacity.\nCDC developed an rRT-PCR test to diagnose COVID-19.\nAs of the evening of March 17, 89 state and local public health labs in 50 states, the District of Columbia, Guam, and Puerto Rico have successfully verified and are currently using CDC COVID-19 diagnostic tests.\nCommercial manufacturers are now producing their own tests.\nCDC has grown the COVID-19 virus in cell culture, which is necessary for further studies, including for additional genetic characterization. The cell-grown virus was sent to NIH’s BEI Resources Repositoryexternal icon for use by the broad scientific community.\nCDC also is developing a serology test for COVID-19.\nOther Available Resources\nThe following resources are available with information on COVID-19\n\nWorld Health Organization, Coronavirusexternal icon" ]	[ 0 ]	2,073	2,836
185	How many states in the U.S. have reported cases of COVID-19?	226	[ "50" ]	[ "CDC Summary 21 MAR 2020,\nhttps://www.cdc.gov/coronavirus/2019-ncov/cases-updates/summary.html\n\nThis is a rapidly evolving situation and CDC will provide updated information and guidance as it becomes available.\n\nUpdated March 21, 2020\n\nCDC is responding to a pandemic of respiratory disease spreading from person-to-person caused by a novel (new) coronavirus. The disease has been named “coronavirus disease 2019” (abbreviated “COVID-19”). This situation poses a serious public health risk. The federal government is working closely with state, local, tribal, and territorial partners, as well as public health partners, to respond to this situation. COVID-19 can cause mild to severe illness; most severe illness occurs in older adults.", "Situation in U.S.\nDifferent parts of the country are seeing different levels of COVID-19 activity. The United States nationally is in the initiation phase of the pandemic. States in which community spread is occurring are in the acceleration phase. The duration and severity of each pandemic phase can vary depending on the characteristics of the virus and the public health response.\n\nCDC and state and local public health laboratories are testing for the virus that causes COVID-19. View CDC’s Public Health Laboratory Testing map.\nAll 50 states have reported cases of COVID-19 to CDC.\nU.S. COVID-19 cases include:\nImported cases in travelers\nCases among close contacts of a known case\nCommunity-acquired cases where the source of the infection is unknown.\nTwenty-seven U.S. states are reporting some community spread of COVID-19.\nView latest case counts, deaths, and a map of states with reported cases.", "CDC Recommends\nEveryone can do their part to help us respond to this emerging public health threat:\nOn March 16, the White House announced a program called “15 Days to Slow the Spread,”pdf iconexternal icon which is a nationwide effort to slow the spread of COVID-19 through the implementation of social distancing at all levels of society.\nOlder people and people with severe chronic conditions should take special precautions because they are at higher risk of developing serious COVID-19 illness.\nIf you are a healthcare provider, use your judgment to determine if a patient has signs and symptoms compatible with COVID-19 and whether the patient should be tested. Factors to consider in addition to clinical symptoms may include:\nDoes the patient have recent travel from an affected area?\nHas the patient been in close contact with someone with COVID-19 or with patients with pneumonia of unknown cause?\nDoes the patient reside in an area where there has been community spread of COVID-19?", "If you are a healthcare provider or a public health responder caring for a COVID-19 patient, please take care of yourself and follow recommended infection control procedures.\nPeople who get a fever or cough should consider whether they might have COVID-19, depending on where they live, their travel history or other exposures. More than half of the U.S. is seeing some level of community spread of COVID-19. Testing for COVID-19 may be accessed through medical providers or public health departments, but there is no treatment for this virus. Most people have mild illness and are able to recover at home without medical care.\nFor people who are ill with COVID-19, but are not sick enough to be hospitalized, please follow CDC guidance on how to reduce the risk of spreading your illness to others. People who are mildly ill with COVID-19 are able to isolate at home during their illness.", "If you have been in China or another affected area or have been exposed to someone sick with COVID-19 in the last 14 days, you will face some limitations on your movement and activity. Please follow instructions during this time. Your cooperation is integral to the ongoing public health response to try to slow spread of this virus.\nCOVID-19 Emergence\nCOVID-19 is caused by a coronavirus. Coronaviruses are a large family of viruses that are common in people and many different species of animals, including camels, cattle, cats, and bats. Rarely, animal coronaviruses can infect people and then spread between people such as with MERS-CoV, SARS-CoV, and now with this new virus (named SARS-CoV-2).", "The SARS-CoV-2 virus is a betacoronavirus, like MERS-CoV and SARS-CoV. All three of these viruses have their origins in bats. The sequences from U.S. patients are similar to the one that China initially posted, suggesting a likely single, recent emergence of this virus from an animal reservoir.", "Early on, many of the patients at the epicenter of the outbreak in Wuhan, Hubei Province, China had some link to a large seafood and live animal market, suggesting animal-to-person spread. Later, a growing number of patients reportedly did not have exposure to animal markets, indicating person-to-person spread. Person-to-person spread was subsequently reported outside Hubei and in countries outside China, including in the United States. Some international destinations now have ongoing community spread with the virus that causes COVID-19, as do some parts of the United States. Community spread means some people have been infected and it is not known how or where they became exposed. Learn more about the spread of this newly emerged coronavirus.", "Severity\nThe complete clinical picture with regard to COVID-19 is not fully known. Reported illnesses have ranged from very mild (including some with no reported symptoms) to severe, including illness resulting in death. While information so far suggests that most COVID-19 illness is mild, a reportexternal icon out of China suggests serious illness occurs in 16% of cases. Older people and people of all ages with severe chronic medical conditions — like heart disease, lung disease and diabetes, for example — seem to be at higher risk of developing serious COVID-19 illness. A CDC Morbidity & Mortality Weekly Report that looked at severity of disease among COVID-19 cases in the United States by age group found that 80% of deaths were among adults 65 years and older with the highest percentage of severe outcomes occurring in people 85 years and older.\n\nLearn more about the symptoms associated with COVID-19.", "COVID-19 Pandemic\nA pandemic is a global outbreak of disease. Pandemics happen when a new virus emerges to infect people and can spread between people sustainably. Because there is little to no pre-existing immunity against the new virus, it spreads worldwide.\n\nThe virus that causes COVID-19 is infecting people and spreading easily from person-to-person. Cases have been detected in most countries worldwide and community spread is being detected in a growing number of countries. On March 11, the COVID-19 outbreak was characterized as a pandemic by the WHOexternal icon.", "This is the first pandemic known to be caused by the emergence of a new coronavirus. In the past century, there have been four pandemics caused by the emergence of novel influenza viruses. As a result, most research and guidance around pandemics is specific to influenza, but the same premises can be applied to the current COVID-19 pandemic. Pandemics of respiratory disease follow a certain progression outlined in a “Pandemic Intervals Framework.” Pandemics begin with an investigation phase, followed by recognition, initiation, and acceleration phases. The peak of illnesses occurs at the end of the acceleration phase, which is followed by a deceleration phase, during which there is a decrease in illnesses. Different countries can be in different phases of the pandemic at any point in time and different parts of the same country can also be in different phases of a pandemic.", "There are ongoing investigations to learn more. This is a rapidly evolving situation and information will be updated as it becomes available.\n\nRisk Assessment\nRisk depends on characteristics of the virus, including how well it spreads between people; the severity of resulting illness; and the medical or other measures available to control the impact of the virus (for example, vaccines or medications that can treat the illness) and the relative success of these. In the absence of vaccine or treatment medications, nonpharmaceutical interventions become the most important response strategy. These are community interventions that can reduce the impact of disease.\n\nThe risk from COVID-19 to Americans can be broken down into risk of exposure versus risk of serious illness and death.\n\nRisk of exposure:", "The immediate risk of being exposed to this virus is still low for most Americans, but as the outbreak expands, that risk will increase. Cases of COVID-19 and instances of community spread are being reported in a growing number of states.\nPeople in places where ongoing community spread of the virus that causes COVID-19 has been reported are at elevated risk of exposure, with the level of risk dependent on the location.\nHealthcare workers caring for patients with COVID-19 are at elevated risk of exposure.\nClose contacts of persons with COVID-19 also are at elevated risk of exposure.\nTravelers returning from affected international locations where community spread is occurring also are at elevated risk of exposure, with level of risk dependent on where they traveled.\nRisk of Severe Illness:\n\nEarly information out of China, where COVID-19 first started, shows that some people are at higher risk of getting very sick from this illness. This includes:", "Older adults, with risk increasing by age.\nPeople who have serious chronic medical conditions like:\nHeart disease\nDiabetes\nLung disease\nCDC has developed guidance to help in the risk assessment and management of people with potential exposures to COVID-19.\n\nWhat May Happen\nMore cases of COVID-19 are likely to be identified in the United States in the coming days, including more instances of community spread. CDC expects that widespread transmission of COVID-19 in the United States will occur. In the coming months, most of the U.S. population will be exposed to this virus.", "Widespread transmission of COVID-19 could translate into large numbers of people needing medical care at the same time. Schools, childcare centers, and workplaces, may experience more absenteeism. Mass gatherings may be sparsely attended or postponed. Public health and healthcare systems may become overloaded, with elevated rates of hospitalizations and deaths. Other critical infrastructure, such as law enforcement, emergency medical services, and sectors of the transportation industry may also be affected. Healthcare providers and hospitals may be overwhelmed. At this time, there is no vaccine to protect against COVID-19 and no medications approved to treat it. Nonpharmaceutical interventions will be the most important response strategy to try to delay the spread of the virus and reduce the impact of disease.", "CDC Response\nGlobal efforts at this time are focused concurrently on lessening the spread and impact of this virus. The federal government is working closely with state, local, tribal, and territorial partners, as well as public health partners, to respond to this public health threat.", "Highlights of CDC’s Response\nCDC established a COVID-19 Incident Management System on January 7, 2020. On January 21, CDC activated its Emergency Operations Center to better provide ongoing support to the COVID-19 response.\nThe U.S. government has taken unprecedented steps with respect to travel in response to the growing public health threat posed by this new coronavirus:\nForeign nationals who have been in China, Iran, the United Kingdom, Ireland and any one of the 26 European countries in the Schengen Area within the past 14 days cannot enter the United States.\nU.S. citizens, residents, and their immediate family members who have been any one of those countries within in the past 14 days can enter the United States, but they are subject to health monitoring and possible quarantine for up to 14 days.\nPeople at higher risk of serious COVID-19 illness avoid cruise travel and non-essential air travel.\nCDC has issued additional specific travel guidance related to COVID-19.", "CDC has issued clinical guidance, including:\nClinical Guidance for Management of Patients with Confirmed Coronavirus Disease (COVID-19).\nInfection Prevention and Control Recommendations for Patients, including guidance on the use of personal protective equipment (PPE) during a shortage.\nCDC also has issued guidance for other settings, including:\nPreparing for COVID-19: Long-term Care Facilities, Nursing Homes\nDiscontinuation of Home Isolation for Persons with COVID-19\nCDC has deployed multidisciplinary teams to support state health departments in case identification, contact tracing, clinical management, and public communications.\nCDC has worked with federal partners to support the safe return of Americans overseas who have been affected by COVID-19.", "An important part of CDC’s role during a public health emergency is to develop a test for the pathogen and equip state and local public health labs with testing capacity.\nCDC developed an rRT-PCR test to diagnose COVID-19.\nAs of the evening of March 17, 89 state and local public health labs in 50 states, the District of Columbia, Guam, and Puerto Rico have successfully verified and are currently using CDC COVID-19 diagnostic tests.\nCommercial manufacturers are now producing their own tests.\nCDC has grown the COVID-19 virus in cell culture, which is necessary for further studies, including for additional genetic characterization. The cell-grown virus was sent to NIH’s BEI Resources Repositoryexternal icon for use by the broad scientific community.\nCDC also is developing a serology test for COVID-19.\nOther Available Resources\nThe following resources are available with information on COVID-19\n\nWorld Health Organization, Coronavirusexternal icon" ]	[ 1 ]	2,073	2,836
185	When did the White House launch the "15 Days to Slow the Spread" program?	227	[ "March 16" ]	[ "CDC Summary 21 MAR 2020,\nhttps://www.cdc.gov/coronavirus/2019-ncov/cases-updates/summary.html\n\nThis is a rapidly evolving situation and CDC will provide updated information and guidance as it becomes available.\n\nUpdated March 21, 2020\n\nCDC is responding to a pandemic of respiratory disease spreading from person-to-person caused by a novel (new) coronavirus. The disease has been named “coronavirus disease 2019” (abbreviated “COVID-19”). This situation poses a serious public health risk. The federal government is working closely with state, local, tribal, and territorial partners, as well as public health partners, to respond to this situation. COVID-19 can cause mild to severe illness; most severe illness occurs in older adults.", "Situation in U.S.\nDifferent parts of the country are seeing different levels of COVID-19 activity. The United States nationally is in the initiation phase of the pandemic. States in which community spread is occurring are in the acceleration phase. The duration and severity of each pandemic phase can vary depending on the characteristics of the virus and the public health response.\n\nCDC and state and local public health laboratories are testing for the virus that causes COVID-19. View CDC’s Public Health Laboratory Testing map.\nAll 50 states have reported cases of COVID-19 to CDC.\nU.S. COVID-19 cases include:\nImported cases in travelers\nCases among close contacts of a known case\nCommunity-acquired cases where the source of the infection is unknown.\nTwenty-seven U.S. states are reporting some community spread of COVID-19.\nView latest case counts, deaths, and a map of states with reported cases.", "CDC Recommends\nEveryone can do their part to help us respond to this emerging public health threat:\nOn March 16, the White House announced a program called “15 Days to Slow the Spread,”pdf iconexternal icon which is a nationwide effort to slow the spread of COVID-19 through the implementation of social distancing at all levels of society.\nOlder people and people with severe chronic conditions should take special precautions because they are at higher risk of developing serious COVID-19 illness.\nIf you are a healthcare provider, use your judgment to determine if a patient has signs and symptoms compatible with COVID-19 and whether the patient should be tested. Factors to consider in addition to clinical symptoms may include:\nDoes the patient have recent travel from an affected area?\nHas the patient been in close contact with someone with COVID-19 or with patients with pneumonia of unknown cause?\nDoes the patient reside in an area where there has been community spread of COVID-19?", "If you are a healthcare provider or a public health responder caring for a COVID-19 patient, please take care of yourself and follow recommended infection control procedures.\nPeople who get a fever or cough should consider whether they might have COVID-19, depending on where they live, their travel history or other exposures. More than half of the U.S. is seeing some level of community spread of COVID-19. Testing for COVID-19 may be accessed through medical providers or public health departments, but there is no treatment for this virus. Most people have mild illness and are able to recover at home without medical care.\nFor people who are ill with COVID-19, but are not sick enough to be hospitalized, please follow CDC guidance on how to reduce the risk of spreading your illness to others. People who are mildly ill with COVID-19 are able to isolate at home during their illness.", "If you have been in China or another affected area or have been exposed to someone sick with COVID-19 in the last 14 days, you will face some limitations on your movement and activity. Please follow instructions during this time. Your cooperation is integral to the ongoing public health response to try to slow spread of this virus.\nCOVID-19 Emergence\nCOVID-19 is caused by a coronavirus. Coronaviruses are a large family of viruses that are common in people and many different species of animals, including camels, cattle, cats, and bats. Rarely, animal coronaviruses can infect people and then spread between people such as with MERS-CoV, SARS-CoV, and now with this new virus (named SARS-CoV-2).", "The SARS-CoV-2 virus is a betacoronavirus, like MERS-CoV and SARS-CoV. All three of these viruses have their origins in bats. The sequences from U.S. patients are similar to the one that China initially posted, suggesting a likely single, recent emergence of this virus from an animal reservoir.", "Early on, many of the patients at the epicenter of the outbreak in Wuhan, Hubei Province, China had some link to a large seafood and live animal market, suggesting animal-to-person spread. Later, a growing number of patients reportedly did not have exposure to animal markets, indicating person-to-person spread. Person-to-person spread was subsequently reported outside Hubei and in countries outside China, including in the United States. Some international destinations now have ongoing community spread with the virus that causes COVID-19, as do some parts of the United States. Community spread means some people have been infected and it is not known how or where they became exposed. Learn more about the spread of this newly emerged coronavirus.", "Severity\nThe complete clinical picture with regard to COVID-19 is not fully known. Reported illnesses have ranged from very mild (including some with no reported symptoms) to severe, including illness resulting in death. While information so far suggests that most COVID-19 illness is mild, a reportexternal icon out of China suggests serious illness occurs in 16% of cases. Older people and people of all ages with severe chronic medical conditions — like heart disease, lung disease and diabetes, for example — seem to be at higher risk of developing serious COVID-19 illness. A CDC Morbidity & Mortality Weekly Report that looked at severity of disease among COVID-19 cases in the United States by age group found that 80% of deaths were among adults 65 years and older with the highest percentage of severe outcomes occurring in people 85 years and older.\n\nLearn more about the symptoms associated with COVID-19.", "COVID-19 Pandemic\nA pandemic is a global outbreak of disease. Pandemics happen when a new virus emerges to infect people and can spread between people sustainably. Because there is little to no pre-existing immunity against the new virus, it spreads worldwide.\n\nThe virus that causes COVID-19 is infecting people and spreading easily from person-to-person. Cases have been detected in most countries worldwide and community spread is being detected in a growing number of countries. On March 11, the COVID-19 outbreak was characterized as a pandemic by the WHOexternal icon.", "This is the first pandemic known to be caused by the emergence of a new coronavirus. In the past century, there have been four pandemics caused by the emergence of novel influenza viruses. As a result, most research and guidance around pandemics is specific to influenza, but the same premises can be applied to the current COVID-19 pandemic. Pandemics of respiratory disease follow a certain progression outlined in a “Pandemic Intervals Framework.” Pandemics begin with an investigation phase, followed by recognition, initiation, and acceleration phases. The peak of illnesses occurs at the end of the acceleration phase, which is followed by a deceleration phase, during which there is a decrease in illnesses. Different countries can be in different phases of the pandemic at any point in time and different parts of the same country can also be in different phases of a pandemic.", "There are ongoing investigations to learn more. This is a rapidly evolving situation and information will be updated as it becomes available.\n\nRisk Assessment\nRisk depends on characteristics of the virus, including how well it spreads between people; the severity of resulting illness; and the medical or other measures available to control the impact of the virus (for example, vaccines or medications that can treat the illness) and the relative success of these. In the absence of vaccine or treatment medications, nonpharmaceutical interventions become the most important response strategy. These are community interventions that can reduce the impact of disease.\n\nThe risk from COVID-19 to Americans can be broken down into risk of exposure versus risk of serious illness and death.\n\nRisk of exposure:", "The immediate risk of being exposed to this virus is still low for most Americans, but as the outbreak expands, that risk will increase. Cases of COVID-19 and instances of community spread are being reported in a growing number of states.\nPeople in places where ongoing community spread of the virus that causes COVID-19 has been reported are at elevated risk of exposure, with the level of risk dependent on the location.\nHealthcare workers caring for patients with COVID-19 are at elevated risk of exposure.\nClose contacts of persons with COVID-19 also are at elevated risk of exposure.\nTravelers returning from affected international locations where community spread is occurring also are at elevated risk of exposure, with level of risk dependent on where they traveled.\nRisk of Severe Illness:\n\nEarly information out of China, where COVID-19 first started, shows that some people are at higher risk of getting very sick from this illness. This includes:", "Older adults, with risk increasing by age.\nPeople who have serious chronic medical conditions like:\nHeart disease\nDiabetes\nLung disease\nCDC has developed guidance to help in the risk assessment and management of people with potential exposures to COVID-19.\n\nWhat May Happen\nMore cases of COVID-19 are likely to be identified in the United States in the coming days, including more instances of community spread. CDC expects that widespread transmission of COVID-19 in the United States will occur. In the coming months, most of the U.S. population will be exposed to this virus.", "Widespread transmission of COVID-19 could translate into large numbers of people needing medical care at the same time. Schools, childcare centers, and workplaces, may experience more absenteeism. Mass gatherings may be sparsely attended or postponed. Public health and healthcare systems may become overloaded, with elevated rates of hospitalizations and deaths. Other critical infrastructure, such as law enforcement, emergency medical services, and sectors of the transportation industry may also be affected. Healthcare providers and hospitals may be overwhelmed. At this time, there is no vaccine to protect against COVID-19 and no medications approved to treat it. Nonpharmaceutical interventions will be the most important response strategy to try to delay the spread of the virus and reduce the impact of disease.", "CDC Response\nGlobal efforts at this time are focused concurrently on lessening the spread and impact of this virus. The federal government is working closely with state, local, tribal, and territorial partners, as well as public health partners, to respond to this public health threat.", "Highlights of CDC’s Response\nCDC established a COVID-19 Incident Management System on January 7, 2020. On January 21, CDC activated its Emergency Operations Center to better provide ongoing support to the COVID-19 response.\nThe U.S. government has taken unprecedented steps with respect to travel in response to the growing public health threat posed by this new coronavirus:\nForeign nationals who have been in China, Iran, the United Kingdom, Ireland and any one of the 26 European countries in the Schengen Area within the past 14 days cannot enter the United States.\nU.S. citizens, residents, and their immediate family members who have been any one of those countries within in the past 14 days can enter the United States, but they are subject to health monitoring and possible quarantine for up to 14 days.\nPeople at higher risk of serious COVID-19 illness avoid cruise travel and non-essential air travel.\nCDC has issued additional specific travel guidance related to COVID-19.", "CDC has issued clinical guidance, including:\nClinical Guidance for Management of Patients with Confirmed Coronavirus Disease (COVID-19).\nInfection Prevention and Control Recommendations for Patients, including guidance on the use of personal protective equipment (PPE) during a shortage.\nCDC also has issued guidance for other settings, including:\nPreparing for COVID-19: Long-term Care Facilities, Nursing Homes\nDiscontinuation of Home Isolation for Persons with COVID-19\nCDC has deployed multidisciplinary teams to support state health departments in case identification, contact tracing, clinical management, and public communications.\nCDC has worked with federal partners to support the safe return of Americans overseas who have been affected by COVID-19.", "An important part of CDC’s role during a public health emergency is to develop a test for the pathogen and equip state and local public health labs with testing capacity.\nCDC developed an rRT-PCR test to diagnose COVID-19.\nAs of the evening of March 17, 89 state and local public health labs in 50 states, the District of Columbia, Guam, and Puerto Rico have successfully verified and are currently using CDC COVID-19 diagnostic tests.\nCommercial manufacturers are now producing their own tests.\nCDC has grown the COVID-19 virus in cell culture, which is necessary for further studies, including for additional genetic characterization. The cell-grown virus was sent to NIH’s BEI Resources Repositoryexternal icon for use by the broad scientific community.\nCDC also is developing a serology test for COVID-19.\nOther Available Resources\nThe following resources are available with information on COVID-19\n\nWorld Health Organization, Coronavirusexternal icon" ]	[ 2 ]	2,073	2,836
185	What should mildly-ill patients do?	230	[ "isolate at home during their illness" ]	[ "CDC Summary 21 MAR 2020,\nhttps://www.cdc.gov/coronavirus/2019-ncov/cases-updates/summary.html\n\nThis is a rapidly evolving situation and CDC will provide updated information and guidance as it becomes available.\n\nUpdated March 21, 2020\n\nCDC is responding to a pandemic of respiratory disease spreading from person-to-person caused by a novel (new) coronavirus. The disease has been named “coronavirus disease 2019” (abbreviated “COVID-19”). This situation poses a serious public health risk. The federal government is working closely with state, local, tribal, and territorial partners, as well as public health partners, to respond to this situation. COVID-19 can cause mild to severe illness; most severe illness occurs in older adults.", "Situation in U.S.\nDifferent parts of the country are seeing different levels of COVID-19 activity. The United States nationally is in the initiation phase of the pandemic. States in which community spread is occurring are in the acceleration phase. The duration and severity of each pandemic phase can vary depending on the characteristics of the virus and the public health response.\n\nCDC and state and local public health laboratories are testing for the virus that causes COVID-19. View CDC’s Public Health Laboratory Testing map.\nAll 50 states have reported cases of COVID-19 to CDC.\nU.S. COVID-19 cases include:\nImported cases in travelers\nCases among close contacts of a known case\nCommunity-acquired cases where the source of the infection is unknown.\nTwenty-seven U.S. states are reporting some community spread of COVID-19.\nView latest case counts, deaths, and a map of states with reported cases.", "CDC Recommends\nEveryone can do their part to help us respond to this emerging public health threat:\nOn March 16, the White House announced a program called “15 Days to Slow the Spread,”pdf iconexternal icon which is a nationwide effort to slow the spread of COVID-19 through the implementation of social distancing at all levels of society.\nOlder people and people with severe chronic conditions should take special precautions because they are at higher risk of developing serious COVID-19 illness.\nIf you are a healthcare provider, use your judgment to determine if a patient has signs and symptoms compatible with COVID-19 and whether the patient should be tested. Factors to consider in addition to clinical symptoms may include:\nDoes the patient have recent travel from an affected area?\nHas the patient been in close contact with someone with COVID-19 or with patients with pneumonia of unknown cause?\nDoes the patient reside in an area where there has been community spread of COVID-19?", "If you are a healthcare provider or a public health responder caring for a COVID-19 patient, please take care of yourself and follow recommended infection control procedures.\nPeople who get a fever or cough should consider whether they might have COVID-19, depending on where they live, their travel history or other exposures. More than half of the U.S. is seeing some level of community spread of COVID-19. Testing for COVID-19 may be accessed through medical providers or public health departments, but there is no treatment for this virus. Most people have mild illness and are able to recover at home without medical care.\nFor people who are ill with COVID-19, but are not sick enough to be hospitalized, please follow CDC guidance on how to reduce the risk of spreading your illness to others. People who are mildly ill with COVID-19 are able to isolate at home during their illness.", "If you have been in China or another affected area or have been exposed to someone sick with COVID-19 in the last 14 days, you will face some limitations on your movement and activity. Please follow instructions during this time. Your cooperation is integral to the ongoing public health response to try to slow spread of this virus.\nCOVID-19 Emergence\nCOVID-19 is caused by a coronavirus. Coronaviruses are a large family of viruses that are common in people and many different species of animals, including camels, cattle, cats, and bats. Rarely, animal coronaviruses can infect people and then spread between people such as with MERS-CoV, SARS-CoV, and now with this new virus (named SARS-CoV-2).", "The SARS-CoV-2 virus is a betacoronavirus, like MERS-CoV and SARS-CoV. All three of these viruses have their origins in bats. The sequences from U.S. patients are similar to the one that China initially posted, suggesting a likely single, recent emergence of this virus from an animal reservoir.", "Early on, many of the patients at the epicenter of the outbreak in Wuhan, Hubei Province, China had some link to a large seafood and live animal market, suggesting animal-to-person spread. Later, a growing number of patients reportedly did not have exposure to animal markets, indicating person-to-person spread. Person-to-person spread was subsequently reported outside Hubei and in countries outside China, including in the United States. Some international destinations now have ongoing community spread with the virus that causes COVID-19, as do some parts of the United States. Community spread means some people have been infected and it is not known how or where they became exposed. Learn more about the spread of this newly emerged coronavirus.", "Severity\nThe complete clinical picture with regard to COVID-19 is not fully known. Reported illnesses have ranged from very mild (including some with no reported symptoms) to severe, including illness resulting in death. While information so far suggests that most COVID-19 illness is mild, a reportexternal icon out of China suggests serious illness occurs in 16% of cases. Older people and people of all ages with severe chronic medical conditions — like heart disease, lung disease and diabetes, for example — seem to be at higher risk of developing serious COVID-19 illness. A CDC Morbidity & Mortality Weekly Report that looked at severity of disease among COVID-19 cases in the United States by age group found that 80% of deaths were among adults 65 years and older with the highest percentage of severe outcomes occurring in people 85 years and older.\n\nLearn more about the symptoms associated with COVID-19.", "COVID-19 Pandemic\nA pandemic is a global outbreak of disease. Pandemics happen when a new virus emerges to infect people and can spread between people sustainably. Because there is little to no pre-existing immunity against the new virus, it spreads worldwide.\n\nThe virus that causes COVID-19 is infecting people and spreading easily from person-to-person. Cases have been detected in most countries worldwide and community spread is being detected in a growing number of countries. On March 11, the COVID-19 outbreak was characterized as a pandemic by the WHOexternal icon.", "This is the first pandemic known to be caused by the emergence of a new coronavirus. In the past century, there have been four pandemics caused by the emergence of novel influenza viruses. As a result, most research and guidance around pandemics is specific to influenza, but the same premises can be applied to the current COVID-19 pandemic. Pandemics of respiratory disease follow a certain progression outlined in a “Pandemic Intervals Framework.” Pandemics begin with an investigation phase, followed by recognition, initiation, and acceleration phases. The peak of illnesses occurs at the end of the acceleration phase, which is followed by a deceleration phase, during which there is a decrease in illnesses. Different countries can be in different phases of the pandemic at any point in time and different parts of the same country can also be in different phases of a pandemic.", "There are ongoing investigations to learn more. This is a rapidly evolving situation and information will be updated as it becomes available.\n\nRisk Assessment\nRisk depends on characteristics of the virus, including how well it spreads between people; the severity of resulting illness; and the medical or other measures available to control the impact of the virus (for example, vaccines or medications that can treat the illness) and the relative success of these. In the absence of vaccine or treatment medications, nonpharmaceutical interventions become the most important response strategy. These are community interventions that can reduce the impact of disease.\n\nThe risk from COVID-19 to Americans can be broken down into risk of exposure versus risk of serious illness and death.\n\nRisk of exposure:", "The immediate risk of being exposed to this virus is still low for most Americans, but as the outbreak expands, that risk will increase. Cases of COVID-19 and instances of community spread are being reported in a growing number of states.\nPeople in places where ongoing community spread of the virus that causes COVID-19 has been reported are at elevated risk of exposure, with the level of risk dependent on the location.\nHealthcare workers caring for patients with COVID-19 are at elevated risk of exposure.\nClose contacts of persons with COVID-19 also are at elevated risk of exposure.\nTravelers returning from affected international locations where community spread is occurring also are at elevated risk of exposure, with level of risk dependent on where they traveled.\nRisk of Severe Illness:\n\nEarly information out of China, where COVID-19 first started, shows that some people are at higher risk of getting very sick from this illness. This includes:", "Older adults, with risk increasing by age.\nPeople who have serious chronic medical conditions like:\nHeart disease\nDiabetes\nLung disease\nCDC has developed guidance to help in the risk assessment and management of people with potential exposures to COVID-19.\n\nWhat May Happen\nMore cases of COVID-19 are likely to be identified in the United States in the coming days, including more instances of community spread. CDC expects that widespread transmission of COVID-19 in the United States will occur. In the coming months, most of the U.S. population will be exposed to this virus.", "Widespread transmission of COVID-19 could translate into large numbers of people needing medical care at the same time. Schools, childcare centers, and workplaces, may experience more absenteeism. Mass gatherings may be sparsely attended or postponed. Public health and healthcare systems may become overloaded, with elevated rates of hospitalizations and deaths. Other critical infrastructure, such as law enforcement, emergency medical services, and sectors of the transportation industry may also be affected. Healthcare providers and hospitals may be overwhelmed. At this time, there is no vaccine to protect against COVID-19 and no medications approved to treat it. Nonpharmaceutical interventions will be the most important response strategy to try to delay the spread of the virus and reduce the impact of disease.", "CDC Response\nGlobal efforts at this time are focused concurrently on lessening the spread and impact of this virus. The federal government is working closely with state, local, tribal, and territorial partners, as well as public health partners, to respond to this public health threat.", "Highlights of CDC’s Response\nCDC established a COVID-19 Incident Management System on January 7, 2020. On January 21, CDC activated its Emergency Operations Center to better provide ongoing support to the COVID-19 response.\nThe U.S. government has taken unprecedented steps with respect to travel in response to the growing public health threat posed by this new coronavirus:\nForeign nationals who have been in China, Iran, the United Kingdom, Ireland and any one of the 26 European countries in the Schengen Area within the past 14 days cannot enter the United States.\nU.S. citizens, residents, and their immediate family members who have been any one of those countries within in the past 14 days can enter the United States, but they are subject to health monitoring and possible quarantine for up to 14 days.\nPeople at higher risk of serious COVID-19 illness avoid cruise travel and non-essential air travel.\nCDC has issued additional specific travel guidance related to COVID-19.", "CDC has issued clinical guidance, including:\nClinical Guidance for Management of Patients with Confirmed Coronavirus Disease (COVID-19).\nInfection Prevention and Control Recommendations for Patients, including guidance on the use of personal protective equipment (PPE) during a shortage.\nCDC also has issued guidance for other settings, including:\nPreparing for COVID-19: Long-term Care Facilities, Nursing Homes\nDiscontinuation of Home Isolation for Persons with COVID-19\nCDC has deployed multidisciplinary teams to support state health departments in case identification, contact tracing, clinical management, and public communications.\nCDC has worked with federal partners to support the safe return of Americans overseas who have been affected by COVID-19.", "An important part of CDC’s role during a public health emergency is to develop a test for the pathogen and equip state and local public health labs with testing capacity.\nCDC developed an rRT-PCR test to diagnose COVID-19.\nAs of the evening of March 17, 89 state and local public health labs in 50 states, the District of Columbia, Guam, and Puerto Rico have successfully verified and are currently using CDC COVID-19 diagnostic tests.\nCommercial manufacturers are now producing their own tests.\nCDC has grown the COVID-19 virus in cell culture, which is necessary for further studies, including for additional genetic characterization. The cell-grown virus was sent to NIH’s BEI Resources Repositoryexternal icon for use by the broad scientific community.\nCDC also is developing a serology test for COVID-19.\nOther Available Resources\nThe following resources are available with information on COVID-19\n\nWorld Health Organization, Coronavirusexternal icon" ]	[ 3 ]	2,073	2,836
185	What type of virus is SARS-CoV-2?	231	[ "betacoronavirus" ]	[ "CDC Summary 21 MAR 2020,\nhttps://www.cdc.gov/coronavirus/2019-ncov/cases-updates/summary.html\n\nThis is a rapidly evolving situation and CDC will provide updated information and guidance as it becomes available.\n\nUpdated March 21, 2020\n\nCDC is responding to a pandemic of respiratory disease spreading from person-to-person caused by a novel (new) coronavirus. The disease has been named “coronavirus disease 2019” (abbreviated “COVID-19”). This situation poses a serious public health risk. The federal government is working closely with state, local, tribal, and territorial partners, as well as public health partners, to respond to this situation. COVID-19 can cause mild to severe illness; most severe illness occurs in older adults.", "Situation in U.S.\nDifferent parts of the country are seeing different levels of COVID-19 activity. The United States nationally is in the initiation phase of the pandemic. States in which community spread is occurring are in the acceleration phase. The duration and severity of each pandemic phase can vary depending on the characteristics of the virus and the public health response.\n\nCDC and state and local public health laboratories are testing for the virus that causes COVID-19. View CDC’s Public Health Laboratory Testing map.\nAll 50 states have reported cases of COVID-19 to CDC.\nU.S. COVID-19 cases include:\nImported cases in travelers\nCases among close contacts of a known case\nCommunity-acquired cases where the source of the infection is unknown.\nTwenty-seven U.S. states are reporting some community spread of COVID-19.\nView latest case counts, deaths, and a map of states with reported cases.", "CDC Recommends\nEveryone can do their part to help us respond to this emerging public health threat:\nOn March 16, the White House announced a program called “15 Days to Slow the Spread,”pdf iconexternal icon which is a nationwide effort to slow the spread of COVID-19 through the implementation of social distancing at all levels of society.\nOlder people and people with severe chronic conditions should take special precautions because they are at higher risk of developing serious COVID-19 illness.\nIf you are a healthcare provider, use your judgment to determine if a patient has signs and symptoms compatible with COVID-19 and whether the patient should be tested. Factors to consider in addition to clinical symptoms may include:\nDoes the patient have recent travel from an affected area?\nHas the patient been in close contact with someone with COVID-19 or with patients with pneumonia of unknown cause?\nDoes the patient reside in an area where there has been community spread of COVID-19?", "If you are a healthcare provider or a public health responder caring for a COVID-19 patient, please take care of yourself and follow recommended infection control procedures.\nPeople who get a fever or cough should consider whether they might have COVID-19, depending on where they live, their travel history or other exposures. More than half of the U.S. is seeing some level of community spread of COVID-19. Testing for COVID-19 may be accessed through medical providers or public health departments, but there is no treatment for this virus. Most people have mild illness and are able to recover at home without medical care.\nFor people who are ill with COVID-19, but are not sick enough to be hospitalized, please follow CDC guidance on how to reduce the risk of spreading your illness to others. People who are mildly ill with COVID-19 are able to isolate at home during their illness.", "If you have been in China or another affected area or have been exposed to someone sick with COVID-19 in the last 14 days, you will face some limitations on your movement and activity. Please follow instructions during this time. Your cooperation is integral to the ongoing public health response to try to slow spread of this virus.\nCOVID-19 Emergence\nCOVID-19 is caused by a coronavirus. Coronaviruses are a large family of viruses that are common in people and many different species of animals, including camels, cattle, cats, and bats. Rarely, animal coronaviruses can infect people and then spread between people such as with MERS-CoV, SARS-CoV, and now with this new virus (named SARS-CoV-2).", "The SARS-CoV-2 virus is a betacoronavirus, like MERS-CoV and SARS-CoV. All three of these viruses have their origins in bats. The sequences from U.S. patients are similar to the one that China initially posted, suggesting a likely single, recent emergence of this virus from an animal reservoir.", "Early on, many of the patients at the epicenter of the outbreak in Wuhan, Hubei Province, China had some link to a large seafood and live animal market, suggesting animal-to-person spread. Later, a growing number of patients reportedly did not have exposure to animal markets, indicating person-to-person spread. Person-to-person spread was subsequently reported outside Hubei and in countries outside China, including in the United States. Some international destinations now have ongoing community spread with the virus that causes COVID-19, as do some parts of the United States. Community spread means some people have been infected and it is not known how or where they became exposed. Learn more about the spread of this newly emerged coronavirus.", "Severity\nThe complete clinical picture with regard to COVID-19 is not fully known. Reported illnesses have ranged from very mild (including some with no reported symptoms) to severe, including illness resulting in death. While information so far suggests that most COVID-19 illness is mild, a reportexternal icon out of China suggests serious illness occurs in 16% of cases. Older people and people of all ages with severe chronic medical conditions — like heart disease, lung disease and diabetes, for example — seem to be at higher risk of developing serious COVID-19 illness. A CDC Morbidity & Mortality Weekly Report that looked at severity of disease among COVID-19 cases in the United States by age group found that 80% of deaths were among adults 65 years and older with the highest percentage of severe outcomes occurring in people 85 years and older.\n\nLearn more about the symptoms associated with COVID-19.", "COVID-19 Pandemic\nA pandemic is a global outbreak of disease. Pandemics happen when a new virus emerges to infect people and can spread between people sustainably. Because there is little to no pre-existing immunity against the new virus, it spreads worldwide.\n\nThe virus that causes COVID-19 is infecting people and spreading easily from person-to-person. Cases have been detected in most countries worldwide and community spread is being detected in a growing number of countries. On March 11, the COVID-19 outbreak was characterized as a pandemic by the WHOexternal icon.", "This is the first pandemic known to be caused by the emergence of a new coronavirus. In the past century, there have been four pandemics caused by the emergence of novel influenza viruses. As a result, most research and guidance around pandemics is specific to influenza, but the same premises can be applied to the current COVID-19 pandemic. Pandemics of respiratory disease follow a certain progression outlined in a “Pandemic Intervals Framework.” Pandemics begin with an investigation phase, followed by recognition, initiation, and acceleration phases. The peak of illnesses occurs at the end of the acceleration phase, which is followed by a deceleration phase, during which there is a decrease in illnesses. Different countries can be in different phases of the pandemic at any point in time and different parts of the same country can also be in different phases of a pandemic.", "There are ongoing investigations to learn more. This is a rapidly evolving situation and information will be updated as it becomes available.\n\nRisk Assessment\nRisk depends on characteristics of the virus, including how well it spreads between people; the severity of resulting illness; and the medical or other measures available to control the impact of the virus (for example, vaccines or medications that can treat the illness) and the relative success of these. In the absence of vaccine or treatment medications, nonpharmaceutical interventions become the most important response strategy. These are community interventions that can reduce the impact of disease.\n\nThe risk from COVID-19 to Americans can be broken down into risk of exposure versus risk of serious illness and death.\n\nRisk of exposure:", "The immediate risk of being exposed to this virus is still low for most Americans, but as the outbreak expands, that risk will increase. Cases of COVID-19 and instances of community spread are being reported in a growing number of states.\nPeople in places where ongoing community spread of the virus that causes COVID-19 has been reported are at elevated risk of exposure, with the level of risk dependent on the location.\nHealthcare workers caring for patients with COVID-19 are at elevated risk of exposure.\nClose contacts of persons with COVID-19 also are at elevated risk of exposure.\nTravelers returning from affected international locations where community spread is occurring also are at elevated risk of exposure, with level of risk dependent on where they traveled.\nRisk of Severe Illness:\n\nEarly information out of China, where COVID-19 first started, shows that some people are at higher risk of getting very sick from this illness. This includes:", "Older adults, with risk increasing by age.\nPeople who have serious chronic medical conditions like:\nHeart disease\nDiabetes\nLung disease\nCDC has developed guidance to help in the risk assessment and management of people with potential exposures to COVID-19.\n\nWhat May Happen\nMore cases of COVID-19 are likely to be identified in the United States in the coming days, including more instances of community spread. CDC expects that widespread transmission of COVID-19 in the United States will occur. In the coming months, most of the U.S. population will be exposed to this virus.", "Widespread transmission of COVID-19 could translate into large numbers of people needing medical care at the same time. Schools, childcare centers, and workplaces, may experience more absenteeism. Mass gatherings may be sparsely attended or postponed. Public health and healthcare systems may become overloaded, with elevated rates of hospitalizations and deaths. Other critical infrastructure, such as law enforcement, emergency medical services, and sectors of the transportation industry may also be affected. Healthcare providers and hospitals may be overwhelmed. At this time, there is no vaccine to protect against COVID-19 and no medications approved to treat it. Nonpharmaceutical interventions will be the most important response strategy to try to delay the spread of the virus and reduce the impact of disease.", "CDC Response\nGlobal efforts at this time are focused concurrently on lessening the spread and impact of this virus. The federal government is working closely with state, local, tribal, and territorial partners, as well as public health partners, to respond to this public health threat.", "Highlights of CDC’s Response\nCDC established a COVID-19 Incident Management System on January 7, 2020. On January 21, CDC activated its Emergency Operations Center to better provide ongoing support to the COVID-19 response.\nThe U.S. government has taken unprecedented steps with respect to travel in response to the growing public health threat posed by this new coronavirus:\nForeign nationals who have been in China, Iran, the United Kingdom, Ireland and any one of the 26 European countries in the Schengen Area within the past 14 days cannot enter the United States.\nU.S. citizens, residents, and their immediate family members who have been any one of those countries within in the past 14 days can enter the United States, but they are subject to health monitoring and possible quarantine for up to 14 days.\nPeople at higher risk of serious COVID-19 illness avoid cruise travel and non-essential air travel.\nCDC has issued additional specific travel guidance related to COVID-19.", "CDC has issued clinical guidance, including:\nClinical Guidance for Management of Patients with Confirmed Coronavirus Disease (COVID-19).\nInfection Prevention and Control Recommendations for Patients, including guidance on the use of personal protective equipment (PPE) during a shortage.\nCDC also has issued guidance for other settings, including:\nPreparing for COVID-19: Long-term Care Facilities, Nursing Homes\nDiscontinuation of Home Isolation for Persons with COVID-19\nCDC has deployed multidisciplinary teams to support state health departments in case identification, contact tracing, clinical management, and public communications.\nCDC has worked with federal partners to support the safe return of Americans overseas who have been affected by COVID-19.", "An important part of CDC’s role during a public health emergency is to develop a test for the pathogen and equip state and local public health labs with testing capacity.\nCDC developed an rRT-PCR test to diagnose COVID-19.\nAs of the evening of March 17, 89 state and local public health labs in 50 states, the District of Columbia, Guam, and Puerto Rico have successfully verified and are currently using CDC COVID-19 diagnostic tests.\nCommercial manufacturers are now producing their own tests.\nCDC has grown the COVID-19 virus in cell culture, which is necessary for further studies, including for additional genetic characterization. The cell-grown virus was sent to NIH’s BEI Resources Repositoryexternal icon for use by the broad scientific community.\nCDC also is developing a serology test for COVID-19.\nOther Available Resources\nThe following resources are available with information on COVID-19\n\nWorld Health Organization, Coronavirusexternal icon" ]	[ 5 ]	2,073	2,836
185	What viruses are similar to the COVID-19 coronavirus?	232	[ "MERS-CoV and SARS-CoV." ]	[ "CDC Summary 21 MAR 2020,\nhttps://www.cdc.gov/coronavirus/2019-ncov/cases-updates/summary.html\n\nThis is a rapidly evolving situation and CDC will provide updated information and guidance as it becomes available.\n\nUpdated March 21, 2020\n\nCDC is responding to a pandemic of respiratory disease spreading from person-to-person caused by a novel (new) coronavirus. The disease has been named “coronavirus disease 2019” (abbreviated “COVID-19”). This situation poses a serious public health risk. The federal government is working closely with state, local, tribal, and territorial partners, as well as public health partners, to respond to this situation. COVID-19 can cause mild to severe illness; most severe illness occurs in older adults.", "Situation in U.S.\nDifferent parts of the country are seeing different levels of COVID-19 activity. The United States nationally is in the initiation phase of the pandemic. States in which community spread is occurring are in the acceleration phase. The duration and severity of each pandemic phase can vary depending on the characteristics of the virus and the public health response.\n\nCDC and state and local public health laboratories are testing for the virus that causes COVID-19. View CDC’s Public Health Laboratory Testing map.\nAll 50 states have reported cases of COVID-19 to CDC.\nU.S. COVID-19 cases include:\nImported cases in travelers\nCases among close contacts of a known case\nCommunity-acquired cases where the source of the infection is unknown.\nTwenty-seven U.S. states are reporting some community spread of COVID-19.\nView latest case counts, deaths, and a map of states with reported cases.", "CDC Recommends\nEveryone can do their part to help us respond to this emerging public health threat:\nOn March 16, the White House announced a program called “15 Days to Slow the Spread,”pdf iconexternal icon which is a nationwide effort to slow the spread of COVID-19 through the implementation of social distancing at all levels of society.\nOlder people and people with severe chronic conditions should take special precautions because they are at higher risk of developing serious COVID-19 illness.\nIf you are a healthcare provider, use your judgment to determine if a patient has signs and symptoms compatible with COVID-19 and whether the patient should be tested. Factors to consider in addition to clinical symptoms may include:\nDoes the patient have recent travel from an affected area?\nHas the patient been in close contact with someone with COVID-19 or with patients with pneumonia of unknown cause?\nDoes the patient reside in an area where there has been community spread of COVID-19?", "If you are a healthcare provider or a public health responder caring for a COVID-19 patient, please take care of yourself and follow recommended infection control procedures.\nPeople who get a fever or cough should consider whether they might have COVID-19, depending on where they live, their travel history or other exposures. More than half of the U.S. is seeing some level of community spread of COVID-19. Testing for COVID-19 may be accessed through medical providers or public health departments, but there is no treatment for this virus. Most people have mild illness and are able to recover at home without medical care.\nFor people who are ill with COVID-19, but are not sick enough to be hospitalized, please follow CDC guidance on how to reduce the risk of spreading your illness to others. People who are mildly ill with COVID-19 are able to isolate at home during their illness.", "If you have been in China or another affected area or have been exposed to someone sick with COVID-19 in the last 14 days, you will face some limitations on your movement and activity. Please follow instructions during this time. Your cooperation is integral to the ongoing public health response to try to slow spread of this virus.\nCOVID-19 Emergence\nCOVID-19 is caused by a coronavirus. Coronaviruses are a large family of viruses that are common in people and many different species of animals, including camels, cattle, cats, and bats. Rarely, animal coronaviruses can infect people and then spread between people such as with MERS-CoV, SARS-CoV, and now with this new virus (named SARS-CoV-2).", "The SARS-CoV-2 virus is a betacoronavirus, like MERS-CoV and SARS-CoV. All three of these viruses have their origins in bats. The sequences from U.S. patients are similar to the one that China initially posted, suggesting a likely single, recent emergence of this virus from an animal reservoir.", "Early on, many of the patients at the epicenter of the outbreak in Wuhan, Hubei Province, China had some link to a large seafood and live animal market, suggesting animal-to-person spread. Later, a growing number of patients reportedly did not have exposure to animal markets, indicating person-to-person spread. Person-to-person spread was subsequently reported outside Hubei and in countries outside China, including in the United States. Some international destinations now have ongoing community spread with the virus that causes COVID-19, as do some parts of the United States. Community spread means some people have been infected and it is not known how or where they became exposed. Learn more about the spread of this newly emerged coronavirus.", "Severity\nThe complete clinical picture with regard to COVID-19 is not fully known. Reported illnesses have ranged from very mild (including some with no reported symptoms) to severe, including illness resulting in death. While information so far suggests that most COVID-19 illness is mild, a reportexternal icon out of China suggests serious illness occurs in 16% of cases. Older people and people of all ages with severe chronic medical conditions — like heart disease, lung disease and diabetes, for example — seem to be at higher risk of developing serious COVID-19 illness. A CDC Morbidity & Mortality Weekly Report that looked at severity of disease among COVID-19 cases in the United States by age group found that 80% of deaths were among adults 65 years and older with the highest percentage of severe outcomes occurring in people 85 years and older.\n\nLearn more about the symptoms associated with COVID-19.", "COVID-19 Pandemic\nA pandemic is a global outbreak of disease. Pandemics happen when a new virus emerges to infect people and can spread between people sustainably. Because there is little to no pre-existing immunity against the new virus, it spreads worldwide.\n\nThe virus that causes COVID-19 is infecting people and spreading easily from person-to-person. Cases have been detected in most countries worldwide and community spread is being detected in a growing number of countries. On March 11, the COVID-19 outbreak was characterized as a pandemic by the WHOexternal icon.", "This is the first pandemic known to be caused by the emergence of a new coronavirus. In the past century, there have been four pandemics caused by the emergence of novel influenza viruses. As a result, most research and guidance around pandemics is specific to influenza, but the same premises can be applied to the current COVID-19 pandemic. Pandemics of respiratory disease follow a certain progression outlined in a “Pandemic Intervals Framework.” Pandemics begin with an investigation phase, followed by recognition, initiation, and acceleration phases. The peak of illnesses occurs at the end of the acceleration phase, which is followed by a deceleration phase, during which there is a decrease in illnesses. Different countries can be in different phases of the pandemic at any point in time and different parts of the same country can also be in different phases of a pandemic.", "There are ongoing investigations to learn more. This is a rapidly evolving situation and information will be updated as it becomes available.\n\nRisk Assessment\nRisk depends on characteristics of the virus, including how well it spreads between people; the severity of resulting illness; and the medical or other measures available to control the impact of the virus (for example, vaccines or medications that can treat the illness) and the relative success of these. In the absence of vaccine or treatment medications, nonpharmaceutical interventions become the most important response strategy. These are community interventions that can reduce the impact of disease.\n\nThe risk from COVID-19 to Americans can be broken down into risk of exposure versus risk of serious illness and death.\n\nRisk of exposure:", "The immediate risk of being exposed to this virus is still low for most Americans, but as the outbreak expands, that risk will increase. Cases of COVID-19 and instances of community spread are being reported in a growing number of states.\nPeople in places where ongoing community spread of the virus that causes COVID-19 has been reported are at elevated risk of exposure, with the level of risk dependent on the location.\nHealthcare workers caring for patients with COVID-19 are at elevated risk of exposure.\nClose contacts of persons with COVID-19 also are at elevated risk of exposure.\nTravelers returning from affected international locations where community spread is occurring also are at elevated risk of exposure, with level of risk dependent on where they traveled.\nRisk of Severe Illness:\n\nEarly information out of China, where COVID-19 first started, shows that some people are at higher risk of getting very sick from this illness. This includes:", "Older adults, with risk increasing by age.\nPeople who have serious chronic medical conditions like:\nHeart disease\nDiabetes\nLung disease\nCDC has developed guidance to help in the risk assessment and management of people with potential exposures to COVID-19.\n\nWhat May Happen\nMore cases of COVID-19 are likely to be identified in the United States in the coming days, including more instances of community spread. CDC expects that widespread transmission of COVID-19 in the United States will occur. In the coming months, most of the U.S. population will be exposed to this virus.", "Widespread transmission of COVID-19 could translate into large numbers of people needing medical care at the same time. Schools, childcare centers, and workplaces, may experience more absenteeism. Mass gatherings may be sparsely attended or postponed. Public health and healthcare systems may become overloaded, with elevated rates of hospitalizations and deaths. Other critical infrastructure, such as law enforcement, emergency medical services, and sectors of the transportation industry may also be affected. Healthcare providers and hospitals may be overwhelmed. At this time, there is no vaccine to protect against COVID-19 and no medications approved to treat it. Nonpharmaceutical interventions will be the most important response strategy to try to delay the spread of the virus and reduce the impact of disease.", "CDC Response\nGlobal efforts at this time are focused concurrently on lessening the spread and impact of this virus. The federal government is working closely with state, local, tribal, and territorial partners, as well as public health partners, to respond to this public health threat.", "Highlights of CDC’s Response\nCDC established a COVID-19 Incident Management System on January 7, 2020. On January 21, CDC activated its Emergency Operations Center to better provide ongoing support to the COVID-19 response.\nThe U.S. government has taken unprecedented steps with respect to travel in response to the growing public health threat posed by this new coronavirus:\nForeign nationals who have been in China, Iran, the United Kingdom, Ireland and any one of the 26 European countries in the Schengen Area within the past 14 days cannot enter the United States.\nU.S. citizens, residents, and their immediate family members who have been any one of those countries within in the past 14 days can enter the United States, but they are subject to health monitoring and possible quarantine for up to 14 days.\nPeople at higher risk of serious COVID-19 illness avoid cruise travel and non-essential air travel.\nCDC has issued additional specific travel guidance related to COVID-19.", "CDC has issued clinical guidance, including:\nClinical Guidance for Management of Patients with Confirmed Coronavirus Disease (COVID-19).\nInfection Prevention and Control Recommendations for Patients, including guidance on the use of personal protective equipment (PPE) during a shortage.\nCDC also has issued guidance for other settings, including:\nPreparing for COVID-19: Long-term Care Facilities, Nursing Homes\nDiscontinuation of Home Isolation for Persons with COVID-19\nCDC has deployed multidisciplinary teams to support state health departments in case identification, contact tracing, clinical management, and public communications.\nCDC has worked with federal partners to support the safe return of Americans overseas who have been affected by COVID-19.", "An important part of CDC’s role during a public health emergency is to develop a test for the pathogen and equip state and local public health labs with testing capacity.\nCDC developed an rRT-PCR test to diagnose COVID-19.\nAs of the evening of March 17, 89 state and local public health labs in 50 states, the District of Columbia, Guam, and Puerto Rico have successfully verified and are currently using CDC COVID-19 diagnostic tests.\nCommercial manufacturers are now producing their own tests.\nCDC has grown the COVID-19 virus in cell culture, which is necessary for further studies, including for additional genetic characterization. The cell-grown virus was sent to NIH’s BEI Resources Repositoryexternal icon for use by the broad scientific community.\nCDC also is developing a serology test for COVID-19.\nOther Available Resources\nThe following resources are available with information on COVID-19\n\nWorld Health Organization, Coronavirusexternal icon" ]	[ 5 ]	2,073	2,836
185	What are the phases of a pandemic?	233	[ "investigation phase, followed by recognition, initiation, and acceleration phases" ]	[ "CDC Summary 21 MAR 2020,\nhttps://www.cdc.gov/coronavirus/2019-ncov/cases-updates/summary.html\n\nThis is a rapidly evolving situation and CDC will provide updated information and guidance as it becomes available.\n\nUpdated March 21, 2020\n\nCDC is responding to a pandemic of respiratory disease spreading from person-to-person caused by a novel (new) coronavirus. The disease has been named “coronavirus disease 2019” (abbreviated “COVID-19”). This situation poses a serious public health risk. The federal government is working closely with state, local, tribal, and territorial partners, as well as public health partners, to respond to this situation. COVID-19 can cause mild to severe illness; most severe illness occurs in older adults.", "Situation in U.S.\nDifferent parts of the country are seeing different levels of COVID-19 activity. The United States nationally is in the initiation phase of the pandemic. States in which community spread is occurring are in the acceleration phase. The duration and severity of each pandemic phase can vary depending on the characteristics of the virus and the public health response.\n\nCDC and state and local public health laboratories are testing for the virus that causes COVID-19. View CDC’s Public Health Laboratory Testing map.\nAll 50 states have reported cases of COVID-19 to CDC.\nU.S. COVID-19 cases include:\nImported cases in travelers\nCases among close contacts of a known case\nCommunity-acquired cases where the source of the infection is unknown.\nTwenty-seven U.S. states are reporting some community spread of COVID-19.\nView latest case counts, deaths, and a map of states with reported cases.", "CDC Recommends\nEveryone can do their part to help us respond to this emerging public health threat:\nOn March 16, the White House announced a program called “15 Days to Slow the Spread,”pdf iconexternal icon which is a nationwide effort to slow the spread of COVID-19 through the implementation of social distancing at all levels of society.\nOlder people and people with severe chronic conditions should take special precautions because they are at higher risk of developing serious COVID-19 illness.\nIf you are a healthcare provider, use your judgment to determine if a patient has signs and symptoms compatible with COVID-19 and whether the patient should be tested. Factors to consider in addition to clinical symptoms may include:\nDoes the patient have recent travel from an affected area?\nHas the patient been in close contact with someone with COVID-19 or with patients with pneumonia of unknown cause?\nDoes the patient reside in an area where there has been community spread of COVID-19?", "If you are a healthcare provider or a public health responder caring for a COVID-19 patient, please take care of yourself and follow recommended infection control procedures.\nPeople who get a fever or cough should consider whether they might have COVID-19, depending on where they live, their travel history or other exposures. More than half of the U.S. is seeing some level of community spread of COVID-19. Testing for COVID-19 may be accessed through medical providers or public health departments, but there is no treatment for this virus. Most people have mild illness and are able to recover at home without medical care.\nFor people who are ill with COVID-19, but are not sick enough to be hospitalized, please follow CDC guidance on how to reduce the risk of spreading your illness to others. People who are mildly ill with COVID-19 are able to isolate at home during their illness.", "If you have been in China or another affected area or have been exposed to someone sick with COVID-19 in the last 14 days, you will face some limitations on your movement and activity. Please follow instructions during this time. Your cooperation is integral to the ongoing public health response to try to slow spread of this virus.\nCOVID-19 Emergence\nCOVID-19 is caused by a coronavirus. Coronaviruses are a large family of viruses that are common in people and many different species of animals, including camels, cattle, cats, and bats. Rarely, animal coronaviruses can infect people and then spread between people such as with MERS-CoV, SARS-CoV, and now with this new virus (named SARS-CoV-2).", "The SARS-CoV-2 virus is a betacoronavirus, like MERS-CoV and SARS-CoV. All three of these viruses have their origins in bats. The sequences from U.S. patients are similar to the one that China initially posted, suggesting a likely single, recent emergence of this virus from an animal reservoir.", "Early on, many of the patients at the epicenter of the outbreak in Wuhan, Hubei Province, China had some link to a large seafood and live animal market, suggesting animal-to-person spread. Later, a growing number of patients reportedly did not have exposure to animal markets, indicating person-to-person spread. Person-to-person spread was subsequently reported outside Hubei and in countries outside China, including in the United States. Some international destinations now have ongoing community spread with the virus that causes COVID-19, as do some parts of the United States. Community spread means some people have been infected and it is not known how or where they became exposed. Learn more about the spread of this newly emerged coronavirus.", "Severity\nThe complete clinical picture with regard to COVID-19 is not fully known. Reported illnesses have ranged from very mild (including some with no reported symptoms) to severe, including illness resulting in death. While information so far suggests that most COVID-19 illness is mild, a reportexternal icon out of China suggests serious illness occurs in 16% of cases. Older people and people of all ages with severe chronic medical conditions — like heart disease, lung disease and diabetes, for example — seem to be at higher risk of developing serious COVID-19 illness. A CDC Morbidity & Mortality Weekly Report that looked at severity of disease among COVID-19 cases in the United States by age group found that 80% of deaths were among adults 65 years and older with the highest percentage of severe outcomes occurring in people 85 years and older.\n\nLearn more about the symptoms associated with COVID-19.", "COVID-19 Pandemic\nA pandemic is a global outbreak of disease. Pandemics happen when a new virus emerges to infect people and can spread between people sustainably. Because there is little to no pre-existing immunity against the new virus, it spreads worldwide.\n\nThe virus that causes COVID-19 is infecting people and spreading easily from person-to-person. Cases have been detected in most countries worldwide and community spread is being detected in a growing number of countries. On March 11, the COVID-19 outbreak was characterized as a pandemic by the WHOexternal icon.", "This is the first pandemic known to be caused by the emergence of a new coronavirus. In the past century, there have been four pandemics caused by the emergence of novel influenza viruses. As a result, most research and guidance around pandemics is specific to influenza, but the same premises can be applied to the current COVID-19 pandemic. Pandemics of respiratory disease follow a certain progression outlined in a “Pandemic Intervals Framework.” Pandemics begin with an investigation phase, followed by recognition, initiation, and acceleration phases. The peak of illnesses occurs at the end of the acceleration phase, which is followed by a deceleration phase, during which there is a decrease in illnesses. Different countries can be in different phases of the pandemic at any point in time and different parts of the same country can also be in different phases of a pandemic.", "There are ongoing investigations to learn more. This is a rapidly evolving situation and information will be updated as it becomes available.\n\nRisk Assessment\nRisk depends on characteristics of the virus, including how well it spreads between people; the severity of resulting illness; and the medical or other measures available to control the impact of the virus (for example, vaccines or medications that can treat the illness) and the relative success of these. In the absence of vaccine or treatment medications, nonpharmaceutical interventions become the most important response strategy. These are community interventions that can reduce the impact of disease.\n\nThe risk from COVID-19 to Americans can be broken down into risk of exposure versus risk of serious illness and death.\n\nRisk of exposure:", "The immediate risk of being exposed to this virus is still low for most Americans, but as the outbreak expands, that risk will increase. Cases of COVID-19 and instances of community spread are being reported in a growing number of states.\nPeople in places where ongoing community spread of the virus that causes COVID-19 has been reported are at elevated risk of exposure, with the level of risk dependent on the location.\nHealthcare workers caring for patients with COVID-19 are at elevated risk of exposure.\nClose contacts of persons with COVID-19 also are at elevated risk of exposure.\nTravelers returning from affected international locations where community spread is occurring also are at elevated risk of exposure, with level of risk dependent on where they traveled.\nRisk of Severe Illness:\n\nEarly information out of China, where COVID-19 first started, shows that some people are at higher risk of getting very sick from this illness. This includes:", "Older adults, with risk increasing by age.\nPeople who have serious chronic medical conditions like:\nHeart disease\nDiabetes\nLung disease\nCDC has developed guidance to help in the risk assessment and management of people with potential exposures to COVID-19.\n\nWhat May Happen\nMore cases of COVID-19 are likely to be identified in the United States in the coming days, including more instances of community spread. CDC expects that widespread transmission of COVID-19 in the United States will occur. In the coming months, most of the U.S. population will be exposed to this virus.", "Widespread transmission of COVID-19 could translate into large numbers of people needing medical care at the same time. Schools, childcare centers, and workplaces, may experience more absenteeism. Mass gatherings may be sparsely attended or postponed. Public health and healthcare systems may become overloaded, with elevated rates of hospitalizations and deaths. Other critical infrastructure, such as law enforcement, emergency medical services, and sectors of the transportation industry may also be affected. Healthcare providers and hospitals may be overwhelmed. At this time, there is no vaccine to protect against COVID-19 and no medications approved to treat it. Nonpharmaceutical interventions will be the most important response strategy to try to delay the spread of the virus and reduce the impact of disease.", "CDC Response\nGlobal efforts at this time are focused concurrently on lessening the spread and impact of this virus. The federal government is working closely with state, local, tribal, and territorial partners, as well as public health partners, to respond to this public health threat.", "Highlights of CDC’s Response\nCDC established a COVID-19 Incident Management System on January 7, 2020. On January 21, CDC activated its Emergency Operations Center to better provide ongoing support to the COVID-19 response.\nThe U.S. government has taken unprecedented steps with respect to travel in response to the growing public health threat posed by this new coronavirus:\nForeign nationals who have been in China, Iran, the United Kingdom, Ireland and any one of the 26 European countries in the Schengen Area within the past 14 days cannot enter the United States.\nU.S. citizens, residents, and their immediate family members who have been any one of those countries within in the past 14 days can enter the United States, but they are subject to health monitoring and possible quarantine for up to 14 days.\nPeople at higher risk of serious COVID-19 illness avoid cruise travel and non-essential air travel.\nCDC has issued additional specific travel guidance related to COVID-19.", "CDC has issued clinical guidance, including:\nClinical Guidance for Management of Patients with Confirmed Coronavirus Disease (COVID-19).\nInfection Prevention and Control Recommendations for Patients, including guidance on the use of personal protective equipment (PPE) during a shortage.\nCDC also has issued guidance for other settings, including:\nPreparing for COVID-19: Long-term Care Facilities, Nursing Homes\nDiscontinuation of Home Isolation for Persons with COVID-19\nCDC has deployed multidisciplinary teams to support state health departments in case identification, contact tracing, clinical management, and public communications.\nCDC has worked with federal partners to support the safe return of Americans overseas who have been affected by COVID-19.", "An important part of CDC’s role during a public health emergency is to develop a test for the pathogen and equip state and local public health labs with testing capacity.\nCDC developed an rRT-PCR test to diagnose COVID-19.\nAs of the evening of March 17, 89 state and local public health labs in 50 states, the District of Columbia, Guam, and Puerto Rico have successfully verified and are currently using CDC COVID-19 diagnostic tests.\nCommercial manufacturers are now producing their own tests.\nCDC has grown the COVID-19 virus in cell culture, which is necessary for further studies, including for additional genetic characterization. The cell-grown virus was sent to NIH’s BEI Resources Repositoryexternal icon for use by the broad scientific community.\nCDC also is developing a serology test for COVID-19.\nOther Available Resources\nThe following resources are available with information on COVID-19\n\nWorld Health Organization, Coronavirusexternal icon" ]	[ 9 ]	2,073	2,836
185	At which phase does the peak of the pandemic occur?	234	[ "at the end of the acceleration phase" ]	[ "CDC Summary 21 MAR 2020,\nhttps://www.cdc.gov/coronavirus/2019-ncov/cases-updates/summary.html\n\nThis is a rapidly evolving situation and CDC will provide updated information and guidance as it becomes available.\n\nUpdated March 21, 2020\n\nCDC is responding to a pandemic of respiratory disease spreading from person-to-person caused by a novel (new) coronavirus. The disease has been named “coronavirus disease 2019” (abbreviated “COVID-19”). This situation poses a serious public health risk. The federal government is working closely with state, local, tribal, and territorial partners, as well as public health partners, to respond to this situation. COVID-19 can cause mild to severe illness; most severe illness occurs in older adults.", "Situation in U.S.\nDifferent parts of the country are seeing different levels of COVID-19 activity. The United States nationally is in the initiation phase of the pandemic. States in which community spread is occurring are in the acceleration phase. The duration and severity of each pandemic phase can vary depending on the characteristics of the virus and the public health response.\n\nCDC and state and local public health laboratories are testing for the virus that causes COVID-19. View CDC’s Public Health Laboratory Testing map.\nAll 50 states have reported cases of COVID-19 to CDC.\nU.S. COVID-19 cases include:\nImported cases in travelers\nCases among close contacts of a known case\nCommunity-acquired cases where the source of the infection is unknown.\nTwenty-seven U.S. states are reporting some community spread of COVID-19.\nView latest case counts, deaths, and a map of states with reported cases.", "CDC Recommends\nEveryone can do their part to help us respond to this emerging public health threat:\nOn March 16, the White House announced a program called “15 Days to Slow the Spread,”pdf iconexternal icon which is a nationwide effort to slow the spread of COVID-19 through the implementation of social distancing at all levels of society.\nOlder people and people with severe chronic conditions should take special precautions because they are at higher risk of developing serious COVID-19 illness.\nIf you are a healthcare provider, use your judgment to determine if a patient has signs and symptoms compatible with COVID-19 and whether the patient should be tested. Factors to consider in addition to clinical symptoms may include:\nDoes the patient have recent travel from an affected area?\nHas the patient been in close contact with someone with COVID-19 or with patients with pneumonia of unknown cause?\nDoes the patient reside in an area where there has been community spread of COVID-19?", "If you are a healthcare provider or a public health responder caring for a COVID-19 patient, please take care of yourself and follow recommended infection control procedures.\nPeople who get a fever or cough should consider whether they might have COVID-19, depending on where they live, their travel history or other exposures. More than half of the U.S. is seeing some level of community spread of COVID-19. Testing for COVID-19 may be accessed through medical providers or public health departments, but there is no treatment for this virus. Most people have mild illness and are able to recover at home without medical care.\nFor people who are ill with COVID-19, but are not sick enough to be hospitalized, please follow CDC guidance on how to reduce the risk of spreading your illness to others. People who are mildly ill with COVID-19 are able to isolate at home during their illness.", "If you have been in China or another affected area or have been exposed to someone sick with COVID-19 in the last 14 days, you will face some limitations on your movement and activity. Please follow instructions during this time. Your cooperation is integral to the ongoing public health response to try to slow spread of this virus.\nCOVID-19 Emergence\nCOVID-19 is caused by a coronavirus. Coronaviruses are a large family of viruses that are common in people and many different species of animals, including camels, cattle, cats, and bats. Rarely, animal coronaviruses can infect people and then spread between people such as with MERS-CoV, SARS-CoV, and now with this new virus (named SARS-CoV-2).", "The SARS-CoV-2 virus is a betacoronavirus, like MERS-CoV and SARS-CoV. All three of these viruses have their origins in bats. The sequences from U.S. patients are similar to the one that China initially posted, suggesting a likely single, recent emergence of this virus from an animal reservoir.", "Early on, many of the patients at the epicenter of the outbreak in Wuhan, Hubei Province, China had some link to a large seafood and live animal market, suggesting animal-to-person spread. Later, a growing number of patients reportedly did not have exposure to animal markets, indicating person-to-person spread. Person-to-person spread was subsequently reported outside Hubei and in countries outside China, including in the United States. Some international destinations now have ongoing community spread with the virus that causes COVID-19, as do some parts of the United States. Community spread means some people have been infected and it is not known how or where they became exposed. Learn more about the spread of this newly emerged coronavirus.", "Severity\nThe complete clinical picture with regard to COVID-19 is not fully known. Reported illnesses have ranged from very mild (including some with no reported symptoms) to severe, including illness resulting in death. While information so far suggests that most COVID-19 illness is mild, a reportexternal icon out of China suggests serious illness occurs in 16% of cases. Older people and people of all ages with severe chronic medical conditions — like heart disease, lung disease and diabetes, for example — seem to be at higher risk of developing serious COVID-19 illness. A CDC Morbidity & Mortality Weekly Report that looked at severity of disease among COVID-19 cases in the United States by age group found that 80% of deaths were among adults 65 years and older with the highest percentage of severe outcomes occurring in people 85 years and older.\n\nLearn more about the symptoms associated with COVID-19.", "COVID-19 Pandemic\nA pandemic is a global outbreak of disease. Pandemics happen when a new virus emerges to infect people and can spread between people sustainably. Because there is little to no pre-existing immunity against the new virus, it spreads worldwide.\n\nThe virus that causes COVID-19 is infecting people and spreading easily from person-to-person. Cases have been detected in most countries worldwide and community spread is being detected in a growing number of countries. On March 11, the COVID-19 outbreak was characterized as a pandemic by the WHOexternal icon.", "This is the first pandemic known to be caused by the emergence of a new coronavirus. In the past century, there have been four pandemics caused by the emergence of novel influenza viruses. As a result, most research and guidance around pandemics is specific to influenza, but the same premises can be applied to the current COVID-19 pandemic. Pandemics of respiratory disease follow a certain progression outlined in a “Pandemic Intervals Framework.” Pandemics begin with an investigation phase, followed by recognition, initiation, and acceleration phases. The peak of illnesses occurs at the end of the acceleration phase, which is followed by a deceleration phase, during which there is a decrease in illnesses. Different countries can be in different phases of the pandemic at any point in time and different parts of the same country can also be in different phases of a pandemic.", "There are ongoing investigations to learn more. This is a rapidly evolving situation and information will be updated as it becomes available.\n\nRisk Assessment\nRisk depends on characteristics of the virus, including how well it spreads between people; the severity of resulting illness; and the medical or other measures available to control the impact of the virus (for example, vaccines or medications that can treat the illness) and the relative success of these. In the absence of vaccine or treatment medications, nonpharmaceutical interventions become the most important response strategy. These are community interventions that can reduce the impact of disease.\n\nThe risk from COVID-19 to Americans can be broken down into risk of exposure versus risk of serious illness and death.\n\nRisk of exposure:", "The immediate risk of being exposed to this virus is still low for most Americans, but as the outbreak expands, that risk will increase. Cases of COVID-19 and instances of community spread are being reported in a growing number of states.\nPeople in places where ongoing community spread of the virus that causes COVID-19 has been reported are at elevated risk of exposure, with the level of risk dependent on the location.\nHealthcare workers caring for patients with COVID-19 are at elevated risk of exposure.\nClose contacts of persons with COVID-19 also are at elevated risk of exposure.\nTravelers returning from affected international locations where community spread is occurring also are at elevated risk of exposure, with level of risk dependent on where they traveled.\nRisk of Severe Illness:\n\nEarly information out of China, where COVID-19 first started, shows that some people are at higher risk of getting very sick from this illness. This includes:", "Older adults, with risk increasing by age.\nPeople who have serious chronic medical conditions like:\nHeart disease\nDiabetes\nLung disease\nCDC has developed guidance to help in the risk assessment and management of people with potential exposures to COVID-19.\n\nWhat May Happen\nMore cases of COVID-19 are likely to be identified in the United States in the coming days, including more instances of community spread. CDC expects that widespread transmission of COVID-19 in the United States will occur. In the coming months, most of the U.S. population will be exposed to this virus.", "Widespread transmission of COVID-19 could translate into large numbers of people needing medical care at the same time. Schools, childcare centers, and workplaces, may experience more absenteeism. Mass gatherings may be sparsely attended or postponed. Public health and healthcare systems may become overloaded, with elevated rates of hospitalizations and deaths. Other critical infrastructure, such as law enforcement, emergency medical services, and sectors of the transportation industry may also be affected. Healthcare providers and hospitals may be overwhelmed. At this time, there is no vaccine to protect against COVID-19 and no medications approved to treat it. Nonpharmaceutical interventions will be the most important response strategy to try to delay the spread of the virus and reduce the impact of disease.", "CDC Response\nGlobal efforts at this time are focused concurrently on lessening the spread and impact of this virus. The federal government is working closely with state, local, tribal, and territorial partners, as well as public health partners, to respond to this public health threat.", "Highlights of CDC’s Response\nCDC established a COVID-19 Incident Management System on January 7, 2020. On January 21, CDC activated its Emergency Operations Center to better provide ongoing support to the COVID-19 response.\nThe U.S. government has taken unprecedented steps with respect to travel in response to the growing public health threat posed by this new coronavirus:\nForeign nationals who have been in China, Iran, the United Kingdom, Ireland and any one of the 26 European countries in the Schengen Area within the past 14 days cannot enter the United States.\nU.S. citizens, residents, and their immediate family members who have been any one of those countries within in the past 14 days can enter the United States, but they are subject to health monitoring and possible quarantine for up to 14 days.\nPeople at higher risk of serious COVID-19 illness avoid cruise travel and non-essential air travel.\nCDC has issued additional specific travel guidance related to COVID-19.", "CDC has issued clinical guidance, including:\nClinical Guidance for Management of Patients with Confirmed Coronavirus Disease (COVID-19).\nInfection Prevention and Control Recommendations for Patients, including guidance on the use of personal protective equipment (PPE) during a shortage.\nCDC also has issued guidance for other settings, including:\nPreparing for COVID-19: Long-term Care Facilities, Nursing Homes\nDiscontinuation of Home Isolation for Persons with COVID-19\nCDC has deployed multidisciplinary teams to support state health departments in case identification, contact tracing, clinical management, and public communications.\nCDC has worked with federal partners to support the safe return of Americans overseas who have been affected by COVID-19.", "An important part of CDC’s role during a public health emergency is to develop a test for the pathogen and equip state and local public health labs with testing capacity.\nCDC developed an rRT-PCR test to diagnose COVID-19.\nAs of the evening of March 17, 89 state and local public health labs in 50 states, the District of Columbia, Guam, and Puerto Rico have successfully verified and are currently using CDC COVID-19 diagnostic tests.\nCommercial manufacturers are now producing their own tests.\nCDC has grown the COVID-19 virus in cell culture, which is necessary for further studies, including for additional genetic characterization. The cell-grown virus was sent to NIH’s BEI Resources Repositoryexternal icon for use by the broad scientific community.\nCDC also is developing a serology test for COVID-19.\nOther Available Resources\nThe following resources are available with information on COVID-19\n\nWorld Health Organization, Coronavirusexternal icon" ]	[ 9 ]	2,073	2,836
185	People with which medical conditions have a higher rate of severe illness?	237	[ "People who have serious chronic medical conditions like:\nHeart disease\nDiabetes\nLung disease" ]	[ "CDC Summary 21 MAR 2020,\nhttps://www.cdc.gov/coronavirus/2019-ncov/cases-updates/summary.html\n\nThis is a rapidly evolving situation and CDC will provide updated information and guidance as it becomes available.\n\nUpdated March 21, 2020\n\nCDC is responding to a pandemic of respiratory disease spreading from person-to-person caused by a novel (new) coronavirus. The disease has been named “coronavirus disease 2019” (abbreviated “COVID-19”). This situation poses a serious public health risk. The federal government is working closely with state, local, tribal, and territorial partners, as well as public health partners, to respond to this situation. COVID-19 can cause mild to severe illness; most severe illness occurs in older adults.", "Situation in U.S.\nDifferent parts of the country are seeing different levels of COVID-19 activity. The United States nationally is in the initiation phase of the pandemic. States in which community spread is occurring are in the acceleration phase. The duration and severity of each pandemic phase can vary depending on the characteristics of the virus and the public health response.\n\nCDC and state and local public health laboratories are testing for the virus that causes COVID-19. View CDC’s Public Health Laboratory Testing map.\nAll 50 states have reported cases of COVID-19 to CDC.\nU.S. COVID-19 cases include:\nImported cases in travelers\nCases among close contacts of a known case\nCommunity-acquired cases where the source of the infection is unknown.\nTwenty-seven U.S. states are reporting some community spread of COVID-19.\nView latest case counts, deaths, and a map of states with reported cases.", "CDC Recommends\nEveryone can do their part to help us respond to this emerging public health threat:\nOn March 16, the White House announced a program called “15 Days to Slow the Spread,”pdf iconexternal icon which is a nationwide effort to slow the spread of COVID-19 through the implementation of social distancing at all levels of society.\nOlder people and people with severe chronic conditions should take special precautions because they are at higher risk of developing serious COVID-19 illness.\nIf you are a healthcare provider, use your judgment to determine if a patient has signs and symptoms compatible with COVID-19 and whether the patient should be tested. Factors to consider in addition to clinical symptoms may include:\nDoes the patient have recent travel from an affected area?\nHas the patient been in close contact with someone with COVID-19 or with patients with pneumonia of unknown cause?\nDoes the patient reside in an area where there has been community spread of COVID-19?", "If you are a healthcare provider or a public health responder caring for a COVID-19 patient, please take care of yourself and follow recommended infection control procedures.\nPeople who get a fever or cough should consider whether they might have COVID-19, depending on where they live, their travel history or other exposures. More than half of the U.S. is seeing some level of community spread of COVID-19. Testing for COVID-19 may be accessed through medical providers or public health departments, but there is no treatment for this virus. Most people have mild illness and are able to recover at home without medical care.\nFor people who are ill with COVID-19, but are not sick enough to be hospitalized, please follow CDC guidance on how to reduce the risk of spreading your illness to others. People who are mildly ill with COVID-19 are able to isolate at home during their illness.", "If you have been in China or another affected area or have been exposed to someone sick with COVID-19 in the last 14 days, you will face some limitations on your movement and activity. Please follow instructions during this time. Your cooperation is integral to the ongoing public health response to try to slow spread of this virus.\nCOVID-19 Emergence\nCOVID-19 is caused by a coronavirus. Coronaviruses are a large family of viruses that are common in people and many different species of animals, including camels, cattle, cats, and bats. Rarely, animal coronaviruses can infect people and then spread between people such as with MERS-CoV, SARS-CoV, and now with this new virus (named SARS-CoV-2).", "The SARS-CoV-2 virus is a betacoronavirus, like MERS-CoV and SARS-CoV. All three of these viruses have their origins in bats. The sequences from U.S. patients are similar to the one that China initially posted, suggesting a likely single, recent emergence of this virus from an animal reservoir.", "Early on, many of the patients at the epicenter of the outbreak in Wuhan, Hubei Province, China had some link to a large seafood and live animal market, suggesting animal-to-person spread. Later, a growing number of patients reportedly did not have exposure to animal markets, indicating person-to-person spread. Person-to-person spread was subsequently reported outside Hubei and in countries outside China, including in the United States. Some international destinations now have ongoing community spread with the virus that causes COVID-19, as do some parts of the United States. Community spread means some people have been infected and it is not known how or where they became exposed. Learn more about the spread of this newly emerged coronavirus.", "Severity\nThe complete clinical picture with regard to COVID-19 is not fully known. Reported illnesses have ranged from very mild (including some with no reported symptoms) to severe, including illness resulting in death. While information so far suggests that most COVID-19 illness is mild, a reportexternal icon out of China suggests serious illness occurs in 16% of cases. Older people and people of all ages with severe chronic medical conditions — like heart disease, lung disease and diabetes, for example — seem to be at higher risk of developing serious COVID-19 illness. A CDC Morbidity & Mortality Weekly Report that looked at severity of disease among COVID-19 cases in the United States by age group found that 80% of deaths were among adults 65 years and older with the highest percentage of severe outcomes occurring in people 85 years and older.\n\nLearn more about the symptoms associated with COVID-19.", "COVID-19 Pandemic\nA pandemic is a global outbreak of disease. Pandemics happen when a new virus emerges to infect people and can spread between people sustainably. Because there is little to no pre-existing immunity against the new virus, it spreads worldwide.\n\nThe virus that causes COVID-19 is infecting people and spreading easily from person-to-person. Cases have been detected in most countries worldwide and community spread is being detected in a growing number of countries. On March 11, the COVID-19 outbreak was characterized as a pandemic by the WHOexternal icon.", "This is the first pandemic known to be caused by the emergence of a new coronavirus. In the past century, there have been four pandemics caused by the emergence of novel influenza viruses. As a result, most research and guidance around pandemics is specific to influenza, but the same premises can be applied to the current COVID-19 pandemic. Pandemics of respiratory disease follow a certain progression outlined in a “Pandemic Intervals Framework.” Pandemics begin with an investigation phase, followed by recognition, initiation, and acceleration phases. The peak of illnesses occurs at the end of the acceleration phase, which is followed by a deceleration phase, during which there is a decrease in illnesses. Different countries can be in different phases of the pandemic at any point in time and different parts of the same country can also be in different phases of a pandemic.", "There are ongoing investigations to learn more. This is a rapidly evolving situation and information will be updated as it becomes available.\n\nRisk Assessment\nRisk depends on characteristics of the virus, including how well it spreads between people; the severity of resulting illness; and the medical or other measures available to control the impact of the virus (for example, vaccines or medications that can treat the illness) and the relative success of these. In the absence of vaccine or treatment medications, nonpharmaceutical interventions become the most important response strategy. These are community interventions that can reduce the impact of disease.\n\nThe risk from COVID-19 to Americans can be broken down into risk of exposure versus risk of serious illness and death.\n\nRisk of exposure:", "The immediate risk of being exposed to this virus is still low for most Americans, but as the outbreak expands, that risk will increase. Cases of COVID-19 and instances of community spread are being reported in a growing number of states.\nPeople in places where ongoing community spread of the virus that causes COVID-19 has been reported are at elevated risk of exposure, with the level of risk dependent on the location.\nHealthcare workers caring for patients with COVID-19 are at elevated risk of exposure.\nClose contacts of persons with COVID-19 also are at elevated risk of exposure.\nTravelers returning from affected international locations where community spread is occurring also are at elevated risk of exposure, with level of risk dependent on where they traveled.\nRisk of Severe Illness:\n\nEarly information out of China, where COVID-19 first started, shows that some people are at higher risk of getting very sick from this illness. This includes:", "Older adults, with risk increasing by age.\nPeople who have serious chronic medical conditions like:\nHeart disease\nDiabetes\nLung disease\nCDC has developed guidance to help in the risk assessment and management of people with potential exposures to COVID-19.\n\nWhat May Happen\nMore cases of COVID-19 are likely to be identified in the United States in the coming days, including more instances of community spread. CDC expects that widespread transmission of COVID-19 in the United States will occur. In the coming months, most of the U.S. population will be exposed to this virus.", "Widespread transmission of COVID-19 could translate into large numbers of people needing medical care at the same time. Schools, childcare centers, and workplaces, may experience more absenteeism. Mass gatherings may be sparsely attended or postponed. Public health and healthcare systems may become overloaded, with elevated rates of hospitalizations and deaths. Other critical infrastructure, such as law enforcement, emergency medical services, and sectors of the transportation industry may also be affected. Healthcare providers and hospitals may be overwhelmed. At this time, there is no vaccine to protect against COVID-19 and no medications approved to treat it. Nonpharmaceutical interventions will be the most important response strategy to try to delay the spread of the virus and reduce the impact of disease.", "CDC Response\nGlobal efforts at this time are focused concurrently on lessening the spread and impact of this virus. The federal government is working closely with state, local, tribal, and territorial partners, as well as public health partners, to respond to this public health threat.", "Highlights of CDC’s Response\nCDC established a COVID-19 Incident Management System on January 7, 2020. On January 21, CDC activated its Emergency Operations Center to better provide ongoing support to the COVID-19 response.\nThe U.S. government has taken unprecedented steps with respect to travel in response to the growing public health threat posed by this new coronavirus:\nForeign nationals who have been in China, Iran, the United Kingdom, Ireland and any one of the 26 European countries in the Schengen Area within the past 14 days cannot enter the United States.\nU.S. citizens, residents, and their immediate family members who have been any one of those countries within in the past 14 days can enter the United States, but they are subject to health monitoring and possible quarantine for up to 14 days.\nPeople at higher risk of serious COVID-19 illness avoid cruise travel and non-essential air travel.\nCDC has issued additional specific travel guidance related to COVID-19.", "CDC has issued clinical guidance, including:\nClinical Guidance for Management of Patients with Confirmed Coronavirus Disease (COVID-19).\nInfection Prevention and Control Recommendations for Patients, including guidance on the use of personal protective equipment (PPE) during a shortage.\nCDC also has issued guidance for other settings, including:\nPreparing for COVID-19: Long-term Care Facilities, Nursing Homes\nDiscontinuation of Home Isolation for Persons with COVID-19\nCDC has deployed multidisciplinary teams to support state health departments in case identification, contact tracing, clinical management, and public communications.\nCDC has worked with federal partners to support the safe return of Americans overseas who have been affected by COVID-19.", "An important part of CDC’s role during a public health emergency is to develop a test for the pathogen and equip state and local public health labs with testing capacity.\nCDC developed an rRT-PCR test to diagnose COVID-19.\nAs of the evening of March 17, 89 state and local public health labs in 50 states, the District of Columbia, Guam, and Puerto Rico have successfully verified and are currently using CDC COVID-19 diagnostic tests.\nCommercial manufacturers are now producing their own tests.\nCDC has grown the COVID-19 virus in cell culture, which is necessary for further studies, including for additional genetic characterization. The cell-grown virus was sent to NIH’s BEI Resources Repositoryexternal icon for use by the broad scientific community.\nCDC also is developing a serology test for COVID-19.\nOther Available Resources\nThe following resources are available with information on COVID-19\n\nWorld Health Organization, Coronavirusexternal icon" ]	[ 12 ]	2,073	2,836
185	What kind of test can diagnose COVID-19?	238	[ "rRT-PCR test" ]	[ "CDC Summary 21 MAR 2020,\nhttps://www.cdc.gov/coronavirus/2019-ncov/cases-updates/summary.html\n\nThis is a rapidly evolving situation and CDC will provide updated information and guidance as it becomes available.\n\nUpdated March 21, 2020\n\nCDC is responding to a pandemic of respiratory disease spreading from person-to-person caused by a novel (new) coronavirus. The disease has been named “coronavirus disease 2019” (abbreviated “COVID-19”). This situation poses a serious public health risk. The federal government is working closely with state, local, tribal, and territorial partners, as well as public health partners, to respond to this situation. COVID-19 can cause mild to severe illness; most severe illness occurs in older adults.", "Situation in U.S.\nDifferent parts of the country are seeing different levels of COVID-19 activity. The United States nationally is in the initiation phase of the pandemic. States in which community spread is occurring are in the acceleration phase. The duration and severity of each pandemic phase can vary depending on the characteristics of the virus and the public health response.\n\nCDC and state and local public health laboratories are testing for the virus that causes COVID-19. View CDC’s Public Health Laboratory Testing map.\nAll 50 states have reported cases of COVID-19 to CDC.\nU.S. COVID-19 cases include:\nImported cases in travelers\nCases among close contacts of a known case\nCommunity-acquired cases where the source of the infection is unknown.\nTwenty-seven U.S. states are reporting some community spread of COVID-19.\nView latest case counts, deaths, and a map of states with reported cases.", "CDC Recommends\nEveryone can do their part to help us respond to this emerging public health threat:\nOn March 16, the White House announced a program called “15 Days to Slow the Spread,”pdf iconexternal icon which is a nationwide effort to slow the spread of COVID-19 through the implementation of social distancing at all levels of society.\nOlder people and people with severe chronic conditions should take special precautions because they are at higher risk of developing serious COVID-19 illness.\nIf you are a healthcare provider, use your judgment to determine if a patient has signs and symptoms compatible with COVID-19 and whether the patient should be tested. Factors to consider in addition to clinical symptoms may include:\nDoes the patient have recent travel from an affected area?\nHas the patient been in close contact with someone with COVID-19 or with patients with pneumonia of unknown cause?\nDoes the patient reside in an area where there has been community spread of COVID-19?", "If you are a healthcare provider or a public health responder caring for a COVID-19 patient, please take care of yourself and follow recommended infection control procedures.\nPeople who get a fever or cough should consider whether they might have COVID-19, depending on where they live, their travel history or other exposures. More than half of the U.S. is seeing some level of community spread of COVID-19. Testing for COVID-19 may be accessed through medical providers or public health departments, but there is no treatment for this virus. Most people have mild illness and are able to recover at home without medical care.\nFor people who are ill with COVID-19, but are not sick enough to be hospitalized, please follow CDC guidance on how to reduce the risk of spreading your illness to others. People who are mildly ill with COVID-19 are able to isolate at home during their illness.", "If you have been in China or another affected area or have been exposed to someone sick with COVID-19 in the last 14 days, you will face some limitations on your movement and activity. Please follow instructions during this time. Your cooperation is integral to the ongoing public health response to try to slow spread of this virus.\nCOVID-19 Emergence\nCOVID-19 is caused by a coronavirus. Coronaviruses are a large family of viruses that are common in people and many different species of animals, including camels, cattle, cats, and bats. Rarely, animal coronaviruses can infect people and then spread between people such as with MERS-CoV, SARS-CoV, and now with this new virus (named SARS-CoV-2).", "The SARS-CoV-2 virus is a betacoronavirus, like MERS-CoV and SARS-CoV. All three of these viruses have their origins in bats. The sequences from U.S. patients are similar to the one that China initially posted, suggesting a likely single, recent emergence of this virus from an animal reservoir.", "Early on, many of the patients at the epicenter of the outbreak in Wuhan, Hubei Province, China had some link to a large seafood and live animal market, suggesting animal-to-person spread. Later, a growing number of patients reportedly did not have exposure to animal markets, indicating person-to-person spread. Person-to-person spread was subsequently reported outside Hubei and in countries outside China, including in the United States. Some international destinations now have ongoing community spread with the virus that causes COVID-19, as do some parts of the United States. Community spread means some people have been infected and it is not known how or where they became exposed. Learn more about the spread of this newly emerged coronavirus.", "Severity\nThe complete clinical picture with regard to COVID-19 is not fully known. Reported illnesses have ranged from very mild (including some with no reported symptoms) to severe, including illness resulting in death. While information so far suggests that most COVID-19 illness is mild, a reportexternal icon out of China suggests serious illness occurs in 16% of cases. Older people and people of all ages with severe chronic medical conditions — like heart disease, lung disease and diabetes, for example — seem to be at higher risk of developing serious COVID-19 illness. A CDC Morbidity & Mortality Weekly Report that looked at severity of disease among COVID-19 cases in the United States by age group found that 80% of deaths were among adults 65 years and older with the highest percentage of severe outcomes occurring in people 85 years and older.\n\nLearn more about the symptoms associated with COVID-19.", "COVID-19 Pandemic\nA pandemic is a global outbreak of disease. Pandemics happen when a new virus emerges to infect people and can spread between people sustainably. Because there is little to no pre-existing immunity against the new virus, it spreads worldwide.\n\nThe virus that causes COVID-19 is infecting people and spreading easily from person-to-person. Cases have been detected in most countries worldwide and community spread is being detected in a growing number of countries. On March 11, the COVID-19 outbreak was characterized as a pandemic by the WHOexternal icon.", "This is the first pandemic known to be caused by the emergence of a new coronavirus. In the past century, there have been four pandemics caused by the emergence of novel influenza viruses. As a result, most research and guidance around pandemics is specific to influenza, but the same premises can be applied to the current COVID-19 pandemic. Pandemics of respiratory disease follow a certain progression outlined in a “Pandemic Intervals Framework.” Pandemics begin with an investigation phase, followed by recognition, initiation, and acceleration phases. The peak of illnesses occurs at the end of the acceleration phase, which is followed by a deceleration phase, during which there is a decrease in illnesses. Different countries can be in different phases of the pandemic at any point in time and different parts of the same country can also be in different phases of a pandemic.", "There are ongoing investigations to learn more. This is a rapidly evolving situation and information will be updated as it becomes available.\n\nRisk Assessment\nRisk depends on characteristics of the virus, including how well it spreads between people; the severity of resulting illness; and the medical or other measures available to control the impact of the virus (for example, vaccines or medications that can treat the illness) and the relative success of these. In the absence of vaccine or treatment medications, nonpharmaceutical interventions become the most important response strategy. These are community interventions that can reduce the impact of disease.\n\nThe risk from COVID-19 to Americans can be broken down into risk of exposure versus risk of serious illness and death.\n\nRisk of exposure:", "The immediate risk of being exposed to this virus is still low for most Americans, but as the outbreak expands, that risk will increase. Cases of COVID-19 and instances of community spread are being reported in a growing number of states.\nPeople in places where ongoing community spread of the virus that causes COVID-19 has been reported are at elevated risk of exposure, with the level of risk dependent on the location.\nHealthcare workers caring for patients with COVID-19 are at elevated risk of exposure.\nClose contacts of persons with COVID-19 also are at elevated risk of exposure.\nTravelers returning from affected international locations where community spread is occurring also are at elevated risk of exposure, with level of risk dependent on where they traveled.\nRisk of Severe Illness:\n\nEarly information out of China, where COVID-19 first started, shows that some people are at higher risk of getting very sick from this illness. This includes:", "Older adults, with risk increasing by age.\nPeople who have serious chronic medical conditions like:\nHeart disease\nDiabetes\nLung disease\nCDC has developed guidance to help in the risk assessment and management of people with potential exposures to COVID-19.\n\nWhat May Happen\nMore cases of COVID-19 are likely to be identified in the United States in the coming days, including more instances of community spread. CDC expects that widespread transmission of COVID-19 in the United States will occur. In the coming months, most of the U.S. population will be exposed to this virus.", "Widespread transmission of COVID-19 could translate into large numbers of people needing medical care at the same time. Schools, childcare centers, and workplaces, may experience more absenteeism. Mass gatherings may be sparsely attended or postponed. Public health and healthcare systems may become overloaded, with elevated rates of hospitalizations and deaths. Other critical infrastructure, such as law enforcement, emergency medical services, and sectors of the transportation industry may also be affected. Healthcare providers and hospitals may be overwhelmed. At this time, there is no vaccine to protect against COVID-19 and no medications approved to treat it. Nonpharmaceutical interventions will be the most important response strategy to try to delay the spread of the virus and reduce the impact of disease.", "CDC Response\nGlobal efforts at this time are focused concurrently on lessening the spread and impact of this virus. The federal government is working closely with state, local, tribal, and territorial partners, as well as public health partners, to respond to this public health threat.", "Highlights of CDC’s Response\nCDC established a COVID-19 Incident Management System on January 7, 2020. On January 21, CDC activated its Emergency Operations Center to better provide ongoing support to the COVID-19 response.\nThe U.S. government has taken unprecedented steps with respect to travel in response to the growing public health threat posed by this new coronavirus:\nForeign nationals who have been in China, Iran, the United Kingdom, Ireland and any one of the 26 European countries in the Schengen Area within the past 14 days cannot enter the United States.\nU.S. citizens, residents, and their immediate family members who have been any one of those countries within in the past 14 days can enter the United States, but they are subject to health monitoring and possible quarantine for up to 14 days.\nPeople at higher risk of serious COVID-19 illness avoid cruise travel and non-essential air travel.\nCDC has issued additional specific travel guidance related to COVID-19.", "CDC has issued clinical guidance, including:\nClinical Guidance for Management of Patients with Confirmed Coronavirus Disease (COVID-19).\nInfection Prevention and Control Recommendations for Patients, including guidance on the use of personal protective equipment (PPE) during a shortage.\nCDC also has issued guidance for other settings, including:\nPreparing for COVID-19: Long-term Care Facilities, Nursing Homes\nDiscontinuation of Home Isolation for Persons with COVID-19\nCDC has deployed multidisciplinary teams to support state health departments in case identification, contact tracing, clinical management, and public communications.\nCDC has worked with federal partners to support the safe return of Americans overseas who have been affected by COVID-19.", "An important part of CDC’s role during a public health emergency is to develop a test for the pathogen and equip state and local public health labs with testing capacity.\nCDC developed an rRT-PCR test to diagnose COVID-19.\nAs of the evening of March 17, 89 state and local public health labs in 50 states, the District of Columbia, Guam, and Puerto Rico have successfully verified and are currently using CDC COVID-19 diagnostic tests.\nCommercial manufacturers are now producing their own tests.\nCDC has grown the COVID-19 virus in cell culture, which is necessary for further studies, including for additional genetic characterization. The cell-grown virus was sent to NIH’s BEI Resources Repositoryexternal icon for use by the broad scientific community.\nCDC also is developing a serology test for COVID-19.\nOther Available Resources\nThe following resources are available with information on COVID-19\n\nWorld Health Organization, Coronavirusexternal icon" ]	[ 17 ]	2,073	2,836
185	In what species did the COVID-19 virus likely originate?	235	[ "bats" ]	[ "CDC Summary 21 MAR 2020,\nhttps://www.cdc.gov/coronavirus/2019-ncov/cases-updates/summary.html\n\nThis is a rapidly evolving situation and CDC will provide updated information and guidance as it becomes available.\n\nUpdated March 21, 2020\n\nCDC is responding to a pandemic of respiratory disease spreading from person-to-person caused by a novel (new) coronavirus. The disease has been named “coronavirus disease 2019” (abbreviated “COVID-19”). This situation poses a serious public health risk. The federal government is working closely with state, local, tribal, and territorial partners, as well as public health partners, to respond to this situation. COVID-19 can cause mild to severe illness; most severe illness occurs in older adults.", "Situation in U.S.\nDifferent parts of the country are seeing different levels of COVID-19 activity. The United States nationally is in the initiation phase of the pandemic. States in which community spread is occurring are in the acceleration phase. The duration and severity of each pandemic phase can vary depending on the characteristics of the virus and the public health response.\n\nCDC and state and local public health laboratories are testing for the virus that causes COVID-19. View CDC’s Public Health Laboratory Testing map.\nAll 50 states have reported cases of COVID-19 to CDC.\nU.S. COVID-19 cases include:\nImported cases in travelers\nCases among close contacts of a known case\nCommunity-acquired cases where the source of the infection is unknown.\nTwenty-seven U.S. states are reporting some community spread of COVID-19.\nView latest case counts, deaths, and a map of states with reported cases.", "CDC Recommends\nEveryone can do their part to help us respond to this emerging public health threat:\nOn March 16, the White House announced a program called “15 Days to Slow the Spread,”pdf iconexternal icon which is a nationwide effort to slow the spread of COVID-19 through the implementation of social distancing at all levels of society.\nOlder people and people with severe chronic conditions should take special precautions because they are at higher risk of developing serious COVID-19 illness.\nIf you are a healthcare provider, use your judgment to determine if a patient has signs and symptoms compatible with COVID-19 and whether the patient should be tested. Factors to consider in addition to clinical symptoms may include:\nDoes the patient have recent travel from an affected area?\nHas the patient been in close contact with someone with COVID-19 or with patients with pneumonia of unknown cause?\nDoes the patient reside in an area where there has been community spread of COVID-19?", "If you are a healthcare provider or a public health responder caring for a COVID-19 patient, please take care of yourself and follow recommended infection control procedures.\nPeople who get a fever or cough should consider whether they might have COVID-19, depending on where they live, their travel history or other exposures. More than half of the U.S. is seeing some level of community spread of COVID-19. Testing for COVID-19 may be accessed through medical providers or public health departments, but there is no treatment for this virus. Most people have mild illness and are able to recover at home without medical care.\nFor people who are ill with COVID-19, but are not sick enough to be hospitalized, please follow CDC guidance on how to reduce the risk of spreading your illness to others. People who are mildly ill with COVID-19 are able to isolate at home during their illness.", "If you have been in China or another affected area or have been exposed to someone sick with COVID-19 in the last 14 days, you will face some limitations on your movement and activity. Please follow instructions during this time. Your cooperation is integral to the ongoing public health response to try to slow spread of this virus.\nCOVID-19 Emergence\nCOVID-19 is caused by a coronavirus. Coronaviruses are a large family of viruses that are common in people and many different species of animals, including camels, cattle, cats, and bats. Rarely, animal coronaviruses can infect people and then spread between people such as with MERS-CoV, SARS-CoV, and now with this new virus (named SARS-CoV-2).", "The SARS-CoV-2 virus is a betacoronavirus, like MERS-CoV and SARS-CoV. All three of these viruses have their origins in bats. The sequences from U.S. patients are similar to the one that China initially posted, suggesting a likely single, recent emergence of this virus from an animal reservoir.", "Early on, many of the patients at the epicenter of the outbreak in Wuhan, Hubei Province, China had some link to a large seafood and live animal market, suggesting animal-to-person spread. Later, a growing number of patients reportedly did not have exposure to animal markets, indicating person-to-person spread. Person-to-person spread was subsequently reported outside Hubei and in countries outside China, including in the United States. Some international destinations now have ongoing community spread with the virus that causes COVID-19, as do some parts of the United States. Community spread means some people have been infected and it is not known how or where they became exposed. Learn more about the spread of this newly emerged coronavirus.", "Severity\nThe complete clinical picture with regard to COVID-19 is not fully known. Reported illnesses have ranged from very mild (including some with no reported symptoms) to severe, including illness resulting in death. While information so far suggests that most COVID-19 illness is mild, a reportexternal icon out of China suggests serious illness occurs in 16% of cases. Older people and people of all ages with severe chronic medical conditions — like heart disease, lung disease and diabetes, for example — seem to be at higher risk of developing serious COVID-19 illness. A CDC Morbidity & Mortality Weekly Report that looked at severity of disease among COVID-19 cases in the United States by age group found that 80% of deaths were among adults 65 years and older with the highest percentage of severe outcomes occurring in people 85 years and older.\n\nLearn more about the symptoms associated with COVID-19.", "COVID-19 Pandemic\nA pandemic is a global outbreak of disease. Pandemics happen when a new virus emerges to infect people and can spread between people sustainably. Because there is little to no pre-existing immunity against the new virus, it spreads worldwide.\n\nThe virus that causes COVID-19 is infecting people and spreading easily from person-to-person. Cases have been detected in most countries worldwide and community spread is being detected in a growing number of countries. On March 11, the COVID-19 outbreak was characterized as a pandemic by the WHOexternal icon.", "This is the first pandemic known to be caused by the emergence of a new coronavirus. In the past century, there have been four pandemics caused by the emergence of novel influenza viruses. As a result, most research and guidance around pandemics is specific to influenza, but the same premises can be applied to the current COVID-19 pandemic. Pandemics of respiratory disease follow a certain progression outlined in a “Pandemic Intervals Framework.” Pandemics begin with an investigation phase, followed by recognition, initiation, and acceleration phases. The peak of illnesses occurs at the end of the acceleration phase, which is followed by a deceleration phase, during which there is a decrease in illnesses. Different countries can be in different phases of the pandemic at any point in time and different parts of the same country can also be in different phases of a pandemic.", "There are ongoing investigations to learn more. This is a rapidly evolving situation and information will be updated as it becomes available.\n\nRisk Assessment\nRisk depends on characteristics of the virus, including how well it spreads between people; the severity of resulting illness; and the medical or other measures available to control the impact of the virus (for example, vaccines or medications that can treat the illness) and the relative success of these. In the absence of vaccine or treatment medications, nonpharmaceutical interventions become the most important response strategy. These are community interventions that can reduce the impact of disease.\n\nThe risk from COVID-19 to Americans can be broken down into risk of exposure versus risk of serious illness and death.\n\nRisk of exposure:", "The immediate risk of being exposed to this virus is still low for most Americans, but as the outbreak expands, that risk will increase. Cases of COVID-19 and instances of community spread are being reported in a growing number of states.\nPeople in places where ongoing community spread of the virus that causes COVID-19 has been reported are at elevated risk of exposure, with the level of risk dependent on the location.\nHealthcare workers caring for patients with COVID-19 are at elevated risk of exposure.\nClose contacts of persons with COVID-19 also are at elevated risk of exposure.\nTravelers returning from affected international locations where community spread is occurring also are at elevated risk of exposure, with level of risk dependent on where they traveled.\nRisk of Severe Illness:\n\nEarly information out of China, where COVID-19 first started, shows that some people are at higher risk of getting very sick from this illness. This includes:", "Older adults, with risk increasing by age.\nPeople who have serious chronic medical conditions like:\nHeart disease\nDiabetes\nLung disease\nCDC has developed guidance to help in the risk assessment and management of people with potential exposures to COVID-19.\n\nWhat May Happen\nMore cases of COVID-19 are likely to be identified in the United States in the coming days, including more instances of community spread. CDC expects that widespread transmission of COVID-19 in the United States will occur. In the coming months, most of the U.S. population will be exposed to this virus.", "Widespread transmission of COVID-19 could translate into large numbers of people needing medical care at the same time. Schools, childcare centers, and workplaces, may experience more absenteeism. Mass gatherings may be sparsely attended or postponed. Public health and healthcare systems may become overloaded, with elevated rates of hospitalizations and deaths. Other critical infrastructure, such as law enforcement, emergency medical services, and sectors of the transportation industry may also be affected. Healthcare providers and hospitals may be overwhelmed. At this time, there is no vaccine to protect against COVID-19 and no medications approved to treat it. Nonpharmaceutical interventions will be the most important response strategy to try to delay the spread of the virus and reduce the impact of disease.", "CDC Response\nGlobal efforts at this time are focused concurrently on lessening the spread and impact of this virus. The federal government is working closely with state, local, tribal, and territorial partners, as well as public health partners, to respond to this public health threat.", "Highlights of CDC’s Response\nCDC established a COVID-19 Incident Management System on January 7, 2020. On January 21, CDC activated its Emergency Operations Center to better provide ongoing support to the COVID-19 response.\nThe U.S. government has taken unprecedented steps with respect to travel in response to the growing public health threat posed by this new coronavirus:\nForeign nationals who have been in China, Iran, the United Kingdom, Ireland and any one of the 26 European countries in the Schengen Area within the past 14 days cannot enter the United States.\nU.S. citizens, residents, and their immediate family members who have been any one of those countries within in the past 14 days can enter the United States, but they are subject to health monitoring and possible quarantine for up to 14 days.\nPeople at higher risk of serious COVID-19 illness avoid cruise travel and non-essential air travel.\nCDC has issued additional specific travel guidance related to COVID-19.", "CDC has issued clinical guidance, including:\nClinical Guidance for Management of Patients with Confirmed Coronavirus Disease (COVID-19).\nInfection Prevention and Control Recommendations for Patients, including guidance on the use of personal protective equipment (PPE) during a shortage.\nCDC also has issued guidance for other settings, including:\nPreparing for COVID-19: Long-term Care Facilities, Nursing Homes\nDiscontinuation of Home Isolation for Persons with COVID-19\nCDC has deployed multidisciplinary teams to support state health departments in case identification, contact tracing, clinical management, and public communications.\nCDC has worked with federal partners to support the safe return of Americans overseas who have been affected by COVID-19.", "An important part of CDC’s role during a public health emergency is to develop a test for the pathogen and equip state and local public health labs with testing capacity.\nCDC developed an rRT-PCR test to diagnose COVID-19.\nAs of the evening of March 17, 89 state and local public health labs in 50 states, the District of Columbia, Guam, and Puerto Rico have successfully verified and are currently using CDC COVID-19 diagnostic tests.\nCommercial manufacturers are now producing their own tests.\nCDC has grown the COVID-19 virus in cell culture, which is necessary for further studies, including for additional genetic characterization. The cell-grown virus was sent to NIH’s BEI Resources Repositoryexternal icon for use by the broad scientific community.\nCDC also is developing a serology test for COVID-19.\nOther Available Resources\nThe following resources are available with information on COVID-19\n\nWorld Health Organization, Coronavirusexternal icon" ]	[ 4 ]	2,073	2,836
185	What risk factors should be considered in addition to clinical symptoms?	228	[ "Does the patient have recent travel from an affected area?\nHas the patient been in close contact with someone with COVID-19 or with patients with pneumonia of unknown cause?\nDoes the patient reside in an area where there has been community spread of COVID-19?" ]	[ "CDC Summary 21 MAR 2020,\nhttps://www.cdc.gov/coronavirus/2019-ncov/cases-updates/summary.html\n\nThis is a rapidly evolving situation and CDC will provide updated information and guidance as it becomes available.\n\nUpdated March 21, 2020\n\nCDC is responding to a pandemic of respiratory disease spreading from person-to-person caused by a novel (new) coronavirus. The disease has been named “coronavirus disease 2019” (abbreviated “COVID-19”). This situation poses a serious public health risk. The federal government is working closely with state, local, tribal, and territorial partners, as well as public health partners, to respond to this situation. COVID-19 can cause mild to severe illness; most severe illness occurs in older adults.", "Situation in U.S.\nDifferent parts of the country are seeing different levels of COVID-19 activity. The United States nationally is in the initiation phase of the pandemic. States in which community spread is occurring are in the acceleration phase. The duration and severity of each pandemic phase can vary depending on the characteristics of the virus and the public health response.\n\nCDC and state and local public health laboratories are testing for the virus that causes COVID-19. View CDC’s Public Health Laboratory Testing map.\nAll 50 states have reported cases of COVID-19 to CDC.\nU.S. COVID-19 cases include:\nImported cases in travelers\nCases among close contacts of a known case\nCommunity-acquired cases where the source of the infection is unknown.\nTwenty-seven U.S. states are reporting some community spread of COVID-19.\nView latest case counts, deaths, and a map of states with reported cases.", "CDC Recommends\nEveryone can do their part to help us respond to this emerging public health threat:\nOn March 16, the White House announced a program called “15 Days to Slow the Spread,”pdf iconexternal icon which is a nationwide effort to slow the spread of COVID-19 through the implementation of social distancing at all levels of society.\nOlder people and people with severe chronic conditions should take special precautions because they are at higher risk of developing serious COVID-19 illness.\nIf you are a healthcare provider, use your judgment to determine if a patient has signs and symptoms compatible with COVID-19 and whether the patient should be tested. Factors to consider in addition to clinical symptoms may include:\nDoes the patient have recent travel from an affected area?\nHas the patient been in close contact with someone with COVID-19 or with patients with pneumonia of unknown cause?\nDoes the patient reside in an area where there has been community spread of COVID-19?", "If you are a healthcare provider or a public health responder caring for a COVID-19 patient, please take care of yourself and follow recommended infection control procedures.\nPeople who get a fever or cough should consider whether they might have COVID-19, depending on where they live, their travel history or other exposures. More than half of the U.S. is seeing some level of community spread of COVID-19. Testing for COVID-19 may be accessed through medical providers or public health departments, but there is no treatment for this virus. Most people have mild illness and are able to recover at home without medical care.\nFor people who are ill with COVID-19, but are not sick enough to be hospitalized, please follow CDC guidance on how to reduce the risk of spreading your illness to others. People who are mildly ill with COVID-19 are able to isolate at home during their illness.", "If you have been in China or another affected area or have been exposed to someone sick with COVID-19 in the last 14 days, you will face some limitations on your movement and activity. Please follow instructions during this time. Your cooperation is integral to the ongoing public health response to try to slow spread of this virus.\nCOVID-19 Emergence\nCOVID-19 is caused by a coronavirus. Coronaviruses are a large family of viruses that are common in people and many different species of animals, including camels, cattle, cats, and bats. Rarely, animal coronaviruses can infect people and then spread between people such as with MERS-CoV, SARS-CoV, and now with this new virus (named SARS-CoV-2).", "The SARS-CoV-2 virus is a betacoronavirus, like MERS-CoV and SARS-CoV. All three of these viruses have their origins in bats. The sequences from U.S. patients are similar to the one that China initially posted, suggesting a likely single, recent emergence of this virus from an animal reservoir.", "Early on, many of the patients at the epicenter of the outbreak in Wuhan, Hubei Province, China had some link to a large seafood and live animal market, suggesting animal-to-person spread. Later, a growing number of patients reportedly did not have exposure to animal markets, indicating person-to-person spread. Person-to-person spread was subsequently reported outside Hubei and in countries outside China, including in the United States. Some international destinations now have ongoing community spread with the virus that causes COVID-19, as do some parts of the United States. Community spread means some people have been infected and it is not known how or where they became exposed. Learn more about the spread of this newly emerged coronavirus.", "Severity\nThe complete clinical picture with regard to COVID-19 is not fully known. Reported illnesses have ranged from very mild (including some with no reported symptoms) to severe, including illness resulting in death. While information so far suggests that most COVID-19 illness is mild, a reportexternal icon out of China suggests serious illness occurs in 16% of cases. Older people and people of all ages with severe chronic medical conditions — like heart disease, lung disease and diabetes, for example — seem to be at higher risk of developing serious COVID-19 illness. A CDC Morbidity & Mortality Weekly Report that looked at severity of disease among COVID-19 cases in the United States by age group found that 80% of deaths were among adults 65 years and older with the highest percentage of severe outcomes occurring in people 85 years and older.\n\nLearn more about the symptoms associated with COVID-19.", "COVID-19 Pandemic\nA pandemic is a global outbreak of disease. Pandemics happen when a new virus emerges to infect people and can spread between people sustainably. Because there is little to no pre-existing immunity against the new virus, it spreads worldwide.\n\nThe virus that causes COVID-19 is infecting people and spreading easily from person-to-person. Cases have been detected in most countries worldwide and community spread is being detected in a growing number of countries. On March 11, the COVID-19 outbreak was characterized as a pandemic by the WHOexternal icon.", "This is the first pandemic known to be caused by the emergence of a new coronavirus. In the past century, there have been four pandemics caused by the emergence of novel influenza viruses. As a result, most research and guidance around pandemics is specific to influenza, but the same premises can be applied to the current COVID-19 pandemic. Pandemics of respiratory disease follow a certain progression outlined in a “Pandemic Intervals Framework.” Pandemics begin with an investigation phase, followed by recognition, initiation, and acceleration phases. The peak of illnesses occurs at the end of the acceleration phase, which is followed by a deceleration phase, during which there is a decrease in illnesses. Different countries can be in different phases of the pandemic at any point in time and different parts of the same country can also be in different phases of a pandemic.", "There are ongoing investigations to learn more. This is a rapidly evolving situation and information will be updated as it becomes available.\n\nRisk Assessment\nRisk depends on characteristics of the virus, including how well it spreads between people; the severity of resulting illness; and the medical or other measures available to control the impact of the virus (for example, vaccines or medications that can treat the illness) and the relative success of these. In the absence of vaccine or treatment medications, nonpharmaceutical interventions become the most important response strategy. These are community interventions that can reduce the impact of disease.\n\nThe risk from COVID-19 to Americans can be broken down into risk of exposure versus risk of serious illness and death.\n\nRisk of exposure:", "The immediate risk of being exposed to this virus is still low for most Americans, but as the outbreak expands, that risk will increase. Cases of COVID-19 and instances of community spread are being reported in a growing number of states.\nPeople in places where ongoing community spread of the virus that causes COVID-19 has been reported are at elevated risk of exposure, with the level of risk dependent on the location.\nHealthcare workers caring for patients with COVID-19 are at elevated risk of exposure.\nClose contacts of persons with COVID-19 also are at elevated risk of exposure.\nTravelers returning from affected international locations where community spread is occurring also are at elevated risk of exposure, with level of risk dependent on where they traveled.\nRisk of Severe Illness:\n\nEarly information out of China, where COVID-19 first started, shows that some people are at higher risk of getting very sick from this illness. This includes:", "Older adults, with risk increasing by age.\nPeople who have serious chronic medical conditions like:\nHeart disease\nDiabetes\nLung disease\nCDC has developed guidance to help in the risk assessment and management of people with potential exposures to COVID-19.\n\nWhat May Happen\nMore cases of COVID-19 are likely to be identified in the United States in the coming days, including more instances of community spread. CDC expects that widespread transmission of COVID-19 in the United States will occur. In the coming months, most of the U.S. population will be exposed to this virus.", "Widespread transmission of COVID-19 could translate into large numbers of people needing medical care at the same time. Schools, childcare centers, and workplaces, may experience more absenteeism. Mass gatherings may be sparsely attended or postponed. Public health and healthcare systems may become overloaded, with elevated rates of hospitalizations and deaths. Other critical infrastructure, such as law enforcement, emergency medical services, and sectors of the transportation industry may also be affected. Healthcare providers and hospitals may be overwhelmed. At this time, there is no vaccine to protect against COVID-19 and no medications approved to treat it. Nonpharmaceutical interventions will be the most important response strategy to try to delay the spread of the virus and reduce the impact of disease.", "CDC Response\nGlobal efforts at this time are focused concurrently on lessening the spread and impact of this virus. The federal government is working closely with state, local, tribal, and territorial partners, as well as public health partners, to respond to this public health threat.", "Highlights of CDC’s Response\nCDC established a COVID-19 Incident Management System on January 7, 2020. On January 21, CDC activated its Emergency Operations Center to better provide ongoing support to the COVID-19 response.\nThe U.S. government has taken unprecedented steps with respect to travel in response to the growing public health threat posed by this new coronavirus:\nForeign nationals who have been in China, Iran, the United Kingdom, Ireland and any one of the 26 European countries in the Schengen Area within the past 14 days cannot enter the United States.\nU.S. citizens, residents, and their immediate family members who have been any one of those countries within in the past 14 days can enter the United States, but they are subject to health monitoring and possible quarantine for up to 14 days.\nPeople at higher risk of serious COVID-19 illness avoid cruise travel and non-essential air travel.\nCDC has issued additional specific travel guidance related to COVID-19.", "CDC has issued clinical guidance, including:\nClinical Guidance for Management of Patients with Confirmed Coronavirus Disease (COVID-19).\nInfection Prevention and Control Recommendations for Patients, including guidance on the use of personal protective equipment (PPE) during a shortage.\nCDC also has issued guidance for other settings, including:\nPreparing for COVID-19: Long-term Care Facilities, Nursing Homes\nDiscontinuation of Home Isolation for Persons with COVID-19\nCDC has deployed multidisciplinary teams to support state health departments in case identification, contact tracing, clinical management, and public communications.\nCDC has worked with federal partners to support the safe return of Americans overseas who have been affected by COVID-19.", "An important part of CDC’s role during a public health emergency is to develop a test for the pathogen and equip state and local public health labs with testing capacity.\nCDC developed an rRT-PCR test to diagnose COVID-19.\nAs of the evening of March 17, 89 state and local public health labs in 50 states, the District of Columbia, Guam, and Puerto Rico have successfully verified and are currently using CDC COVID-19 diagnostic tests.\nCommercial manufacturers are now producing their own tests.\nCDC has grown the COVID-19 virus in cell culture, which is necessary for further studies, including for additional genetic characterization. The cell-grown virus was sent to NIH’s BEI Resources Repositoryexternal icon for use by the broad scientific community.\nCDC also is developing a serology test for COVID-19.\nOther Available Resources\nThe following resources are available with information on COVID-19\n\nWorld Health Organization, Coronavirusexternal icon" ]	[ 2 ]	2,073	2,836
186	What is the acronym SARS-CoV-2?	244	[ "severe acute respiratory syndrome coronavirus 2" ]	[ "Identifying Locations with Possible Undetected Imported Severe Acute Respiratory Syndrome Coronavirus 2 Cases by Using Importation Predictions,\nhttps://wwwnc.cdc.gov/eid/article/26/7/20-0250_article\nVolume 26, Number 7—July 2020\nResearch\n\nPablo Martinez De Salazar1Comments to Author , René Niehus, Aimee Taylor1, Caroline O’Flaherty Buckee, and Marc LipsitchComments to Author\nAuthor affiliations: Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA\nSuggested citation for this article", "Abstract\nCases of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection exported from mainland China could lead to self-sustained outbreaks in other countries. By February 2020, several countries were reporting imported SARS-CoV-2 cases. To contain the virus, early detection of imported SARS-CoV-2 cases is critical. We used air travel volume estimates from Wuhan, China, to international destinations and a generalized linear regression model to identify locations that could have undetected imported cases. Our model can be adjusted to account for exportation of cases from other locations as the virus spreads and more information on importations and transmission becomes available. Early detection and appropriate control measures can reduce the risk for transmission in all locations.", "A novel coronavirus, later named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was identified in December 2019 in the city of Wuhan, capital of Hubei Province, China, where cases were first confirmed (1). During December 2019–February 2020, the number of confirmed cases increased drastically. Model estimates suggested that >75,000 persons were infected by January 25, 2020, and the epidemic had a doubling time of ≈6 days (2). By the end of January 2020, travel restrictions were implemented for Wuhan and neighboring cities. Nonetheless, the virus spread from Wuhan to other cities in China and outside the country. By February 4, 2020, a total of 23 locations outside mainland China reported cases, 22 of which reported imported cases; Spain reported a case caused by secondary transmission (3).", "Most cases imported to other locations have been linked to recent travel history from China (3), suggesting that air travel plays a major role in exportation of cases to locations outside of China. To prevent other cities and countries from becoming epicenters of the SARS-CoV-2 epidemic, substantial targeted public health interventions are required to detect cases and control local spread of the virus. We collected estimates of air travel volume from Wuhan to 194 international destinations. We then identified 49 countries that had a score of >49.2/100 on category 2, Early Detection and Reporting of Epidemics of Potential International Concern, of the Global Health Security (GHS) Index (4). We assumed these locations would be proficient at detecting SARS-CoV-2 and reporting confirmed imported cases, which we refer to as imported-and-reported cases. We ran a generalized linear regression model on this subset; based on the results, we generated predictions for the remainder of the", "sample. Using these predictions, we identified locations that might not be detecting imported cases.", "Methods\nTo identify locations reporting fewer than predicted imported SARS-CoV-2 infected cases, we fit a model to data from 49 locations outside mainland China with high surveillance capacity according to the GHS Index (4). Among these, 17 had high travel connectivity to Wuhan and 32 have low connectivity to Wuhan. We considered locations to be countries without any position on territorial claims. We performed a Poisson regression by using the cumulative number of imported-and-reported SARS-CoV-2 cases in these 49 countries and the estimated number of daily airline passengers from the Wuhan airport. We then compared predictions from this model with imported-and-reported cases across 194 locations from the GHS Index, excluding China as the epicenter of the outbreak.", "The model requires data on imported-and-reported cases of SARS-CoV-2 infection, daily air travel volume, and surveillance capacity. We obtained data on imported-and-reported cases aggregated by destination from the World Health Organization technical report issued February 4, 2020 (3). We assumed a case count of 0 for locations not listed. We used February 4 as the cutoff for cumulative imported-and-reported case counts because exported cases from Hubei Province dropped rapidly after this date (3), likely because of travel restrictions for the province implement on January 23. We defined imported-and-reported cases as those with known travel history from China; of those, 83% had a travel history from Hubei Province and 17% traveled from unknown locations in China (3). We excluded reported cases likely caused by transmission outside of China or cases in which the transmission source was still under investigation (3). In addition, we excluded Hong Kong, Macau, and Taiwan from our model", "because locally transmitted and imported cases were not disaggregated in these locations.", "We obtained data on daily air travel from a network-based modeling study (S. Lai et al., unpub. data, https://doi.org/10.1101/2020.02.04.20020479External Link) that reported monthly air travel volume estimates for the 27 locations outside mainland China that are most connected to Wuhan. These estimates were calculated from International Air Travel Association data from February 2018, which includes direct and indirect flight itineraries from Wuhan. For these 27 locations, estimated air travel volumes are >6 passengers/day. We assumed that travel volumes for locations not among the most connected are censored by a detection limit. We used a common method of dealing with censored data from environmental sampling (5), or metabolomics (6), to set the daily air travel volume to half the minimum previously reported. Therefore, we used 3 passengers/day for estimated travel volumes for the 167 locations from the GHS Index not listed by Lai et al. We tested the robustness of our results by", "using a set of alternative values of 0.1, 1, and 6 passengers/day for the censored data.", "We defined high surveillance locations as those with a GHS Index for category 2 above the 75th quantile. We assessed the number of high surveillance locations, those with 0 imported-and-reported cases, and low surveillance locations, those with case counts >1 (Table).", "For our model, we assumed that the cumulative imported-and-reported case counts across 49 high surveillance locations follow a Poisson distribution from the beginning of the epidemic until February 4, 2020. Then the expected case count is linearly proportional to the daily air travel volume in the following formula:where i denotes location, Ci denotes the imported-and-reported case count in a location, λi denotes the expected case count in a location, β denotes the regression coefficient, and xi denotes the daily air travel volume of a location. The Poisson model assumes cases are independent and that the variance is equal to the expected case count. Imported-and-reported cases likely meet the independence assumption because the value excludes cases with local transmission. We also checked the robustness of our results by using an over dispersed model with a negative binomial likelihood. We computed the p value of the overdispersion parameter as shown in Gelman and Hill (7).", "Thumbnail of Regression plot of locations with possible undetected imported cases of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by air travel volume from Wuhan, China. Air travel volume measured in number of persons/day. No. cases refers to possible undetected imported SARS-CoV-2 cases. Solid line indicates the expected imported-and-reported case counts for locations. Dashed lines represent 95% prediction interval bounds smoothed for all locations. Purple dots indicate location\nFigure 1. Regression plot of locations with possible undetected imported cases of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by air travel volume from Wuhan, China. Air travel volume measured in number of...", "We used R version 3.6.1 (https://www.r-project.orgExternal Link) to compute , the maximum likelihood estimate of β, and the expected imported-and-reported case count given high surveillance (Figure 1). We also computed the 95% prediction interval (PI) bounds under this model of high surveillance for all 194 values of daily air travel volume (Figure 1). First, we generated a bootstrapped dataset by sampling n locations with replacement among high surveillance locations. Then, we reestimated β by using the bootstrapped dataset. Finally, we simulated imported-and-reported case counts for all 194 locations under our model by using the estimate of β from the bootstrapped dataset. We repeated the 3 steps 50,000 times to generate 50,000 simulated imported-and-reported case counts for each of the locations computed to the lower and upper PI bounds (PI 2.5%–97.5%). We smoothed the 95% PI bounds by using ggplot2 in R (8). We fit the imported-and-reported case counts of the 49 high surveillance", "locations to the model and plotted these alongside 145 locations with low surveillance capacity (Figure 1). We noted some overlap between high and low surveillance locations (Figure 1).", "Thumbnail of Analyses of imported-and-reported cases and daily air travel volume using a model to predict locations with potentially undetected cases of severe acute respiratory virus 2 (SARS-CoV-2). Air travel volume measured in number of persons/day. No. cases refers to possible undetected imported SARS-CoV-2 cases. Solid line shows the expected imported-and-reported case counts based on our model fitted to high surveillance locations, indicated by purple dots. Dashed lines indicate the 95% pr\nFigure 2. Analyses of imported-and-reported cases and daily air travel volume using a model to predict locations with potentially undetected cases of severe acute respiratory virus 2 (SARS-CoV-2). Air travel volume measured in...", "To assess the robustness of our results we ran 8 additional regression analyses by implementing a series of changes to the analysis. The changes included the following: set the daily air travel volume to 0.1, 1, or 6 passengers/day for locations not listed by Lai et al. (unpub. data, https://doi.org/10.1101/2020.02.04.20020479External Link) (Figure 2, panels A–C); removed all locations not listed by Lai et al. before fitting (Figure 2, panel D); defined high surveillance locations by using a more lenient GHS Index criterion, 50th quantile (Figure 2, panel E), and a more stringent criterion, 95th quantile (Figure 2, panel F); excluded Thailand from the model because it is a high-leverage point (Figure 2, panel G); or used an overdispersed Poisson likelihood with a negative-binomial likelihood (Figure 2, panel H). We provide code for these analyses on GitHub (https://github.com/c2-d2/cov19flightimportExternal Link).\n\nTop", "Results", "We found that daily air travel volume positively correlates with imported-and-reported case counts of SARS-CoV-2 infection among high surveillance locations (Figure 1). We noted that increasing flight volume by 31 passengers/day is associated with 1 additional expected imported-and-reported case. In addition, Singapore and India lie above the 95% PI in our model; Singapore had 12 more imported-and-reported cases (95% PI 6–17 cases) than expected and India had 3 (95% PI 1–3 cases) more than expected. Thailand has a relatively high air travel volume compared with other locations, but it lies below the 95% PI, reporting 16 (95% PI 1–40 cases) fewer imported-and-reported cases than expected under the model. Indonesia lies below the PI and has no imported-and-reported cases, but the expected case count is 5 (95% PI 1–10 cases) in our model. Across all 8 robustness regression analyses, we consistently observed that Singapore lies above the 95% PI and Thailand and Indonesia lie below (Figure", "2). India remains above the 95% PI in all robustness analyses except when we used the more stringent GHS Index, 95th quantile, for fitting; then India lies on the upper bound of the 95% PI (Figure 2, panel F).", "Top", "Discussion", "We aimed to identify locations with likely undetected or underdetected imported cases of SARS-CoV-2 by fitting a model to the case counts in locations with high surveillance capacity and Wuhan-to-location air travel volumes. Our model can be adjusted to account for exportation of cases from locations other than Wuhan as the outbreak develops and more information on importations and self-sustained transmission becomes available. One key advantage of this model is that it does not rely on estimates of incidence or prevalence in the epicenter of the outbreak. Also, we intentionally used a simple generalized linear model. The linearity of the expected case count means that we have only 1 regression coefficient in the model and no extra parameters. The Poisson likelihood then captures the many 0-counts observed for less highly connected locations but also describes the slope between case-count and flight data among more connected locations. We believe this model provides the most", "parsimonious phenomenologic description of the data.", "According to our model, locations above the 95% PI of imported-and-reported cases could have higher case-detection capacity. Locations below the 95% PI might have undetected cases because of expected imported-and-reported case counts under high surveillance. Underdetection of cases could increase the international spread of the outbreak because the transmission chain could be lost, reducing opportunities to deploy case-based control strategies. We recommend rapid strengthening of outbreak surveillance and control efforts in locations below the 95% PI lower bound, particularly Indonesia, to curb potential local transmission. Early detection of cases and implantation of appropriate control measures can reduce the risk for self-sustained transmission in all locations.\n\nTop", "Dr. De Salazar is a research fellow at Harvard T.H. Chan School of Public Health, working on multiscale statistical models of infectious diseases within host, population, and metapopulation models. His research interests include diagnostic laboratory methods and public health response.\n\nTop\n\nAcknowledgments\nWe thank Pamela Martinez, Nicholas Jewel, and Stephen Kissler for valuable feedback.\n\nThis work was supported by US National Institute of General Medical Sciences (award no. U54GM088558). P.M.D was supported by the Fellowship Foundation Ramon Areces. A.R.T. and C.O.B. were supported by a Maximizing Investigator’s Research Award (no. R35GM124715-02) from the US National Institute of General Medical Sciences.\n\nThe authors are solely responsible for this content and it does not necessarily represent the official views of the National Institute of General Medical Sciences or the National Institutes of Health.", "Declaration of interests: Marc Lipsitch has received consulting fees from Merck. All other authors declare no competing interests.\n\nTop", "References\nZhou P, Yang XL, Wang XG, Hu B, Zhang L, Zhang W, et al. A pneumonia outbreak associated with a new coronavirus of probable bat origin. Nature. 2020;579:270–3.\nWu JT, Leung K, Leung GM. Nowcasting and forecasting the potential domestic and international spread of the 2019-nCoV outbreak originating in Wuhan, China: a modelling study. Lancet. 2020;395:689–97. DOIExternal LinkPubMedExternal Link\nWorld Health Organization. Coronavirus disease 2019 (COVID-19) situation report—15, 4 Feb 2020 [cited 2020 Feb 14]. https://www.who.int/docs/default-source/coronaviruse/situation-reports/20200204-sitrep-15-ncov.pdfExternal Link\nNuclear Threat Initiative and Johns Hopkins Center for Health Security. Global health security index [cited 2020 Feb 14]. https://www.ghsindex.orgExternal Link", "US Environmental Protection Agency. Data quality assessment: statistical methods for practitioners EPA QA/G9-S [cited 2020 Feb 14]. Washington: The Agency; 2006. https://www.epa.gov/sites/production/files/2015-08/documents/g9s-final.pdfExternal Link\nLamichhane S, Sen P, Dickens AM, Hyötyläinen T, Orešič M. An overview of metabolomics data analysis: current tools and future perspectives. In: Jaumot J, Bedia C, Tauler R, editors. Comprehensive analytical chemistry. Vol. 82. Amsterdam: Elsevier; 2018. p. 387–413.\nGelman A, Hill J. Analytical methods for social research. In: Data analysis using regression and multilevel/hierarchical models. Cambridge: Cambridge University Press; 2006. p. 235–236.\nWickham H. ggplot2: elegant graphics for data analysis. New York: Springer; 2016.\nTop", "Figures\nFigure 1. Regression plot of locations with possible undetected imported cases of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by air travel volume from Wuhan, China. Air travel volume measured in...\nFigure 2. Analyses of imported-and-reported cases and daily air travel volume using a model to predict locations with potentially undetected cases of severe acute respiratory virus 2 (SARS-CoV-2). Air travel volume...\nTable\nTable. Surveillance capacity of locations with and without imported-and-reported cases of severe acute respiratory syndrome coronavirus 2, 2020\nTop\n\nSuggested citation for this article: De Salazar PM, Niehus R, Taylor A, O’Flaherty Buckee C, Lipsitch M. Identifying locations with possible undetected imported severe acute respiratory syndrome coronavirus 2 cases by using importation predictions. Emerg Infect Dis. 2020 Jul [date cited]. https://doi.org/10.3201/eid2607.200250\n\nDOI: 10.3201/eid2607.200250\n\nOriginal Publication Date: 3/24/2020", "1These authors contributed equally to this article.\n\nTable of Contents – Volume 26, Number 7—July 2020" ]	[ 1 ]	2,548	3,863
186	When was SARS-CoV-2 first identified?	245	[ "December 2019" ]	[ "Identifying Locations with Possible Undetected Imported Severe Acute Respiratory Syndrome Coronavirus 2 Cases by Using Importation Predictions,\nhttps://wwwnc.cdc.gov/eid/article/26/7/20-0250_article\nVolume 26, Number 7—July 2020\nResearch\n\nPablo Martinez De Salazar1Comments to Author , René Niehus, Aimee Taylor1, Caroline O’Flaherty Buckee, and Marc LipsitchComments to Author\nAuthor affiliations: Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA\nSuggested citation for this article", "Abstract\nCases of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection exported from mainland China could lead to self-sustained outbreaks in other countries. By February 2020, several countries were reporting imported SARS-CoV-2 cases. To contain the virus, early detection of imported SARS-CoV-2 cases is critical. We used air travel volume estimates from Wuhan, China, to international destinations and a generalized linear regression model to identify locations that could have undetected imported cases. Our model can be adjusted to account for exportation of cases from other locations as the virus spreads and more information on importations and transmission becomes available. Early detection and appropriate control measures can reduce the risk for transmission in all locations.", "A novel coronavirus, later named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was identified in December 2019 in the city of Wuhan, capital of Hubei Province, China, where cases were first confirmed (1). During December 2019–February 2020, the number of confirmed cases increased drastically. Model estimates suggested that >75,000 persons were infected by January 25, 2020, and the epidemic had a doubling time of ≈6 days (2). By the end of January 2020, travel restrictions were implemented for Wuhan and neighboring cities. Nonetheless, the virus spread from Wuhan to other cities in China and outside the country. By February 4, 2020, a total of 23 locations outside mainland China reported cases, 22 of which reported imported cases; Spain reported a case caused by secondary transmission (3).", "Most cases imported to other locations have been linked to recent travel history from China (3), suggesting that air travel plays a major role in exportation of cases to locations outside of China. To prevent other cities and countries from becoming epicenters of the SARS-CoV-2 epidemic, substantial targeted public health interventions are required to detect cases and control local spread of the virus. We collected estimates of air travel volume from Wuhan to 194 international destinations. We then identified 49 countries that had a score of >49.2/100 on category 2, Early Detection and Reporting of Epidemics of Potential International Concern, of the Global Health Security (GHS) Index (4). We assumed these locations would be proficient at detecting SARS-CoV-2 and reporting confirmed imported cases, which we refer to as imported-and-reported cases. We ran a generalized linear regression model on this subset; based on the results, we generated predictions for the remainder of the", "sample. Using these predictions, we identified locations that might not be detecting imported cases.", "Methods\nTo identify locations reporting fewer than predicted imported SARS-CoV-2 infected cases, we fit a model to data from 49 locations outside mainland China with high surveillance capacity according to the GHS Index (4). Among these, 17 had high travel connectivity to Wuhan and 32 have low connectivity to Wuhan. We considered locations to be countries without any position on territorial claims. We performed a Poisson regression by using the cumulative number of imported-and-reported SARS-CoV-2 cases in these 49 countries and the estimated number of daily airline passengers from the Wuhan airport. We then compared predictions from this model with imported-and-reported cases across 194 locations from the GHS Index, excluding China as the epicenter of the outbreak.", "The model requires data on imported-and-reported cases of SARS-CoV-2 infection, daily air travel volume, and surveillance capacity. We obtained data on imported-and-reported cases aggregated by destination from the World Health Organization technical report issued February 4, 2020 (3). We assumed a case count of 0 for locations not listed. We used February 4 as the cutoff for cumulative imported-and-reported case counts because exported cases from Hubei Province dropped rapidly after this date (3), likely because of travel restrictions for the province implement on January 23. We defined imported-and-reported cases as those with known travel history from China; of those, 83% had a travel history from Hubei Province and 17% traveled from unknown locations in China (3). We excluded reported cases likely caused by transmission outside of China or cases in which the transmission source was still under investigation (3). In addition, we excluded Hong Kong, Macau, and Taiwan from our model", "because locally transmitted and imported cases were not disaggregated in these locations.", "We obtained data on daily air travel from a network-based modeling study (S. Lai et al., unpub. data, https://doi.org/10.1101/2020.02.04.20020479External Link) that reported monthly air travel volume estimates for the 27 locations outside mainland China that are most connected to Wuhan. These estimates were calculated from International Air Travel Association data from February 2018, which includes direct and indirect flight itineraries from Wuhan. For these 27 locations, estimated air travel volumes are >6 passengers/day. We assumed that travel volumes for locations not among the most connected are censored by a detection limit. We used a common method of dealing with censored data from environmental sampling (5), or metabolomics (6), to set the daily air travel volume to half the minimum previously reported. Therefore, we used 3 passengers/day for estimated travel volumes for the 167 locations from the GHS Index not listed by Lai et al. We tested the robustness of our results by", "using a set of alternative values of 0.1, 1, and 6 passengers/day for the censored data.", "We defined high surveillance locations as those with a GHS Index for category 2 above the 75th quantile. We assessed the number of high surveillance locations, those with 0 imported-and-reported cases, and low surveillance locations, those with case counts >1 (Table).", "For our model, we assumed that the cumulative imported-and-reported case counts across 49 high surveillance locations follow a Poisson distribution from the beginning of the epidemic until February 4, 2020. Then the expected case count is linearly proportional to the daily air travel volume in the following formula:where i denotes location, Ci denotes the imported-and-reported case count in a location, λi denotes the expected case count in a location, β denotes the regression coefficient, and xi denotes the daily air travel volume of a location. The Poisson model assumes cases are independent and that the variance is equal to the expected case count. Imported-and-reported cases likely meet the independence assumption because the value excludes cases with local transmission. We also checked the robustness of our results by using an over dispersed model with a negative binomial likelihood. We computed the p value of the overdispersion parameter as shown in Gelman and Hill (7).", "Thumbnail of Regression plot of locations with possible undetected imported cases of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by air travel volume from Wuhan, China. Air travel volume measured in number of persons/day. No. cases refers to possible undetected imported SARS-CoV-2 cases. Solid line indicates the expected imported-and-reported case counts for locations. Dashed lines represent 95% prediction interval bounds smoothed for all locations. Purple dots indicate location\nFigure 1. Regression plot of locations with possible undetected imported cases of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by air travel volume from Wuhan, China. Air travel volume measured in number of...", "We used R version 3.6.1 (https://www.r-project.orgExternal Link) to compute , the maximum likelihood estimate of β, and the expected imported-and-reported case count given high surveillance (Figure 1). We also computed the 95% prediction interval (PI) bounds under this model of high surveillance for all 194 values of daily air travel volume (Figure 1). First, we generated a bootstrapped dataset by sampling n locations with replacement among high surveillance locations. Then, we reestimated β by using the bootstrapped dataset. Finally, we simulated imported-and-reported case counts for all 194 locations under our model by using the estimate of β from the bootstrapped dataset. We repeated the 3 steps 50,000 times to generate 50,000 simulated imported-and-reported case counts for each of the locations computed to the lower and upper PI bounds (PI 2.5%–97.5%). We smoothed the 95% PI bounds by using ggplot2 in R (8). We fit the imported-and-reported case counts of the 49 high surveillance", "locations to the model and plotted these alongside 145 locations with low surveillance capacity (Figure 1). We noted some overlap between high and low surveillance locations (Figure 1).", "Thumbnail of Analyses of imported-and-reported cases and daily air travel volume using a model to predict locations with potentially undetected cases of severe acute respiratory virus 2 (SARS-CoV-2). Air travel volume measured in number of persons/day. No. cases refers to possible undetected imported SARS-CoV-2 cases. Solid line shows the expected imported-and-reported case counts based on our model fitted to high surveillance locations, indicated by purple dots. Dashed lines indicate the 95% pr\nFigure 2. Analyses of imported-and-reported cases and daily air travel volume using a model to predict locations with potentially undetected cases of severe acute respiratory virus 2 (SARS-CoV-2). Air travel volume measured in...", "To assess the robustness of our results we ran 8 additional regression analyses by implementing a series of changes to the analysis. The changes included the following: set the daily air travel volume to 0.1, 1, or 6 passengers/day for locations not listed by Lai et al. (unpub. data, https://doi.org/10.1101/2020.02.04.20020479External Link) (Figure 2, panels A–C); removed all locations not listed by Lai et al. before fitting (Figure 2, panel D); defined high surveillance locations by using a more lenient GHS Index criterion, 50th quantile (Figure 2, panel E), and a more stringent criterion, 95th quantile (Figure 2, panel F); excluded Thailand from the model because it is a high-leverage point (Figure 2, panel G); or used an overdispersed Poisson likelihood with a negative-binomial likelihood (Figure 2, panel H). We provide code for these analyses on GitHub (https://github.com/c2-d2/cov19flightimportExternal Link).\n\nTop", "Results", "We found that daily air travel volume positively correlates with imported-and-reported case counts of SARS-CoV-2 infection among high surveillance locations (Figure 1). We noted that increasing flight volume by 31 passengers/day is associated with 1 additional expected imported-and-reported case. In addition, Singapore and India lie above the 95% PI in our model; Singapore had 12 more imported-and-reported cases (95% PI 6–17 cases) than expected and India had 3 (95% PI 1–3 cases) more than expected. Thailand has a relatively high air travel volume compared with other locations, but it lies below the 95% PI, reporting 16 (95% PI 1–40 cases) fewer imported-and-reported cases than expected under the model. Indonesia lies below the PI and has no imported-and-reported cases, but the expected case count is 5 (95% PI 1–10 cases) in our model. Across all 8 robustness regression analyses, we consistently observed that Singapore lies above the 95% PI and Thailand and Indonesia lie below (Figure", "2). India remains above the 95% PI in all robustness analyses except when we used the more stringent GHS Index, 95th quantile, for fitting; then India lies on the upper bound of the 95% PI (Figure 2, panel F).", "Top", "Discussion", "We aimed to identify locations with likely undetected or underdetected imported cases of SARS-CoV-2 by fitting a model to the case counts in locations with high surveillance capacity and Wuhan-to-location air travel volumes. Our model can be adjusted to account for exportation of cases from locations other than Wuhan as the outbreak develops and more information on importations and self-sustained transmission becomes available. One key advantage of this model is that it does not rely on estimates of incidence or prevalence in the epicenter of the outbreak. Also, we intentionally used a simple generalized linear model. The linearity of the expected case count means that we have only 1 regression coefficient in the model and no extra parameters. The Poisson likelihood then captures the many 0-counts observed for less highly connected locations but also describes the slope between case-count and flight data among more connected locations. We believe this model provides the most", "parsimonious phenomenologic description of the data.", "According to our model, locations above the 95% PI of imported-and-reported cases could have higher case-detection capacity. Locations below the 95% PI might have undetected cases because of expected imported-and-reported case counts under high surveillance. Underdetection of cases could increase the international spread of the outbreak because the transmission chain could be lost, reducing opportunities to deploy case-based control strategies. We recommend rapid strengthening of outbreak surveillance and control efforts in locations below the 95% PI lower bound, particularly Indonesia, to curb potential local transmission. Early detection of cases and implantation of appropriate control measures can reduce the risk for self-sustained transmission in all locations.\n\nTop", "Dr. De Salazar is a research fellow at Harvard T.H. Chan School of Public Health, working on multiscale statistical models of infectious diseases within host, population, and metapopulation models. His research interests include diagnostic laboratory methods and public health response.\n\nTop\n\nAcknowledgments\nWe thank Pamela Martinez, Nicholas Jewel, and Stephen Kissler for valuable feedback.\n\nThis work was supported by US National Institute of General Medical Sciences (award no. U54GM088558). P.M.D was supported by the Fellowship Foundation Ramon Areces. A.R.T. and C.O.B. were supported by a Maximizing Investigator’s Research Award (no. R35GM124715-02) from the US National Institute of General Medical Sciences.\n\nThe authors are solely responsible for this content and it does not necessarily represent the official views of the National Institute of General Medical Sciences or the National Institutes of Health.", "Declaration of interests: Marc Lipsitch has received consulting fees from Merck. All other authors declare no competing interests.\n\nTop", "References\nZhou P, Yang XL, Wang XG, Hu B, Zhang L, Zhang W, et al. A pneumonia outbreak associated with a new coronavirus of probable bat origin. Nature. 2020;579:270–3.\nWu JT, Leung K, Leung GM. Nowcasting and forecasting the potential domestic and international spread of the 2019-nCoV outbreak originating in Wuhan, China: a modelling study. Lancet. 2020;395:689–97. DOIExternal LinkPubMedExternal Link\nWorld Health Organization. Coronavirus disease 2019 (COVID-19) situation report—15, 4 Feb 2020 [cited 2020 Feb 14]. https://www.who.int/docs/default-source/coronaviruse/situation-reports/20200204-sitrep-15-ncov.pdfExternal Link\nNuclear Threat Initiative and Johns Hopkins Center for Health Security. Global health security index [cited 2020 Feb 14]. https://www.ghsindex.orgExternal Link", "US Environmental Protection Agency. Data quality assessment: statistical methods for practitioners EPA QA/G9-S [cited 2020 Feb 14]. Washington: The Agency; 2006. https://www.epa.gov/sites/production/files/2015-08/documents/g9s-final.pdfExternal Link\nLamichhane S, Sen P, Dickens AM, Hyötyläinen T, Orešič M. An overview of metabolomics data analysis: current tools and future perspectives. In: Jaumot J, Bedia C, Tauler R, editors. Comprehensive analytical chemistry. Vol. 82. Amsterdam: Elsevier; 2018. p. 387–413.\nGelman A, Hill J. Analytical methods for social research. In: Data analysis using regression and multilevel/hierarchical models. Cambridge: Cambridge University Press; 2006. p. 235–236.\nWickham H. ggplot2: elegant graphics for data analysis. New York: Springer; 2016.\nTop", "Figures\nFigure 1. Regression plot of locations with possible undetected imported cases of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by air travel volume from Wuhan, China. Air travel volume measured in...\nFigure 2. Analyses of imported-and-reported cases and daily air travel volume using a model to predict locations with potentially undetected cases of severe acute respiratory virus 2 (SARS-CoV-2). Air travel volume...\nTable\nTable. Surveillance capacity of locations with and without imported-and-reported cases of severe acute respiratory syndrome coronavirus 2, 2020\nTop\n\nSuggested citation for this article: De Salazar PM, Niehus R, Taylor A, O’Flaherty Buckee C, Lipsitch M. Identifying locations with possible undetected imported severe acute respiratory syndrome coronavirus 2 cases by using importation predictions. Emerg Infect Dis. 2020 Jul [date cited]. https://doi.org/10.3201/eid2607.200250\n\nDOI: 10.3201/eid2607.200250\n\nOriginal Publication Date: 3/24/2020", "1These authors contributed equally to this article.\n\nTable of Contents – Volume 26, Number 7—July 2020" ]	[ 2 ]	2,548	3,863
186	Where was SARS-CoV-2 first identified?	246	[ "Wuhan, capital of Hubei Province, China" ]	[ "Identifying Locations with Possible Undetected Imported Severe Acute Respiratory Syndrome Coronavirus 2 Cases by Using Importation Predictions,\nhttps://wwwnc.cdc.gov/eid/article/26/7/20-0250_article\nVolume 26, Number 7—July 2020\nResearch\n\nPablo Martinez De Salazar1Comments to Author , René Niehus, Aimee Taylor1, Caroline O’Flaherty Buckee, and Marc LipsitchComments to Author\nAuthor affiliations: Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA\nSuggested citation for this article", "Abstract\nCases of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection exported from mainland China could lead to self-sustained outbreaks in other countries. By February 2020, several countries were reporting imported SARS-CoV-2 cases. To contain the virus, early detection of imported SARS-CoV-2 cases is critical. We used air travel volume estimates from Wuhan, China, to international destinations and a generalized linear regression model to identify locations that could have undetected imported cases. Our model can be adjusted to account for exportation of cases from other locations as the virus spreads and more information on importations and transmission becomes available. Early detection and appropriate control measures can reduce the risk for transmission in all locations.", "A novel coronavirus, later named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was identified in December 2019 in the city of Wuhan, capital of Hubei Province, China, where cases were first confirmed (1). During December 2019–February 2020, the number of confirmed cases increased drastically. Model estimates suggested that >75,000 persons were infected by January 25, 2020, and the epidemic had a doubling time of ≈6 days (2). By the end of January 2020, travel restrictions were implemented for Wuhan and neighboring cities. Nonetheless, the virus spread from Wuhan to other cities in China and outside the country. By February 4, 2020, a total of 23 locations outside mainland China reported cases, 22 of which reported imported cases; Spain reported a case caused by secondary transmission (3).", "Most cases imported to other locations have been linked to recent travel history from China (3), suggesting that air travel plays a major role in exportation of cases to locations outside of China. To prevent other cities and countries from becoming epicenters of the SARS-CoV-2 epidemic, substantial targeted public health interventions are required to detect cases and control local spread of the virus. We collected estimates of air travel volume from Wuhan to 194 international destinations. We then identified 49 countries that had a score of >49.2/100 on category 2, Early Detection and Reporting of Epidemics of Potential International Concern, of the Global Health Security (GHS) Index (4). We assumed these locations would be proficient at detecting SARS-CoV-2 and reporting confirmed imported cases, which we refer to as imported-and-reported cases. We ran a generalized linear regression model on this subset; based on the results, we generated predictions for the remainder of the", "sample. Using these predictions, we identified locations that might not be detecting imported cases.", "Methods\nTo identify locations reporting fewer than predicted imported SARS-CoV-2 infected cases, we fit a model to data from 49 locations outside mainland China with high surveillance capacity according to the GHS Index (4). Among these, 17 had high travel connectivity to Wuhan and 32 have low connectivity to Wuhan. We considered locations to be countries without any position on territorial claims. We performed a Poisson regression by using the cumulative number of imported-and-reported SARS-CoV-2 cases in these 49 countries and the estimated number of daily airline passengers from the Wuhan airport. We then compared predictions from this model with imported-and-reported cases across 194 locations from the GHS Index, excluding China as the epicenter of the outbreak.", "The model requires data on imported-and-reported cases of SARS-CoV-2 infection, daily air travel volume, and surveillance capacity. We obtained data on imported-and-reported cases aggregated by destination from the World Health Organization technical report issued February 4, 2020 (3). We assumed a case count of 0 for locations not listed. We used February 4 as the cutoff for cumulative imported-and-reported case counts because exported cases from Hubei Province dropped rapidly after this date (3), likely because of travel restrictions for the province implement on January 23. We defined imported-and-reported cases as those with known travel history from China; of those, 83% had a travel history from Hubei Province and 17% traveled from unknown locations in China (3). We excluded reported cases likely caused by transmission outside of China or cases in which the transmission source was still under investigation (3). In addition, we excluded Hong Kong, Macau, and Taiwan from our model", "because locally transmitted and imported cases were not disaggregated in these locations.", "We obtained data on daily air travel from a network-based modeling study (S. Lai et al., unpub. data, https://doi.org/10.1101/2020.02.04.20020479External Link) that reported monthly air travel volume estimates for the 27 locations outside mainland China that are most connected to Wuhan. These estimates were calculated from International Air Travel Association data from February 2018, which includes direct and indirect flight itineraries from Wuhan. For these 27 locations, estimated air travel volumes are >6 passengers/day. We assumed that travel volumes for locations not among the most connected are censored by a detection limit. We used a common method of dealing with censored data from environmental sampling (5), or metabolomics (6), to set the daily air travel volume to half the minimum previously reported. Therefore, we used 3 passengers/day for estimated travel volumes for the 167 locations from the GHS Index not listed by Lai et al. We tested the robustness of our results by", "using a set of alternative values of 0.1, 1, and 6 passengers/day for the censored data.", "We defined high surveillance locations as those with a GHS Index for category 2 above the 75th quantile. We assessed the number of high surveillance locations, those with 0 imported-and-reported cases, and low surveillance locations, those with case counts >1 (Table).", "For our model, we assumed that the cumulative imported-and-reported case counts across 49 high surveillance locations follow a Poisson distribution from the beginning of the epidemic until February 4, 2020. Then the expected case count is linearly proportional to the daily air travel volume in the following formula:where i denotes location, Ci denotes the imported-and-reported case count in a location, λi denotes the expected case count in a location, β denotes the regression coefficient, and xi denotes the daily air travel volume of a location. The Poisson model assumes cases are independent and that the variance is equal to the expected case count. Imported-and-reported cases likely meet the independence assumption because the value excludes cases with local transmission. We also checked the robustness of our results by using an over dispersed model with a negative binomial likelihood. We computed the p value of the overdispersion parameter as shown in Gelman and Hill (7).", "Thumbnail of Regression plot of locations with possible undetected imported cases of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by air travel volume from Wuhan, China. Air travel volume measured in number of persons/day. No. cases refers to possible undetected imported SARS-CoV-2 cases. Solid line indicates the expected imported-and-reported case counts for locations. Dashed lines represent 95% prediction interval bounds smoothed for all locations. Purple dots indicate location\nFigure 1. Regression plot of locations with possible undetected imported cases of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by air travel volume from Wuhan, China. Air travel volume measured in number of...", "We used R version 3.6.1 (https://www.r-project.orgExternal Link) to compute , the maximum likelihood estimate of β, and the expected imported-and-reported case count given high surveillance (Figure 1). We also computed the 95% prediction interval (PI) bounds under this model of high surveillance for all 194 values of daily air travel volume (Figure 1). First, we generated a bootstrapped dataset by sampling n locations with replacement among high surveillance locations. Then, we reestimated β by using the bootstrapped dataset. Finally, we simulated imported-and-reported case counts for all 194 locations under our model by using the estimate of β from the bootstrapped dataset. We repeated the 3 steps 50,000 times to generate 50,000 simulated imported-and-reported case counts for each of the locations computed to the lower and upper PI bounds (PI 2.5%–97.5%). We smoothed the 95% PI bounds by using ggplot2 in R (8). We fit the imported-and-reported case counts of the 49 high surveillance", "locations to the model and plotted these alongside 145 locations with low surveillance capacity (Figure 1). We noted some overlap between high and low surveillance locations (Figure 1).", "Thumbnail of Analyses of imported-and-reported cases and daily air travel volume using a model to predict locations with potentially undetected cases of severe acute respiratory virus 2 (SARS-CoV-2). Air travel volume measured in number of persons/day. No. cases refers to possible undetected imported SARS-CoV-2 cases. Solid line shows the expected imported-and-reported case counts based on our model fitted to high surveillance locations, indicated by purple dots. Dashed lines indicate the 95% pr\nFigure 2. Analyses of imported-and-reported cases and daily air travel volume using a model to predict locations with potentially undetected cases of severe acute respiratory virus 2 (SARS-CoV-2). Air travel volume measured in...", "To assess the robustness of our results we ran 8 additional regression analyses by implementing a series of changes to the analysis. The changes included the following: set the daily air travel volume to 0.1, 1, or 6 passengers/day for locations not listed by Lai et al. (unpub. data, https://doi.org/10.1101/2020.02.04.20020479External Link) (Figure 2, panels A–C); removed all locations not listed by Lai et al. before fitting (Figure 2, panel D); defined high surveillance locations by using a more lenient GHS Index criterion, 50th quantile (Figure 2, panel E), and a more stringent criterion, 95th quantile (Figure 2, panel F); excluded Thailand from the model because it is a high-leverage point (Figure 2, panel G); or used an overdispersed Poisson likelihood with a negative-binomial likelihood (Figure 2, panel H). We provide code for these analyses on GitHub (https://github.com/c2-d2/cov19flightimportExternal Link).\n\nTop", "Results", "We found that daily air travel volume positively correlates with imported-and-reported case counts of SARS-CoV-2 infection among high surveillance locations (Figure 1). We noted that increasing flight volume by 31 passengers/day is associated with 1 additional expected imported-and-reported case. In addition, Singapore and India lie above the 95% PI in our model; Singapore had 12 more imported-and-reported cases (95% PI 6–17 cases) than expected and India had 3 (95% PI 1–3 cases) more than expected. Thailand has a relatively high air travel volume compared with other locations, but it lies below the 95% PI, reporting 16 (95% PI 1–40 cases) fewer imported-and-reported cases than expected under the model. Indonesia lies below the PI and has no imported-and-reported cases, but the expected case count is 5 (95% PI 1–10 cases) in our model. Across all 8 robustness regression analyses, we consistently observed that Singapore lies above the 95% PI and Thailand and Indonesia lie below (Figure", "2). India remains above the 95% PI in all robustness analyses except when we used the more stringent GHS Index, 95th quantile, for fitting; then India lies on the upper bound of the 95% PI (Figure 2, panel F).", "Top", "Discussion", "We aimed to identify locations with likely undetected or underdetected imported cases of SARS-CoV-2 by fitting a model to the case counts in locations with high surveillance capacity and Wuhan-to-location air travel volumes. Our model can be adjusted to account for exportation of cases from locations other than Wuhan as the outbreak develops and more information on importations and self-sustained transmission becomes available. One key advantage of this model is that it does not rely on estimates of incidence or prevalence in the epicenter of the outbreak. Also, we intentionally used a simple generalized linear model. The linearity of the expected case count means that we have only 1 regression coefficient in the model and no extra parameters. The Poisson likelihood then captures the many 0-counts observed for less highly connected locations but also describes the slope between case-count and flight data among more connected locations. We believe this model provides the most", "parsimonious phenomenologic description of the data.", "According to our model, locations above the 95% PI of imported-and-reported cases could have higher case-detection capacity. Locations below the 95% PI might have undetected cases because of expected imported-and-reported case counts under high surveillance. Underdetection of cases could increase the international spread of the outbreak because the transmission chain could be lost, reducing opportunities to deploy case-based control strategies. We recommend rapid strengthening of outbreak surveillance and control efforts in locations below the 95% PI lower bound, particularly Indonesia, to curb potential local transmission. Early detection of cases and implantation of appropriate control measures can reduce the risk for self-sustained transmission in all locations.\n\nTop", "Dr. De Salazar is a research fellow at Harvard T.H. Chan School of Public Health, working on multiscale statistical models of infectious diseases within host, population, and metapopulation models. His research interests include diagnostic laboratory methods and public health response.\n\nTop\n\nAcknowledgments\nWe thank Pamela Martinez, Nicholas Jewel, and Stephen Kissler for valuable feedback.\n\nThis work was supported by US National Institute of General Medical Sciences (award no. U54GM088558). P.M.D was supported by the Fellowship Foundation Ramon Areces. A.R.T. and C.O.B. were supported by a Maximizing Investigator’s Research Award (no. R35GM124715-02) from the US National Institute of General Medical Sciences.\n\nThe authors are solely responsible for this content and it does not necessarily represent the official views of the National Institute of General Medical Sciences or the National Institutes of Health.", "Declaration of interests: Marc Lipsitch has received consulting fees from Merck. All other authors declare no competing interests.\n\nTop", "References\nZhou P, Yang XL, Wang XG, Hu B, Zhang L, Zhang W, et al. A pneumonia outbreak associated with a new coronavirus of probable bat origin. Nature. 2020;579:270–3.\nWu JT, Leung K, Leung GM. Nowcasting and forecasting the potential domestic and international spread of the 2019-nCoV outbreak originating in Wuhan, China: a modelling study. Lancet. 2020;395:689–97. DOIExternal LinkPubMedExternal Link\nWorld Health Organization. Coronavirus disease 2019 (COVID-19) situation report—15, 4 Feb 2020 [cited 2020 Feb 14]. https://www.who.int/docs/default-source/coronaviruse/situation-reports/20200204-sitrep-15-ncov.pdfExternal Link\nNuclear Threat Initiative and Johns Hopkins Center for Health Security. Global health security index [cited 2020 Feb 14]. https://www.ghsindex.orgExternal Link", "US Environmental Protection Agency. Data quality assessment: statistical methods for practitioners EPA QA/G9-S [cited 2020 Feb 14]. Washington: The Agency; 2006. https://www.epa.gov/sites/production/files/2015-08/documents/g9s-final.pdfExternal Link\nLamichhane S, Sen P, Dickens AM, Hyötyläinen T, Orešič M. An overview of metabolomics data analysis: current tools and future perspectives. In: Jaumot J, Bedia C, Tauler R, editors. Comprehensive analytical chemistry. Vol. 82. Amsterdam: Elsevier; 2018. p. 387–413.\nGelman A, Hill J. Analytical methods for social research. In: Data analysis using regression and multilevel/hierarchical models. Cambridge: Cambridge University Press; 2006. p. 235–236.\nWickham H. ggplot2: elegant graphics for data analysis. New York: Springer; 2016.\nTop", "Figures\nFigure 1. Regression plot of locations with possible undetected imported cases of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by air travel volume from Wuhan, China. Air travel volume measured in...\nFigure 2. Analyses of imported-and-reported cases and daily air travel volume using a model to predict locations with potentially undetected cases of severe acute respiratory virus 2 (SARS-CoV-2). Air travel volume...\nTable\nTable. Surveillance capacity of locations with and without imported-and-reported cases of severe acute respiratory syndrome coronavirus 2, 2020\nTop\n\nSuggested citation for this article: De Salazar PM, Niehus R, Taylor A, O’Flaherty Buckee C, Lipsitch M. Identifying locations with possible undetected imported severe acute respiratory syndrome coronavirus 2 cases by using importation predictions. Emerg Infect Dis. 2020 Jul [date cited]. https://doi.org/10.3201/eid2607.200250\n\nDOI: 10.3201/eid2607.200250\n\nOriginal Publication Date: 3/24/2020", "1These authors contributed equally to this article.\n\nTable of Contents – Volume 26, Number 7—July 2020" ]	[ 2 ]	2,548	3,863
186	What factor positively correlates with imported-and-reported cases counts of SARS-CoV-2 infection?	247	[ "daily air travel volume" ]	[ "Identifying Locations with Possible Undetected Imported Severe Acute Respiratory Syndrome Coronavirus 2 Cases by Using Importation Predictions,\nhttps://wwwnc.cdc.gov/eid/article/26/7/20-0250_article\nVolume 26, Number 7—July 2020\nResearch\n\nPablo Martinez De Salazar1Comments to Author , René Niehus, Aimee Taylor1, Caroline O’Flaherty Buckee, and Marc LipsitchComments to Author\nAuthor affiliations: Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA\nSuggested citation for this article", "Abstract\nCases of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection exported from mainland China could lead to self-sustained outbreaks in other countries. By February 2020, several countries were reporting imported SARS-CoV-2 cases. To contain the virus, early detection of imported SARS-CoV-2 cases is critical. We used air travel volume estimates from Wuhan, China, to international destinations and a generalized linear regression model to identify locations that could have undetected imported cases. Our model can be adjusted to account for exportation of cases from other locations as the virus spreads and more information on importations and transmission becomes available. Early detection and appropriate control measures can reduce the risk for transmission in all locations.", "A novel coronavirus, later named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was identified in December 2019 in the city of Wuhan, capital of Hubei Province, China, where cases were first confirmed (1). During December 2019–February 2020, the number of confirmed cases increased drastically. Model estimates suggested that >75,000 persons were infected by January 25, 2020, and the epidemic had a doubling time of ≈6 days (2). By the end of January 2020, travel restrictions were implemented for Wuhan and neighboring cities. Nonetheless, the virus spread from Wuhan to other cities in China and outside the country. By February 4, 2020, a total of 23 locations outside mainland China reported cases, 22 of which reported imported cases; Spain reported a case caused by secondary transmission (3).", "Most cases imported to other locations have been linked to recent travel history from China (3), suggesting that air travel plays a major role in exportation of cases to locations outside of China. To prevent other cities and countries from becoming epicenters of the SARS-CoV-2 epidemic, substantial targeted public health interventions are required to detect cases and control local spread of the virus. We collected estimates of air travel volume from Wuhan to 194 international destinations. We then identified 49 countries that had a score of >49.2/100 on category 2, Early Detection and Reporting of Epidemics of Potential International Concern, of the Global Health Security (GHS) Index (4). We assumed these locations would be proficient at detecting SARS-CoV-2 and reporting confirmed imported cases, which we refer to as imported-and-reported cases. We ran a generalized linear regression model on this subset; based on the results, we generated predictions for the remainder of the", "sample. Using these predictions, we identified locations that might not be detecting imported cases.", "Methods\nTo identify locations reporting fewer than predicted imported SARS-CoV-2 infected cases, we fit a model to data from 49 locations outside mainland China with high surveillance capacity according to the GHS Index (4). Among these, 17 had high travel connectivity to Wuhan and 32 have low connectivity to Wuhan. We considered locations to be countries without any position on territorial claims. We performed a Poisson regression by using the cumulative number of imported-and-reported SARS-CoV-2 cases in these 49 countries and the estimated number of daily airline passengers from the Wuhan airport. We then compared predictions from this model with imported-and-reported cases across 194 locations from the GHS Index, excluding China as the epicenter of the outbreak.", "The model requires data on imported-and-reported cases of SARS-CoV-2 infection, daily air travel volume, and surveillance capacity. We obtained data on imported-and-reported cases aggregated by destination from the World Health Organization technical report issued February 4, 2020 (3). We assumed a case count of 0 for locations not listed. We used February 4 as the cutoff for cumulative imported-and-reported case counts because exported cases from Hubei Province dropped rapidly after this date (3), likely because of travel restrictions for the province implement on January 23. We defined imported-and-reported cases as those with known travel history from China; of those, 83% had a travel history from Hubei Province and 17% traveled from unknown locations in China (3). We excluded reported cases likely caused by transmission outside of China or cases in which the transmission source was still under investigation (3). In addition, we excluded Hong Kong, Macau, and Taiwan from our model", "because locally transmitted and imported cases were not disaggregated in these locations.", "We obtained data on daily air travel from a network-based modeling study (S. Lai et al., unpub. data, https://doi.org/10.1101/2020.02.04.20020479External Link) that reported monthly air travel volume estimates for the 27 locations outside mainland China that are most connected to Wuhan. These estimates were calculated from International Air Travel Association data from February 2018, which includes direct and indirect flight itineraries from Wuhan. For these 27 locations, estimated air travel volumes are >6 passengers/day. We assumed that travel volumes for locations not among the most connected are censored by a detection limit. We used a common method of dealing with censored data from environmental sampling (5), or metabolomics (6), to set the daily air travel volume to half the minimum previously reported. Therefore, we used 3 passengers/day for estimated travel volumes for the 167 locations from the GHS Index not listed by Lai et al. We tested the robustness of our results by", "using a set of alternative values of 0.1, 1, and 6 passengers/day for the censored data.", "We defined high surveillance locations as those with a GHS Index for category 2 above the 75th quantile. We assessed the number of high surveillance locations, those with 0 imported-and-reported cases, and low surveillance locations, those with case counts >1 (Table).", "For our model, we assumed that the cumulative imported-and-reported case counts across 49 high surveillance locations follow a Poisson distribution from the beginning of the epidemic until February 4, 2020. Then the expected case count is linearly proportional to the daily air travel volume in the following formula:where i denotes location, Ci denotes the imported-and-reported case count in a location, λi denotes the expected case count in a location, β denotes the regression coefficient, and xi denotes the daily air travel volume of a location. The Poisson model assumes cases are independent and that the variance is equal to the expected case count. Imported-and-reported cases likely meet the independence assumption because the value excludes cases with local transmission. We also checked the robustness of our results by using an over dispersed model with a negative binomial likelihood. We computed the p value of the overdispersion parameter as shown in Gelman and Hill (7).", "Thumbnail of Regression plot of locations with possible undetected imported cases of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by air travel volume from Wuhan, China. Air travel volume measured in number of persons/day. No. cases refers to possible undetected imported SARS-CoV-2 cases. Solid line indicates the expected imported-and-reported case counts for locations. Dashed lines represent 95% prediction interval bounds smoothed for all locations. Purple dots indicate location\nFigure 1. Regression plot of locations with possible undetected imported cases of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by air travel volume from Wuhan, China. Air travel volume measured in number of...", "We used R version 3.6.1 (https://www.r-project.orgExternal Link) to compute , the maximum likelihood estimate of β, and the expected imported-and-reported case count given high surveillance (Figure 1). We also computed the 95% prediction interval (PI) bounds under this model of high surveillance for all 194 values of daily air travel volume (Figure 1). First, we generated a bootstrapped dataset by sampling n locations with replacement among high surveillance locations. Then, we reestimated β by using the bootstrapped dataset. Finally, we simulated imported-and-reported case counts for all 194 locations under our model by using the estimate of β from the bootstrapped dataset. We repeated the 3 steps 50,000 times to generate 50,000 simulated imported-and-reported case counts for each of the locations computed to the lower and upper PI bounds (PI 2.5%–97.5%). We smoothed the 95% PI bounds by using ggplot2 in R (8). We fit the imported-and-reported case counts of the 49 high surveillance", "locations to the model and plotted these alongside 145 locations with low surveillance capacity (Figure 1). We noted some overlap between high and low surveillance locations (Figure 1).", "Thumbnail of Analyses of imported-and-reported cases and daily air travel volume using a model to predict locations with potentially undetected cases of severe acute respiratory virus 2 (SARS-CoV-2). Air travel volume measured in number of persons/day. No. cases refers to possible undetected imported SARS-CoV-2 cases. Solid line shows the expected imported-and-reported case counts based on our model fitted to high surveillance locations, indicated by purple dots. Dashed lines indicate the 95% pr\nFigure 2. Analyses of imported-and-reported cases and daily air travel volume using a model to predict locations with potentially undetected cases of severe acute respiratory virus 2 (SARS-CoV-2). Air travel volume measured in...", "To assess the robustness of our results we ran 8 additional regression analyses by implementing a series of changes to the analysis. The changes included the following: set the daily air travel volume to 0.1, 1, or 6 passengers/day for locations not listed by Lai et al. (unpub. data, https://doi.org/10.1101/2020.02.04.20020479External Link) (Figure 2, panels A–C); removed all locations not listed by Lai et al. before fitting (Figure 2, panel D); defined high surveillance locations by using a more lenient GHS Index criterion, 50th quantile (Figure 2, panel E), and a more stringent criterion, 95th quantile (Figure 2, panel F); excluded Thailand from the model because it is a high-leverage point (Figure 2, panel G); or used an overdispersed Poisson likelihood with a negative-binomial likelihood (Figure 2, panel H). We provide code for these analyses on GitHub (https://github.com/c2-d2/cov19flightimportExternal Link).\n\nTop", "Results", "We found that daily air travel volume positively correlates with imported-and-reported case counts of SARS-CoV-2 infection among high surveillance locations (Figure 1). We noted that increasing flight volume by 31 passengers/day is associated with 1 additional expected imported-and-reported case. In addition, Singapore and India lie above the 95% PI in our model; Singapore had 12 more imported-and-reported cases (95% PI 6–17 cases) than expected and India had 3 (95% PI 1–3 cases) more than expected. Thailand has a relatively high air travel volume compared with other locations, but it lies below the 95% PI, reporting 16 (95% PI 1–40 cases) fewer imported-and-reported cases than expected under the model. Indonesia lies below the PI and has no imported-and-reported cases, but the expected case count is 5 (95% PI 1–10 cases) in our model. Across all 8 robustness regression analyses, we consistently observed that Singapore lies above the 95% PI and Thailand and Indonesia lie below (Figure", "2). India remains above the 95% PI in all robustness analyses except when we used the more stringent GHS Index, 95th quantile, for fitting; then India lies on the upper bound of the 95% PI (Figure 2, panel F).", "Top", "Discussion", "We aimed to identify locations with likely undetected or underdetected imported cases of SARS-CoV-2 by fitting a model to the case counts in locations with high surveillance capacity and Wuhan-to-location air travel volumes. Our model can be adjusted to account for exportation of cases from locations other than Wuhan as the outbreak develops and more information on importations and self-sustained transmission becomes available. One key advantage of this model is that it does not rely on estimates of incidence or prevalence in the epicenter of the outbreak. Also, we intentionally used a simple generalized linear model. The linearity of the expected case count means that we have only 1 regression coefficient in the model and no extra parameters. The Poisson likelihood then captures the many 0-counts observed for less highly connected locations but also describes the slope between case-count and flight data among more connected locations. We believe this model provides the most", "parsimonious phenomenologic description of the data.", "According to our model, locations above the 95% PI of imported-and-reported cases could have higher case-detection capacity. Locations below the 95% PI might have undetected cases because of expected imported-and-reported case counts under high surveillance. Underdetection of cases could increase the international spread of the outbreak because the transmission chain could be lost, reducing opportunities to deploy case-based control strategies. We recommend rapid strengthening of outbreak surveillance and control efforts in locations below the 95% PI lower bound, particularly Indonesia, to curb potential local transmission. Early detection of cases and implantation of appropriate control measures can reduce the risk for self-sustained transmission in all locations.\n\nTop", "Dr. De Salazar is a research fellow at Harvard T.H. Chan School of Public Health, working on multiscale statistical models of infectious diseases within host, population, and metapopulation models. His research interests include diagnostic laboratory methods and public health response.\n\nTop\n\nAcknowledgments\nWe thank Pamela Martinez, Nicholas Jewel, and Stephen Kissler for valuable feedback.\n\nThis work was supported by US National Institute of General Medical Sciences (award no. U54GM088558). P.M.D was supported by the Fellowship Foundation Ramon Areces. A.R.T. and C.O.B. were supported by a Maximizing Investigator’s Research Award (no. R35GM124715-02) from the US National Institute of General Medical Sciences.\n\nThe authors are solely responsible for this content and it does not necessarily represent the official views of the National Institute of General Medical Sciences or the National Institutes of Health.", "Declaration of interests: Marc Lipsitch has received consulting fees from Merck. All other authors declare no competing interests.\n\nTop", "References\nZhou P, Yang XL, Wang XG, Hu B, Zhang L, Zhang W, et al. A pneumonia outbreak associated with a new coronavirus of probable bat origin. Nature. 2020;579:270–3.\nWu JT, Leung K, Leung GM. Nowcasting and forecasting the potential domestic and international spread of the 2019-nCoV outbreak originating in Wuhan, China: a modelling study. Lancet. 2020;395:689–97. DOIExternal LinkPubMedExternal Link\nWorld Health Organization. Coronavirus disease 2019 (COVID-19) situation report—15, 4 Feb 2020 [cited 2020 Feb 14]. https://www.who.int/docs/default-source/coronaviruse/situation-reports/20200204-sitrep-15-ncov.pdfExternal Link\nNuclear Threat Initiative and Johns Hopkins Center for Health Security. Global health security index [cited 2020 Feb 14]. https://www.ghsindex.orgExternal Link", "US Environmental Protection Agency. Data quality assessment: statistical methods for practitioners EPA QA/G9-S [cited 2020 Feb 14]. Washington: The Agency; 2006. https://www.epa.gov/sites/production/files/2015-08/documents/g9s-final.pdfExternal Link\nLamichhane S, Sen P, Dickens AM, Hyötyläinen T, Orešič M. An overview of metabolomics data analysis: current tools and future perspectives. In: Jaumot J, Bedia C, Tauler R, editors. Comprehensive analytical chemistry. Vol. 82. Amsterdam: Elsevier; 2018. p. 387–413.\nGelman A, Hill J. Analytical methods for social research. In: Data analysis using regression and multilevel/hierarchical models. Cambridge: Cambridge University Press; 2006. p. 235–236.\nWickham H. ggplot2: elegant graphics for data analysis. New York: Springer; 2016.\nTop", "Figures\nFigure 1. Regression plot of locations with possible undetected imported cases of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by air travel volume from Wuhan, China. Air travel volume measured in...\nFigure 2. Analyses of imported-and-reported cases and daily air travel volume using a model to predict locations with potentially undetected cases of severe acute respiratory virus 2 (SARS-CoV-2). Air travel volume...\nTable\nTable. Surveillance capacity of locations with and without imported-and-reported cases of severe acute respiratory syndrome coronavirus 2, 2020\nTop\n\nSuggested citation for this article: De Salazar PM, Niehus R, Taylor A, O’Flaherty Buckee C, Lipsitch M. Identifying locations with possible undetected imported severe acute respiratory syndrome coronavirus 2 cases by using importation predictions. Emerg Infect Dis. 2020 Jul [date cited]. https://doi.org/10.3201/eid2607.200250\n\nDOI: 10.3201/eid2607.200250\n\nOriginal Publication Date: 3/24/2020", "1These authors contributed equally to this article.\n\nTable of Contents – Volume 26, Number 7—July 2020" ]	[ 6 ]	2,548	3,863
186	What is the doubling time of the COVID-19 pandemic?	272	[ "≈6 days" ]	[ "Identifying Locations with Possible Undetected Imported Severe Acute Respiratory Syndrome Coronavirus 2 Cases by Using Importation Predictions,\nhttps://wwwnc.cdc.gov/eid/article/26/7/20-0250_article\nVolume 26, Number 7—July 2020\nResearch\n\nPablo Martinez De Salazar1Comments to Author , René Niehus, Aimee Taylor1, Caroline O’Flaherty Buckee, and Marc LipsitchComments to Author\nAuthor affiliations: Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA\nSuggested citation for this article", "Abstract\nCases of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection exported from mainland China could lead to self-sustained outbreaks in other countries. By February 2020, several countries were reporting imported SARS-CoV-2 cases. To contain the virus, early detection of imported SARS-CoV-2 cases is critical. We used air travel volume estimates from Wuhan, China, to international destinations and a generalized linear regression model to identify locations that could have undetected imported cases. Our model can be adjusted to account for exportation of cases from other locations as the virus spreads and more information on importations and transmission becomes available. Early detection and appropriate control measures can reduce the risk for transmission in all locations.", "A novel coronavirus, later named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was identified in December 2019 in the city of Wuhan, capital of Hubei Province, China, where cases were first confirmed (1). During December 2019–February 2020, the number of confirmed cases increased drastically. Model estimates suggested that >75,000 persons were infected by January 25, 2020, and the epidemic had a doubling time of ≈6 days (2). By the end of January 2020, travel restrictions were implemented for Wuhan and neighboring cities. Nonetheless, the virus spread from Wuhan to other cities in China and outside the country. By February 4, 2020, a total of 23 locations outside mainland China reported cases, 22 of which reported imported cases; Spain reported a case caused by secondary transmission (3).", "Most cases imported to other locations have been linked to recent travel history from China (3), suggesting that air travel plays a major role in exportation of cases to locations outside of China. To prevent other cities and countries from becoming epicenters of the SARS-CoV-2 epidemic, substantial targeted public health interventions are required to detect cases and control local spread of the virus. We collected estimates of air travel volume from Wuhan to 194 international destinations. We then identified 49 countries that had a score of >49.2/100 on category 2, Early Detection and Reporting of Epidemics of Potential International Concern, of the Global Health Security (GHS) Index (4). We assumed these locations would be proficient at detecting SARS-CoV-2 and reporting confirmed imported cases, which we refer to as imported-and-reported cases. We ran a generalized linear regression model on this subset; based on the results, we generated predictions for the remainder of the", "sample. Using these predictions, we identified locations that might not be detecting imported cases.", "Methods\nTo identify locations reporting fewer than predicted imported SARS-CoV-2 infected cases, we fit a model to data from 49 locations outside mainland China with high surveillance capacity according to the GHS Index (4). Among these, 17 had high travel connectivity to Wuhan and 32 have low connectivity to Wuhan. We considered locations to be countries without any position on territorial claims. We performed a Poisson regression by using the cumulative number of imported-and-reported SARS-CoV-2 cases in these 49 countries and the estimated number of daily airline passengers from the Wuhan airport. We then compared predictions from this model with imported-and-reported cases across 194 locations from the GHS Index, excluding China as the epicenter of the outbreak.", "The model requires data on imported-and-reported cases of SARS-CoV-2 infection, daily air travel volume, and surveillance capacity. We obtained data on imported-and-reported cases aggregated by destination from the World Health Organization technical report issued February 4, 2020 (3). We assumed a case count of 0 for locations not listed. We used February 4 as the cutoff for cumulative imported-and-reported case counts because exported cases from Hubei Province dropped rapidly after this date (3), likely because of travel restrictions for the province implement on January 23. We defined imported-and-reported cases as those with known travel history from China; of those, 83% had a travel history from Hubei Province and 17% traveled from unknown locations in China (3). We excluded reported cases likely caused by transmission outside of China or cases in which the transmission source was still under investigation (3). In addition, we excluded Hong Kong, Macau, and Taiwan from our model", "because locally transmitted and imported cases were not disaggregated in these locations.", "We obtained data on daily air travel from a network-based modeling study (S. Lai et al., unpub. data, https://doi.org/10.1101/2020.02.04.20020479External Link) that reported monthly air travel volume estimates for the 27 locations outside mainland China that are most connected to Wuhan. These estimates were calculated from International Air Travel Association data from February 2018, which includes direct and indirect flight itineraries from Wuhan. For these 27 locations, estimated air travel volumes are >6 passengers/day. We assumed that travel volumes for locations not among the most connected are censored by a detection limit. We used a common method of dealing with censored data from environmental sampling (5), or metabolomics (6), to set the daily air travel volume to half the minimum previously reported. Therefore, we used 3 passengers/day for estimated travel volumes for the 167 locations from the GHS Index not listed by Lai et al. We tested the robustness of our results by", "using a set of alternative values of 0.1, 1, and 6 passengers/day for the censored data.", "We defined high surveillance locations as those with a GHS Index for category 2 above the 75th quantile. We assessed the number of high surveillance locations, those with 0 imported-and-reported cases, and low surveillance locations, those with case counts >1 (Table).", "For our model, we assumed that the cumulative imported-and-reported case counts across 49 high surveillance locations follow a Poisson distribution from the beginning of the epidemic until February 4, 2020. Then the expected case count is linearly proportional to the daily air travel volume in the following formula:where i denotes location, Ci denotes the imported-and-reported case count in a location, λi denotes the expected case count in a location, β denotes the regression coefficient, and xi denotes the daily air travel volume of a location. The Poisson model assumes cases are independent and that the variance is equal to the expected case count. Imported-and-reported cases likely meet the independence assumption because the value excludes cases with local transmission. We also checked the robustness of our results by using an over dispersed model with a negative binomial likelihood. We computed the p value of the overdispersion parameter as shown in Gelman and Hill (7).", "Thumbnail of Regression plot of locations with possible undetected imported cases of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by air travel volume from Wuhan, China. Air travel volume measured in number of persons/day. No. cases refers to possible undetected imported SARS-CoV-2 cases. Solid line indicates the expected imported-and-reported case counts for locations. Dashed lines represent 95% prediction interval bounds smoothed for all locations. Purple dots indicate location\nFigure 1. Regression plot of locations with possible undetected imported cases of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by air travel volume from Wuhan, China. Air travel volume measured in number of...", "We used R version 3.6.1 (https://www.r-project.orgExternal Link) to compute , the maximum likelihood estimate of β, and the expected imported-and-reported case count given high surveillance (Figure 1). We also computed the 95% prediction interval (PI) bounds under this model of high surveillance for all 194 values of daily air travel volume (Figure 1). First, we generated a bootstrapped dataset by sampling n locations with replacement among high surveillance locations. Then, we reestimated β by using the bootstrapped dataset. Finally, we simulated imported-and-reported case counts for all 194 locations under our model by using the estimate of β from the bootstrapped dataset. We repeated the 3 steps 50,000 times to generate 50,000 simulated imported-and-reported case counts for each of the locations computed to the lower and upper PI bounds (PI 2.5%–97.5%). We smoothed the 95% PI bounds by using ggplot2 in R (8). We fit the imported-and-reported case counts of the 49 high surveillance", "locations to the model and plotted these alongside 145 locations with low surveillance capacity (Figure 1). We noted some overlap between high and low surveillance locations (Figure 1).", "Thumbnail of Analyses of imported-and-reported cases and daily air travel volume using a model to predict locations with potentially undetected cases of severe acute respiratory virus 2 (SARS-CoV-2). Air travel volume measured in number of persons/day. No. cases refers to possible undetected imported SARS-CoV-2 cases. Solid line shows the expected imported-and-reported case counts based on our model fitted to high surveillance locations, indicated by purple dots. Dashed lines indicate the 95% pr\nFigure 2. Analyses of imported-and-reported cases and daily air travel volume using a model to predict locations with potentially undetected cases of severe acute respiratory virus 2 (SARS-CoV-2). Air travel volume measured in...", "To assess the robustness of our results we ran 8 additional regression analyses by implementing a series of changes to the analysis. The changes included the following: set the daily air travel volume to 0.1, 1, or 6 passengers/day for locations not listed by Lai et al. (unpub. data, https://doi.org/10.1101/2020.02.04.20020479External Link) (Figure 2, panels A–C); removed all locations not listed by Lai et al. before fitting (Figure 2, panel D); defined high surveillance locations by using a more lenient GHS Index criterion, 50th quantile (Figure 2, panel E), and a more stringent criterion, 95th quantile (Figure 2, panel F); excluded Thailand from the model because it is a high-leverage point (Figure 2, panel G); or used an overdispersed Poisson likelihood with a negative-binomial likelihood (Figure 2, panel H). We provide code for these analyses on GitHub (https://github.com/c2-d2/cov19flightimportExternal Link).\n\nTop", "Results", "We found that daily air travel volume positively correlates with imported-and-reported case counts of SARS-CoV-2 infection among high surveillance locations (Figure 1). We noted that increasing flight volume by 31 passengers/day is associated with 1 additional expected imported-and-reported case. In addition, Singapore and India lie above the 95% PI in our model; Singapore had 12 more imported-and-reported cases (95% PI 6–17 cases) than expected and India had 3 (95% PI 1–3 cases) more than expected. Thailand has a relatively high air travel volume compared with other locations, but it lies below the 95% PI, reporting 16 (95% PI 1–40 cases) fewer imported-and-reported cases than expected under the model. Indonesia lies below the PI and has no imported-and-reported cases, but the expected case count is 5 (95% PI 1–10 cases) in our model. Across all 8 robustness regression analyses, we consistently observed that Singapore lies above the 95% PI and Thailand and Indonesia lie below (Figure", "2). India remains above the 95% PI in all robustness analyses except when we used the more stringent GHS Index, 95th quantile, for fitting; then India lies on the upper bound of the 95% PI (Figure 2, panel F).", "Top", "Discussion", "We aimed to identify locations with likely undetected or underdetected imported cases of SARS-CoV-2 by fitting a model to the case counts in locations with high surveillance capacity and Wuhan-to-location air travel volumes. Our model can be adjusted to account for exportation of cases from locations other than Wuhan as the outbreak develops and more information on importations and self-sustained transmission becomes available. One key advantage of this model is that it does not rely on estimates of incidence or prevalence in the epicenter of the outbreak. Also, we intentionally used a simple generalized linear model. The linearity of the expected case count means that we have only 1 regression coefficient in the model and no extra parameters. The Poisson likelihood then captures the many 0-counts observed for less highly connected locations but also describes the slope between case-count and flight data among more connected locations. We believe this model provides the most", "parsimonious phenomenologic description of the data.", "According to our model, locations above the 95% PI of imported-and-reported cases could have higher case-detection capacity. Locations below the 95% PI might have undetected cases because of expected imported-and-reported case counts under high surveillance. Underdetection of cases could increase the international spread of the outbreak because the transmission chain could be lost, reducing opportunities to deploy case-based control strategies. We recommend rapid strengthening of outbreak surveillance and control efforts in locations below the 95% PI lower bound, particularly Indonesia, to curb potential local transmission. Early detection of cases and implantation of appropriate control measures can reduce the risk for self-sustained transmission in all locations.\n\nTop", "Dr. De Salazar is a research fellow at Harvard T.H. Chan School of Public Health, working on multiscale statistical models of infectious diseases within host, population, and metapopulation models. His research interests include diagnostic laboratory methods and public health response.\n\nTop\n\nAcknowledgments\nWe thank Pamela Martinez, Nicholas Jewel, and Stephen Kissler for valuable feedback.\n\nThis work was supported by US National Institute of General Medical Sciences (award no. U54GM088558). P.M.D was supported by the Fellowship Foundation Ramon Areces. A.R.T. and C.O.B. were supported by a Maximizing Investigator’s Research Award (no. R35GM124715-02) from the US National Institute of General Medical Sciences.\n\nThe authors are solely responsible for this content and it does not necessarily represent the official views of the National Institute of General Medical Sciences or the National Institutes of Health.", "Declaration of interests: Marc Lipsitch has received consulting fees from Merck. All other authors declare no competing interests.\n\nTop", "References\nZhou P, Yang XL, Wang XG, Hu B, Zhang L, Zhang W, et al. A pneumonia outbreak associated with a new coronavirus of probable bat origin. Nature. 2020;579:270–3.\nWu JT, Leung K, Leung GM. Nowcasting and forecasting the potential domestic and international spread of the 2019-nCoV outbreak originating in Wuhan, China: a modelling study. Lancet. 2020;395:689–97. DOIExternal LinkPubMedExternal Link\nWorld Health Organization. Coronavirus disease 2019 (COVID-19) situation report—15, 4 Feb 2020 [cited 2020 Feb 14]. https://www.who.int/docs/default-source/coronaviruse/situation-reports/20200204-sitrep-15-ncov.pdfExternal Link\nNuclear Threat Initiative and Johns Hopkins Center for Health Security. Global health security index [cited 2020 Feb 14]. https://www.ghsindex.orgExternal Link", "US Environmental Protection Agency. Data quality assessment: statistical methods for practitioners EPA QA/G9-S [cited 2020 Feb 14]. Washington: The Agency; 2006. https://www.epa.gov/sites/production/files/2015-08/documents/g9s-final.pdfExternal Link\nLamichhane S, Sen P, Dickens AM, Hyötyläinen T, Orešič M. An overview of metabolomics data analysis: current tools and future perspectives. In: Jaumot J, Bedia C, Tauler R, editors. Comprehensive analytical chemistry. Vol. 82. Amsterdam: Elsevier; 2018. p. 387–413.\nGelman A, Hill J. Analytical methods for social research. In: Data analysis using regression and multilevel/hierarchical models. Cambridge: Cambridge University Press; 2006. p. 235–236.\nWickham H. ggplot2: elegant graphics for data analysis. New York: Springer; 2016.\nTop", "Figures\nFigure 1. Regression plot of locations with possible undetected imported cases of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by air travel volume from Wuhan, China. Air travel volume measured in...\nFigure 2. Analyses of imported-and-reported cases and daily air travel volume using a model to predict locations with potentially undetected cases of severe acute respiratory virus 2 (SARS-CoV-2). Air travel volume...\nTable\nTable. Surveillance capacity of locations with and without imported-and-reported cases of severe acute respiratory syndrome coronavirus 2, 2020\nTop\n\nSuggested citation for this article: De Salazar PM, Niehus R, Taylor A, O’Flaherty Buckee C, Lipsitch M. Identifying locations with possible undetected imported severe acute respiratory syndrome coronavirus 2 cases by using importation predictions. Emerg Infect Dis. 2020 Jul [date cited]. https://doi.org/10.3201/eid2607.200250\n\nDOI: 10.3201/eid2607.200250\n\nOriginal Publication Date: 3/24/2020", "1These authors contributed equally to this article.\n\nTable of Contents – Volume 26, Number 7—July 2020" ]	[ 2 ]	2,548	3,863
2,527	What is PHEIC?	1,238	[ "Public Health Emergency of International Concern'" ]	[ "On the Coronavirus (COVID-19) Outbreak and the Smart City Network: Universal Data Sharing Standards Coupled with Artificial Intelligence (AI) to Benefit Urban Health Monitoring and Management\n\nhttps://doi.org/10.3390/healthcare8010046\n\nSHA: 90d04764b497a224a1d969f4e317fc19a5feab35\n\nAuthors: Allam, Zaheer; Jones, David S.\nDate: 2020\nDOI: 10.3390/healthcare8010046\nLicense: cc-by", "Abstract: As the Coronavirus (COVID-19) expands its impact from China, expanding its catchment into surrounding regions and other countries, increased national and international measures are being taken to contain the outbreak. The placing of entire cities in ‘lockdown’ directly affects urban economies on a multi-lateral level, including from social and economic standpoints. This is being emphasised as the outbreak gains ground in other countries, leading towards a global health emergency, and as global collaboration is sought in numerous quarters. However, while effective protocols in regard to the sharing of health data is emphasised, urban data, on the other hand, specifically relating to urban health and safe city concepts, is still viewed from a nationalist perspective as solely benefiting a nation’s economy and its economic and political influence. This perspective paper, written one month after detection and during the outbreak, surveys the virus outbreak from an urban", "standpoint and advances how smart city networks should work towards enhancing standardization protocols for increased data sharing in the event of outbreaks or disasters, leading to better global understanding and management of the same.", "Text: The novel Coronavirus outbreak, (previously known as the 2019-nCoV and later renamed COVID-19 during the writing of this manuscript) is leading to the closure of entire cities in China, and causing stringent measures to be taken in others. While in distant different continents, far from China where the virus was first reported, places are being placed on high alert. In Wuhan, where the virus broke, schools, roads and markets have been shut down [1] . The same is true in Hong Kong, Beijing and Hubei Province amongst surrounding areas, as precautionary measures are being emphasized to ensure that the spread of the virus is minimized, and complete and accurate information on the virus is being obtained [2] . However, the rate of spread of the virus and the uncertainties surrounding the entire situation has led the World Health Organization (WHO) on 30 January 2019 to declare the Coronavirus outbreak a 'Global Public Health Emergency'. WHO determined, however, not to declare the", "outbreak a 'Public Health Emergency of International Concern' (PHEIC) which is a higher level of declaration. A PHEIC is defined as \"an extraordinary event which is determined to constitute a public health risk to other States through the international spread of disease and to potentially require a coordinated international response\" whose scope may include: serious, sudden, unusual or unexpected; carries implications for public health beyond the affected State's national border; and may require immediate international action [3] .", "With the world having experienced some notable influenza pandemics in the past, a Global Initiative on Sharing All Influenza Data (GISAID) platform [4] was established and was instrumental in the rapid sharing of information by the Chinese scientists regarding the emergence of the COVID-19 virus. Through this platform, scientists from other regions were observed to gain access to information and are, subsequently, able to act in a much faster capacity; like in the case of scientists from the Virus Identification Laboratory based at Doherty Institute, Australia, who managed to grow a similar virus in the laboratory after accessing the data shared by the Chinese scientists [5] .", "Beyond the aspect of pandemic preparedness and response, the case of COVID-19 virus and its spread provide a fascinating case study for the thematics of urban health. Here, as technological tools and laboratories around the world share data and collectively work to devise tools and cures, similar efforts should be considered between smart city professionals on how collaborative strategies could allow for the maximization of public safety on such and similar scenarios. This is valid as smart cities host a rich array of technological products [6, 7] that can assist in early detection of outbreaks; either through thermal cameras or Internet of Things (IoT) sensors, and early discussions could render efforts towards better management of similar situations in case of future potential outbreaks, and to improve the health fabric of cities generally. While thermal cameras are not sufficient on their own for the detection of pandemics -like the case of the COVID-19, the integration of such", "products with artificial intelligence (AI) can provide added benefits. The fact that initial screenings of temperature is being pursued for the case of the COVID-19 at airports and in areas of mass convergence is a testament to its potential in an automated fashion. Kamel Boulos et al. [8] supports that data from various technological products can help enrich health databases, provide more accurate, efficient, comprehensive and real-time information on outbreaks and their dispersal, thus aiding in the provision of better urban fabric risk management decisions.", "The above improvements in the healthcare sector can only be achieved if different smart city products are fashioned to support standardized protocols that would allow for seamless communication between themselves. Weber and Podnar Žarko [9] suggest that IoT devices in use should support open protocols, and at the same time, the device provider should ensure that those fashioned uphold data integrity and safety during communication and transmission. Unfortunately, this has not been the case and, as Vermesan and Friess [10] explain, most smart city products use proprietary solutions that are only understood by the service providers. This situation often creates unnecessary fragmentation of information rendering only a partial integrated view on the dynamics of the urban realm. With restricted knowledge on emergent trends, urban managers cannot effectively take decisions to contain outbreaks and adequately act without compromising the social and economic integrity of their city. This", "paper, inspired by the case of the COVID-19 virus, explores how urban resilience can be further achieved, and outlines the importance of seeking standardization of communication across and between smart cities.", "With the advent of the digital age and the plethora of Internet of Things (IoT) devices it brings, there has been a substantial rise in the amount of data gathered by these devices in different sectors like transport, environment, entertainment, sport and health sectors, amongst others [11] . To put this into perspective, it is believed that by the end of 2020, over 2314 exabytes (1 exabyte = 1 billion gigabytes) of data will be generated globally [12] from the health sector. Stanford Medicine [12] acknowledges that this increase, especially in the medical field, is witnessing a proportional increase due to the increase in sources of data that are not limited to hospital records. Rather, the increase is being underpinned by drawing upon a myriad and increasing number of IoT smart devices, that are projected to exponentially increase the global healthcare market to a value of more than USD $543.3 billion by 2025 [13] . However, while the potential for the data market is understood,", "such issues like privacy of information, data protection and sharing, and obligatory requirements of healthcare management and monitoring, among others, are critical. Moreover, in the present case of the Coronavirus outbreak, this ought to be handled with care to avoid jeopardizing efforts already in place to combat the pandemic. On the foremost, since these cut across different countries, which are part of the global community and have their unique laws and regulations concerning issues mentioned above, it is paramount to observe them as per the dictate of their source country's laws and regulations; hence, underlining the importance of working towards not only the promoting of data through its usage but also the need for standardized and universally agreed protocols.", "While the significance of such data in advancing efficiency, productivity and processes in different sectors is being lauded, there are criticisms arising as to the nature of data collection, storage, management and accessibility by only a small group of users. The latter particularly includes select ICT corporations that are also located in specific geographies [6, [14] [15] [16] [17] . These criticisms are justified, as in recent years, big data is seen as the new 'gold rush' of the 21st century and limiting its access means higher economic returns and increased influence and control at various scales to those who control data. These associated benefits with big data are clearly influencing geopolitical standings, in both corporate and conventional governance realms, and there is increased competition between powerful economies to ensure that they have the maximum control of big data. As case in point is the amount of 'push and pull' that has arisen from Huawei's 5G internet planned", "rollout [18] . Though the latter service offers unprecedented opportunities to increase internet speeds, and thereby influence the handling of big data, countries like the U.S. and some European countries that are key proponents and players in global political, economic and health landscapes, are against this rollout, arguing that it is a deceptive way of gathering private data under the guise of espionage. On this, it has been noted that the issue of data control and handling by a few corporations accords with their principles of nationalism, and that these work for their own wellbeing as well as to benefit the territories they are registered in. Therefore, geopolitical issues are expected on the technological front as most large data-rich corporations are located in powerful countries that have influence both economically, health-wise and politically [19] [20] [21] . Such are deemed prized tokens on the international landscape, and it is expected that these economies will continue", "to work towards their predominant control as much as possible. On the health sector, the same approach is being upheld where critical information and data are not freely shared between economies as that would be seen to be benefiting other in-competition economies, whereas different economies would cherish the maximization of benefits from such data collections.", "In addition to the obvious deep-rooted social issues related to nationalism, other challenges include the increasing movement of people globally that is being enhanced by reduced costs and higher speed. In particular, these challenges are more pronounced when it comes to public health. This is because most of the health-related data collected not only can compromise local nations, but also captures those of travelers. In such cases, in a bid to improve the health status of a nation, it becomes paramount to factor in data from other regions necessitating unhindered sharing of this data.", "Such data-sharing truth is emphasized in situations like the recent case of Coronavirus outbreak threatening the global health environment, facilitated by air transportation. The virus was first reported in Wuhan, China, and in a matter of three weeks (by 17th January 2020) over 300 cases were confirmed in that region, and 10 days later (26th January 2020), a total of 2014 cases of Coronavirus have been reported, with 684 of those being confirmed, and with 29 reported outside China. The fatalities from the virus stands at 56 as of 26th January 2020 [22] . The virus had then been confirmed in various countries including Taiwan, South Korea, Japan, Thailand, France, the United States, Singapore and Vietnam [23] .", "In the above case, though major cities are known to prepare themselves for potential outbreaks, their health policies and protocols are observed to diverge from one another. Thus, without a global collaborative approach, progress towards working for a cure and universally acceptable policy approach can take longer. Such fears, of a lack of international collaboration, were highlighted by the World Health Organization (WHO) during an emergency meeting in Geneva on 22nd January 2020 to determine whether the virus outbreak had reached a level warranting international emergency concern. However, WHO was satisfied that China was being proactive in this case, unlike in 2002, when China withheld information on the outbreak for far too long, causing delays in addressing the epidemic [3] . As in this instance, it is the opinion in this paper that if there was seamless collaboration and seamless sharing of data between different cities, it would not warrant such a high-level meeting to result", "in action, and instead, a decision could have been made much earlier. On this, the saddest part is that some global cities are less prepared to handle the challenges posed by this type of outbreak for lack of information on issues like symptoms of the virus, the protective measures to be taken, and the treatment procedures that an infected person should be processed through, amongst other issues.", "The timely response by stakeholders in regard to this new outbreak are commendable compared to previous cases. The latter includes the Severe Acute Respiratory Syndrome (SARS) outbreak in 2002 that took substantial time (from November 2002 to April 2003) to identify and be dealt with [24] ; the Ebola outbreak in West Africa in 2013 that took months to determine; and the Zika Virus that was first reported in 2014 before being successfully identified in 2015.", "With the Coronavirus (COVID-19) , it took only 17 days (31st December 2019 to 17th January 2020) to be identified. The sharing of data has also been quicker, as immediately after the virus' genetic sequence was discovered, Chinese scientists were able to share the information with the WHO, thus helping in its identification and enabling the auctioning of precautionary measures in other countries. Latest technological tools have also allowed for the receipt of information in realtime, in contrast to traditional epidemiological approaches that would have required months to identify the outbreak type [25] . Similarly, though substantial data and information on the disease has been shared, Wetsman [26] acknowledges that there is a lack of some vital information, like the ease of spread of the virus from person-to-person, and this is a key to containing the disease as interactions between people from different parts of the globe are still active. This hindrance can be made further possible", "as many cities advance in their smart and safe city model implementation towards constructing sufficient soft and hard urban infrastructures equipped with, for example, thermal imagery sensors to allow for early detections. However, while that is the case, data access to many is a challenge because the information is often seen as being sensitive for national security reasons, whilst at the same time, acknowledging that a virus outbreak is an equal threat to both national security and the economy.", "The outbreak of any disease has significant impacts on local economies across the globe. For instance, when SARS (Severe Acute Respiratory Syndrome) (SARS-CoV) broke in China in 2002, it was estimated, that the Asian region incurred tremendous negative impacts socially, health-wise and economically, potentially amounting to Asian regional economy losses of between USD $12-18 billion from tourism, travel and retail sales industries alone [27] . The Zika virus outbreak, spread by daytime-active Aedes mosquitoes, is estimated to have cost equator-belt local economies in affected areas between USD $7 and USD $18 billion [28] . The Ebola virus (or Ebola hemorrhagic fever (EHF)) caused an estimated loss of USD $2.2 billion in GDP in three West African economies (Guinea, Liberia and Sierra Leone) in 2015 alone [29] . In regard to the current epidemic of Coronavirus, though it is too early to quantify or project its impacts on the global economy, there are fears that it may take the precedent", "of other outbreaks where billions of dollars will be lost. The foundations for this escalating loss can be witnessed in the rapid growth of travel bans being enacted by some countries and their international airports, especially specifically restricting people from visiting the affected regions in China and their growth into general non-Chinese travel movements. On this, noting that the outbreak came almost on the eve of the Lunar New Year celebrations, and that it had been estimated that over 400 million people were expected to travel in different parts of the world and China to observe this festivity, the majority have had to reconsider their options as to flights, hotels and entertainment events due to service provider cancellations [30] . Those who had already booked their flights are expected to receive their refunds following the directive by the Civil Aviation Administration of China, however, this move has already affected the share value of Chinese airline companies [30] .", "The above impacts demonstrate that the issues of virus outbreaks transcend urban safety and impacts upon all other facets of our urban fabric. Therefore, it becomes paramount to ensure that the measures taken to contain a virus transcend nationalist agendas where data and information sharing is normally restricted, to a more global agenda where humanity and global order are encouraged. With such an approach, it would be easier to share urban health data across geographies to better monitor emerging health threats in order to provide more economic stability, thereby ensuring no disruptions on such sectors like tourism and travel industries, amongst others. This is possible by ensuring collaborative, proactive measures to control outbreak spread and thus, human movements. This would remove fears on travelers, and would have positive impacts upon the tourism industry, that has been seen to bear the economic brunt whenever such outbreaks occur. This can be achieved by ensuring that", "protocols on data sharing are calibrated to remove all hurdles pertaining to sharing of information. On this, Lawpoolsri et al. [31] posits that such issues, like transparency, timelessness of sharing and access and quality of data, should be upheld so that continuous monitoring and assessment can be pursued.", "Virus outbreaks in recent years have shown that, in the urban realm, data, including health data, can be sourced from diverse places. Presently, in the case of Coronavirus (COVID-19) outbreak, data is being collected from airports through screening and monitoring, through the use of smart sensors installed in airport infrastructures and from personnel working in those air/seaports. For instance, it has been reported that in the U.S.A., screening is being carried out at 20 different airports to ensure that possible affected people are intercepted for quarantine at the point of entry. Beside airports, as reported by Buckley and May [2] , data is also being collected at bus terminals, market places (in Wuhan), subways, and also in health facilities where patients are taken for further medical attention. Such is prevalent especially in China, and other Asian regions where cases of the virus have been recorded and confirmed.", "In addition to these methods, other smart city data sources include the application of terminal tracking systems that are mostly emphasized in Safe City concepts, where, at the point of entry or departure, relevant data is collected and analyzed. Li et al. [32] highlights that sensors installed in such locations have the potential to receive and distribute data in real-time to digital infrastructures within the network, and their interconnectedness in the network renders them extremely efficient in providing real-time updates on different issues. Urban areas are also known to be amassed with numerous Urban Health sensors, some of which are wearable. Though these are not specifically fashioned to track the present case of virus outbreak, they are able to track other related parameters like heartbeat, blood pressure, body temperature and others variables, that when analyzed can offer valuable insights. Loncar-Turukalo et al. [33] hail these devices for their role in transforming the", "health care sector especially by allowing for Connected Health (CH) care, where data collected from them can be analyzed and provide insightful information on the health scenario in any given area. Vashist et al. [34] further highlight how emerging features such as spatiotemporal mapping, remote monitoring and management, and enhanced cloud computing capabilities can emanate from such endeavours, leading to better urban management potential.", "While it is true that the basic source of medical data is generally sourced from general practitioners or medical laboratories-a fact that has also been affirmed in the case of the current epidemic-this paper explores how data sourced from an urban perspective can contribute to the medical narrative. The conviction to dwell on the urban realm in this manuscript is based on the fact that the current epidemic (COVID-19) is transmitted majorly through human-to-human contact, and in most cases, especially where the spread is reported in a different country, the first point of contact is an urban area, where large groups of people convene, like airports or subway stations. In most cases, such facilities, which are mostly based in urban areas, are observed to have installed surveillance technologies to ensure that anyone showing any symptoms of the disease are identified and quarantined. However, even in such cases, as underlined in the present manuscript, the need for anonymizing medical", "data is emphasized to ensure that the use of current technologies does not breach data privacy and security requirements, across different geographies. In this case, novel technologies like Blockchain technologies and quantum cryptography can aid in the discussion and be made to integrate with data collecting technologies. This would render an increased wealth of data from both the medical field and smart city operators, while ensuring privacy and security; hence, aiding in providing relevant information for better informed decisions.", "However, despite the indisputable roles that installed devices play in providing relevant health information, their data communication aspect needs to be reviewed. First, communications are seen to be geography-restricted (restricted to a given location), such that they seldom expand or communicate with their like, installed beyond their restricted areas. Secondly, these devices are usually sourced and installed by separate corporations that maintain unique and specific standards for data processing and sharing, and accordingly, tying cities to the sole usage of their product(s). Such strategies are adopted as private corporations try to maximize their economic gains, since the digital solution market is a lucrative one and is expected to continue growing and expanding [6, 7] .", "For its current application, the standardization of protocols as elaborated in this manuscript need to be pursued to ensure that there is seamless sharing of information and data. By doing this, it is expected that issues like burdens of collecting data, accuracy and other complexity that are experienced (when systems are fragmented) are reduced or eliminated altogether. The standardization can be achieved by, for example, ensuring that all the devices and systems are linked into a single network, like was done in the U.S., where all the surveillance of healthcare were combined into the National Healthcare Safety Network (NHSH) [35] . The fact that cities are increasingly tuning on the concept of Smart Cities and boasting an increased adoption rate of technological and connected products, existing surveillance networks can be re-calibrated to make use of those new sets of databases. Appropriate protocols however have to be drafted to ensure effective actions while ensuring privacy and", "security of data and people.", "With scenarios like the present Coronavirus (COVID-19) outbreak, that not only impacts upon the economic status of cities, but also affects their social standing, it becomes imperative to emphasize the adoption of universal standards for data sharing. Such a move could have far reaching impact across cities and territories especially in positively combating outbreaks and disasters in a quicker, safer and standardized way, such that when the cure is discovered, the results can be replicated in various parts of the globe. With a collaborated data sharing protocol, it would be possible to have a larger dataset resulting in increased processing capabilities especially with technologies that are powered by artificial intelligence (AI) tools. Through this way, as noted by Jiang et al. [36] and Allam [37] , it would be possible to facilitate early detection, achieve better diagnosis and provide better urban management decisions for increased efficiency for virus containment.", "An example of how beneficial collaboration and sharing of data can be occurred during the 2014 Ebola outbreak in West Africa where scientists, health workers and clinicians, amongst other stakeholders from around the world, openly worked together and were able to contain the spread of this pandemic [38] . On this front, Boué et al. [39] highlight that levels of trust and transparency need to be reviewed and enhanced to facilitate unfettered data generation and sharing. Such could lead to an even earlier detection scenario of future virus outbreaks, and in the better curative management of the same, without minimal compromise on urban functions and on an urban economy.", "Furthermore, in cases of emergencies like the current outbreak of COVID-19 and any other, the need for observance of regulatory practices and international healthcare guidelines are paramount. This would ensure that both healthcare professionals and the general populace are informed, protected and remain within the prescribed rules and regulations. As noted by the WHO [40] , the healthcare guidelines and regulatory practices are advanced to also ensure that the health risk in question is reduced together with its consequences. In the current era of technological advancement, such regulations and guidelines are paramount as they have potential to lead to positive or negative outcomes. The position of this paper is to advance that it now possible to integrate technologies like the use of smart devices through IoT networks and wearable devices, data from mobile apps and others to help users to share information with accredited and certified health professionals, and in this case, improve", "the outcomes for better cross disciplinary and more resilient protocols and policies." ]	[ 4 ]	4,173	5,172
2,527	How is PHEIC defined?	1,239	[ "an extraordinary event which is determined to constitute a public health risk to other States through the international spread of disease and to potentially require a coordinated international response" ]	[ "On the Coronavirus (COVID-19) Outbreak and the Smart City Network: Universal Data Sharing Standards Coupled with Artificial Intelligence (AI) to Benefit Urban Health Monitoring and Management\n\nhttps://doi.org/10.3390/healthcare8010046\n\nSHA: 90d04764b497a224a1d969f4e317fc19a5feab35\n\nAuthors: Allam, Zaheer; Jones, David S.\nDate: 2020\nDOI: 10.3390/healthcare8010046\nLicense: cc-by", "Abstract: As the Coronavirus (COVID-19) expands its impact from China, expanding its catchment into surrounding regions and other countries, increased national and international measures are being taken to contain the outbreak. The placing of entire cities in ‘lockdown’ directly affects urban economies on a multi-lateral level, including from social and economic standpoints. This is being emphasised as the outbreak gains ground in other countries, leading towards a global health emergency, and as global collaboration is sought in numerous quarters. However, while effective protocols in regard to the sharing of health data is emphasised, urban data, on the other hand, specifically relating to urban health and safe city concepts, is still viewed from a nationalist perspective as solely benefiting a nation’s economy and its economic and political influence. This perspective paper, written one month after detection and during the outbreak, surveys the virus outbreak from an urban", "standpoint and advances how smart city networks should work towards enhancing standardization protocols for increased data sharing in the event of outbreaks or disasters, leading to better global understanding and management of the same.", "Text: The novel Coronavirus outbreak, (previously known as the 2019-nCoV and later renamed COVID-19 during the writing of this manuscript) is leading to the closure of entire cities in China, and causing stringent measures to be taken in others. While in distant different continents, far from China where the virus was first reported, places are being placed on high alert. In Wuhan, where the virus broke, schools, roads and markets have been shut down [1] . The same is true in Hong Kong, Beijing and Hubei Province amongst surrounding areas, as precautionary measures are being emphasized to ensure that the spread of the virus is minimized, and complete and accurate information on the virus is being obtained [2] . However, the rate of spread of the virus and the uncertainties surrounding the entire situation has led the World Health Organization (WHO) on 30 January 2019 to declare the Coronavirus outbreak a 'Global Public Health Emergency'. WHO determined, however, not to declare the", "outbreak a 'Public Health Emergency of International Concern' (PHEIC) which is a higher level of declaration. A PHEIC is defined as \"an extraordinary event which is determined to constitute a public health risk to other States through the international spread of disease and to potentially require a coordinated international response\" whose scope may include: serious, sudden, unusual or unexpected; carries implications for public health beyond the affected State's national border; and may require immediate international action [3] .", "With the world having experienced some notable influenza pandemics in the past, a Global Initiative on Sharing All Influenza Data (GISAID) platform [4] was established and was instrumental in the rapid sharing of information by the Chinese scientists regarding the emergence of the COVID-19 virus. Through this platform, scientists from other regions were observed to gain access to information and are, subsequently, able to act in a much faster capacity; like in the case of scientists from the Virus Identification Laboratory based at Doherty Institute, Australia, who managed to grow a similar virus in the laboratory after accessing the data shared by the Chinese scientists [5] .", "Beyond the aspect of pandemic preparedness and response, the case of COVID-19 virus and its spread provide a fascinating case study for the thematics of urban health. Here, as technological tools and laboratories around the world share data and collectively work to devise tools and cures, similar efforts should be considered between smart city professionals on how collaborative strategies could allow for the maximization of public safety on such and similar scenarios. This is valid as smart cities host a rich array of technological products [6, 7] that can assist in early detection of outbreaks; either through thermal cameras or Internet of Things (IoT) sensors, and early discussions could render efforts towards better management of similar situations in case of future potential outbreaks, and to improve the health fabric of cities generally. While thermal cameras are not sufficient on their own for the detection of pandemics -like the case of the COVID-19, the integration of such", "products with artificial intelligence (AI) can provide added benefits. The fact that initial screenings of temperature is being pursued for the case of the COVID-19 at airports and in areas of mass convergence is a testament to its potential in an automated fashion. Kamel Boulos et al. [8] supports that data from various technological products can help enrich health databases, provide more accurate, efficient, comprehensive and real-time information on outbreaks and their dispersal, thus aiding in the provision of better urban fabric risk management decisions.", "The above improvements in the healthcare sector can only be achieved if different smart city products are fashioned to support standardized protocols that would allow for seamless communication between themselves. Weber and Podnar Žarko [9] suggest that IoT devices in use should support open protocols, and at the same time, the device provider should ensure that those fashioned uphold data integrity and safety during communication and transmission. Unfortunately, this has not been the case and, as Vermesan and Friess [10] explain, most smart city products use proprietary solutions that are only understood by the service providers. This situation often creates unnecessary fragmentation of information rendering only a partial integrated view on the dynamics of the urban realm. With restricted knowledge on emergent trends, urban managers cannot effectively take decisions to contain outbreaks and adequately act without compromising the social and economic integrity of their city. This", "paper, inspired by the case of the COVID-19 virus, explores how urban resilience can be further achieved, and outlines the importance of seeking standardization of communication across and between smart cities.", "With the advent of the digital age and the plethora of Internet of Things (IoT) devices it brings, there has been a substantial rise in the amount of data gathered by these devices in different sectors like transport, environment, entertainment, sport and health sectors, amongst others [11] . To put this into perspective, it is believed that by the end of 2020, over 2314 exabytes (1 exabyte = 1 billion gigabytes) of data will be generated globally [12] from the health sector. Stanford Medicine [12] acknowledges that this increase, especially in the medical field, is witnessing a proportional increase due to the increase in sources of data that are not limited to hospital records. Rather, the increase is being underpinned by drawing upon a myriad and increasing number of IoT smart devices, that are projected to exponentially increase the global healthcare market to a value of more than USD $543.3 billion by 2025 [13] . However, while the potential for the data market is understood,", "such issues like privacy of information, data protection and sharing, and obligatory requirements of healthcare management and monitoring, among others, are critical. Moreover, in the present case of the Coronavirus outbreak, this ought to be handled with care to avoid jeopardizing efforts already in place to combat the pandemic. On the foremost, since these cut across different countries, which are part of the global community and have their unique laws and regulations concerning issues mentioned above, it is paramount to observe them as per the dictate of their source country's laws and regulations; hence, underlining the importance of working towards not only the promoting of data through its usage but also the need for standardized and universally agreed protocols.", "While the significance of such data in advancing efficiency, productivity and processes in different sectors is being lauded, there are criticisms arising as to the nature of data collection, storage, management and accessibility by only a small group of users. The latter particularly includes select ICT corporations that are also located in specific geographies [6, [14] [15] [16] [17] . These criticisms are justified, as in recent years, big data is seen as the new 'gold rush' of the 21st century and limiting its access means higher economic returns and increased influence and control at various scales to those who control data. These associated benefits with big data are clearly influencing geopolitical standings, in both corporate and conventional governance realms, and there is increased competition between powerful economies to ensure that they have the maximum control of big data. As case in point is the amount of 'push and pull' that has arisen from Huawei's 5G internet planned", "rollout [18] . Though the latter service offers unprecedented opportunities to increase internet speeds, and thereby influence the handling of big data, countries like the U.S. and some European countries that are key proponents and players in global political, economic and health landscapes, are against this rollout, arguing that it is a deceptive way of gathering private data under the guise of espionage. On this, it has been noted that the issue of data control and handling by a few corporations accords with their principles of nationalism, and that these work for their own wellbeing as well as to benefit the territories they are registered in. Therefore, geopolitical issues are expected on the technological front as most large data-rich corporations are located in powerful countries that have influence both economically, health-wise and politically [19] [20] [21] . Such are deemed prized tokens on the international landscape, and it is expected that these economies will continue", "to work towards their predominant control as much as possible. On the health sector, the same approach is being upheld where critical information and data are not freely shared between economies as that would be seen to be benefiting other in-competition economies, whereas different economies would cherish the maximization of benefits from such data collections.", "In addition to the obvious deep-rooted social issues related to nationalism, other challenges include the increasing movement of people globally that is being enhanced by reduced costs and higher speed. In particular, these challenges are more pronounced when it comes to public health. This is because most of the health-related data collected not only can compromise local nations, but also captures those of travelers. In such cases, in a bid to improve the health status of a nation, it becomes paramount to factor in data from other regions necessitating unhindered sharing of this data.", "Such data-sharing truth is emphasized in situations like the recent case of Coronavirus outbreak threatening the global health environment, facilitated by air transportation. The virus was first reported in Wuhan, China, and in a matter of three weeks (by 17th January 2020) over 300 cases were confirmed in that region, and 10 days later (26th January 2020), a total of 2014 cases of Coronavirus have been reported, with 684 of those being confirmed, and with 29 reported outside China. The fatalities from the virus stands at 56 as of 26th January 2020 [22] . The virus had then been confirmed in various countries including Taiwan, South Korea, Japan, Thailand, France, the United States, Singapore and Vietnam [23] .", "In the above case, though major cities are known to prepare themselves for potential outbreaks, their health policies and protocols are observed to diverge from one another. Thus, without a global collaborative approach, progress towards working for a cure and universally acceptable policy approach can take longer. Such fears, of a lack of international collaboration, were highlighted by the World Health Organization (WHO) during an emergency meeting in Geneva on 22nd January 2020 to determine whether the virus outbreak had reached a level warranting international emergency concern. However, WHO was satisfied that China was being proactive in this case, unlike in 2002, when China withheld information on the outbreak for far too long, causing delays in addressing the epidemic [3] . As in this instance, it is the opinion in this paper that if there was seamless collaboration and seamless sharing of data between different cities, it would not warrant such a high-level meeting to result", "in action, and instead, a decision could have been made much earlier. On this, the saddest part is that some global cities are less prepared to handle the challenges posed by this type of outbreak for lack of information on issues like symptoms of the virus, the protective measures to be taken, and the treatment procedures that an infected person should be processed through, amongst other issues.", "The timely response by stakeholders in regard to this new outbreak are commendable compared to previous cases. The latter includes the Severe Acute Respiratory Syndrome (SARS) outbreak in 2002 that took substantial time (from November 2002 to April 2003) to identify and be dealt with [24] ; the Ebola outbreak in West Africa in 2013 that took months to determine; and the Zika Virus that was first reported in 2014 before being successfully identified in 2015.", "With the Coronavirus (COVID-19) , it took only 17 days (31st December 2019 to 17th January 2020) to be identified. The sharing of data has also been quicker, as immediately after the virus' genetic sequence was discovered, Chinese scientists were able to share the information with the WHO, thus helping in its identification and enabling the auctioning of precautionary measures in other countries. Latest technological tools have also allowed for the receipt of information in realtime, in contrast to traditional epidemiological approaches that would have required months to identify the outbreak type [25] . Similarly, though substantial data and information on the disease has been shared, Wetsman [26] acknowledges that there is a lack of some vital information, like the ease of spread of the virus from person-to-person, and this is a key to containing the disease as interactions between people from different parts of the globe are still active. This hindrance can be made further possible", "as many cities advance in their smart and safe city model implementation towards constructing sufficient soft and hard urban infrastructures equipped with, for example, thermal imagery sensors to allow for early detections. However, while that is the case, data access to many is a challenge because the information is often seen as being sensitive for national security reasons, whilst at the same time, acknowledging that a virus outbreak is an equal threat to both national security and the economy.", "The outbreak of any disease has significant impacts on local economies across the globe. For instance, when SARS (Severe Acute Respiratory Syndrome) (SARS-CoV) broke in China in 2002, it was estimated, that the Asian region incurred tremendous negative impacts socially, health-wise and economically, potentially amounting to Asian regional economy losses of between USD $12-18 billion from tourism, travel and retail sales industries alone [27] . The Zika virus outbreak, spread by daytime-active Aedes mosquitoes, is estimated to have cost equator-belt local economies in affected areas between USD $7 and USD $18 billion [28] . The Ebola virus (or Ebola hemorrhagic fever (EHF)) caused an estimated loss of USD $2.2 billion in GDP in three West African economies (Guinea, Liberia and Sierra Leone) in 2015 alone [29] . In regard to the current epidemic of Coronavirus, though it is too early to quantify or project its impacts on the global economy, there are fears that it may take the precedent", "of other outbreaks where billions of dollars will be lost. The foundations for this escalating loss can be witnessed in the rapid growth of travel bans being enacted by some countries and their international airports, especially specifically restricting people from visiting the affected regions in China and their growth into general non-Chinese travel movements. On this, noting that the outbreak came almost on the eve of the Lunar New Year celebrations, and that it had been estimated that over 400 million people were expected to travel in different parts of the world and China to observe this festivity, the majority have had to reconsider their options as to flights, hotels and entertainment events due to service provider cancellations [30] . Those who had already booked their flights are expected to receive their refunds following the directive by the Civil Aviation Administration of China, however, this move has already affected the share value of Chinese airline companies [30] .", "The above impacts demonstrate that the issues of virus outbreaks transcend urban safety and impacts upon all other facets of our urban fabric. Therefore, it becomes paramount to ensure that the measures taken to contain a virus transcend nationalist agendas where data and information sharing is normally restricted, to a more global agenda where humanity and global order are encouraged. With such an approach, it would be easier to share urban health data across geographies to better monitor emerging health threats in order to provide more economic stability, thereby ensuring no disruptions on such sectors like tourism and travel industries, amongst others. This is possible by ensuring collaborative, proactive measures to control outbreak spread and thus, human movements. This would remove fears on travelers, and would have positive impacts upon the tourism industry, that has been seen to bear the economic brunt whenever such outbreaks occur. This can be achieved by ensuring that", "protocols on data sharing are calibrated to remove all hurdles pertaining to sharing of information. On this, Lawpoolsri et al. [31] posits that such issues, like transparency, timelessness of sharing and access and quality of data, should be upheld so that continuous monitoring and assessment can be pursued.", "Virus outbreaks in recent years have shown that, in the urban realm, data, including health data, can be sourced from diverse places. Presently, in the case of Coronavirus (COVID-19) outbreak, data is being collected from airports through screening and monitoring, through the use of smart sensors installed in airport infrastructures and from personnel working in those air/seaports. For instance, it has been reported that in the U.S.A., screening is being carried out at 20 different airports to ensure that possible affected people are intercepted for quarantine at the point of entry. Beside airports, as reported by Buckley and May [2] , data is also being collected at bus terminals, market places (in Wuhan), subways, and also in health facilities where patients are taken for further medical attention. Such is prevalent especially in China, and other Asian regions where cases of the virus have been recorded and confirmed.", "In addition to these methods, other smart city data sources include the application of terminal tracking systems that are mostly emphasized in Safe City concepts, where, at the point of entry or departure, relevant data is collected and analyzed. Li et al. [32] highlights that sensors installed in such locations have the potential to receive and distribute data in real-time to digital infrastructures within the network, and their interconnectedness in the network renders them extremely efficient in providing real-time updates on different issues. Urban areas are also known to be amassed with numerous Urban Health sensors, some of which are wearable. Though these are not specifically fashioned to track the present case of virus outbreak, they are able to track other related parameters like heartbeat, blood pressure, body temperature and others variables, that when analyzed can offer valuable insights. Loncar-Turukalo et al. [33] hail these devices for their role in transforming the", "health care sector especially by allowing for Connected Health (CH) care, where data collected from them can be analyzed and provide insightful information on the health scenario in any given area. Vashist et al. [34] further highlight how emerging features such as spatiotemporal mapping, remote monitoring and management, and enhanced cloud computing capabilities can emanate from such endeavours, leading to better urban management potential.", "While it is true that the basic source of medical data is generally sourced from general practitioners or medical laboratories-a fact that has also been affirmed in the case of the current epidemic-this paper explores how data sourced from an urban perspective can contribute to the medical narrative. The conviction to dwell on the urban realm in this manuscript is based on the fact that the current epidemic (COVID-19) is transmitted majorly through human-to-human contact, and in most cases, especially where the spread is reported in a different country, the first point of contact is an urban area, where large groups of people convene, like airports or subway stations. In most cases, such facilities, which are mostly based in urban areas, are observed to have installed surveillance technologies to ensure that anyone showing any symptoms of the disease are identified and quarantined. However, even in such cases, as underlined in the present manuscript, the need for anonymizing medical", "data is emphasized to ensure that the use of current technologies does not breach data privacy and security requirements, across different geographies. In this case, novel technologies like Blockchain technologies and quantum cryptography can aid in the discussion and be made to integrate with data collecting technologies. This would render an increased wealth of data from both the medical field and smart city operators, while ensuring privacy and security; hence, aiding in providing relevant information for better informed decisions.", "However, despite the indisputable roles that installed devices play in providing relevant health information, their data communication aspect needs to be reviewed. First, communications are seen to be geography-restricted (restricted to a given location), such that they seldom expand or communicate with their like, installed beyond their restricted areas. Secondly, these devices are usually sourced and installed by separate corporations that maintain unique and specific standards for data processing and sharing, and accordingly, tying cities to the sole usage of their product(s). Such strategies are adopted as private corporations try to maximize their economic gains, since the digital solution market is a lucrative one and is expected to continue growing and expanding [6, 7] .", "For its current application, the standardization of protocols as elaborated in this manuscript need to be pursued to ensure that there is seamless sharing of information and data. By doing this, it is expected that issues like burdens of collecting data, accuracy and other complexity that are experienced (when systems are fragmented) are reduced or eliminated altogether. The standardization can be achieved by, for example, ensuring that all the devices and systems are linked into a single network, like was done in the U.S., where all the surveillance of healthcare were combined into the National Healthcare Safety Network (NHSH) [35] . The fact that cities are increasingly tuning on the concept of Smart Cities and boasting an increased adoption rate of technological and connected products, existing surveillance networks can be re-calibrated to make use of those new sets of databases. Appropriate protocols however have to be drafted to ensure effective actions while ensuring privacy and", "security of data and people.", "With scenarios like the present Coronavirus (COVID-19) outbreak, that not only impacts upon the economic status of cities, but also affects their social standing, it becomes imperative to emphasize the adoption of universal standards for data sharing. Such a move could have far reaching impact across cities and territories especially in positively combating outbreaks and disasters in a quicker, safer and standardized way, such that when the cure is discovered, the results can be replicated in various parts of the globe. With a collaborated data sharing protocol, it would be possible to have a larger dataset resulting in increased processing capabilities especially with technologies that are powered by artificial intelligence (AI) tools. Through this way, as noted by Jiang et al. [36] and Allam [37] , it would be possible to facilitate early detection, achieve better diagnosis and provide better urban management decisions for increased efficiency for virus containment.", "An example of how beneficial collaboration and sharing of data can be occurred during the 2014 Ebola outbreak in West Africa where scientists, health workers and clinicians, amongst other stakeholders from around the world, openly worked together and were able to contain the spread of this pandemic [38] . On this front, Boué et al. [39] highlight that levels of trust and transparency need to be reviewed and enhanced to facilitate unfettered data generation and sharing. Such could lead to an even earlier detection scenario of future virus outbreaks, and in the better curative management of the same, without minimal compromise on urban functions and on an urban economy.", "Furthermore, in cases of emergencies like the current outbreak of COVID-19 and any other, the need for observance of regulatory practices and international healthcare guidelines are paramount. This would ensure that both healthcare professionals and the general populace are informed, protected and remain within the prescribed rules and regulations. As noted by the WHO [40] , the healthcare guidelines and regulatory practices are advanced to also ensure that the health risk in question is reduced together with its consequences. In the current era of technological advancement, such regulations and guidelines are paramount as they have potential to lead to positive or negative outcomes. The position of this paper is to advance that it now possible to integrate technologies like the use of smart devices through IoT networks and wearable devices, data from mobile apps and others to help users to share information with accredited and certified health professionals, and in this case, improve", "the outcomes for better cross disciplinary and more resilient protocols and policies." ]	[ 4 ]	4,173	5,172
2,527	What platform was instrumental in rapid sharing of COVID-19 information?	1,240	[ "Global Initiative on Sharing All Influenza Data (GISAID)" ]	[ "On the Coronavirus (COVID-19) Outbreak and the Smart City Network: Universal Data Sharing Standards Coupled with Artificial Intelligence (AI) to Benefit Urban Health Monitoring and Management\n\nhttps://doi.org/10.3390/healthcare8010046\n\nSHA: 90d04764b497a224a1d969f4e317fc19a5feab35\n\nAuthors: Allam, Zaheer; Jones, David S.\nDate: 2020\nDOI: 10.3390/healthcare8010046\nLicense: cc-by", "Abstract: As the Coronavirus (COVID-19) expands its impact from China, expanding its catchment into surrounding regions and other countries, increased national and international measures are being taken to contain the outbreak. The placing of entire cities in ‘lockdown’ directly affects urban economies on a multi-lateral level, including from social and economic standpoints. This is being emphasised as the outbreak gains ground in other countries, leading towards a global health emergency, and as global collaboration is sought in numerous quarters. However, while effective protocols in regard to the sharing of health data is emphasised, urban data, on the other hand, specifically relating to urban health and safe city concepts, is still viewed from a nationalist perspective as solely benefiting a nation’s economy and its economic and political influence. This perspective paper, written one month after detection and during the outbreak, surveys the virus outbreak from an urban", "standpoint and advances how smart city networks should work towards enhancing standardization protocols for increased data sharing in the event of outbreaks or disasters, leading to better global understanding and management of the same.", "Text: The novel Coronavirus outbreak, (previously known as the 2019-nCoV and later renamed COVID-19 during the writing of this manuscript) is leading to the closure of entire cities in China, and causing stringent measures to be taken in others. While in distant different continents, far from China where the virus was first reported, places are being placed on high alert. In Wuhan, where the virus broke, schools, roads and markets have been shut down [1] . The same is true in Hong Kong, Beijing and Hubei Province amongst surrounding areas, as precautionary measures are being emphasized to ensure that the spread of the virus is minimized, and complete and accurate information on the virus is being obtained [2] . However, the rate of spread of the virus and the uncertainties surrounding the entire situation has led the World Health Organization (WHO) on 30 January 2019 to declare the Coronavirus outbreak a 'Global Public Health Emergency'. WHO determined, however, not to declare the", "outbreak a 'Public Health Emergency of International Concern' (PHEIC) which is a higher level of declaration. A PHEIC is defined as \"an extraordinary event which is determined to constitute a public health risk to other States through the international spread of disease and to potentially require a coordinated international response\" whose scope may include: serious, sudden, unusual or unexpected; carries implications for public health beyond the affected State's national border; and may require immediate international action [3] .", "With the world having experienced some notable influenza pandemics in the past, a Global Initiative on Sharing All Influenza Data (GISAID) platform [4] was established and was instrumental in the rapid sharing of information by the Chinese scientists regarding the emergence of the COVID-19 virus. Through this platform, scientists from other regions were observed to gain access to information and are, subsequently, able to act in a much faster capacity; like in the case of scientists from the Virus Identification Laboratory based at Doherty Institute, Australia, who managed to grow a similar virus in the laboratory after accessing the data shared by the Chinese scientists [5] .", "Beyond the aspect of pandemic preparedness and response, the case of COVID-19 virus and its spread provide a fascinating case study for the thematics of urban health. Here, as technological tools and laboratories around the world share data and collectively work to devise tools and cures, similar efforts should be considered between smart city professionals on how collaborative strategies could allow for the maximization of public safety on such and similar scenarios. This is valid as smart cities host a rich array of technological products [6, 7] that can assist in early detection of outbreaks; either through thermal cameras or Internet of Things (IoT) sensors, and early discussions could render efforts towards better management of similar situations in case of future potential outbreaks, and to improve the health fabric of cities generally. While thermal cameras are not sufficient on their own for the detection of pandemics -like the case of the COVID-19, the integration of such", "products with artificial intelligence (AI) can provide added benefits. The fact that initial screenings of temperature is being pursued for the case of the COVID-19 at airports and in areas of mass convergence is a testament to its potential in an automated fashion. Kamel Boulos et al. [8] supports that data from various technological products can help enrich health databases, provide more accurate, efficient, comprehensive and real-time information on outbreaks and their dispersal, thus aiding in the provision of better urban fabric risk management decisions.", "The above improvements in the healthcare sector can only be achieved if different smart city products are fashioned to support standardized protocols that would allow for seamless communication between themselves. Weber and Podnar Žarko [9] suggest that IoT devices in use should support open protocols, and at the same time, the device provider should ensure that those fashioned uphold data integrity and safety during communication and transmission. Unfortunately, this has not been the case and, as Vermesan and Friess [10] explain, most smart city products use proprietary solutions that are only understood by the service providers. This situation often creates unnecessary fragmentation of information rendering only a partial integrated view on the dynamics of the urban realm. With restricted knowledge on emergent trends, urban managers cannot effectively take decisions to contain outbreaks and adequately act without compromising the social and economic integrity of their city. This", "paper, inspired by the case of the COVID-19 virus, explores how urban resilience can be further achieved, and outlines the importance of seeking standardization of communication across and between smart cities.", "With the advent of the digital age and the plethora of Internet of Things (IoT) devices it brings, there has been a substantial rise in the amount of data gathered by these devices in different sectors like transport, environment, entertainment, sport and health sectors, amongst others [11] . To put this into perspective, it is believed that by the end of 2020, over 2314 exabytes (1 exabyte = 1 billion gigabytes) of data will be generated globally [12] from the health sector. Stanford Medicine [12] acknowledges that this increase, especially in the medical field, is witnessing a proportional increase due to the increase in sources of data that are not limited to hospital records. Rather, the increase is being underpinned by drawing upon a myriad and increasing number of IoT smart devices, that are projected to exponentially increase the global healthcare market to a value of more than USD $543.3 billion by 2025 [13] . However, while the potential for the data market is understood,", "such issues like privacy of information, data protection and sharing, and obligatory requirements of healthcare management and monitoring, among others, are critical. Moreover, in the present case of the Coronavirus outbreak, this ought to be handled with care to avoid jeopardizing efforts already in place to combat the pandemic. On the foremost, since these cut across different countries, which are part of the global community and have their unique laws and regulations concerning issues mentioned above, it is paramount to observe them as per the dictate of their source country's laws and regulations; hence, underlining the importance of working towards not only the promoting of data through its usage but also the need for standardized and universally agreed protocols.", "While the significance of such data in advancing efficiency, productivity and processes in different sectors is being lauded, there are criticisms arising as to the nature of data collection, storage, management and accessibility by only a small group of users. The latter particularly includes select ICT corporations that are also located in specific geographies [6, [14] [15] [16] [17] . These criticisms are justified, as in recent years, big data is seen as the new 'gold rush' of the 21st century and limiting its access means higher economic returns and increased influence and control at various scales to those who control data. These associated benefits with big data are clearly influencing geopolitical standings, in both corporate and conventional governance realms, and there is increased competition between powerful economies to ensure that they have the maximum control of big data. As case in point is the amount of 'push and pull' that has arisen from Huawei's 5G internet planned", "rollout [18] . Though the latter service offers unprecedented opportunities to increase internet speeds, and thereby influence the handling of big data, countries like the U.S. and some European countries that are key proponents and players in global political, economic and health landscapes, are against this rollout, arguing that it is a deceptive way of gathering private data under the guise of espionage. On this, it has been noted that the issue of data control and handling by a few corporations accords with their principles of nationalism, and that these work for their own wellbeing as well as to benefit the territories they are registered in. Therefore, geopolitical issues are expected on the technological front as most large data-rich corporations are located in powerful countries that have influence both economically, health-wise and politically [19] [20] [21] . Such are deemed prized tokens on the international landscape, and it is expected that these economies will continue", "to work towards their predominant control as much as possible. On the health sector, the same approach is being upheld where critical information and data are not freely shared between economies as that would be seen to be benefiting other in-competition economies, whereas different economies would cherish the maximization of benefits from such data collections.", "In addition to the obvious deep-rooted social issues related to nationalism, other challenges include the increasing movement of people globally that is being enhanced by reduced costs and higher speed. In particular, these challenges are more pronounced when it comes to public health. This is because most of the health-related data collected not only can compromise local nations, but also captures those of travelers. In such cases, in a bid to improve the health status of a nation, it becomes paramount to factor in data from other regions necessitating unhindered sharing of this data.", "Such data-sharing truth is emphasized in situations like the recent case of Coronavirus outbreak threatening the global health environment, facilitated by air transportation. The virus was first reported in Wuhan, China, and in a matter of three weeks (by 17th January 2020) over 300 cases were confirmed in that region, and 10 days later (26th January 2020), a total of 2014 cases of Coronavirus have been reported, with 684 of those being confirmed, and with 29 reported outside China. The fatalities from the virus stands at 56 as of 26th January 2020 [22] . The virus had then been confirmed in various countries including Taiwan, South Korea, Japan, Thailand, France, the United States, Singapore and Vietnam [23] .", "In the above case, though major cities are known to prepare themselves for potential outbreaks, their health policies and protocols are observed to diverge from one another. Thus, without a global collaborative approach, progress towards working for a cure and universally acceptable policy approach can take longer. Such fears, of a lack of international collaboration, were highlighted by the World Health Organization (WHO) during an emergency meeting in Geneva on 22nd January 2020 to determine whether the virus outbreak had reached a level warranting international emergency concern. However, WHO was satisfied that China was being proactive in this case, unlike in 2002, when China withheld information on the outbreak for far too long, causing delays in addressing the epidemic [3] . As in this instance, it is the opinion in this paper that if there was seamless collaboration and seamless sharing of data between different cities, it would not warrant such a high-level meeting to result", "in action, and instead, a decision could have been made much earlier. On this, the saddest part is that some global cities are less prepared to handle the challenges posed by this type of outbreak for lack of information on issues like symptoms of the virus, the protective measures to be taken, and the treatment procedures that an infected person should be processed through, amongst other issues.", "The timely response by stakeholders in regard to this new outbreak are commendable compared to previous cases. The latter includes the Severe Acute Respiratory Syndrome (SARS) outbreak in 2002 that took substantial time (from November 2002 to April 2003) to identify and be dealt with [24] ; the Ebola outbreak in West Africa in 2013 that took months to determine; and the Zika Virus that was first reported in 2014 before being successfully identified in 2015.", "With the Coronavirus (COVID-19) , it took only 17 days (31st December 2019 to 17th January 2020) to be identified. The sharing of data has also been quicker, as immediately after the virus' genetic sequence was discovered, Chinese scientists were able to share the information with the WHO, thus helping in its identification and enabling the auctioning of precautionary measures in other countries. Latest technological tools have also allowed for the receipt of information in realtime, in contrast to traditional epidemiological approaches that would have required months to identify the outbreak type [25] . Similarly, though substantial data and information on the disease has been shared, Wetsman [26] acknowledges that there is a lack of some vital information, like the ease of spread of the virus from person-to-person, and this is a key to containing the disease as interactions between people from different parts of the globe are still active. This hindrance can be made further possible", "as many cities advance in their smart and safe city model implementation towards constructing sufficient soft and hard urban infrastructures equipped with, for example, thermal imagery sensors to allow for early detections. However, while that is the case, data access to many is a challenge because the information is often seen as being sensitive for national security reasons, whilst at the same time, acknowledging that a virus outbreak is an equal threat to both national security and the economy.", "The outbreak of any disease has significant impacts on local economies across the globe. For instance, when SARS (Severe Acute Respiratory Syndrome) (SARS-CoV) broke in China in 2002, it was estimated, that the Asian region incurred tremendous negative impacts socially, health-wise and economically, potentially amounting to Asian regional economy losses of between USD $12-18 billion from tourism, travel and retail sales industries alone [27] . The Zika virus outbreak, spread by daytime-active Aedes mosquitoes, is estimated to have cost equator-belt local economies in affected areas between USD $7 and USD $18 billion [28] . The Ebola virus (or Ebola hemorrhagic fever (EHF)) caused an estimated loss of USD $2.2 billion in GDP in three West African economies (Guinea, Liberia and Sierra Leone) in 2015 alone [29] . In regard to the current epidemic of Coronavirus, though it is too early to quantify or project its impacts on the global economy, there are fears that it may take the precedent", "of other outbreaks where billions of dollars will be lost. The foundations for this escalating loss can be witnessed in the rapid growth of travel bans being enacted by some countries and their international airports, especially specifically restricting people from visiting the affected regions in China and their growth into general non-Chinese travel movements. On this, noting that the outbreak came almost on the eve of the Lunar New Year celebrations, and that it had been estimated that over 400 million people were expected to travel in different parts of the world and China to observe this festivity, the majority have had to reconsider their options as to flights, hotels and entertainment events due to service provider cancellations [30] . Those who had already booked their flights are expected to receive their refunds following the directive by the Civil Aviation Administration of China, however, this move has already affected the share value of Chinese airline companies [30] .", "The above impacts demonstrate that the issues of virus outbreaks transcend urban safety and impacts upon all other facets of our urban fabric. Therefore, it becomes paramount to ensure that the measures taken to contain a virus transcend nationalist agendas where data and information sharing is normally restricted, to a more global agenda where humanity and global order are encouraged. With such an approach, it would be easier to share urban health data across geographies to better monitor emerging health threats in order to provide more economic stability, thereby ensuring no disruptions on such sectors like tourism and travel industries, amongst others. This is possible by ensuring collaborative, proactive measures to control outbreak spread and thus, human movements. This would remove fears on travelers, and would have positive impacts upon the tourism industry, that has been seen to bear the economic brunt whenever such outbreaks occur. This can be achieved by ensuring that", "protocols on data sharing are calibrated to remove all hurdles pertaining to sharing of information. On this, Lawpoolsri et al. [31] posits that such issues, like transparency, timelessness of sharing and access and quality of data, should be upheld so that continuous monitoring and assessment can be pursued.", "Virus outbreaks in recent years have shown that, in the urban realm, data, including health data, can be sourced from diverse places. Presently, in the case of Coronavirus (COVID-19) outbreak, data is being collected from airports through screening and monitoring, through the use of smart sensors installed in airport infrastructures and from personnel working in those air/seaports. For instance, it has been reported that in the U.S.A., screening is being carried out at 20 different airports to ensure that possible affected people are intercepted for quarantine at the point of entry. Beside airports, as reported by Buckley and May [2] , data is also being collected at bus terminals, market places (in Wuhan), subways, and also in health facilities where patients are taken for further medical attention. Such is prevalent especially in China, and other Asian regions where cases of the virus have been recorded and confirmed.", "In addition to these methods, other smart city data sources include the application of terminal tracking systems that are mostly emphasized in Safe City concepts, where, at the point of entry or departure, relevant data is collected and analyzed. Li et al. [32] highlights that sensors installed in such locations have the potential to receive and distribute data in real-time to digital infrastructures within the network, and their interconnectedness in the network renders them extremely efficient in providing real-time updates on different issues. Urban areas are also known to be amassed with numerous Urban Health sensors, some of which are wearable. Though these are not specifically fashioned to track the present case of virus outbreak, they are able to track other related parameters like heartbeat, blood pressure, body temperature and others variables, that when analyzed can offer valuable insights. Loncar-Turukalo et al. [33] hail these devices for their role in transforming the", "health care sector especially by allowing for Connected Health (CH) care, where data collected from them can be analyzed and provide insightful information on the health scenario in any given area. Vashist et al. [34] further highlight how emerging features such as spatiotemporal mapping, remote monitoring and management, and enhanced cloud computing capabilities can emanate from such endeavours, leading to better urban management potential.", "While it is true that the basic source of medical data is generally sourced from general practitioners or medical laboratories-a fact that has also been affirmed in the case of the current epidemic-this paper explores how data sourced from an urban perspective can contribute to the medical narrative. The conviction to dwell on the urban realm in this manuscript is based on the fact that the current epidemic (COVID-19) is transmitted majorly through human-to-human contact, and in most cases, especially where the spread is reported in a different country, the first point of contact is an urban area, where large groups of people convene, like airports or subway stations. In most cases, such facilities, which are mostly based in urban areas, are observed to have installed surveillance technologies to ensure that anyone showing any symptoms of the disease are identified and quarantined. However, even in such cases, as underlined in the present manuscript, the need for anonymizing medical", "data is emphasized to ensure that the use of current technologies does not breach data privacy and security requirements, across different geographies. In this case, novel technologies like Blockchain technologies and quantum cryptography can aid in the discussion and be made to integrate with data collecting technologies. This would render an increased wealth of data from both the medical field and smart city operators, while ensuring privacy and security; hence, aiding in providing relevant information for better informed decisions.", "However, despite the indisputable roles that installed devices play in providing relevant health information, their data communication aspect needs to be reviewed. First, communications are seen to be geography-restricted (restricted to a given location), such that they seldom expand or communicate with their like, installed beyond their restricted areas. Secondly, these devices are usually sourced and installed by separate corporations that maintain unique and specific standards for data processing and sharing, and accordingly, tying cities to the sole usage of their product(s). Such strategies are adopted as private corporations try to maximize their economic gains, since the digital solution market is a lucrative one and is expected to continue growing and expanding [6, 7] .", "For its current application, the standardization of protocols as elaborated in this manuscript need to be pursued to ensure that there is seamless sharing of information and data. By doing this, it is expected that issues like burdens of collecting data, accuracy and other complexity that are experienced (when systems are fragmented) are reduced or eliminated altogether. The standardization can be achieved by, for example, ensuring that all the devices and systems are linked into a single network, like was done in the U.S., where all the surveillance of healthcare were combined into the National Healthcare Safety Network (NHSH) [35] . The fact that cities are increasingly tuning on the concept of Smart Cities and boasting an increased adoption rate of technological and connected products, existing surveillance networks can be re-calibrated to make use of those new sets of databases. Appropriate protocols however have to be drafted to ensure effective actions while ensuring privacy and", "security of data and people.", "With scenarios like the present Coronavirus (COVID-19) outbreak, that not only impacts upon the economic status of cities, but also affects their social standing, it becomes imperative to emphasize the adoption of universal standards for data sharing. Such a move could have far reaching impact across cities and territories especially in positively combating outbreaks and disasters in a quicker, safer and standardized way, such that when the cure is discovered, the results can be replicated in various parts of the globe. With a collaborated data sharing protocol, it would be possible to have a larger dataset resulting in increased processing capabilities especially with technologies that are powered by artificial intelligence (AI) tools. Through this way, as noted by Jiang et al. [36] and Allam [37] , it would be possible to facilitate early detection, achieve better diagnosis and provide better urban management decisions for increased efficiency for virus containment.", "An example of how beneficial collaboration and sharing of data can be occurred during the 2014 Ebola outbreak in West Africa where scientists, health workers and clinicians, amongst other stakeholders from around the world, openly worked together and were able to contain the spread of this pandemic [38] . On this front, Boué et al. [39] highlight that levels of trust and transparency need to be reviewed and enhanced to facilitate unfettered data generation and sharing. Such could lead to an even earlier detection scenario of future virus outbreaks, and in the better curative management of the same, without minimal compromise on urban functions and on an urban economy.", "Furthermore, in cases of emergencies like the current outbreak of COVID-19 and any other, the need for observance of regulatory practices and international healthcare guidelines are paramount. This would ensure that both healthcare professionals and the general populace are informed, protected and remain within the prescribed rules and regulations. As noted by the WHO [40] , the healthcare guidelines and regulatory practices are advanced to also ensure that the health risk in question is reduced together with its consequences. In the current era of technological advancement, such regulations and guidelines are paramount as they have potential to lead to positive or negative outcomes. The position of this paper is to advance that it now possible to integrate technologies like the use of smart devices through IoT networks and wearable devices, data from mobile apps and others to help users to share information with accredited and certified health professionals, and in this case, improve", "the outcomes for better cross disciplinary and more resilient protocols and policies." ]	[ 5 ]	4,173	5,172
188	What's the recommended procedure to disinfect at CT scanner after a COVID-19 exposure?	239	[ "The equipment in the contaminated area are wiped with\n2000mg/L chlorine-containing disinfectant. The DR and CT gantry in the contaminated\narea are wiped with 75% ethanol. The equipment in the buffer area is wiped with\n500-1000mg/L chlorine-containing disinfectant or alcohol-containing disposable\ndisinfectant wipes twice a day." ]	[ "The Battle Against Coronavirus Disease 2019 (COVID-19): Emergency Management\nand Infection Control in a Radiology Department\nhttps://www.jacr.org/article/S1546-1440(20)30285-4/pdf\nJournal Pre-proof\nZixing Huang, Shuang Zhao, Zhenlin Li, Weixia Chen, Lihong Zhao, Lipeng Deng, Bin\nSong\nPII: S1546-1440(20)30285-4\nDOI: https://doi.org/10.1016/j.jacr.2020.03.011\nReference: JACR 5139\nTo appear in: Journal of the American College of Radiology\nReceived Date: 24 February 2020\nRevised Date: 13 March 2020\nAccepted Date: 15 March 2020\nPlease cite this article as: Huang Z, Zhao S, Li Z, Chen W, Zhao L, Deng L, Song B, The Battle Against\nCoronavirus Disease 2019 (COVID-19): Emergency Management and Infection Control in a Radiology\nDepartment, Journal of the American College of Radiology (2020), doi: https://doi.org/10.1016/\nj.jacr.2020.03.011.\nThis is a PDF file of an article that has undergone enhancements after acceptance, such as the addition", "of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of\nrecord. This version will undergo additional copyediting, typesetting and review before it is published\nin its final form, but we are providing this version to give early visibility of the article. Please note that,\nduring the production process, errors may be discovered which could affect the content, and all legal\ndisclaimers that apply to the journal pertain.\n© 2020 Published by Elsevier Inc. on behalf of American College of Radiology\nThe Battle Against Coronavirus Disease 2019 (COVID-19): Emergency Management\nand Infection Control in a Radiology Department\nZixing Huang, Shuang Zhao, Zhenlin Li, Weixia Chen, Lihong Zhao, Lipeng Deng,\nBin Song\nDepartment of Radiology, West China Hospital, Sichuan University, Chengdu, China\n*Zixing Huang and Shuang Zhao contributed equally to this work as co-first author.\nCorresponding Author: Bin Song, MD", "Address: Department of Radiology, West China Hospital, Sichuan University.\nNo. 37, GUOXUE Alley, Chengdu, 610041, China\nTel.: (+86)28 85423680, Fax: (+86)28 85582944\nEmail: [email protected].\nAuthors’ contributions\nZXH: conceived the study and drafted the manuscript.\nZS: conceived the study and drafted the manuscript.\nZLL: The member of the emergency management and infection control team (EMICT)\nand was involved in the formulation of the measures.\nWXC: The member of the EMICT and was involved in the formulation of the\nmeasures.\nLHZ: The member of the EMICT and was involved in the formulation of the\nmeasures.\nLPD: The member of the EMICT and was involved in the formulation of the\nmeasures.\nBS: Leader of the EMICT, conceived the study and reviewed the manuscript.\nAll authors read and approved the final manuscript.\nThe authors declare no conflict of interest.\nThe authors declare that they had full access to all of the data in this study and the", "authors take complete responsibility for the integrity of the data and the accuracy of\nthe data analysis\n1\nThe Battle Against Novel Coronavirus Pneumonia (COVID-19): Emergency\nManagement and Infection Control in a Radiology Department\nAbstract\nObjective: To describe the strategy and the emergency management and infection control\nprocedure of our radiology department during the COVID-19 outbreak.\nMethods: We set up emergency management and sensing control teams. The team formulated\nvarious measures: reconfiguration of the radiology department, personal protection and training\nof staff, examination procedures for patients suspected of or confirmed with COVID-19 as well\nas patients without an exposure history or symptoms. Those with suspected or confirmed\nCOVID-19 infection were scanned in the designated fever-CT unit.\nResults: From January 21, 2020 to March 9, 2020, 3,083 people suspected of or confirmed with\nCOVID-19 underwent fever-CT examinations. Including initial examinations and", "reexaminations, the total number of fever-CT examinations numbered 3,340. As a result of our\nprecautions, none of the staff of the radiology department were infected with COVID-19.\nConclusion: Strategic planning and adequate protections can help protect patients and staff\nagainst a highly infectious disease while maintaining function at a high volume capacity.\nKeywords: Coronavirus, COVID-19, novel coronavirus pneumonia, infection control", "2\nIntroduction\nThe whole world has been closely focusing on an outbreak of respiratory disease caused by a\nnovel coronavirus that was first reported in Wuhan, China, on December 31, 2019, and that\ncontinues to spread. On February 11, 2020, the World Health Organization (WHO) named the\ndisease “coronavirus disease 2019” (COVID-19).\nAs of 24:00 on March 11, 2020, the National Health Commission (NHC) had received reports\nof 80,793 confirmed cases and 3,169 deaths on the Chinese mainland. There remain 14,831\nconfirmed cases (including 4,257 in serious condition) and 253 suspected cases still\nhospitalized. To date, 677,243 people have been identified as having had close contact with\ninfected patients of whom13,701 are under medical observation [1]. Outside China, 44,067\nlaboratory-confirmed cases and 1,440 deaths have occurred in 117 countries /territories/areas\naccording to the WHO [2]. COVID-19 poses significant threats to international health. Like the", "flu, COVID-19 is thought to spread mainly from person-to-person between people who are in\nclose contact with one another through respiratory droplets produced when an infected person\ncoughs or sneezes. In light of the infectious nature of this disease, healthcare workers are at\nhigh risk of infection of COVID-19. In China, healthcare workers account for 1,716 confirmed\ncases of COVID-19, including six deaths [3].\n Computed tomography (CT) can play a role in both diagnosing and categorizing\nCOVID-19 on the basis of case definitions issued by the WHO and the treatment guidelines\nfrom the NHC [4]. Suspected patients having the virus may undergo chest CT. Isolation and\nbarrier procedures are necessary to protect both the department staff and other patients in the\nhospital. Note should be made that due to overlap of imaging findings with other respiratory\n3\ndiseases, CT is not helpful as a screening tool. But it can help identify the degree of pulmonary\ninvolvement and disease course.", "Our hospital is a national regional medical center with 4,300 beds and a tertiary referral\ncenter in Sichuan province. The initial response started on January 21, 2020, after transmission\nof COVID-19 was confirmed to be human-to-human on January 20, 2020. The first suspected\ncase of COVID-19 in Sichuan province was reported on January 21, 2020. The Sichuan\nprovincial government immediately launched the first-level response to major public health\nemergencies. On the same day, our hospital was designated to care for Sichuan province\npatients with COVID-19.\nThis article describes the emergency management procedure of our radiology department\nfor situations involving severe infectious diseases, such as COVID-19, and the\ninfection-protection experience of the department staff.\nMethods\nThe hospital provided personal protective equipment (medical protective clothing,\nsurgical cap, N95 mask, gloves, face shields, and goggles) to all its healthcare staff, erected", "three medical tents (fever tents) for screening of fever cases in the parking lot of the emergency\ndepartment, planned an examination route and examination area for patients suspected of\nharboring the virus, and placed confirmed patients in an isolation ward. “Fever” was the\ncolloquial term used to designate suspected COVID-19 based on symptoms such as a fever or\nwith an epidemiological history of a potential exposure as well as those with confirmed\nCOVID-19 referred for treatment. Further, during outbreak, emergency and outpatient patients\n4\nwithout fever were asked for information such as epidemiological history and sent to fever tents\nas long as they met suspected criteria.\nThe radiology department has 65 diagnostic radiologists and 161 other staff members\n(trained technologists, nurses, engineers, and support staff). The equipment of the radiology\ndepartment includes 12 magnetic resonance (MR) scanners, 14 CT scanners, 15 digital", "subtraction angiography (DSA) systems, 32 sets of digital radiography (DR) systems\n(including nine mobile bedside DR sets), and 130 imaging diagnostic workstations for picture\narchiving and communication systems (PACS). Most of the equipment is distributed among\nfour buildings at the hospital main campus. 4 CT scanners, 4 MR scanners, 1 DR are located on\nthe first floor of the first inpatient building, and 9 DR and 8 DSA are located on the second\nfloor. 1 CT and 1 MR scanner are located in the third inpatient building. 1 CT and 1 MR scanner\nare located in the sixth inpatient building. 2 CT scanners, 2 MR scanners and 7 DSA are located\nin the technical building. The rest of the equipment is located in the seventh inpatient building\nin the branch campus.\nThe first inpatient building, located next to the emergency department, was reconfigured to\nhandle cases of COVID-19. Fever tents were set up by the emergency department in the", "emergency department parking lot to separate normal emergency patients from patients with\nsymptoms or exposure history suspicious of COVID-19. We established separate means of\naccess between fever tents and between the fever examination area of the radiology department\nto avoid cross-contamination.\nThe emergency management and infection control measures, as described below and\nimplemented in the radiology department during the outbreak, have been approved by the\n5\ninfection control committee of hospital. These measures are in accordance with relevant laws\nand regulations, in order to protect patients as well as the staff.\nRadiology Emergency Management and Infection Control Team (EMICT)\nThe radiology department director chaired the EMICT. Its members include the deputy\ndirector, chief technologist, head nurse, equipment engineer supervisor, and infection control\nnurse of the radiology department. Team responsibilities included (1) coordination between the", "hospital’s management and planning of infection control and radiology departments; (2)\ncollection of the most up-to-date protection-related information to educate and train staff in the\ndepartment; (3) reallocation of staff according to the actual situation; (4) establishment of the\nCT procedures for patients with COVID-19; and (5) establishment of an emergency\nmanagement plan for the radiology department to ensure that the department would run\nnormally.\nSuspected patients\nThe suspected patients were identified according to the Diagnosis and Treatment Program of\nthe Novel Coronavirus Pneumonia of the NHC [5], mainly based on epidemiological history.\nReconfiguration of the radiology department\nThe radiology department was divided into four areas [6]: contaminated, semicontaminated,\nbuffer, and clean areas (Figure 1). The contaminated area is connected to the fever clinic and\nincludes the fever accessway, the CT examination room, and the DR examination room for\n6", "confirmed and suspected cases. One CT scanner and one DR system closest to the emergency\ndepartment are designated the fever-CT and fever-DR to examine patients with suspected and\nconfirmed COVID-19. There is a separate dedicated access between the contaminated area and\nthe fever screening tents. The semicontaminated area includes the fever-CT control room,\nfever-DR control room, and other patient examination access areas. The buffer zone includes\naccess areas for medical personnel and a dressing area for technologists. The clean area\nincludes the administrative office and the diagnostic room.\nThe contaminated area was isolated from other areas using physical barricades.\nDirectional signs were newly installed to guide patients and staff.\nPersonal protection and training of staff\nFor providing care for patients with confirmed and suspected COVID-19, all hospital staff\nare required to wear complete personal protective equipment [7]: medical protective clothing,", "surgical cap, N95 mask, gloves, face shields, and goggles. Wearing and removing of the\nequipment must be performed in accordance with the procedures and under the supervision of\nthe infection control nurse.\nBecause staff members working in the contaminated area are under much situational\npressure, periodically taking time off could lower their physical and mental stress levels. The\ntechnologists on fever-CT duty shifts are provided a break once a week for four hours. In\naddition, the health of staff in the contaminated area must be monitored closely for the\nsymptoms of COVID-19. Pregnant staff must be assigned to the clean area.\n7\nThe EMICT formulates and continually updates guidelines and educates all staff for West\nChina Hospital of Sichuan University. The EMICT training for staff is mainly involves\ndocuments regarding infection control and CT findings of COVID-19 and maintains an EMICT\nWeChat group for West China Hospital of Sichuan University. WeChat is the most widely used", "social media app in China. The EMICT releases the latest national and hospital-based\ninformation regarding COVID-19, guidance documents, and other notices from the hospital\nand radiology department in the WeChat group on a daily basis. Staff can also report to the\nEMICT in the WeChat group any time. Protocols for each modality and infection control\ninstructions are posted on the walls in all examination rooms. The EMICT periodically reminds\nstaff to undertake personal measures to reduce infection, such as wearing masks at all instances\nin the radiology department and N95 masks if working in the contaminated area; not touching\nthe mask and the eyes; practicing hand hygiene; facing away from colleagues when eating,\ndrinking, and talking; and not using personal cell phones while on duty.\n In addition, the chief thoracic radiologist provided lectures on all radiologists and\ntechnologists on typical CT findings of COVID-19 infection using materials developed in", "Wuhan, the epicenter of the outbreak in China.\nCT examination procedures\nThere are two sets of procedures for CT examination: the fever-CT procedure and routine CT\nprocedure for those not suspected of COVID-19.\nThe fever-CT procedure for suspected or confirmed COVID-19 (Figure 2)\n8\nBefore the fever-CT technologist operates the equipment, he or she should wear personal\nprotective equipment according to three-level protection standard [8]. Before the CT\nexamination of patients with suspected and confirmed COVID-19 begins, the fever tent or\nisolation ward notifies the radiologist in advance. The fever-CT technologist checks the\nequipment and prepares to disinfect the imaging equipment immediately after the examination.\nThe patient enters the fever-CT waiting area through the fever access area. If the patient\ncan get onto and off the examination table by themselves, the patient is allowed to do so. If the", "patient cannot get onto or off the examination table independently, the person accompanying\nthe patient assists the patient, rather than the technologist. The technologist checks the patient\ninformation and, using an intercom system in the examination room, asks the patient to remove\nany metal ornaments on the neck and chest. Also, by intercom, the technologist trains the\npatient to hold his or her breath during the examination.\nThe technologist uses a low-dose chest CT protocol to scan the patient. After scanning, the\noriginal images are reconstructed as 1 mm-thick layers. The technologist browses the images to\nensure that their quality meets the diagnostic requirements and then guides the patient to leave\nthrough the fever access area. The disposable sheets for patient examination are changed after\neach patient. The equipment is disinfected according to the procedure below.\nTo protect themselves, the technologists assigned to the fever-CT wear N95 mask and", "other personal protection as established by the EMICT.\nThe CT procedure for regular patients (figure.3)\n9\nSome patients with COVID-19 have no symptoms, and they may call at the general clinic for\nother reasons. The following CT procedure is applicable under these circumstances:\nWhen the patient makes an appointment for examination, the staff asks the patient about\ntheir epidemiological history, symptoms, and signs. If suspected criteria are met, the patient\nwill be sent to the fever tent for further screening. When a patient presents to the radiology\ndepartment entrance, his/her temperature is measured. If the temperature is higher than 37.2 , ℃\nthe patient is sent to the fever tent for further investigation.\nThose with no exposure history, suspicious symptoms or fever are screened in one of the\nnon-contaminated CT scanners. The technologists assigned to these scanners wear surgical\nmasks. All patients and the person accompanying them are required to wear surgical masks.", "After the CT examination, the technologist browses the images quickly. If the CT appearance is\ntypical of lung infection, the technologist immediately reports it to the chest radiologist on duty\nand asks the patient to wait in the CT examination room. If the chest radiologist does not\nsuspect COVID-19 infection, the patient can leave the CT examination room. If the chest\nradiologist does suspect COVID-19 infection, the technologist immediately reports it to the\nEMICT and sends the patient to the fever tent. The floor and equipment in the CT examination\nroom are disinfected according to regulations, and air disinfection is conducted for 30 min\nbefore examining other patients. These CT scanners are considered noncontaminated (not\nfever-CTs) after these sterilization procedures.\nFever-DR examination procedure\n10\nThe COVID-19 guideline of the NHC does not recommend chest DR because its ability in\ndiagnosing COVID-19 is limited. At our hospital, we only use mobile DR units to provide", "bedside examination for critically ill patients. The technologist operating the mobile DR\nwears personal protective equipment according to the three-level protection standard and\nsterilizes the mobile DR according to the ward management requirements as described below.\nEquipment and environment disinfection procedures\nRoutine disinfection procedure [9]\n1) Object surface disinfection: Object surface is wiped with 1000mg/L chlorine-containing\ndisinfectant, wipe twice with 75% ethanol for non-corrosion resistance, once /4 hours.\n2) Equipment disinfection: The equipment in the contaminated area are wiped with\n2000mg/L chlorine-containing disinfectant. The DR and CT gantry in the contaminated\narea are wiped with 75% ethanol. The equipment in the buffer area is wiped with\n500-1000mg/L chlorine-containing disinfectant or alcohol-containing disposable\ndisinfectant wipes twice a day.\n3) Air disinfection: Turning off all central air conditioners to prevent air contamination with", "each other. Polluted area: open the door for ventilation, each time more than 30 minutes,\nonce /4 hours; The air sterilizer is continuously sterilized or the ultraviolet ray is\ncontinuously used in the unmanned state for 60 minutes, four times a day, remembered to\nclose the inner shielding door when air disinfection. Other ambient air is sprayed with\n1000mg/L chlorine-containing disinfectant and ventilated twice a day\n4) Ground disinfection: The ground is wiped with 1000mg/L chlorine-containing\ndisinfectant, once /4 hours.\n5) When contaminated, disinfect at any time. In case of visible contamination, disposable\nabsorbent materials should be used first to completely remove the pollutants, and then a\ncloth soaked with 2000mg/L chlorine-containing disinfectant should be used for 30\nminutes before wiping.\n11\nFever-CT disinfection procedures after examination\nIn addition to the above, disinfect the examination bed and ground with chlorinated disinfectant\ncontaining 2000mg/L [10].", "Noncontaminated CT disinfection procedures after suspected COVID-19 case examination\nIn addition to the above routine disinfection procedure, air disinfection is conducted for 30 min\nbefore examining other patients.\nResults\nFrom January 21, 2020 when screening for epidemiological history or symptoms\nsuspicious for COVID-19, to March 9, 2020, our hospital screened a total of 7,203 individuals\nand confirmed 24 cases of COVID-19. Of these, 3,083 people underwent fever-CT\nexaminations. Including the initial examination and reexamination, the total number of fever\nCT examination numbered 3,340. The fever-CT scanned a patient approximately every 21.5\nminutes. As a result of our precautions, none of the staff of the radiology department developed\nsymptoms suspicious for COVID-19. The fever-CT technologist, with the highest probability\nof exposure, remains PCR negative.\nDiscussion\nIt has been 17 years since the severe acute respiratory syndrome (SARS) epidemic, the last", "national spread of severe infectious disease, broke out. Currently, the Chinese people are\npanicking again. The speed and extent by which COVID-19 has spread in 2 months are\n12\nunprecedented, beyond those of SARS, and this has been aided by its contagious nature and\nrapid spread via droplets and contact. The droplet mode of transmission means that a person can\nbe infected easily by means of casual contact or even fomites on contaminated environmental\nsurfaces. Another theory has yet to be proved: aerosol propagation.\nHow radiology departments respond to any infectious disease outbreak is determined\nprimarily by the estimated risk of cross-infection to the staff and other patients. Appropriate\nprecautions taken only by staff in direct contact with patients may be adequate when the risk is\nlow. The strongest measures need to be implemented to limit the spread of the disease when the\nrisk is high. With severe infectious diseases such as COVID-19, the highest level of infection", "control measures must be implemented; these include providing adequate standard protective\nequipment, training staff, and instituting proper emergency plans.\nOnce a contagious infectious disease has been identified, the EMICT must consider four\nmain areas of response: data gathering, collaboration, needs assessment, and expert advice [10].\nData gathering includes dissemination of up-to-date case definitions and information about\nconfirmatory tests to all staff with direct patient contact to allow appropriate barrier precautions\nto be taken. All typical and atypical imaging features of the disease should be made known to\nall radiologists to assist in recognition of the disease on images and to allow accurate reporting\nof these findings. We have stored images of all probable cases of COVID-19 in the PACS so\nthat these images were readily available for any radiologist to review, and images from\nprevious imaging studies are also available for comparison.", "Collaboration with the radiology departments of other hospitals is very important because\npatients may initially present to different centers, depending on geographic location and travel\n13\ndistance. These patients may be few in number at a single hospital, but if data from patients at\nseveral hospitals are available, a more accurate overall understanding of both imaging features\nand epidemiology can be achieved. Dissemination of this information to all healthcare facilities\nwill also lead to early recognition of the disease, and appropriate isolation measures may be\ninstituted.\nThe Internet and social media apps, especially WeChat, have been used for distribution of\nmedical information, and because the exchange of information regarding infectious disease\noutbreaks is almost instantaneous, it is an indispensable tool for radiologists. In fact, within a\nmonth of the outbreak, the hospital that received the most infected patients from the source of", "the outbreak made a PowerPoint presentation of the CT manifestations of COVID-19, which\nwas shared via WeChat and disseminated across the country in a very short time. Subsequently,\nCOVID-19-teaching PowerPoint presentations from various hospitals appeared and were\nquickly shared via WeChat.\nOur diagnostic process is limited as chest CT along is not diagnostic of COVID-19\nbecause of lack of imaging specificity. But when combined with other epidemiological,\nclinical, laboratory and virus nucleic acid information, typical chest CT imaging findings are\nhelpful for making the diagnosis. In our opinion, the major role of chest CT is to understand the\nextent and dynamic evolution of lung lesions induced by COVID-19. The reasons why we\nadopted the low-dose chest CT scan protocol are as follows: low-dose chest CT has been\nwidely used in the screening of early lung cancer. It is well known that many early lung cancers", "are ground-glass opacities (GGO), so we believe that low-dose screening is also applicable for\nCOVID-19. In addition, considering the rapid development of COVID-19, many CT\n14\nexaminations may be conducted in the same individual to monitor disease progress. Low-dose\nscanning can reduce the radiation damage to patients.\nAlthough the processes we established minimized the exposure of hospital staff, ancillary\npersonnel and other patients, it remains limited as follows. Sichuan province is not the center of\nthe epidemic. The number of patients with COVID-19 whom we have treated has not been\nhigh, and most cases are from other provinces of China. However, we believe that our\nexperience in management, the reconfiguration of our radiology department, and the workflow\nchanges implemented in the current COVID-19 situation are useful for other radiology\ndepartments that must prepare for dealing with patients with COVID-19. While no radiology", "personnel developed symptoms suspicious for or were confirmed as having COVID-19, there\nmay be asymptomatic personnel.\nREFERENCES\n1. National Health Commission of the People’s Republic of China.(2020). March 12: Daily briefing\non novel coronavirus cases in China. Retrieved from\nhttp://en.nhc.gov.cn/2020-03/12/c_77618.htm. Accessed March 11, 2020.\n2. World Health Organization. (2020). Coronavirus disease 2019 (COVID-19) Situation Report-52.\nRetrieved from\nhttps://www.who.int/docs/default-source/coronaviruse/20200312-sitrep-52-covid-19.pdf?sfvrsn=e\n2bfc9c0_2 9. Accessed March 11, 2020.\n3. National Health Commission of the People’s Republic of China.(2020). Latest developments in\nepidemic control on Feb 15. Retrieved from http://en.nhc.gov.cn/2020-02/16/c_76622. Accessed\nMarch 11, 2020.\n15\n4. Health Commission of the People’s Republic of China.(2020). The notification of the trial\noperation based on the guideline version 6 in the coronavirus disease diagnosis and treatment.", "Retrieved from\nhttp://www.nhc.gov.cn/xcs/zhengcwj/202002/8334a8326dd94d329df351d7da8aefc2.shtml.\nAccessed March 11, 2020\n5. Health Commission of the People’s Republic of China.(2020). The notification of the trial\noperation based on the guideline version 6 in the coronavirus disease diagnosis and treatment.\nRetrieved from\nhttp://www.nhc.gov.cn/xcs/zhengcwj/202002/8334a8326dd94d329df351d7da8aefc2.shtml.\nAccessed March 11, 2020.\n6. Health Commission of the People’s Republic of China.(2009). The guideline for pathogens\nisolated operations in hospital. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/200904/40116.shtml. Accessed March 11, 2020.\n7. Health Commission of the People’s Republic of China.(2017). The guideline for prevention and\ncontrol of hospital acquired infections of airborne pathogens. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201701/7e0e8fc6725843aabba8f841f2f585d2.shtml. Accessed\nMarch 11, 2020.", "8. Health Commission of the People’s Republic of China.(2017). The guideline for prevention and\ncontrol of hospital acquired infections of airborne pathogens. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201701/7e0e8fc6725843aabba8f841f2f585d2.shtml. Accessed\nMarch 11, 2020.\n9. Health Commission of the People’s Republic of China.(2012). The standardization for\nsterilization techniques in hospital. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201204/54510.shtml. Accessed March 11, 2020.\n10. Health Commission of the People’s Republic of China.(2012). The standardization for\nsterilization techniques in hospital. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201204/54510.shtml. Accessed March 11, 2020.\n11. Katona P. Bioterrorism Preparedness: Generic Blueprint for Health Departments, Hospitals, and\nPhysicians. Infectious Diseases in Clinical Practice. 2002;11(3):115-122. Accessed March 11,\n2020.\n16\nFigure Legends", "Figure 1. Diagram of the layout of our radiology department was divided into four areas: contaminated\n(shaded in black), semicontaminated (shaded in dark gray), buffer (shaded in light gray), and clean areas\n(shaded in white). The contaminated area was separated from other areas by barriers.\nFigure 2. Diagram shows CT protocol for suspected and confirmed patients with COVID-19.\nFigure 3. Diagram shows CT protocol for regular patients.\nAbbreviations:\nCOVID-19: coronavirus disease 2019\nCT: computed tomography\nDR: digital radiography\nEMICT: emergency management and infection control team\nNHC: National Health Commission\nPACS: picture archiving and communication system\nSARS: severe acute respiratory syndrome", "Sentence Summary\nWith severe infectious diseases such as COVID-19, the highest level of infection control\nmeasures must be implemented, collaboration with the radiology departments of other\nhospitals be needed, and social media be employed.\nTake-home points\n1. To response to a community infection emergency, a special emergency management team\nneeds to be setup at the departmental level to implement infection containment and\ncontrol procedures that continues to allow the imaging examination and imaging\ndiagnosis of those with suspected infection, and to prevent intra-departmental spreading\nof infection (EMICT).\n2. Infection control measures, such as reconfiguration of department areas, personal\nprotection and anti-infection training of all staff, standardized procedures including\ncontact minimization for chest CT and DR examinations, and timely disinfection of CT\nand DR examination rooms, should be implemented properly.", "3. If there are more than one scanner in a hospital, only one of them should be assigned to\nsuspected cases." ]	[ 19 ]	3,975	6,764
188	What's the recommended method to disinfect floors for COVID-19?	240	[ "The ground is wiped with 1000mg/L chlorine-containing\ndisinfectant, once /4 hours." ]	[ "The Battle Against Coronavirus Disease 2019 (COVID-19): Emergency Management\nand Infection Control in a Radiology Department\nhttps://www.jacr.org/article/S1546-1440(20)30285-4/pdf\nJournal Pre-proof\nZixing Huang, Shuang Zhao, Zhenlin Li, Weixia Chen, Lihong Zhao, Lipeng Deng, Bin\nSong\nPII: S1546-1440(20)30285-4\nDOI: https://doi.org/10.1016/j.jacr.2020.03.011\nReference: JACR 5139\nTo appear in: Journal of the American College of Radiology\nReceived Date: 24 February 2020\nRevised Date: 13 March 2020\nAccepted Date: 15 March 2020\nPlease cite this article as: Huang Z, Zhao S, Li Z, Chen W, Zhao L, Deng L, Song B, The Battle Against\nCoronavirus Disease 2019 (COVID-19): Emergency Management and Infection Control in a Radiology\nDepartment, Journal of the American College of Radiology (2020), doi: https://doi.org/10.1016/\nj.jacr.2020.03.011.\nThis is a PDF file of an article that has undergone enhancements after acceptance, such as the addition", "of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of\nrecord. This version will undergo additional copyediting, typesetting and review before it is published\nin its final form, but we are providing this version to give early visibility of the article. Please note that,\nduring the production process, errors may be discovered which could affect the content, and all legal\ndisclaimers that apply to the journal pertain.\n© 2020 Published by Elsevier Inc. on behalf of American College of Radiology\nThe Battle Against Coronavirus Disease 2019 (COVID-19): Emergency Management\nand Infection Control in a Radiology Department\nZixing Huang, Shuang Zhao, Zhenlin Li, Weixia Chen, Lihong Zhao, Lipeng Deng,\nBin Song\nDepartment of Radiology, West China Hospital, Sichuan University, Chengdu, China\n*Zixing Huang and Shuang Zhao contributed equally to this work as co-first author.\nCorresponding Author: Bin Song, MD", "Address: Department of Radiology, West China Hospital, Sichuan University.\nNo. 37, GUOXUE Alley, Chengdu, 610041, China\nTel.: (+86)28 85423680, Fax: (+86)28 85582944\nEmail: [email protected].\nAuthors’ contributions\nZXH: conceived the study and drafted the manuscript.\nZS: conceived the study and drafted the manuscript.\nZLL: The member of the emergency management and infection control team (EMICT)\nand was involved in the formulation of the measures.\nWXC: The member of the EMICT and was involved in the formulation of the\nmeasures.\nLHZ: The member of the EMICT and was involved in the formulation of the\nmeasures.\nLPD: The member of the EMICT and was involved in the formulation of the\nmeasures.\nBS: Leader of the EMICT, conceived the study and reviewed the manuscript.\nAll authors read and approved the final manuscript.\nThe authors declare no conflict of interest.\nThe authors declare that they had full access to all of the data in this study and the", "authors take complete responsibility for the integrity of the data and the accuracy of\nthe data analysis\n1\nThe Battle Against Novel Coronavirus Pneumonia (COVID-19): Emergency\nManagement and Infection Control in a Radiology Department\nAbstract\nObjective: To describe the strategy and the emergency management and infection control\nprocedure of our radiology department during the COVID-19 outbreak.\nMethods: We set up emergency management and sensing control teams. The team formulated\nvarious measures: reconfiguration of the radiology department, personal protection and training\nof staff, examination procedures for patients suspected of or confirmed with COVID-19 as well\nas patients without an exposure history or symptoms. Those with suspected or confirmed\nCOVID-19 infection were scanned in the designated fever-CT unit.\nResults: From January 21, 2020 to March 9, 2020, 3,083 people suspected of or confirmed with\nCOVID-19 underwent fever-CT examinations. Including initial examinations and", "reexaminations, the total number of fever-CT examinations numbered 3,340. As a result of our\nprecautions, none of the staff of the radiology department were infected with COVID-19.\nConclusion: Strategic planning and adequate protections can help protect patients and staff\nagainst a highly infectious disease while maintaining function at a high volume capacity.\nKeywords: Coronavirus, COVID-19, novel coronavirus pneumonia, infection control", "2\nIntroduction\nThe whole world has been closely focusing on an outbreak of respiratory disease caused by a\nnovel coronavirus that was first reported in Wuhan, China, on December 31, 2019, and that\ncontinues to spread. On February 11, 2020, the World Health Organization (WHO) named the\ndisease “coronavirus disease 2019” (COVID-19).\nAs of 24:00 on March 11, 2020, the National Health Commission (NHC) had received reports\nof 80,793 confirmed cases and 3,169 deaths on the Chinese mainland. There remain 14,831\nconfirmed cases (including 4,257 in serious condition) and 253 suspected cases still\nhospitalized. To date, 677,243 people have been identified as having had close contact with\ninfected patients of whom13,701 are under medical observation [1]. Outside China, 44,067\nlaboratory-confirmed cases and 1,440 deaths have occurred in 117 countries /territories/areas\naccording to the WHO [2]. COVID-19 poses significant threats to international health. Like the", "flu, COVID-19 is thought to spread mainly from person-to-person between people who are in\nclose contact with one another through respiratory droplets produced when an infected person\ncoughs or sneezes. In light of the infectious nature of this disease, healthcare workers are at\nhigh risk of infection of COVID-19. In China, healthcare workers account for 1,716 confirmed\ncases of COVID-19, including six deaths [3].\n Computed tomography (CT) can play a role in both diagnosing and categorizing\nCOVID-19 on the basis of case definitions issued by the WHO and the treatment guidelines\nfrom the NHC [4]. Suspected patients having the virus may undergo chest CT. Isolation and\nbarrier procedures are necessary to protect both the department staff and other patients in the\nhospital. Note should be made that due to overlap of imaging findings with other respiratory\n3\ndiseases, CT is not helpful as a screening tool. But it can help identify the degree of pulmonary\ninvolvement and disease course.", "Our hospital is a national regional medical center with 4,300 beds and a tertiary referral\ncenter in Sichuan province. The initial response started on January 21, 2020, after transmission\nof COVID-19 was confirmed to be human-to-human on January 20, 2020. The first suspected\ncase of COVID-19 in Sichuan province was reported on January 21, 2020. The Sichuan\nprovincial government immediately launched the first-level response to major public health\nemergencies. On the same day, our hospital was designated to care for Sichuan province\npatients with COVID-19.\nThis article describes the emergency management procedure of our radiology department\nfor situations involving severe infectious diseases, such as COVID-19, and the\ninfection-protection experience of the department staff.\nMethods\nThe hospital provided personal protective equipment (medical protective clothing,\nsurgical cap, N95 mask, gloves, face shields, and goggles) to all its healthcare staff, erected", "three medical tents (fever tents) for screening of fever cases in the parking lot of the emergency\ndepartment, planned an examination route and examination area for patients suspected of\nharboring the virus, and placed confirmed patients in an isolation ward. “Fever” was the\ncolloquial term used to designate suspected COVID-19 based on symptoms such as a fever or\nwith an epidemiological history of a potential exposure as well as those with confirmed\nCOVID-19 referred for treatment. Further, during outbreak, emergency and outpatient patients\n4\nwithout fever were asked for information such as epidemiological history and sent to fever tents\nas long as they met suspected criteria.\nThe radiology department has 65 diagnostic radiologists and 161 other staff members\n(trained technologists, nurses, engineers, and support staff). The equipment of the radiology\ndepartment includes 12 magnetic resonance (MR) scanners, 14 CT scanners, 15 digital", "subtraction angiography (DSA) systems, 32 sets of digital radiography (DR) systems\n(including nine mobile bedside DR sets), and 130 imaging diagnostic workstations for picture\narchiving and communication systems (PACS). Most of the equipment is distributed among\nfour buildings at the hospital main campus. 4 CT scanners, 4 MR scanners, 1 DR are located on\nthe first floor of the first inpatient building, and 9 DR and 8 DSA are located on the second\nfloor. 1 CT and 1 MR scanner are located in the third inpatient building. 1 CT and 1 MR scanner\nare located in the sixth inpatient building. 2 CT scanners, 2 MR scanners and 7 DSA are located\nin the technical building. The rest of the equipment is located in the seventh inpatient building\nin the branch campus.\nThe first inpatient building, located next to the emergency department, was reconfigured to\nhandle cases of COVID-19. Fever tents were set up by the emergency department in the", "emergency department parking lot to separate normal emergency patients from patients with\nsymptoms or exposure history suspicious of COVID-19. We established separate means of\naccess between fever tents and between the fever examination area of the radiology department\nto avoid cross-contamination.\nThe emergency management and infection control measures, as described below and\nimplemented in the radiology department during the outbreak, have been approved by the\n5\ninfection control committee of hospital. These measures are in accordance with relevant laws\nand regulations, in order to protect patients as well as the staff.\nRadiology Emergency Management and Infection Control Team (EMICT)\nThe radiology department director chaired the EMICT. Its members include the deputy\ndirector, chief technologist, head nurse, equipment engineer supervisor, and infection control\nnurse of the radiology department. Team responsibilities included (1) coordination between the", "hospital’s management and planning of infection control and radiology departments; (2)\ncollection of the most up-to-date protection-related information to educate and train staff in the\ndepartment; (3) reallocation of staff according to the actual situation; (4) establishment of the\nCT procedures for patients with COVID-19; and (5) establishment of an emergency\nmanagement plan for the radiology department to ensure that the department would run\nnormally.\nSuspected patients\nThe suspected patients were identified according to the Diagnosis and Treatment Program of\nthe Novel Coronavirus Pneumonia of the NHC [5], mainly based on epidemiological history.\nReconfiguration of the radiology department\nThe radiology department was divided into four areas [6]: contaminated, semicontaminated,\nbuffer, and clean areas (Figure 1). The contaminated area is connected to the fever clinic and\nincludes the fever accessway, the CT examination room, and the DR examination room for\n6", "confirmed and suspected cases. One CT scanner and one DR system closest to the emergency\ndepartment are designated the fever-CT and fever-DR to examine patients with suspected and\nconfirmed COVID-19. There is a separate dedicated access between the contaminated area and\nthe fever screening tents. The semicontaminated area includes the fever-CT control room,\nfever-DR control room, and other patient examination access areas. The buffer zone includes\naccess areas for medical personnel and a dressing area for technologists. The clean area\nincludes the administrative office and the diagnostic room.\nThe contaminated area was isolated from other areas using physical barricades.\nDirectional signs were newly installed to guide patients and staff.\nPersonal protection and training of staff\nFor providing care for patients with confirmed and suspected COVID-19, all hospital staff\nare required to wear complete personal protective equipment [7]: medical protective clothing,", "surgical cap, N95 mask, gloves, face shields, and goggles. Wearing and removing of the\nequipment must be performed in accordance with the procedures and under the supervision of\nthe infection control nurse.\nBecause staff members working in the contaminated area are under much situational\npressure, periodically taking time off could lower their physical and mental stress levels. The\ntechnologists on fever-CT duty shifts are provided a break once a week for four hours. In\naddition, the health of staff in the contaminated area must be monitored closely for the\nsymptoms of COVID-19. Pregnant staff must be assigned to the clean area.\n7\nThe EMICT formulates and continually updates guidelines and educates all staff for West\nChina Hospital of Sichuan University. The EMICT training for staff is mainly involves\ndocuments regarding infection control and CT findings of COVID-19 and maintains an EMICT\nWeChat group for West China Hospital of Sichuan University. WeChat is the most widely used", "social media app in China. The EMICT releases the latest national and hospital-based\ninformation regarding COVID-19, guidance documents, and other notices from the hospital\nand radiology department in the WeChat group on a daily basis. Staff can also report to the\nEMICT in the WeChat group any time. Protocols for each modality and infection control\ninstructions are posted on the walls in all examination rooms. The EMICT periodically reminds\nstaff to undertake personal measures to reduce infection, such as wearing masks at all instances\nin the radiology department and N95 masks if working in the contaminated area; not touching\nthe mask and the eyes; practicing hand hygiene; facing away from colleagues when eating,\ndrinking, and talking; and not using personal cell phones while on duty.\n In addition, the chief thoracic radiologist provided lectures on all radiologists and\ntechnologists on typical CT findings of COVID-19 infection using materials developed in", "Wuhan, the epicenter of the outbreak in China.\nCT examination procedures\nThere are two sets of procedures for CT examination: the fever-CT procedure and routine CT\nprocedure for those not suspected of COVID-19.\nThe fever-CT procedure for suspected or confirmed COVID-19 (Figure 2)\n8\nBefore the fever-CT technologist operates the equipment, he or she should wear personal\nprotective equipment according to three-level protection standard [8]. Before the CT\nexamination of patients with suspected and confirmed COVID-19 begins, the fever tent or\nisolation ward notifies the radiologist in advance. The fever-CT technologist checks the\nequipment and prepares to disinfect the imaging equipment immediately after the examination.\nThe patient enters the fever-CT waiting area through the fever access area. If the patient\ncan get onto and off the examination table by themselves, the patient is allowed to do so. If the", "patient cannot get onto or off the examination table independently, the person accompanying\nthe patient assists the patient, rather than the technologist. The technologist checks the patient\ninformation and, using an intercom system in the examination room, asks the patient to remove\nany metal ornaments on the neck and chest. Also, by intercom, the technologist trains the\npatient to hold his or her breath during the examination.\nThe technologist uses a low-dose chest CT protocol to scan the patient. After scanning, the\noriginal images are reconstructed as 1 mm-thick layers. The technologist browses the images to\nensure that their quality meets the diagnostic requirements and then guides the patient to leave\nthrough the fever access area. The disposable sheets for patient examination are changed after\neach patient. The equipment is disinfected according to the procedure below.\nTo protect themselves, the technologists assigned to the fever-CT wear N95 mask and", "other personal protection as established by the EMICT.\nThe CT procedure for regular patients (figure.3)\n9\nSome patients with COVID-19 have no symptoms, and they may call at the general clinic for\nother reasons. The following CT procedure is applicable under these circumstances:\nWhen the patient makes an appointment for examination, the staff asks the patient about\ntheir epidemiological history, symptoms, and signs. If suspected criteria are met, the patient\nwill be sent to the fever tent for further screening. When a patient presents to the radiology\ndepartment entrance, his/her temperature is measured. If the temperature is higher than 37.2 , ℃\nthe patient is sent to the fever tent for further investigation.\nThose with no exposure history, suspicious symptoms or fever are screened in one of the\nnon-contaminated CT scanners. The technologists assigned to these scanners wear surgical\nmasks. All patients and the person accompanying them are required to wear surgical masks.", "After the CT examination, the technologist browses the images quickly. If the CT appearance is\ntypical of lung infection, the technologist immediately reports it to the chest radiologist on duty\nand asks the patient to wait in the CT examination room. If the chest radiologist does not\nsuspect COVID-19 infection, the patient can leave the CT examination room. If the chest\nradiologist does suspect COVID-19 infection, the technologist immediately reports it to the\nEMICT and sends the patient to the fever tent. The floor and equipment in the CT examination\nroom are disinfected according to regulations, and air disinfection is conducted for 30 min\nbefore examining other patients. These CT scanners are considered noncontaminated (not\nfever-CTs) after these sterilization procedures.\nFever-DR examination procedure\n10\nThe COVID-19 guideline of the NHC does not recommend chest DR because its ability in\ndiagnosing COVID-19 is limited. At our hospital, we only use mobile DR units to provide", "bedside examination for critically ill patients. The technologist operating the mobile DR\nwears personal protective equipment according to the three-level protection standard and\nsterilizes the mobile DR according to the ward management requirements as described below.\nEquipment and environment disinfection procedures\nRoutine disinfection procedure [9]\n1) Object surface disinfection: Object surface is wiped with 1000mg/L chlorine-containing\ndisinfectant, wipe twice with 75% ethanol for non-corrosion resistance, once /4 hours.\n2) Equipment disinfection: The equipment in the contaminated area are wiped with\n2000mg/L chlorine-containing disinfectant. The DR and CT gantry in the contaminated\narea are wiped with 75% ethanol. The equipment in the buffer area is wiped with\n500-1000mg/L chlorine-containing disinfectant or alcohol-containing disposable\ndisinfectant wipes twice a day.\n3) Air disinfection: Turning off all central air conditioners to prevent air contamination with", "each other. Polluted area: open the door for ventilation, each time more than 30 minutes,\nonce /4 hours; The air sterilizer is continuously sterilized or the ultraviolet ray is\ncontinuously used in the unmanned state for 60 minutes, four times a day, remembered to\nclose the inner shielding door when air disinfection. Other ambient air is sprayed with\n1000mg/L chlorine-containing disinfectant and ventilated twice a day\n4) Ground disinfection: The ground is wiped with 1000mg/L chlorine-containing\ndisinfectant, once /4 hours.\n5) When contaminated, disinfect at any time. In case of visible contamination, disposable\nabsorbent materials should be used first to completely remove the pollutants, and then a\ncloth soaked with 2000mg/L chlorine-containing disinfectant should be used for 30\nminutes before wiping.\n11\nFever-CT disinfection procedures after examination\nIn addition to the above, disinfect the examination bed and ground with chlorinated disinfectant\ncontaining 2000mg/L [10].", "Noncontaminated CT disinfection procedures after suspected COVID-19 case examination\nIn addition to the above routine disinfection procedure, air disinfection is conducted for 30 min\nbefore examining other patients.\nResults\nFrom January 21, 2020 when screening for epidemiological history or symptoms\nsuspicious for COVID-19, to March 9, 2020, our hospital screened a total of 7,203 individuals\nand confirmed 24 cases of COVID-19. Of these, 3,083 people underwent fever-CT\nexaminations. Including the initial examination and reexamination, the total number of fever\nCT examination numbered 3,340. The fever-CT scanned a patient approximately every 21.5\nminutes. As a result of our precautions, none of the staff of the radiology department developed\nsymptoms suspicious for COVID-19. The fever-CT technologist, with the highest probability\nof exposure, remains PCR negative.\nDiscussion\nIt has been 17 years since the severe acute respiratory syndrome (SARS) epidemic, the last", "national spread of severe infectious disease, broke out. Currently, the Chinese people are\npanicking again. The speed and extent by which COVID-19 has spread in 2 months are\n12\nunprecedented, beyond those of SARS, and this has been aided by its contagious nature and\nrapid spread via droplets and contact. The droplet mode of transmission means that a person can\nbe infected easily by means of casual contact or even fomites on contaminated environmental\nsurfaces. Another theory has yet to be proved: aerosol propagation.\nHow radiology departments respond to any infectious disease outbreak is determined\nprimarily by the estimated risk of cross-infection to the staff and other patients. Appropriate\nprecautions taken only by staff in direct contact with patients may be adequate when the risk is\nlow. The strongest measures need to be implemented to limit the spread of the disease when the\nrisk is high. With severe infectious diseases such as COVID-19, the highest level of infection", "control measures must be implemented; these include providing adequate standard protective\nequipment, training staff, and instituting proper emergency plans.\nOnce a contagious infectious disease has been identified, the EMICT must consider four\nmain areas of response: data gathering, collaboration, needs assessment, and expert advice [10].\nData gathering includes dissemination of up-to-date case definitions and information about\nconfirmatory tests to all staff with direct patient contact to allow appropriate barrier precautions\nto be taken. All typical and atypical imaging features of the disease should be made known to\nall radiologists to assist in recognition of the disease on images and to allow accurate reporting\nof these findings. We have stored images of all probable cases of COVID-19 in the PACS so\nthat these images were readily available for any radiologist to review, and images from\nprevious imaging studies are also available for comparison.", "Collaboration with the radiology departments of other hospitals is very important because\npatients may initially present to different centers, depending on geographic location and travel\n13\ndistance. These patients may be few in number at a single hospital, but if data from patients at\nseveral hospitals are available, a more accurate overall understanding of both imaging features\nand epidemiology can be achieved. Dissemination of this information to all healthcare facilities\nwill also lead to early recognition of the disease, and appropriate isolation measures may be\ninstituted.\nThe Internet and social media apps, especially WeChat, have been used for distribution of\nmedical information, and because the exchange of information regarding infectious disease\noutbreaks is almost instantaneous, it is an indispensable tool for radiologists. In fact, within a\nmonth of the outbreak, the hospital that received the most infected patients from the source of", "the outbreak made a PowerPoint presentation of the CT manifestations of COVID-19, which\nwas shared via WeChat and disseminated across the country in a very short time. Subsequently,\nCOVID-19-teaching PowerPoint presentations from various hospitals appeared and were\nquickly shared via WeChat.\nOur diagnostic process is limited as chest CT along is not diagnostic of COVID-19\nbecause of lack of imaging specificity. But when combined with other epidemiological,\nclinical, laboratory and virus nucleic acid information, typical chest CT imaging findings are\nhelpful for making the diagnosis. In our opinion, the major role of chest CT is to understand the\nextent and dynamic evolution of lung lesions induced by COVID-19. The reasons why we\nadopted the low-dose chest CT scan protocol are as follows: low-dose chest CT has been\nwidely used in the screening of early lung cancer. It is well known that many early lung cancers", "are ground-glass opacities (GGO), so we believe that low-dose screening is also applicable for\nCOVID-19. In addition, considering the rapid development of COVID-19, many CT\n14\nexaminations may be conducted in the same individual to monitor disease progress. Low-dose\nscanning can reduce the radiation damage to patients.\nAlthough the processes we established minimized the exposure of hospital staff, ancillary\npersonnel and other patients, it remains limited as follows. Sichuan province is not the center of\nthe epidemic. The number of patients with COVID-19 whom we have treated has not been\nhigh, and most cases are from other provinces of China. However, we believe that our\nexperience in management, the reconfiguration of our radiology department, and the workflow\nchanges implemented in the current COVID-19 situation are useful for other radiology\ndepartments that must prepare for dealing with patients with COVID-19. While no radiology", "personnel developed symptoms suspicious for or were confirmed as having COVID-19, there\nmay be asymptomatic personnel.\nREFERENCES\n1. National Health Commission of the People’s Republic of China.(2020). March 12: Daily briefing\non novel coronavirus cases in China. Retrieved from\nhttp://en.nhc.gov.cn/2020-03/12/c_77618.htm. Accessed March 11, 2020.\n2. World Health Organization. (2020). Coronavirus disease 2019 (COVID-19) Situation Report-52.\nRetrieved from\nhttps://www.who.int/docs/default-source/coronaviruse/20200312-sitrep-52-covid-19.pdf?sfvrsn=e\n2bfc9c0_2 9. Accessed March 11, 2020.\n3. National Health Commission of the People’s Republic of China.(2020). Latest developments in\nepidemic control on Feb 15. Retrieved from http://en.nhc.gov.cn/2020-02/16/c_76622. Accessed\nMarch 11, 2020.\n15\n4. Health Commission of the People’s Republic of China.(2020). The notification of the trial\noperation based on the guideline version 6 in the coronavirus disease diagnosis and treatment.", "Retrieved from\nhttp://www.nhc.gov.cn/xcs/zhengcwj/202002/8334a8326dd94d329df351d7da8aefc2.shtml.\nAccessed March 11, 2020\n5. Health Commission of the People’s Republic of China.(2020). The notification of the trial\noperation based on the guideline version 6 in the coronavirus disease diagnosis and treatment.\nRetrieved from\nhttp://www.nhc.gov.cn/xcs/zhengcwj/202002/8334a8326dd94d329df351d7da8aefc2.shtml.\nAccessed March 11, 2020.\n6. Health Commission of the People’s Republic of China.(2009). The guideline for pathogens\nisolated operations in hospital. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/200904/40116.shtml. Accessed March 11, 2020.\n7. Health Commission of the People’s Republic of China.(2017). The guideline for prevention and\ncontrol of hospital acquired infections of airborne pathogens. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201701/7e0e8fc6725843aabba8f841f2f585d2.shtml. Accessed\nMarch 11, 2020.", "8. Health Commission of the People’s Republic of China.(2017). The guideline for prevention and\ncontrol of hospital acquired infections of airborne pathogens. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201701/7e0e8fc6725843aabba8f841f2f585d2.shtml. Accessed\nMarch 11, 2020.\n9. Health Commission of the People’s Republic of China.(2012). The standardization for\nsterilization techniques in hospital. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201204/54510.shtml. Accessed March 11, 2020.\n10. Health Commission of the People’s Republic of China.(2012). The standardization for\nsterilization techniques in hospital. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201204/54510.shtml. Accessed March 11, 2020.\n11. Katona P. Bioterrorism Preparedness: Generic Blueprint for Health Departments, Hospitals, and\nPhysicians. Infectious Diseases in Clinical Practice. 2002;11(3):115-122. Accessed March 11,\n2020.\n16\nFigure Legends", "Figure 1. Diagram of the layout of our radiology department was divided into four areas: contaminated\n(shaded in black), semicontaminated (shaded in dark gray), buffer (shaded in light gray), and clean areas\n(shaded in white). The contaminated area was separated from other areas by barriers.\nFigure 2. Diagram shows CT protocol for suspected and confirmed patients with COVID-19.\nFigure 3. Diagram shows CT protocol for regular patients.\nAbbreviations:\nCOVID-19: coronavirus disease 2019\nCT: computed tomography\nDR: digital radiography\nEMICT: emergency management and infection control team\nNHC: National Health Commission\nPACS: picture archiving and communication system\nSARS: severe acute respiratory syndrome", "Sentence Summary\nWith severe infectious diseases such as COVID-19, the highest level of infection control\nmeasures must be implemented, collaboration with the radiology departments of other\nhospitals be needed, and social media be employed.\nTake-home points\n1. To response to a community infection emergency, a special emergency management team\nneeds to be setup at the departmental level to implement infection containment and\ncontrol procedures that continues to allow the imaging examination and imaging\ndiagnosis of those with suspected infection, and to prevent intra-departmental spreading\nof infection (EMICT).\n2. Infection control measures, such as reconfiguration of department areas, personal\nprotection and anti-infection training of all staff, standardized procedures including\ncontact minimization for chest CT and DR examinations, and timely disinfection of CT\nand DR examination rooms, should be implemented properly.", "3. If there are more than one scanner in a hospital, only one of them should be assigned to\nsuspected cases." ]	[ 20 ]	3,975	6,764
188	What is the role of computed tomography (CT) in COVID-19?	241	[ "diagnosing and categorizing\nCOVID-19 on the basis of case definitions issued by the WHO" ]	[ "The Battle Against Coronavirus Disease 2019 (COVID-19): Emergency Management\nand Infection Control in a Radiology Department\nhttps://www.jacr.org/article/S1546-1440(20)30285-4/pdf\nJournal Pre-proof\nZixing Huang, Shuang Zhao, Zhenlin Li, Weixia Chen, Lihong Zhao, Lipeng Deng, Bin\nSong\nPII: S1546-1440(20)30285-4\nDOI: https://doi.org/10.1016/j.jacr.2020.03.011\nReference: JACR 5139\nTo appear in: Journal of the American College of Radiology\nReceived Date: 24 February 2020\nRevised Date: 13 March 2020\nAccepted Date: 15 March 2020\nPlease cite this article as: Huang Z, Zhao S, Li Z, Chen W, Zhao L, Deng L, Song B, The Battle Against\nCoronavirus Disease 2019 (COVID-19): Emergency Management and Infection Control in a Radiology\nDepartment, Journal of the American College of Radiology (2020), doi: https://doi.org/10.1016/\nj.jacr.2020.03.011.\nThis is a PDF file of an article that has undergone enhancements after acceptance, such as the addition", "of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of\nrecord. This version will undergo additional copyediting, typesetting and review before it is published\nin its final form, but we are providing this version to give early visibility of the article. Please note that,\nduring the production process, errors may be discovered which could affect the content, and all legal\ndisclaimers that apply to the journal pertain.\n© 2020 Published by Elsevier Inc. on behalf of American College of Radiology\nThe Battle Against Coronavirus Disease 2019 (COVID-19): Emergency Management\nand Infection Control in a Radiology Department\nZixing Huang, Shuang Zhao, Zhenlin Li, Weixia Chen, Lihong Zhao, Lipeng Deng,\nBin Song\nDepartment of Radiology, West China Hospital, Sichuan University, Chengdu, China\n*Zixing Huang and Shuang Zhao contributed equally to this work as co-first author.\nCorresponding Author: Bin Song, MD", "Address: Department of Radiology, West China Hospital, Sichuan University.\nNo. 37, GUOXUE Alley, Chengdu, 610041, China\nTel.: (+86)28 85423680, Fax: (+86)28 85582944\nEmail: [email protected].\nAuthors’ contributions\nZXH: conceived the study and drafted the manuscript.\nZS: conceived the study and drafted the manuscript.\nZLL: The member of the emergency management and infection control team (EMICT)\nand was involved in the formulation of the measures.\nWXC: The member of the EMICT and was involved in the formulation of the\nmeasures.\nLHZ: The member of the EMICT and was involved in the formulation of the\nmeasures.\nLPD: The member of the EMICT and was involved in the formulation of the\nmeasures.\nBS: Leader of the EMICT, conceived the study and reviewed the manuscript.\nAll authors read and approved the final manuscript.\nThe authors declare no conflict of interest.\nThe authors declare that they had full access to all of the data in this study and the", "authors take complete responsibility for the integrity of the data and the accuracy of\nthe data analysis\n1\nThe Battle Against Novel Coronavirus Pneumonia (COVID-19): Emergency\nManagement and Infection Control in a Radiology Department\nAbstract\nObjective: To describe the strategy and the emergency management and infection control\nprocedure of our radiology department during the COVID-19 outbreak.\nMethods: We set up emergency management and sensing control teams. The team formulated\nvarious measures: reconfiguration of the radiology department, personal protection and training\nof staff, examination procedures for patients suspected of or confirmed with COVID-19 as well\nas patients without an exposure history or symptoms. Those with suspected or confirmed\nCOVID-19 infection were scanned in the designated fever-CT unit.\nResults: From January 21, 2020 to March 9, 2020, 3,083 people suspected of or confirmed with\nCOVID-19 underwent fever-CT examinations. Including initial examinations and", "reexaminations, the total number of fever-CT examinations numbered 3,340. As a result of our\nprecautions, none of the staff of the radiology department were infected with COVID-19.\nConclusion: Strategic planning and adequate protections can help protect patients and staff\nagainst a highly infectious disease while maintaining function at a high volume capacity.\nKeywords: Coronavirus, COVID-19, novel coronavirus pneumonia, infection control", "2\nIntroduction\nThe whole world has been closely focusing on an outbreak of respiratory disease caused by a\nnovel coronavirus that was first reported in Wuhan, China, on December 31, 2019, and that\ncontinues to spread. On February 11, 2020, the World Health Organization (WHO) named the\ndisease “coronavirus disease 2019” (COVID-19).\nAs of 24:00 on March 11, 2020, the National Health Commission (NHC) had received reports\nof 80,793 confirmed cases and 3,169 deaths on the Chinese mainland. There remain 14,831\nconfirmed cases (including 4,257 in serious condition) and 253 suspected cases still\nhospitalized. To date, 677,243 people have been identified as having had close contact with\ninfected patients of whom13,701 are under medical observation [1]. Outside China, 44,067\nlaboratory-confirmed cases and 1,440 deaths have occurred in 117 countries /territories/areas\naccording to the WHO [2]. COVID-19 poses significant threats to international health. Like the", "flu, COVID-19 is thought to spread mainly from person-to-person between people who are in\nclose contact with one another through respiratory droplets produced when an infected person\ncoughs or sneezes. In light of the infectious nature of this disease, healthcare workers are at\nhigh risk of infection of COVID-19. In China, healthcare workers account for 1,716 confirmed\ncases of COVID-19, including six deaths [3].\n Computed tomography (CT) can play a role in both diagnosing and categorizing\nCOVID-19 on the basis of case definitions issued by the WHO and the treatment guidelines\nfrom the NHC [4]. Suspected patients having the virus may undergo chest CT. Isolation and\nbarrier procedures are necessary to protect both the department staff and other patients in the\nhospital. Note should be made that due to overlap of imaging findings with other respiratory\n3\ndiseases, CT is not helpful as a screening tool. But it can help identify the degree of pulmonary\ninvolvement and disease course.", "Our hospital is a national regional medical center with 4,300 beds and a tertiary referral\ncenter in Sichuan province. The initial response started on January 21, 2020, after transmission\nof COVID-19 was confirmed to be human-to-human on January 20, 2020. The first suspected\ncase of COVID-19 in Sichuan province was reported on January 21, 2020. The Sichuan\nprovincial government immediately launched the first-level response to major public health\nemergencies. On the same day, our hospital was designated to care for Sichuan province\npatients with COVID-19.\nThis article describes the emergency management procedure of our radiology department\nfor situations involving severe infectious diseases, such as COVID-19, and the\ninfection-protection experience of the department staff.\nMethods\nThe hospital provided personal protective equipment (medical protective clothing,\nsurgical cap, N95 mask, gloves, face shields, and goggles) to all its healthcare staff, erected", "three medical tents (fever tents) for screening of fever cases in the parking lot of the emergency\ndepartment, planned an examination route and examination area for patients suspected of\nharboring the virus, and placed confirmed patients in an isolation ward. “Fever” was the\ncolloquial term used to designate suspected COVID-19 based on symptoms such as a fever or\nwith an epidemiological history of a potential exposure as well as those with confirmed\nCOVID-19 referred for treatment. Further, during outbreak, emergency and outpatient patients\n4\nwithout fever were asked for information such as epidemiological history and sent to fever tents\nas long as they met suspected criteria.\nThe radiology department has 65 diagnostic radiologists and 161 other staff members\n(trained technologists, nurses, engineers, and support staff). The equipment of the radiology\ndepartment includes 12 magnetic resonance (MR) scanners, 14 CT scanners, 15 digital", "subtraction angiography (DSA) systems, 32 sets of digital radiography (DR) systems\n(including nine mobile bedside DR sets), and 130 imaging diagnostic workstations for picture\narchiving and communication systems (PACS). Most of the equipment is distributed among\nfour buildings at the hospital main campus. 4 CT scanners, 4 MR scanners, 1 DR are located on\nthe first floor of the first inpatient building, and 9 DR and 8 DSA are located on the second\nfloor. 1 CT and 1 MR scanner are located in the third inpatient building. 1 CT and 1 MR scanner\nare located in the sixth inpatient building. 2 CT scanners, 2 MR scanners and 7 DSA are located\nin the technical building. The rest of the equipment is located in the seventh inpatient building\nin the branch campus.\nThe first inpatient building, located next to the emergency department, was reconfigured to\nhandle cases of COVID-19. Fever tents were set up by the emergency department in the", "emergency department parking lot to separate normal emergency patients from patients with\nsymptoms or exposure history suspicious of COVID-19. We established separate means of\naccess between fever tents and between the fever examination area of the radiology department\nto avoid cross-contamination.\nThe emergency management and infection control measures, as described below and\nimplemented in the radiology department during the outbreak, have been approved by the\n5\ninfection control committee of hospital. These measures are in accordance with relevant laws\nand regulations, in order to protect patients as well as the staff.\nRadiology Emergency Management and Infection Control Team (EMICT)\nThe radiology department director chaired the EMICT. Its members include the deputy\ndirector, chief technologist, head nurse, equipment engineer supervisor, and infection control\nnurse of the radiology department. Team responsibilities included (1) coordination between the", "hospital’s management and planning of infection control and radiology departments; (2)\ncollection of the most up-to-date protection-related information to educate and train staff in the\ndepartment; (3) reallocation of staff according to the actual situation; (4) establishment of the\nCT procedures for patients with COVID-19; and (5) establishment of an emergency\nmanagement plan for the radiology department to ensure that the department would run\nnormally.\nSuspected patients\nThe suspected patients were identified according to the Diagnosis and Treatment Program of\nthe Novel Coronavirus Pneumonia of the NHC [5], mainly based on epidemiological history.\nReconfiguration of the radiology department\nThe radiology department was divided into four areas [6]: contaminated, semicontaminated,\nbuffer, and clean areas (Figure 1). The contaminated area is connected to the fever clinic and\nincludes the fever accessway, the CT examination room, and the DR examination room for\n6", "confirmed and suspected cases. One CT scanner and one DR system closest to the emergency\ndepartment are designated the fever-CT and fever-DR to examine patients with suspected and\nconfirmed COVID-19. There is a separate dedicated access between the contaminated area and\nthe fever screening tents. The semicontaminated area includes the fever-CT control room,\nfever-DR control room, and other patient examination access areas. The buffer zone includes\naccess areas for medical personnel and a dressing area for technologists. The clean area\nincludes the administrative office and the diagnostic room.\nThe contaminated area was isolated from other areas using physical barricades.\nDirectional signs were newly installed to guide patients and staff.\nPersonal protection and training of staff\nFor providing care for patients with confirmed and suspected COVID-19, all hospital staff\nare required to wear complete personal protective equipment [7]: medical protective clothing,", "surgical cap, N95 mask, gloves, face shields, and goggles. Wearing and removing of the\nequipment must be performed in accordance with the procedures and under the supervision of\nthe infection control nurse.\nBecause staff members working in the contaminated area are under much situational\npressure, periodically taking time off could lower their physical and mental stress levels. The\ntechnologists on fever-CT duty shifts are provided a break once a week for four hours. In\naddition, the health of staff in the contaminated area must be monitored closely for the\nsymptoms of COVID-19. Pregnant staff must be assigned to the clean area.\n7\nThe EMICT formulates and continually updates guidelines and educates all staff for West\nChina Hospital of Sichuan University. The EMICT training for staff is mainly involves\ndocuments regarding infection control and CT findings of COVID-19 and maintains an EMICT\nWeChat group for West China Hospital of Sichuan University. WeChat is the most widely used", "social media app in China. The EMICT releases the latest national and hospital-based\ninformation regarding COVID-19, guidance documents, and other notices from the hospital\nand radiology department in the WeChat group on a daily basis. Staff can also report to the\nEMICT in the WeChat group any time. Protocols for each modality and infection control\ninstructions are posted on the walls in all examination rooms. The EMICT periodically reminds\nstaff to undertake personal measures to reduce infection, such as wearing masks at all instances\nin the radiology department and N95 masks if working in the contaminated area; not touching\nthe mask and the eyes; practicing hand hygiene; facing away from colleagues when eating,\ndrinking, and talking; and not using personal cell phones while on duty.\n In addition, the chief thoracic radiologist provided lectures on all radiologists and\ntechnologists on typical CT findings of COVID-19 infection using materials developed in", "Wuhan, the epicenter of the outbreak in China.\nCT examination procedures\nThere are two sets of procedures for CT examination: the fever-CT procedure and routine CT\nprocedure for those not suspected of COVID-19.\nThe fever-CT procedure for suspected or confirmed COVID-19 (Figure 2)\n8\nBefore the fever-CT technologist operates the equipment, he or she should wear personal\nprotective equipment according to three-level protection standard [8]. Before the CT\nexamination of patients with suspected and confirmed COVID-19 begins, the fever tent or\nisolation ward notifies the radiologist in advance. The fever-CT technologist checks the\nequipment and prepares to disinfect the imaging equipment immediately after the examination.\nThe patient enters the fever-CT waiting area through the fever access area. If the patient\ncan get onto and off the examination table by themselves, the patient is allowed to do so. If the", "patient cannot get onto or off the examination table independently, the person accompanying\nthe patient assists the patient, rather than the technologist. The technologist checks the patient\ninformation and, using an intercom system in the examination room, asks the patient to remove\nany metal ornaments on the neck and chest. Also, by intercom, the technologist trains the\npatient to hold his or her breath during the examination.\nThe technologist uses a low-dose chest CT protocol to scan the patient. After scanning, the\noriginal images are reconstructed as 1 mm-thick layers. The technologist browses the images to\nensure that their quality meets the diagnostic requirements and then guides the patient to leave\nthrough the fever access area. The disposable sheets for patient examination are changed after\neach patient. The equipment is disinfected according to the procedure below.\nTo protect themselves, the technologists assigned to the fever-CT wear N95 mask and", "other personal protection as established by the EMICT.\nThe CT procedure for regular patients (figure.3)\n9\nSome patients with COVID-19 have no symptoms, and they may call at the general clinic for\nother reasons. The following CT procedure is applicable under these circumstances:\nWhen the patient makes an appointment for examination, the staff asks the patient about\ntheir epidemiological history, symptoms, and signs. If suspected criteria are met, the patient\nwill be sent to the fever tent for further screening. When a patient presents to the radiology\ndepartment entrance, his/her temperature is measured. If the temperature is higher than 37.2 , ℃\nthe patient is sent to the fever tent for further investigation.\nThose with no exposure history, suspicious symptoms or fever are screened in one of the\nnon-contaminated CT scanners. The technologists assigned to these scanners wear surgical\nmasks. All patients and the person accompanying them are required to wear surgical masks.", "After the CT examination, the technologist browses the images quickly. If the CT appearance is\ntypical of lung infection, the technologist immediately reports it to the chest radiologist on duty\nand asks the patient to wait in the CT examination room. If the chest radiologist does not\nsuspect COVID-19 infection, the patient can leave the CT examination room. If the chest\nradiologist does suspect COVID-19 infection, the technologist immediately reports it to the\nEMICT and sends the patient to the fever tent. The floor and equipment in the CT examination\nroom are disinfected according to regulations, and air disinfection is conducted for 30 min\nbefore examining other patients. These CT scanners are considered noncontaminated (not\nfever-CTs) after these sterilization procedures.\nFever-DR examination procedure\n10\nThe COVID-19 guideline of the NHC does not recommend chest DR because its ability in\ndiagnosing COVID-19 is limited. At our hospital, we only use mobile DR units to provide", "bedside examination for critically ill patients. The technologist operating the mobile DR\nwears personal protective equipment according to the three-level protection standard and\nsterilizes the mobile DR according to the ward management requirements as described below.\nEquipment and environment disinfection procedures\nRoutine disinfection procedure [9]\n1) Object surface disinfection: Object surface is wiped with 1000mg/L chlorine-containing\ndisinfectant, wipe twice with 75% ethanol for non-corrosion resistance, once /4 hours.\n2) Equipment disinfection: The equipment in the contaminated area are wiped with\n2000mg/L chlorine-containing disinfectant. The DR and CT gantry in the contaminated\narea are wiped with 75% ethanol. The equipment in the buffer area is wiped with\n500-1000mg/L chlorine-containing disinfectant or alcohol-containing disposable\ndisinfectant wipes twice a day.\n3) Air disinfection: Turning off all central air conditioners to prevent air contamination with", "each other. Polluted area: open the door for ventilation, each time more than 30 minutes,\nonce /4 hours; The air sterilizer is continuously sterilized or the ultraviolet ray is\ncontinuously used in the unmanned state for 60 minutes, four times a day, remembered to\nclose the inner shielding door when air disinfection. Other ambient air is sprayed with\n1000mg/L chlorine-containing disinfectant and ventilated twice a day\n4) Ground disinfection: The ground is wiped with 1000mg/L chlorine-containing\ndisinfectant, once /4 hours.\n5) When contaminated, disinfect at any time. In case of visible contamination, disposable\nabsorbent materials should be used first to completely remove the pollutants, and then a\ncloth soaked with 2000mg/L chlorine-containing disinfectant should be used for 30\nminutes before wiping.\n11\nFever-CT disinfection procedures after examination\nIn addition to the above, disinfect the examination bed and ground with chlorinated disinfectant\ncontaining 2000mg/L [10].", "Noncontaminated CT disinfection procedures after suspected COVID-19 case examination\nIn addition to the above routine disinfection procedure, air disinfection is conducted for 30 min\nbefore examining other patients.\nResults\nFrom January 21, 2020 when screening for epidemiological history or symptoms\nsuspicious for COVID-19, to March 9, 2020, our hospital screened a total of 7,203 individuals\nand confirmed 24 cases of COVID-19. Of these, 3,083 people underwent fever-CT\nexaminations. Including the initial examination and reexamination, the total number of fever\nCT examination numbered 3,340. The fever-CT scanned a patient approximately every 21.5\nminutes. As a result of our precautions, none of the staff of the radiology department developed\nsymptoms suspicious for COVID-19. The fever-CT technologist, with the highest probability\nof exposure, remains PCR negative.\nDiscussion\nIt has been 17 years since the severe acute respiratory syndrome (SARS) epidemic, the last", "national spread of severe infectious disease, broke out. Currently, the Chinese people are\npanicking again. The speed and extent by which COVID-19 has spread in 2 months are\n12\nunprecedented, beyond those of SARS, and this has been aided by its contagious nature and\nrapid spread via droplets and contact. The droplet mode of transmission means that a person can\nbe infected easily by means of casual contact or even fomites on contaminated environmental\nsurfaces. Another theory has yet to be proved: aerosol propagation.\nHow radiology departments respond to any infectious disease outbreak is determined\nprimarily by the estimated risk of cross-infection to the staff and other patients. Appropriate\nprecautions taken only by staff in direct contact with patients may be adequate when the risk is\nlow. The strongest measures need to be implemented to limit the spread of the disease when the\nrisk is high. With severe infectious diseases such as COVID-19, the highest level of infection", "control measures must be implemented; these include providing adequate standard protective\nequipment, training staff, and instituting proper emergency plans.\nOnce a contagious infectious disease has been identified, the EMICT must consider four\nmain areas of response: data gathering, collaboration, needs assessment, and expert advice [10].\nData gathering includes dissemination of up-to-date case definitions and information about\nconfirmatory tests to all staff with direct patient contact to allow appropriate barrier precautions\nto be taken. All typical and atypical imaging features of the disease should be made known to\nall radiologists to assist in recognition of the disease on images and to allow accurate reporting\nof these findings. We have stored images of all probable cases of COVID-19 in the PACS so\nthat these images were readily available for any radiologist to review, and images from\nprevious imaging studies are also available for comparison.", "Collaboration with the radiology departments of other hospitals is very important because\npatients may initially present to different centers, depending on geographic location and travel\n13\ndistance. These patients may be few in number at a single hospital, but if data from patients at\nseveral hospitals are available, a more accurate overall understanding of both imaging features\nand epidemiology can be achieved. Dissemination of this information to all healthcare facilities\nwill also lead to early recognition of the disease, and appropriate isolation measures may be\ninstituted.\nThe Internet and social media apps, especially WeChat, have been used for distribution of\nmedical information, and because the exchange of information regarding infectious disease\noutbreaks is almost instantaneous, it is an indispensable tool for radiologists. In fact, within a\nmonth of the outbreak, the hospital that received the most infected patients from the source of", "the outbreak made a PowerPoint presentation of the CT manifestations of COVID-19, which\nwas shared via WeChat and disseminated across the country in a very short time. Subsequently,\nCOVID-19-teaching PowerPoint presentations from various hospitals appeared and were\nquickly shared via WeChat.\nOur diagnostic process is limited as chest CT along is not diagnostic of COVID-19\nbecause of lack of imaging specificity. But when combined with other epidemiological,\nclinical, laboratory and virus nucleic acid information, typical chest CT imaging findings are\nhelpful for making the diagnosis. In our opinion, the major role of chest CT is to understand the\nextent and dynamic evolution of lung lesions induced by COVID-19. The reasons why we\nadopted the low-dose chest CT scan protocol are as follows: low-dose chest CT has been\nwidely used in the screening of early lung cancer. It is well known that many early lung cancers", "are ground-glass opacities (GGO), so we believe that low-dose screening is also applicable for\nCOVID-19. In addition, considering the rapid development of COVID-19, many CT\n14\nexaminations may be conducted in the same individual to monitor disease progress. Low-dose\nscanning can reduce the radiation damage to patients.\nAlthough the processes we established minimized the exposure of hospital staff, ancillary\npersonnel and other patients, it remains limited as follows. Sichuan province is not the center of\nthe epidemic. The number of patients with COVID-19 whom we have treated has not been\nhigh, and most cases are from other provinces of China. However, we believe that our\nexperience in management, the reconfiguration of our radiology department, and the workflow\nchanges implemented in the current COVID-19 situation are useful for other radiology\ndepartments that must prepare for dealing with patients with COVID-19. While no radiology", "personnel developed symptoms suspicious for or were confirmed as having COVID-19, there\nmay be asymptomatic personnel.\nREFERENCES\n1. National Health Commission of the People’s Republic of China.(2020). March 12: Daily briefing\non novel coronavirus cases in China. Retrieved from\nhttp://en.nhc.gov.cn/2020-03/12/c_77618.htm. Accessed March 11, 2020.\n2. World Health Organization. (2020). Coronavirus disease 2019 (COVID-19) Situation Report-52.\nRetrieved from\nhttps://www.who.int/docs/default-source/coronaviruse/20200312-sitrep-52-covid-19.pdf?sfvrsn=e\n2bfc9c0_2 9. Accessed March 11, 2020.\n3. National Health Commission of the People’s Republic of China.(2020). Latest developments in\nepidemic control on Feb 15. Retrieved from http://en.nhc.gov.cn/2020-02/16/c_76622. Accessed\nMarch 11, 2020.\n15\n4. Health Commission of the People’s Republic of China.(2020). The notification of the trial\noperation based on the guideline version 6 in the coronavirus disease diagnosis and treatment.", "Retrieved from\nhttp://www.nhc.gov.cn/xcs/zhengcwj/202002/8334a8326dd94d329df351d7da8aefc2.shtml.\nAccessed March 11, 2020\n5. Health Commission of the People’s Republic of China.(2020). The notification of the trial\noperation based on the guideline version 6 in the coronavirus disease diagnosis and treatment.\nRetrieved from\nhttp://www.nhc.gov.cn/xcs/zhengcwj/202002/8334a8326dd94d329df351d7da8aefc2.shtml.\nAccessed March 11, 2020.\n6. Health Commission of the People’s Republic of China.(2009). The guideline for pathogens\nisolated operations in hospital. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/200904/40116.shtml. Accessed March 11, 2020.\n7. Health Commission of the People’s Republic of China.(2017). The guideline for prevention and\ncontrol of hospital acquired infections of airborne pathogens. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201701/7e0e8fc6725843aabba8f841f2f585d2.shtml. Accessed\nMarch 11, 2020.", "8. Health Commission of the People’s Republic of China.(2017). The guideline for prevention and\ncontrol of hospital acquired infections of airborne pathogens. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201701/7e0e8fc6725843aabba8f841f2f585d2.shtml. Accessed\nMarch 11, 2020.\n9. Health Commission of the People’s Republic of China.(2012). The standardization for\nsterilization techniques in hospital. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201204/54510.shtml. Accessed March 11, 2020.\n10. Health Commission of the People’s Republic of China.(2012). The standardization for\nsterilization techniques in hospital. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201204/54510.shtml. Accessed March 11, 2020.\n11. Katona P. Bioterrorism Preparedness: Generic Blueprint for Health Departments, Hospitals, and\nPhysicians. Infectious Diseases in Clinical Practice. 2002;11(3):115-122. Accessed March 11,\n2020.\n16\nFigure Legends", "Figure 1. Diagram of the layout of our radiology department was divided into four areas: contaminated\n(shaded in black), semicontaminated (shaded in dark gray), buffer (shaded in light gray), and clean areas\n(shaded in white). The contaminated area was separated from other areas by barriers.\nFigure 2. Diagram shows CT protocol for suspected and confirmed patients with COVID-19.\nFigure 3. Diagram shows CT protocol for regular patients.\nAbbreviations:\nCOVID-19: coronavirus disease 2019\nCT: computed tomography\nDR: digital radiography\nEMICT: emergency management and infection control team\nNHC: National Health Commission\nPACS: picture archiving and communication system\nSARS: severe acute respiratory syndrome", "Sentence Summary\nWith severe infectious diseases such as COVID-19, the highest level of infection control\nmeasures must be implemented, collaboration with the radiology departments of other\nhospitals be needed, and social media be employed.\nTake-home points\n1. To response to a community infection emergency, a special emergency management team\nneeds to be setup at the departmental level to implement infection containment and\ncontrol procedures that continues to allow the imaging examination and imaging\ndiagnosis of those with suspected infection, and to prevent intra-departmental spreading\nof infection (EMICT).\n2. Infection control measures, such as reconfiguration of department areas, personal\nprotection and anti-infection training of all staff, standardized procedures including\ncontact minimization for chest CT and DR examinations, and timely disinfection of CT\nand DR examination rooms, should be implemented properly.", "3. If there are more than one scanner in a hospital, only one of them should be assigned to\nsuspected cases." ]	[ 6 ]	3,975	6,764
188	What kind of masks are recommended to protect healthcare workers from COVID-19 exposure?	242	[ "N95 mask" ]	[ "The Battle Against Coronavirus Disease 2019 (COVID-19): Emergency Management\nand Infection Control in a Radiology Department\nhttps://www.jacr.org/article/S1546-1440(20)30285-4/pdf\nJournal Pre-proof\nZixing Huang, Shuang Zhao, Zhenlin Li, Weixia Chen, Lihong Zhao, Lipeng Deng, Bin\nSong\nPII: S1546-1440(20)30285-4\nDOI: https://doi.org/10.1016/j.jacr.2020.03.011\nReference: JACR 5139\nTo appear in: Journal of the American College of Radiology\nReceived Date: 24 February 2020\nRevised Date: 13 March 2020\nAccepted Date: 15 March 2020\nPlease cite this article as: Huang Z, Zhao S, Li Z, Chen W, Zhao L, Deng L, Song B, The Battle Against\nCoronavirus Disease 2019 (COVID-19): Emergency Management and Infection Control in a Radiology\nDepartment, Journal of the American College of Radiology (2020), doi: https://doi.org/10.1016/\nj.jacr.2020.03.011.\nThis is a PDF file of an article that has undergone enhancements after acceptance, such as the addition", "of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of\nrecord. This version will undergo additional copyediting, typesetting and review before it is published\nin its final form, but we are providing this version to give early visibility of the article. Please note that,\nduring the production process, errors may be discovered which could affect the content, and all legal\ndisclaimers that apply to the journal pertain.\n© 2020 Published by Elsevier Inc. on behalf of American College of Radiology\nThe Battle Against Coronavirus Disease 2019 (COVID-19): Emergency Management\nand Infection Control in a Radiology Department\nZixing Huang, Shuang Zhao, Zhenlin Li, Weixia Chen, Lihong Zhao, Lipeng Deng,\nBin Song\nDepartment of Radiology, West China Hospital, Sichuan University, Chengdu, China\n*Zixing Huang and Shuang Zhao contributed equally to this work as co-first author.\nCorresponding Author: Bin Song, MD", "Address: Department of Radiology, West China Hospital, Sichuan University.\nNo. 37, GUOXUE Alley, Chengdu, 610041, China\nTel.: (+86)28 85423680, Fax: (+86)28 85582944\nEmail: [email protected].\nAuthors’ contributions\nZXH: conceived the study and drafted the manuscript.\nZS: conceived the study and drafted the manuscript.\nZLL: The member of the emergency management and infection control team (EMICT)\nand was involved in the formulation of the measures.\nWXC: The member of the EMICT and was involved in the formulation of the\nmeasures.\nLHZ: The member of the EMICT and was involved in the formulation of the\nmeasures.\nLPD: The member of the EMICT and was involved in the formulation of the\nmeasures.\nBS: Leader of the EMICT, conceived the study and reviewed the manuscript.\nAll authors read and approved the final manuscript.\nThe authors declare no conflict of interest.\nThe authors declare that they had full access to all of the data in this study and the", "authors take complete responsibility for the integrity of the data and the accuracy of\nthe data analysis\n1\nThe Battle Against Novel Coronavirus Pneumonia (COVID-19): Emergency\nManagement and Infection Control in a Radiology Department\nAbstract\nObjective: To describe the strategy and the emergency management and infection control\nprocedure of our radiology department during the COVID-19 outbreak.\nMethods: We set up emergency management and sensing control teams. The team formulated\nvarious measures: reconfiguration of the radiology department, personal protection and training\nof staff, examination procedures for patients suspected of or confirmed with COVID-19 as well\nas patients without an exposure history or symptoms. Those with suspected or confirmed\nCOVID-19 infection were scanned in the designated fever-CT unit.\nResults: From January 21, 2020 to March 9, 2020, 3,083 people suspected of or confirmed with\nCOVID-19 underwent fever-CT examinations. Including initial examinations and", "reexaminations, the total number of fever-CT examinations numbered 3,340. As a result of our\nprecautions, none of the staff of the radiology department were infected with COVID-19.\nConclusion: Strategic planning and adequate protections can help protect patients and staff\nagainst a highly infectious disease while maintaining function at a high volume capacity.\nKeywords: Coronavirus, COVID-19, novel coronavirus pneumonia, infection control", "2\nIntroduction\nThe whole world has been closely focusing on an outbreak of respiratory disease caused by a\nnovel coronavirus that was first reported in Wuhan, China, on December 31, 2019, and that\ncontinues to spread. On February 11, 2020, the World Health Organization (WHO) named the\ndisease “coronavirus disease 2019” (COVID-19).\nAs of 24:00 on March 11, 2020, the National Health Commission (NHC) had received reports\nof 80,793 confirmed cases and 3,169 deaths on the Chinese mainland. There remain 14,831\nconfirmed cases (including 4,257 in serious condition) and 253 suspected cases still\nhospitalized. To date, 677,243 people have been identified as having had close contact with\ninfected patients of whom13,701 are under medical observation [1]. Outside China, 44,067\nlaboratory-confirmed cases and 1,440 deaths have occurred in 117 countries /territories/areas\naccording to the WHO [2]. COVID-19 poses significant threats to international health. Like the", "flu, COVID-19 is thought to spread mainly from person-to-person between people who are in\nclose contact with one another through respiratory droplets produced when an infected person\ncoughs or sneezes. In light of the infectious nature of this disease, healthcare workers are at\nhigh risk of infection of COVID-19. In China, healthcare workers account for 1,716 confirmed\ncases of COVID-19, including six deaths [3].\n Computed tomography (CT) can play a role in both diagnosing and categorizing\nCOVID-19 on the basis of case definitions issued by the WHO and the treatment guidelines\nfrom the NHC [4]. Suspected patients having the virus may undergo chest CT. Isolation and\nbarrier procedures are necessary to protect both the department staff and other patients in the\nhospital. Note should be made that due to overlap of imaging findings with other respiratory\n3\ndiseases, CT is not helpful as a screening tool. But it can help identify the degree of pulmonary\ninvolvement and disease course.", "Our hospital is a national regional medical center with 4,300 beds and a tertiary referral\ncenter in Sichuan province. The initial response started on January 21, 2020, after transmission\nof COVID-19 was confirmed to be human-to-human on January 20, 2020. The first suspected\ncase of COVID-19 in Sichuan province was reported on January 21, 2020. The Sichuan\nprovincial government immediately launched the first-level response to major public health\nemergencies. On the same day, our hospital was designated to care for Sichuan province\npatients with COVID-19.\nThis article describes the emergency management procedure of our radiology department\nfor situations involving severe infectious diseases, such as COVID-19, and the\ninfection-protection experience of the department staff.\nMethods\nThe hospital provided personal protective equipment (medical protective clothing,\nsurgical cap, N95 mask, gloves, face shields, and goggles) to all its healthcare staff, erected", "three medical tents (fever tents) for screening of fever cases in the parking lot of the emergency\ndepartment, planned an examination route and examination area for patients suspected of\nharboring the virus, and placed confirmed patients in an isolation ward. “Fever” was the\ncolloquial term used to designate suspected COVID-19 based on symptoms such as a fever or\nwith an epidemiological history of a potential exposure as well as those with confirmed\nCOVID-19 referred for treatment. Further, during outbreak, emergency and outpatient patients\n4\nwithout fever were asked for information such as epidemiological history and sent to fever tents\nas long as they met suspected criteria.\nThe radiology department has 65 diagnostic radiologists and 161 other staff members\n(trained technologists, nurses, engineers, and support staff). The equipment of the radiology\ndepartment includes 12 magnetic resonance (MR) scanners, 14 CT scanners, 15 digital", "subtraction angiography (DSA) systems, 32 sets of digital radiography (DR) systems\n(including nine mobile bedside DR sets), and 130 imaging diagnostic workstations for picture\narchiving and communication systems (PACS). Most of the equipment is distributed among\nfour buildings at the hospital main campus. 4 CT scanners, 4 MR scanners, 1 DR are located on\nthe first floor of the first inpatient building, and 9 DR and 8 DSA are located on the second\nfloor. 1 CT and 1 MR scanner are located in the third inpatient building. 1 CT and 1 MR scanner\nare located in the sixth inpatient building. 2 CT scanners, 2 MR scanners and 7 DSA are located\nin the technical building. The rest of the equipment is located in the seventh inpatient building\nin the branch campus.\nThe first inpatient building, located next to the emergency department, was reconfigured to\nhandle cases of COVID-19. Fever tents were set up by the emergency department in the", "emergency department parking lot to separate normal emergency patients from patients with\nsymptoms or exposure history suspicious of COVID-19. We established separate means of\naccess between fever tents and between the fever examination area of the radiology department\nto avoid cross-contamination.\nThe emergency management and infection control measures, as described below and\nimplemented in the radiology department during the outbreak, have been approved by the\n5\ninfection control committee of hospital. These measures are in accordance with relevant laws\nand regulations, in order to protect patients as well as the staff.\nRadiology Emergency Management and Infection Control Team (EMICT)\nThe radiology department director chaired the EMICT. Its members include the deputy\ndirector, chief technologist, head nurse, equipment engineer supervisor, and infection control\nnurse of the radiology department. Team responsibilities included (1) coordination between the", "hospital’s management and planning of infection control and radiology departments; (2)\ncollection of the most up-to-date protection-related information to educate and train staff in the\ndepartment; (3) reallocation of staff according to the actual situation; (4) establishment of the\nCT procedures for patients with COVID-19; and (5) establishment of an emergency\nmanagement plan for the radiology department to ensure that the department would run\nnormally.\nSuspected patients\nThe suspected patients were identified according to the Diagnosis and Treatment Program of\nthe Novel Coronavirus Pneumonia of the NHC [5], mainly based on epidemiological history.\nReconfiguration of the radiology department\nThe radiology department was divided into four areas [6]: contaminated, semicontaminated,\nbuffer, and clean areas (Figure 1). The contaminated area is connected to the fever clinic and\nincludes the fever accessway, the CT examination room, and the DR examination room for\n6", "confirmed and suspected cases. One CT scanner and one DR system closest to the emergency\ndepartment are designated the fever-CT and fever-DR to examine patients with suspected and\nconfirmed COVID-19. There is a separate dedicated access between the contaminated area and\nthe fever screening tents. The semicontaminated area includes the fever-CT control room,\nfever-DR control room, and other patient examination access areas. The buffer zone includes\naccess areas for medical personnel and a dressing area for technologists. The clean area\nincludes the administrative office and the diagnostic room.\nThe contaminated area was isolated from other areas using physical barricades.\nDirectional signs were newly installed to guide patients and staff.\nPersonal protection and training of staff\nFor providing care for patients with confirmed and suspected COVID-19, all hospital staff\nare required to wear complete personal protective equipment [7]: medical protective clothing,", "surgical cap, N95 mask, gloves, face shields, and goggles. Wearing and removing of the\nequipment must be performed in accordance with the procedures and under the supervision of\nthe infection control nurse.\nBecause staff members working in the contaminated area are under much situational\npressure, periodically taking time off could lower their physical and mental stress levels. The\ntechnologists on fever-CT duty shifts are provided a break once a week for four hours. In\naddition, the health of staff in the contaminated area must be monitored closely for the\nsymptoms of COVID-19. Pregnant staff must be assigned to the clean area.\n7\nThe EMICT formulates and continually updates guidelines and educates all staff for West\nChina Hospital of Sichuan University. The EMICT training for staff is mainly involves\ndocuments regarding infection control and CT findings of COVID-19 and maintains an EMICT\nWeChat group for West China Hospital of Sichuan University. WeChat is the most widely used", "social media app in China. The EMICT releases the latest national and hospital-based\ninformation regarding COVID-19, guidance documents, and other notices from the hospital\nand radiology department in the WeChat group on a daily basis. Staff can also report to the\nEMICT in the WeChat group any time. Protocols for each modality and infection control\ninstructions are posted on the walls in all examination rooms. The EMICT periodically reminds\nstaff to undertake personal measures to reduce infection, such as wearing masks at all instances\nin the radiology department and N95 masks if working in the contaminated area; not touching\nthe mask and the eyes; practicing hand hygiene; facing away from colleagues when eating,\ndrinking, and talking; and not using personal cell phones while on duty.\n In addition, the chief thoracic radiologist provided lectures on all radiologists and\ntechnologists on typical CT findings of COVID-19 infection using materials developed in", "Wuhan, the epicenter of the outbreak in China.\nCT examination procedures\nThere are two sets of procedures for CT examination: the fever-CT procedure and routine CT\nprocedure for those not suspected of COVID-19.\nThe fever-CT procedure for suspected or confirmed COVID-19 (Figure 2)\n8\nBefore the fever-CT technologist operates the equipment, he or she should wear personal\nprotective equipment according to three-level protection standard [8]. Before the CT\nexamination of patients with suspected and confirmed COVID-19 begins, the fever tent or\nisolation ward notifies the radiologist in advance. The fever-CT technologist checks the\nequipment and prepares to disinfect the imaging equipment immediately after the examination.\nThe patient enters the fever-CT waiting area through the fever access area. If the patient\ncan get onto and off the examination table by themselves, the patient is allowed to do so. If the", "patient cannot get onto or off the examination table independently, the person accompanying\nthe patient assists the patient, rather than the technologist. The technologist checks the patient\ninformation and, using an intercom system in the examination room, asks the patient to remove\nany metal ornaments on the neck and chest. Also, by intercom, the technologist trains the\npatient to hold his or her breath during the examination.\nThe technologist uses a low-dose chest CT protocol to scan the patient. After scanning, the\noriginal images are reconstructed as 1 mm-thick layers. The technologist browses the images to\nensure that their quality meets the diagnostic requirements and then guides the patient to leave\nthrough the fever access area. The disposable sheets for patient examination are changed after\neach patient. The equipment is disinfected according to the procedure below.\nTo protect themselves, the technologists assigned to the fever-CT wear N95 mask and", "other personal protection as established by the EMICT.\nThe CT procedure for regular patients (figure.3)\n9\nSome patients with COVID-19 have no symptoms, and they may call at the general clinic for\nother reasons. The following CT procedure is applicable under these circumstances:\nWhen the patient makes an appointment for examination, the staff asks the patient about\ntheir epidemiological history, symptoms, and signs. If suspected criteria are met, the patient\nwill be sent to the fever tent for further screening. When a patient presents to the radiology\ndepartment entrance, his/her temperature is measured. If the temperature is higher than 37.2 , ℃\nthe patient is sent to the fever tent for further investigation.\nThose with no exposure history, suspicious symptoms or fever are screened in one of the\nnon-contaminated CT scanners. The technologists assigned to these scanners wear surgical\nmasks. All patients and the person accompanying them are required to wear surgical masks.", "After the CT examination, the technologist browses the images quickly. If the CT appearance is\ntypical of lung infection, the technologist immediately reports it to the chest radiologist on duty\nand asks the patient to wait in the CT examination room. If the chest radiologist does not\nsuspect COVID-19 infection, the patient can leave the CT examination room. If the chest\nradiologist does suspect COVID-19 infection, the technologist immediately reports it to the\nEMICT and sends the patient to the fever tent. The floor and equipment in the CT examination\nroom are disinfected according to regulations, and air disinfection is conducted for 30 min\nbefore examining other patients. These CT scanners are considered noncontaminated (not\nfever-CTs) after these sterilization procedures.\nFever-DR examination procedure\n10\nThe COVID-19 guideline of the NHC does not recommend chest DR because its ability in\ndiagnosing COVID-19 is limited. At our hospital, we only use mobile DR units to provide", "bedside examination for critically ill patients. The technologist operating the mobile DR\nwears personal protective equipment according to the three-level protection standard and\nsterilizes the mobile DR according to the ward management requirements as described below.\nEquipment and environment disinfection procedures\nRoutine disinfection procedure [9]\n1) Object surface disinfection: Object surface is wiped with 1000mg/L chlorine-containing\ndisinfectant, wipe twice with 75% ethanol for non-corrosion resistance, once /4 hours.\n2) Equipment disinfection: The equipment in the contaminated area are wiped with\n2000mg/L chlorine-containing disinfectant. The DR and CT gantry in the contaminated\narea are wiped with 75% ethanol. The equipment in the buffer area is wiped with\n500-1000mg/L chlorine-containing disinfectant or alcohol-containing disposable\ndisinfectant wipes twice a day.\n3) Air disinfection: Turning off all central air conditioners to prevent air contamination with", "each other. Polluted area: open the door for ventilation, each time more than 30 minutes,\nonce /4 hours; The air sterilizer is continuously sterilized or the ultraviolet ray is\ncontinuously used in the unmanned state for 60 minutes, four times a day, remembered to\nclose the inner shielding door when air disinfection. Other ambient air is sprayed with\n1000mg/L chlorine-containing disinfectant and ventilated twice a day\n4) Ground disinfection: The ground is wiped with 1000mg/L chlorine-containing\ndisinfectant, once /4 hours.\n5) When contaminated, disinfect at any time. In case of visible contamination, disposable\nabsorbent materials should be used first to completely remove the pollutants, and then a\ncloth soaked with 2000mg/L chlorine-containing disinfectant should be used for 30\nminutes before wiping.\n11\nFever-CT disinfection procedures after examination\nIn addition to the above, disinfect the examination bed and ground with chlorinated disinfectant\ncontaining 2000mg/L [10].", "Noncontaminated CT disinfection procedures after suspected COVID-19 case examination\nIn addition to the above routine disinfection procedure, air disinfection is conducted for 30 min\nbefore examining other patients.\nResults\nFrom January 21, 2020 when screening for epidemiological history or symptoms\nsuspicious for COVID-19, to March 9, 2020, our hospital screened a total of 7,203 individuals\nand confirmed 24 cases of COVID-19. Of these, 3,083 people underwent fever-CT\nexaminations. Including the initial examination and reexamination, the total number of fever\nCT examination numbered 3,340. The fever-CT scanned a patient approximately every 21.5\nminutes. As a result of our precautions, none of the staff of the radiology department developed\nsymptoms suspicious for COVID-19. The fever-CT technologist, with the highest probability\nof exposure, remains PCR negative.\nDiscussion\nIt has been 17 years since the severe acute respiratory syndrome (SARS) epidemic, the last", "national spread of severe infectious disease, broke out. Currently, the Chinese people are\npanicking again. The speed and extent by which COVID-19 has spread in 2 months are\n12\nunprecedented, beyond those of SARS, and this has been aided by its contagious nature and\nrapid spread via droplets and contact. The droplet mode of transmission means that a person can\nbe infected easily by means of casual contact or even fomites on contaminated environmental\nsurfaces. Another theory has yet to be proved: aerosol propagation.\nHow radiology departments respond to any infectious disease outbreak is determined\nprimarily by the estimated risk of cross-infection to the staff and other patients. Appropriate\nprecautions taken only by staff in direct contact with patients may be adequate when the risk is\nlow. The strongest measures need to be implemented to limit the spread of the disease when the\nrisk is high. With severe infectious diseases such as COVID-19, the highest level of infection", "control measures must be implemented; these include providing adequate standard protective\nequipment, training staff, and instituting proper emergency plans.\nOnce a contagious infectious disease has been identified, the EMICT must consider four\nmain areas of response: data gathering, collaboration, needs assessment, and expert advice [10].\nData gathering includes dissemination of up-to-date case definitions and information about\nconfirmatory tests to all staff with direct patient contact to allow appropriate barrier precautions\nto be taken. All typical and atypical imaging features of the disease should be made known to\nall radiologists to assist in recognition of the disease on images and to allow accurate reporting\nof these findings. We have stored images of all probable cases of COVID-19 in the PACS so\nthat these images were readily available for any radiologist to review, and images from\nprevious imaging studies are also available for comparison.", "Collaboration with the radiology departments of other hospitals is very important because\npatients may initially present to different centers, depending on geographic location and travel\n13\ndistance. These patients may be few in number at a single hospital, but if data from patients at\nseveral hospitals are available, a more accurate overall understanding of both imaging features\nand epidemiology can be achieved. Dissemination of this information to all healthcare facilities\nwill also lead to early recognition of the disease, and appropriate isolation measures may be\ninstituted.\nThe Internet and social media apps, especially WeChat, have been used for distribution of\nmedical information, and because the exchange of information regarding infectious disease\noutbreaks is almost instantaneous, it is an indispensable tool for radiologists. In fact, within a\nmonth of the outbreak, the hospital that received the most infected patients from the source of", "the outbreak made a PowerPoint presentation of the CT manifestations of COVID-19, which\nwas shared via WeChat and disseminated across the country in a very short time. Subsequently,\nCOVID-19-teaching PowerPoint presentations from various hospitals appeared and were\nquickly shared via WeChat.\nOur diagnostic process is limited as chest CT along is not diagnostic of COVID-19\nbecause of lack of imaging specificity. But when combined with other epidemiological,\nclinical, laboratory and virus nucleic acid information, typical chest CT imaging findings are\nhelpful for making the diagnosis. In our opinion, the major role of chest CT is to understand the\nextent and dynamic evolution of lung lesions induced by COVID-19. The reasons why we\nadopted the low-dose chest CT scan protocol are as follows: low-dose chest CT has been\nwidely used in the screening of early lung cancer. It is well known that many early lung cancers", "are ground-glass opacities (GGO), so we believe that low-dose screening is also applicable for\nCOVID-19. In addition, considering the rapid development of COVID-19, many CT\n14\nexaminations may be conducted in the same individual to monitor disease progress. Low-dose\nscanning can reduce the radiation damage to patients.\nAlthough the processes we established minimized the exposure of hospital staff, ancillary\npersonnel and other patients, it remains limited as follows. Sichuan province is not the center of\nthe epidemic. The number of patients with COVID-19 whom we have treated has not been\nhigh, and most cases are from other provinces of China. However, we believe that our\nexperience in management, the reconfiguration of our radiology department, and the workflow\nchanges implemented in the current COVID-19 situation are useful for other radiology\ndepartments that must prepare for dealing with patients with COVID-19. While no radiology", "personnel developed symptoms suspicious for or were confirmed as having COVID-19, there\nmay be asymptomatic personnel.\nREFERENCES\n1. National Health Commission of the People’s Republic of China.(2020). March 12: Daily briefing\non novel coronavirus cases in China. Retrieved from\nhttp://en.nhc.gov.cn/2020-03/12/c_77618.htm. Accessed March 11, 2020.\n2. World Health Organization. (2020). Coronavirus disease 2019 (COVID-19) Situation Report-52.\nRetrieved from\nhttps://www.who.int/docs/default-source/coronaviruse/20200312-sitrep-52-covid-19.pdf?sfvrsn=e\n2bfc9c0_2 9. Accessed March 11, 2020.\n3. National Health Commission of the People’s Republic of China.(2020). Latest developments in\nepidemic control on Feb 15. Retrieved from http://en.nhc.gov.cn/2020-02/16/c_76622. Accessed\nMarch 11, 2020.\n15\n4. Health Commission of the People’s Republic of China.(2020). The notification of the trial\noperation based on the guideline version 6 in the coronavirus disease diagnosis and treatment.", "Retrieved from\nhttp://www.nhc.gov.cn/xcs/zhengcwj/202002/8334a8326dd94d329df351d7da8aefc2.shtml.\nAccessed March 11, 2020\n5. Health Commission of the People’s Republic of China.(2020). The notification of the trial\noperation based on the guideline version 6 in the coronavirus disease diagnosis and treatment.\nRetrieved from\nhttp://www.nhc.gov.cn/xcs/zhengcwj/202002/8334a8326dd94d329df351d7da8aefc2.shtml.\nAccessed March 11, 2020.\n6. Health Commission of the People’s Republic of China.(2009). The guideline for pathogens\nisolated operations in hospital. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/200904/40116.shtml. Accessed March 11, 2020.\n7. Health Commission of the People’s Republic of China.(2017). The guideline for prevention and\ncontrol of hospital acquired infections of airborne pathogens. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201701/7e0e8fc6725843aabba8f841f2f585d2.shtml. Accessed\nMarch 11, 2020.", "8. Health Commission of the People’s Republic of China.(2017). The guideline for prevention and\ncontrol of hospital acquired infections of airborne pathogens. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201701/7e0e8fc6725843aabba8f841f2f585d2.shtml. Accessed\nMarch 11, 2020.\n9. Health Commission of the People’s Republic of China.(2012). The standardization for\nsterilization techniques in hospital. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201204/54510.shtml. Accessed March 11, 2020.\n10. Health Commission of the People’s Republic of China.(2012). The standardization for\nsterilization techniques in hospital. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201204/54510.shtml. Accessed March 11, 2020.\n11. Katona P. Bioterrorism Preparedness: Generic Blueprint for Health Departments, Hospitals, and\nPhysicians. Infectious Diseases in Clinical Practice. 2002;11(3):115-122. Accessed March 11,\n2020.\n16\nFigure Legends", "Figure 1. Diagram of the layout of our radiology department was divided into four areas: contaminated\n(shaded in black), semicontaminated (shaded in dark gray), buffer (shaded in light gray), and clean areas\n(shaded in white). The contaminated area was separated from other areas by barriers.\nFigure 2. Diagram shows CT protocol for suspected and confirmed patients with COVID-19.\nFigure 3. Diagram shows CT protocol for regular patients.\nAbbreviations:\nCOVID-19: coronavirus disease 2019\nCT: computed tomography\nDR: digital radiography\nEMICT: emergency management and infection control team\nNHC: National Health Commission\nPACS: picture archiving and communication system\nSARS: severe acute respiratory syndrome", "Sentence Summary\nWith severe infectious diseases such as COVID-19, the highest level of infection control\nmeasures must be implemented, collaboration with the radiology departments of other\nhospitals be needed, and social media be employed.\nTake-home points\n1. To response to a community infection emergency, a special emergency management team\nneeds to be setup at the departmental level to implement infection containment and\ncontrol procedures that continues to allow the imaging examination and imaging\ndiagnosis of those with suspected infection, and to prevent intra-departmental spreading\nof infection (EMICT).\n2. Infection control measures, such as reconfiguration of department areas, personal\nprotection and anti-infection training of all staff, standardized procedures including\ncontact minimization for chest CT and DR examinations, and timely disinfection of CT\nand DR examination rooms, should be implemented properly.", "3. If there are more than one scanner in a hospital, only one of them should be assigned to\nsuspected cases." ]	[ 7 ]	3,975	6,764
188	What thickness of layers is recommended for CT image reconstruction in COVID-19 assessment?	243	[ "1 mm-thick layers" ]	[ "The Battle Against Coronavirus Disease 2019 (COVID-19): Emergency Management\nand Infection Control in a Radiology Department\nhttps://www.jacr.org/article/S1546-1440(20)30285-4/pdf\nJournal Pre-proof\nZixing Huang, Shuang Zhao, Zhenlin Li, Weixia Chen, Lihong Zhao, Lipeng Deng, Bin\nSong\nPII: S1546-1440(20)30285-4\nDOI: https://doi.org/10.1016/j.jacr.2020.03.011\nReference: JACR 5139\nTo appear in: Journal of the American College of Radiology\nReceived Date: 24 February 2020\nRevised Date: 13 March 2020\nAccepted Date: 15 March 2020\nPlease cite this article as: Huang Z, Zhao S, Li Z, Chen W, Zhao L, Deng L, Song B, The Battle Against\nCoronavirus Disease 2019 (COVID-19): Emergency Management and Infection Control in a Radiology\nDepartment, Journal of the American College of Radiology (2020), doi: https://doi.org/10.1016/\nj.jacr.2020.03.011.\nThis is a PDF file of an article that has undergone enhancements after acceptance, such as the addition", "of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of\nrecord. This version will undergo additional copyediting, typesetting and review before it is published\nin its final form, but we are providing this version to give early visibility of the article. Please note that,\nduring the production process, errors may be discovered which could affect the content, and all legal\ndisclaimers that apply to the journal pertain.\n© 2020 Published by Elsevier Inc. on behalf of American College of Radiology\nThe Battle Against Coronavirus Disease 2019 (COVID-19): Emergency Management\nand Infection Control in a Radiology Department\nZixing Huang, Shuang Zhao, Zhenlin Li, Weixia Chen, Lihong Zhao, Lipeng Deng,\nBin Song\nDepartment of Radiology, West China Hospital, Sichuan University, Chengdu, China\n*Zixing Huang and Shuang Zhao contributed equally to this work as co-first author.\nCorresponding Author: Bin Song, MD", "Address: Department of Radiology, West China Hospital, Sichuan University.\nNo. 37, GUOXUE Alley, Chengdu, 610041, China\nTel.: (+86)28 85423680, Fax: (+86)28 85582944\nEmail: [email protected].\nAuthors’ contributions\nZXH: conceived the study and drafted the manuscript.\nZS: conceived the study and drafted the manuscript.\nZLL: The member of the emergency management and infection control team (EMICT)\nand was involved in the formulation of the measures.\nWXC: The member of the EMICT and was involved in the formulation of the\nmeasures.\nLHZ: The member of the EMICT and was involved in the formulation of the\nmeasures.\nLPD: The member of the EMICT and was involved in the formulation of the\nmeasures.\nBS: Leader of the EMICT, conceived the study and reviewed the manuscript.\nAll authors read and approved the final manuscript.\nThe authors declare no conflict of interest.\nThe authors declare that they had full access to all of the data in this study and the", "authors take complete responsibility for the integrity of the data and the accuracy of\nthe data analysis\n1\nThe Battle Against Novel Coronavirus Pneumonia (COVID-19): Emergency\nManagement and Infection Control in a Radiology Department\nAbstract\nObjective: To describe the strategy and the emergency management and infection control\nprocedure of our radiology department during the COVID-19 outbreak.\nMethods: We set up emergency management and sensing control teams. The team formulated\nvarious measures: reconfiguration of the radiology department, personal protection and training\nof staff, examination procedures for patients suspected of or confirmed with COVID-19 as well\nas patients without an exposure history or symptoms. Those with suspected or confirmed\nCOVID-19 infection were scanned in the designated fever-CT unit.\nResults: From January 21, 2020 to March 9, 2020, 3,083 people suspected of or confirmed with\nCOVID-19 underwent fever-CT examinations. Including initial examinations and", "reexaminations, the total number of fever-CT examinations numbered 3,340. As a result of our\nprecautions, none of the staff of the radiology department were infected with COVID-19.\nConclusion: Strategic planning and adequate protections can help protect patients and staff\nagainst a highly infectious disease while maintaining function at a high volume capacity.\nKeywords: Coronavirus, COVID-19, novel coronavirus pneumonia, infection control", "2\nIntroduction\nThe whole world has been closely focusing on an outbreak of respiratory disease caused by a\nnovel coronavirus that was first reported in Wuhan, China, on December 31, 2019, and that\ncontinues to spread. On February 11, 2020, the World Health Organization (WHO) named the\ndisease “coronavirus disease 2019” (COVID-19).\nAs of 24:00 on March 11, 2020, the National Health Commission (NHC) had received reports\nof 80,793 confirmed cases and 3,169 deaths on the Chinese mainland. There remain 14,831\nconfirmed cases (including 4,257 in serious condition) and 253 suspected cases still\nhospitalized. To date, 677,243 people have been identified as having had close contact with\ninfected patients of whom13,701 are under medical observation [1]. Outside China, 44,067\nlaboratory-confirmed cases and 1,440 deaths have occurred in 117 countries /territories/areas\naccording to the WHO [2]. COVID-19 poses significant threats to international health. Like the", "flu, COVID-19 is thought to spread mainly from person-to-person between people who are in\nclose contact with one another through respiratory droplets produced when an infected person\ncoughs or sneezes. In light of the infectious nature of this disease, healthcare workers are at\nhigh risk of infection of COVID-19. In China, healthcare workers account for 1,716 confirmed\ncases of COVID-19, including six deaths [3].\n Computed tomography (CT) can play a role in both diagnosing and categorizing\nCOVID-19 on the basis of case definitions issued by the WHO and the treatment guidelines\nfrom the NHC [4]. Suspected patients having the virus may undergo chest CT. Isolation and\nbarrier procedures are necessary to protect both the department staff and other patients in the\nhospital. Note should be made that due to overlap of imaging findings with other respiratory\n3\ndiseases, CT is not helpful as a screening tool. But it can help identify the degree of pulmonary\ninvolvement and disease course.", "Our hospital is a national regional medical center with 4,300 beds and a tertiary referral\ncenter in Sichuan province. The initial response started on January 21, 2020, after transmission\nof COVID-19 was confirmed to be human-to-human on January 20, 2020. The first suspected\ncase of COVID-19 in Sichuan province was reported on January 21, 2020. The Sichuan\nprovincial government immediately launched the first-level response to major public health\nemergencies. On the same day, our hospital was designated to care for Sichuan province\npatients with COVID-19.\nThis article describes the emergency management procedure of our radiology department\nfor situations involving severe infectious diseases, such as COVID-19, and the\ninfection-protection experience of the department staff.\nMethods\nThe hospital provided personal protective equipment (medical protective clothing,\nsurgical cap, N95 mask, gloves, face shields, and goggles) to all its healthcare staff, erected", "three medical tents (fever tents) for screening of fever cases in the parking lot of the emergency\ndepartment, planned an examination route and examination area for patients suspected of\nharboring the virus, and placed confirmed patients in an isolation ward. “Fever” was the\ncolloquial term used to designate suspected COVID-19 based on symptoms such as a fever or\nwith an epidemiological history of a potential exposure as well as those with confirmed\nCOVID-19 referred for treatment. Further, during outbreak, emergency and outpatient patients\n4\nwithout fever were asked for information such as epidemiological history and sent to fever tents\nas long as they met suspected criteria.\nThe radiology department has 65 diagnostic radiologists and 161 other staff members\n(trained technologists, nurses, engineers, and support staff). The equipment of the radiology\ndepartment includes 12 magnetic resonance (MR) scanners, 14 CT scanners, 15 digital", "subtraction angiography (DSA) systems, 32 sets of digital radiography (DR) systems\n(including nine mobile bedside DR sets), and 130 imaging diagnostic workstations for picture\narchiving and communication systems (PACS). Most of the equipment is distributed among\nfour buildings at the hospital main campus. 4 CT scanners, 4 MR scanners, 1 DR are located on\nthe first floor of the first inpatient building, and 9 DR and 8 DSA are located on the second\nfloor. 1 CT and 1 MR scanner are located in the third inpatient building. 1 CT and 1 MR scanner\nare located in the sixth inpatient building. 2 CT scanners, 2 MR scanners and 7 DSA are located\nin the technical building. The rest of the equipment is located in the seventh inpatient building\nin the branch campus.\nThe first inpatient building, located next to the emergency department, was reconfigured to\nhandle cases of COVID-19. Fever tents were set up by the emergency department in the", "emergency department parking lot to separate normal emergency patients from patients with\nsymptoms or exposure history suspicious of COVID-19. We established separate means of\naccess between fever tents and between the fever examination area of the radiology department\nto avoid cross-contamination.\nThe emergency management and infection control measures, as described below and\nimplemented in the radiology department during the outbreak, have been approved by the\n5\ninfection control committee of hospital. These measures are in accordance with relevant laws\nand regulations, in order to protect patients as well as the staff.\nRadiology Emergency Management and Infection Control Team (EMICT)\nThe radiology department director chaired the EMICT. Its members include the deputy\ndirector, chief technologist, head nurse, equipment engineer supervisor, and infection control\nnurse of the radiology department. Team responsibilities included (1) coordination between the", "hospital’s management and planning of infection control and radiology departments; (2)\ncollection of the most up-to-date protection-related information to educate and train staff in the\ndepartment; (3) reallocation of staff according to the actual situation; (4) establishment of the\nCT procedures for patients with COVID-19; and (5) establishment of an emergency\nmanagement plan for the radiology department to ensure that the department would run\nnormally.\nSuspected patients\nThe suspected patients were identified according to the Diagnosis and Treatment Program of\nthe Novel Coronavirus Pneumonia of the NHC [5], mainly based on epidemiological history.\nReconfiguration of the radiology department\nThe radiology department was divided into four areas [6]: contaminated, semicontaminated,\nbuffer, and clean areas (Figure 1). The contaminated area is connected to the fever clinic and\nincludes the fever accessway, the CT examination room, and the DR examination room for\n6", "confirmed and suspected cases. One CT scanner and one DR system closest to the emergency\ndepartment are designated the fever-CT and fever-DR to examine patients with suspected and\nconfirmed COVID-19. There is a separate dedicated access between the contaminated area and\nthe fever screening tents. The semicontaminated area includes the fever-CT control room,\nfever-DR control room, and other patient examination access areas. The buffer zone includes\naccess areas for medical personnel and a dressing area for technologists. The clean area\nincludes the administrative office and the diagnostic room.\nThe contaminated area was isolated from other areas using physical barricades.\nDirectional signs were newly installed to guide patients and staff.\nPersonal protection and training of staff\nFor providing care for patients with confirmed and suspected COVID-19, all hospital staff\nare required to wear complete personal protective equipment [7]: medical protective clothing,", "surgical cap, N95 mask, gloves, face shields, and goggles. Wearing and removing of the\nequipment must be performed in accordance with the procedures and under the supervision of\nthe infection control nurse.\nBecause staff members working in the contaminated area are under much situational\npressure, periodically taking time off could lower their physical and mental stress levels. The\ntechnologists on fever-CT duty shifts are provided a break once a week for four hours. In\naddition, the health of staff in the contaminated area must be monitored closely for the\nsymptoms of COVID-19. Pregnant staff must be assigned to the clean area.\n7\nThe EMICT formulates and continually updates guidelines and educates all staff for West\nChina Hospital of Sichuan University. The EMICT training for staff is mainly involves\ndocuments regarding infection control and CT findings of COVID-19 and maintains an EMICT\nWeChat group for West China Hospital of Sichuan University. WeChat is the most widely used", "social media app in China. The EMICT releases the latest national and hospital-based\ninformation regarding COVID-19, guidance documents, and other notices from the hospital\nand radiology department in the WeChat group on a daily basis. Staff can also report to the\nEMICT in the WeChat group any time. Protocols for each modality and infection control\ninstructions are posted on the walls in all examination rooms. The EMICT periodically reminds\nstaff to undertake personal measures to reduce infection, such as wearing masks at all instances\nin the radiology department and N95 masks if working in the contaminated area; not touching\nthe mask and the eyes; practicing hand hygiene; facing away from colleagues when eating,\ndrinking, and talking; and not using personal cell phones while on duty.\n In addition, the chief thoracic radiologist provided lectures on all radiologists and\ntechnologists on typical CT findings of COVID-19 infection using materials developed in", "Wuhan, the epicenter of the outbreak in China.\nCT examination procedures\nThere are two sets of procedures for CT examination: the fever-CT procedure and routine CT\nprocedure for those not suspected of COVID-19.\nThe fever-CT procedure for suspected or confirmed COVID-19 (Figure 2)\n8\nBefore the fever-CT technologist operates the equipment, he or she should wear personal\nprotective equipment according to three-level protection standard [8]. Before the CT\nexamination of patients with suspected and confirmed COVID-19 begins, the fever tent or\nisolation ward notifies the radiologist in advance. The fever-CT technologist checks the\nequipment and prepares to disinfect the imaging equipment immediately after the examination.\nThe patient enters the fever-CT waiting area through the fever access area. If the patient\ncan get onto and off the examination table by themselves, the patient is allowed to do so. If the", "patient cannot get onto or off the examination table independently, the person accompanying\nthe patient assists the patient, rather than the technologist. The technologist checks the patient\ninformation and, using an intercom system in the examination room, asks the patient to remove\nany metal ornaments on the neck and chest. Also, by intercom, the technologist trains the\npatient to hold his or her breath during the examination.\nThe technologist uses a low-dose chest CT protocol to scan the patient. After scanning, the\noriginal images are reconstructed as 1 mm-thick layers. The technologist browses the images to\nensure that their quality meets the diagnostic requirements and then guides the patient to leave\nthrough the fever access area. The disposable sheets for patient examination are changed after\neach patient. The equipment is disinfected according to the procedure below.\nTo protect themselves, the technologists assigned to the fever-CT wear N95 mask and", "other personal protection as established by the EMICT.\nThe CT procedure for regular patients (figure.3)\n9\nSome patients with COVID-19 have no symptoms, and they may call at the general clinic for\nother reasons. The following CT procedure is applicable under these circumstances:\nWhen the patient makes an appointment for examination, the staff asks the patient about\ntheir epidemiological history, symptoms, and signs. If suspected criteria are met, the patient\nwill be sent to the fever tent for further screening. When a patient presents to the radiology\ndepartment entrance, his/her temperature is measured. If the temperature is higher than 37.2 , ℃\nthe patient is sent to the fever tent for further investigation.\nThose with no exposure history, suspicious symptoms or fever are screened in one of the\nnon-contaminated CT scanners. The technologists assigned to these scanners wear surgical\nmasks. All patients and the person accompanying them are required to wear surgical masks.", "After the CT examination, the technologist browses the images quickly. If the CT appearance is\ntypical of lung infection, the technologist immediately reports it to the chest radiologist on duty\nand asks the patient to wait in the CT examination room. If the chest radiologist does not\nsuspect COVID-19 infection, the patient can leave the CT examination room. If the chest\nradiologist does suspect COVID-19 infection, the technologist immediately reports it to the\nEMICT and sends the patient to the fever tent. The floor and equipment in the CT examination\nroom are disinfected according to regulations, and air disinfection is conducted for 30 min\nbefore examining other patients. These CT scanners are considered noncontaminated (not\nfever-CTs) after these sterilization procedures.\nFever-DR examination procedure\n10\nThe COVID-19 guideline of the NHC does not recommend chest DR because its ability in\ndiagnosing COVID-19 is limited. At our hospital, we only use mobile DR units to provide", "bedside examination for critically ill patients. The technologist operating the mobile DR\nwears personal protective equipment according to the three-level protection standard and\nsterilizes the mobile DR according to the ward management requirements as described below.\nEquipment and environment disinfection procedures\nRoutine disinfection procedure [9]\n1) Object surface disinfection: Object surface is wiped with 1000mg/L chlorine-containing\ndisinfectant, wipe twice with 75% ethanol for non-corrosion resistance, once /4 hours.\n2) Equipment disinfection: The equipment in the contaminated area are wiped with\n2000mg/L chlorine-containing disinfectant. The DR and CT gantry in the contaminated\narea are wiped with 75% ethanol. The equipment in the buffer area is wiped with\n500-1000mg/L chlorine-containing disinfectant or alcohol-containing disposable\ndisinfectant wipes twice a day.\n3) Air disinfection: Turning off all central air conditioners to prevent air contamination with", "each other. Polluted area: open the door for ventilation, each time more than 30 minutes,\nonce /4 hours; The air sterilizer is continuously sterilized or the ultraviolet ray is\ncontinuously used in the unmanned state for 60 minutes, four times a day, remembered to\nclose the inner shielding door when air disinfection. Other ambient air is sprayed with\n1000mg/L chlorine-containing disinfectant and ventilated twice a day\n4) Ground disinfection: The ground is wiped with 1000mg/L chlorine-containing\ndisinfectant, once /4 hours.\n5) When contaminated, disinfect at any time. In case of visible contamination, disposable\nabsorbent materials should be used first to completely remove the pollutants, and then a\ncloth soaked with 2000mg/L chlorine-containing disinfectant should be used for 30\nminutes before wiping.\n11\nFever-CT disinfection procedures after examination\nIn addition to the above, disinfect the examination bed and ground with chlorinated disinfectant\ncontaining 2000mg/L [10].", "Noncontaminated CT disinfection procedures after suspected COVID-19 case examination\nIn addition to the above routine disinfection procedure, air disinfection is conducted for 30 min\nbefore examining other patients.\nResults\nFrom January 21, 2020 when screening for epidemiological history or symptoms\nsuspicious for COVID-19, to March 9, 2020, our hospital screened a total of 7,203 individuals\nand confirmed 24 cases of COVID-19. Of these, 3,083 people underwent fever-CT\nexaminations. Including the initial examination and reexamination, the total number of fever\nCT examination numbered 3,340. The fever-CT scanned a patient approximately every 21.5\nminutes. As a result of our precautions, none of the staff of the radiology department developed\nsymptoms suspicious for COVID-19. The fever-CT technologist, with the highest probability\nof exposure, remains PCR negative.\nDiscussion\nIt has been 17 years since the severe acute respiratory syndrome (SARS) epidemic, the last", "national spread of severe infectious disease, broke out. Currently, the Chinese people are\npanicking again. The speed and extent by which COVID-19 has spread in 2 months are\n12\nunprecedented, beyond those of SARS, and this has been aided by its contagious nature and\nrapid spread via droplets and contact. The droplet mode of transmission means that a person can\nbe infected easily by means of casual contact or even fomites on contaminated environmental\nsurfaces. Another theory has yet to be proved: aerosol propagation.\nHow radiology departments respond to any infectious disease outbreak is determined\nprimarily by the estimated risk of cross-infection to the staff and other patients. Appropriate\nprecautions taken only by staff in direct contact with patients may be adequate when the risk is\nlow. The strongest measures need to be implemented to limit the spread of the disease when the\nrisk is high. With severe infectious diseases such as COVID-19, the highest level of infection", "control measures must be implemented; these include providing adequate standard protective\nequipment, training staff, and instituting proper emergency plans.\nOnce a contagious infectious disease has been identified, the EMICT must consider four\nmain areas of response: data gathering, collaboration, needs assessment, and expert advice [10].\nData gathering includes dissemination of up-to-date case definitions and information about\nconfirmatory tests to all staff with direct patient contact to allow appropriate barrier precautions\nto be taken. All typical and atypical imaging features of the disease should be made known to\nall radiologists to assist in recognition of the disease on images and to allow accurate reporting\nof these findings. We have stored images of all probable cases of COVID-19 in the PACS so\nthat these images were readily available for any radiologist to review, and images from\nprevious imaging studies are also available for comparison.", "Collaboration with the radiology departments of other hospitals is very important because\npatients may initially present to different centers, depending on geographic location and travel\n13\ndistance. These patients may be few in number at a single hospital, but if data from patients at\nseveral hospitals are available, a more accurate overall understanding of both imaging features\nand epidemiology can be achieved. Dissemination of this information to all healthcare facilities\nwill also lead to early recognition of the disease, and appropriate isolation measures may be\ninstituted.\nThe Internet and social media apps, especially WeChat, have been used for distribution of\nmedical information, and because the exchange of information regarding infectious disease\noutbreaks is almost instantaneous, it is an indispensable tool for radiologists. In fact, within a\nmonth of the outbreak, the hospital that received the most infected patients from the source of", "the outbreak made a PowerPoint presentation of the CT manifestations of COVID-19, which\nwas shared via WeChat and disseminated across the country in a very short time. Subsequently,\nCOVID-19-teaching PowerPoint presentations from various hospitals appeared and were\nquickly shared via WeChat.\nOur diagnostic process is limited as chest CT along is not diagnostic of COVID-19\nbecause of lack of imaging specificity. But when combined with other epidemiological,\nclinical, laboratory and virus nucleic acid information, typical chest CT imaging findings are\nhelpful for making the diagnosis. In our opinion, the major role of chest CT is to understand the\nextent and dynamic evolution of lung lesions induced by COVID-19. The reasons why we\nadopted the low-dose chest CT scan protocol are as follows: low-dose chest CT has been\nwidely used in the screening of early lung cancer. It is well known that many early lung cancers", "are ground-glass opacities (GGO), so we believe that low-dose screening is also applicable for\nCOVID-19. In addition, considering the rapid development of COVID-19, many CT\n14\nexaminations may be conducted in the same individual to monitor disease progress. Low-dose\nscanning can reduce the radiation damage to patients.\nAlthough the processes we established minimized the exposure of hospital staff, ancillary\npersonnel and other patients, it remains limited as follows. Sichuan province is not the center of\nthe epidemic. The number of patients with COVID-19 whom we have treated has not been\nhigh, and most cases are from other provinces of China. However, we believe that our\nexperience in management, the reconfiguration of our radiology department, and the workflow\nchanges implemented in the current COVID-19 situation are useful for other radiology\ndepartments that must prepare for dealing with patients with COVID-19. While no radiology", "personnel developed symptoms suspicious for or were confirmed as having COVID-19, there\nmay be asymptomatic personnel.\nREFERENCES\n1. National Health Commission of the People’s Republic of China.(2020). March 12: Daily briefing\non novel coronavirus cases in China. Retrieved from\nhttp://en.nhc.gov.cn/2020-03/12/c_77618.htm. Accessed March 11, 2020.\n2. World Health Organization. (2020). Coronavirus disease 2019 (COVID-19) Situation Report-52.\nRetrieved from\nhttps://www.who.int/docs/default-source/coronaviruse/20200312-sitrep-52-covid-19.pdf?sfvrsn=e\n2bfc9c0_2 9. Accessed March 11, 2020.\n3. National Health Commission of the People’s Republic of China.(2020). Latest developments in\nepidemic control on Feb 15. Retrieved from http://en.nhc.gov.cn/2020-02/16/c_76622. Accessed\nMarch 11, 2020.\n15\n4. Health Commission of the People’s Republic of China.(2020). The notification of the trial\noperation based on the guideline version 6 in the coronavirus disease diagnosis and treatment.", "Retrieved from\nhttp://www.nhc.gov.cn/xcs/zhengcwj/202002/8334a8326dd94d329df351d7da8aefc2.shtml.\nAccessed March 11, 2020\n5. Health Commission of the People’s Republic of China.(2020). The notification of the trial\noperation based on the guideline version 6 in the coronavirus disease diagnosis and treatment.\nRetrieved from\nhttp://www.nhc.gov.cn/xcs/zhengcwj/202002/8334a8326dd94d329df351d7da8aefc2.shtml.\nAccessed March 11, 2020.\n6. Health Commission of the People’s Republic of China.(2009). The guideline for pathogens\nisolated operations in hospital. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/200904/40116.shtml. Accessed March 11, 2020.\n7. Health Commission of the People’s Republic of China.(2017). The guideline for prevention and\ncontrol of hospital acquired infections of airborne pathogens. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201701/7e0e8fc6725843aabba8f841f2f585d2.shtml. Accessed\nMarch 11, 2020.", "8. Health Commission of the People’s Republic of China.(2017). The guideline for prevention and\ncontrol of hospital acquired infections of airborne pathogens. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201701/7e0e8fc6725843aabba8f841f2f585d2.shtml. Accessed\nMarch 11, 2020.\n9. Health Commission of the People’s Republic of China.(2012). The standardization for\nsterilization techniques in hospital. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201204/54510.shtml. Accessed March 11, 2020.\n10. Health Commission of the People’s Republic of China.(2012). The standardization for\nsterilization techniques in hospital. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201204/54510.shtml. Accessed March 11, 2020.\n11. Katona P. Bioterrorism Preparedness: Generic Blueprint for Health Departments, Hospitals, and\nPhysicians. Infectious Diseases in Clinical Practice. 2002;11(3):115-122. Accessed March 11,\n2020.\n16\nFigure Legends", "Figure 1. Diagram of the layout of our radiology department was divided into four areas: contaminated\n(shaded in black), semicontaminated (shaded in dark gray), buffer (shaded in light gray), and clean areas\n(shaded in white). The contaminated area was separated from other areas by barriers.\nFigure 2. Diagram shows CT protocol for suspected and confirmed patients with COVID-19.\nFigure 3. Diagram shows CT protocol for regular patients.\nAbbreviations:\nCOVID-19: coronavirus disease 2019\nCT: computed tomography\nDR: digital radiography\nEMICT: emergency management and infection control team\nNHC: National Health Commission\nPACS: picture archiving and communication system\nSARS: severe acute respiratory syndrome", "Sentence Summary\nWith severe infectious diseases such as COVID-19, the highest level of infection control\nmeasures must be implemented, collaboration with the radiology departments of other\nhospitals be needed, and social media be employed.\nTake-home points\n1. To response to a community infection emergency, a special emergency management team\nneeds to be setup at the departmental level to implement infection containment and\ncontrol procedures that continues to allow the imaging examination and imaging\ndiagnosis of those with suspected infection, and to prevent intra-departmental spreading\nof infection (EMICT).\n2. Infection control measures, such as reconfiguration of department areas, personal\nprotection and anti-infection training of all staff, standardized procedures including\ncontact minimization for chest CT and DR examinations, and timely disinfection of CT\nand DR examination rooms, should be implemented properly.", "3. If there are more than one scanner in a hospital, only one of them should be assigned to\nsuspected cases." ]	[ 16 ]	3,975	6,764
188	What must the data gathering include?	2,458	[ "up-to-date case definitions and information about\nconfirmatory tests to all staff with direct patient contact to allow appropriate barrier precautions\nto be taken." ]	[ "The Battle Against Coronavirus Disease 2019 (COVID-19): Emergency Management\nand Infection Control in a Radiology Department\nhttps://www.jacr.org/article/S1546-1440(20)30285-4/pdf\nJournal Pre-proof\nZixing Huang, Shuang Zhao, Zhenlin Li, Weixia Chen, Lihong Zhao, Lipeng Deng, Bin\nSong\nPII: S1546-1440(20)30285-4\nDOI: https://doi.org/10.1016/j.jacr.2020.03.011\nReference: JACR 5139\nTo appear in: Journal of the American College of Radiology\nReceived Date: 24 February 2020\nRevised Date: 13 March 2020\nAccepted Date: 15 March 2020\nPlease cite this article as: Huang Z, Zhao S, Li Z, Chen W, Zhao L, Deng L, Song B, The Battle Against\nCoronavirus Disease 2019 (COVID-19): Emergency Management and Infection Control in a Radiology\nDepartment, Journal of the American College of Radiology (2020), doi: https://doi.org/10.1016/\nj.jacr.2020.03.011.\nThis is a PDF file of an article that has undergone enhancements after acceptance, such as the addition", "of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of\nrecord. This version will undergo additional copyediting, typesetting and review before it is published\nin its final form, but we are providing this version to give early visibility of the article. Please note that,\nduring the production process, errors may be discovered which could affect the content, and all legal\ndisclaimers that apply to the journal pertain.\n© 2020 Published by Elsevier Inc. on behalf of American College of Radiology\nThe Battle Against Coronavirus Disease 2019 (COVID-19): Emergency Management\nand Infection Control in a Radiology Department\nZixing Huang, Shuang Zhao, Zhenlin Li, Weixia Chen, Lihong Zhao, Lipeng Deng,\nBin Song\nDepartment of Radiology, West China Hospital, Sichuan University, Chengdu, China\n*Zixing Huang and Shuang Zhao contributed equally to this work as co-first author.\nCorresponding Author: Bin Song, MD", "Address: Department of Radiology, West China Hospital, Sichuan University.\nNo. 37, GUOXUE Alley, Chengdu, 610041, China\nTel.: (+86)28 85423680, Fax: (+86)28 85582944\nEmail: [email protected].\nAuthors’ contributions\nZXH: conceived the study and drafted the manuscript.\nZS: conceived the study and drafted the manuscript.\nZLL: The member of the emergency management and infection control team (EMICT)\nand was involved in the formulation of the measures.\nWXC: The member of the EMICT and was involved in the formulation of the\nmeasures.\nLHZ: The member of the EMICT and was involved in the formulation of the\nmeasures.\nLPD: The member of the EMICT and was involved in the formulation of the\nmeasures.\nBS: Leader of the EMICT, conceived the study and reviewed the manuscript.\nAll authors read and approved the final manuscript.\nThe authors declare no conflict of interest.\nThe authors declare that they had full access to all of the data in this study and the", "authors take complete responsibility for the integrity of the data and the accuracy of\nthe data analysis\n1\nThe Battle Against Novel Coronavirus Pneumonia (COVID-19): Emergency\nManagement and Infection Control in a Radiology Department\nAbstract\nObjective: To describe the strategy and the emergency management and infection control\nprocedure of our radiology department during the COVID-19 outbreak.\nMethods: We set up emergency management and sensing control teams. The team formulated\nvarious measures: reconfiguration of the radiology department, personal protection and training\nof staff, examination procedures for patients suspected of or confirmed with COVID-19 as well\nas patients without an exposure history or symptoms. Those with suspected or confirmed\nCOVID-19 infection were scanned in the designated fever-CT unit.\nResults: From January 21, 2020 to March 9, 2020, 3,083 people suspected of or confirmed with\nCOVID-19 underwent fever-CT examinations. Including initial examinations and", "reexaminations, the total number of fever-CT examinations numbered 3,340. As a result of our\nprecautions, none of the staff of the radiology department were infected with COVID-19.\nConclusion: Strategic planning and adequate protections can help protect patients and staff\nagainst a highly infectious disease while maintaining function at a high volume capacity.\nKeywords: Coronavirus, COVID-19, novel coronavirus pneumonia, infection control", "2\nIntroduction\nThe whole world has been closely focusing on an outbreak of respiratory disease caused by a\nnovel coronavirus that was first reported in Wuhan, China, on December 31, 2019, and that\ncontinues to spread. On February 11, 2020, the World Health Organization (WHO) named the\ndisease “coronavirus disease 2019” (COVID-19).\nAs of 24:00 on March 11, 2020, the National Health Commission (NHC) had received reports\nof 80,793 confirmed cases and 3,169 deaths on the Chinese mainland. There remain 14,831\nconfirmed cases (including 4,257 in serious condition) and 253 suspected cases still\nhospitalized. To date, 677,243 people have been identified as having had close contact with\ninfected patients of whom13,701 are under medical observation [1]. Outside China, 44,067\nlaboratory-confirmed cases and 1,440 deaths have occurred in 117 countries /territories/areas\naccording to the WHO [2]. COVID-19 poses significant threats to international health. Like the", "flu, COVID-19 is thought to spread mainly from person-to-person between people who are in\nclose contact with one another through respiratory droplets produced when an infected person\ncoughs or sneezes. In light of the infectious nature of this disease, healthcare workers are at\nhigh risk of infection of COVID-19. In China, healthcare workers account for 1,716 confirmed\ncases of COVID-19, including six deaths [3].\n Computed tomography (CT) can play a role in both diagnosing and categorizing\nCOVID-19 on the basis of case definitions issued by the WHO and the treatment guidelines\nfrom the NHC [4]. Suspected patients having the virus may undergo chest CT. Isolation and\nbarrier procedures are necessary to protect both the department staff and other patients in the\nhospital. Note should be made that due to overlap of imaging findings with other respiratory\n3\ndiseases, CT is not helpful as a screening tool. But it can help identify the degree of pulmonary\ninvolvement and disease course.", "Our hospital is a national regional medical center with 4,300 beds and a tertiary referral\ncenter in Sichuan province. The initial response started on January 21, 2020, after transmission\nof COVID-19 was confirmed to be human-to-human on January 20, 2020. The first suspected\ncase of COVID-19 in Sichuan province was reported on January 21, 2020. The Sichuan\nprovincial government immediately launched the first-level response to major public health\nemergencies. On the same day, our hospital was designated to care for Sichuan province\npatients with COVID-19.\nThis article describes the emergency management procedure of our radiology department\nfor situations involving severe infectious diseases, such as COVID-19, and the\ninfection-protection experience of the department staff.\nMethods\nThe hospital provided personal protective equipment (medical protective clothing,\nsurgical cap, N95 mask, gloves, face shields, and goggles) to all its healthcare staff, erected", "three medical tents (fever tents) for screening of fever cases in the parking lot of the emergency\ndepartment, planned an examination route and examination area for patients suspected of\nharboring the virus, and placed confirmed patients in an isolation ward. “Fever” was the\ncolloquial term used to designate suspected COVID-19 based on symptoms such as a fever or\nwith an epidemiological history of a potential exposure as well as those with confirmed\nCOVID-19 referred for treatment. Further, during outbreak, emergency and outpatient patients\n4\nwithout fever were asked for information such as epidemiological history and sent to fever tents\nas long as they met suspected criteria.\nThe radiology department has 65 diagnostic radiologists and 161 other staff members\n(trained technologists, nurses, engineers, and support staff). The equipment of the radiology\ndepartment includes 12 magnetic resonance (MR) scanners, 14 CT scanners, 15 digital", "subtraction angiography (DSA) systems, 32 sets of digital radiography (DR) systems\n(including nine mobile bedside DR sets), and 130 imaging diagnostic workstations for picture\narchiving and communication systems (PACS). Most of the equipment is distributed among\nfour buildings at the hospital main campus. 4 CT scanners, 4 MR scanners, 1 DR are located on\nthe first floor of the first inpatient building, and 9 DR and 8 DSA are located on the second\nfloor. 1 CT and 1 MR scanner are located in the third inpatient building. 1 CT and 1 MR scanner\nare located in the sixth inpatient building. 2 CT scanners, 2 MR scanners and 7 DSA are located\nin the technical building. The rest of the equipment is located in the seventh inpatient building\nin the branch campus.\nThe first inpatient building, located next to the emergency department, was reconfigured to\nhandle cases of COVID-19. Fever tents were set up by the emergency department in the", "emergency department parking lot to separate normal emergency patients from patients with\nsymptoms or exposure history suspicious of COVID-19. We established separate means of\naccess between fever tents and between the fever examination area of the radiology department\nto avoid cross-contamination.\nThe emergency management and infection control measures, as described below and\nimplemented in the radiology department during the outbreak, have been approved by the\n5\ninfection control committee of hospital. These measures are in accordance with relevant laws\nand regulations, in order to protect patients as well as the staff.\nRadiology Emergency Management and Infection Control Team (EMICT)\nThe radiology department director chaired the EMICT. Its members include the deputy\ndirector, chief technologist, head nurse, equipment engineer supervisor, and infection control\nnurse of the radiology department. Team responsibilities included (1) coordination between the", "hospital’s management and planning of infection control and radiology departments; (2)\ncollection of the most up-to-date protection-related information to educate and train staff in the\ndepartment; (3) reallocation of staff according to the actual situation; (4) establishment of the\nCT procedures for patients with COVID-19; and (5) establishment of an emergency\nmanagement plan for the radiology department to ensure that the department would run\nnormally.\nSuspected patients\nThe suspected patients were identified according to the Diagnosis and Treatment Program of\nthe Novel Coronavirus Pneumonia of the NHC [5], mainly based on epidemiological history.\nReconfiguration of the radiology department\nThe radiology department was divided into four areas [6]: contaminated, semicontaminated,\nbuffer, and clean areas (Figure 1). The contaminated area is connected to the fever clinic and\nincludes the fever accessway, the CT examination room, and the DR examination room for\n6", "confirmed and suspected cases. One CT scanner and one DR system closest to the emergency\ndepartment are designated the fever-CT and fever-DR to examine patients with suspected and\nconfirmed COVID-19. There is a separate dedicated access between the contaminated area and\nthe fever screening tents. The semicontaminated area includes the fever-CT control room,\nfever-DR control room, and other patient examination access areas. The buffer zone includes\naccess areas for medical personnel and a dressing area for technologists. The clean area\nincludes the administrative office and the diagnostic room.\nThe contaminated area was isolated from other areas using physical barricades.\nDirectional signs were newly installed to guide patients and staff.\nPersonal protection and training of staff\nFor providing care for patients with confirmed and suspected COVID-19, all hospital staff\nare required to wear complete personal protective equipment [7]: medical protective clothing,", "surgical cap, N95 mask, gloves, face shields, and goggles. Wearing and removing of the\nequipment must be performed in accordance with the procedures and under the supervision of\nthe infection control nurse.\nBecause staff members working in the contaminated area are under much situational\npressure, periodically taking time off could lower their physical and mental stress levels. The\ntechnologists on fever-CT duty shifts are provided a break once a week for four hours. In\naddition, the health of staff in the contaminated area must be monitored closely for the\nsymptoms of COVID-19. Pregnant staff must be assigned to the clean area.\n7\nThe EMICT formulates and continually updates guidelines and educates all staff for West\nChina Hospital of Sichuan University. The EMICT training for staff is mainly involves\ndocuments regarding infection control and CT findings of COVID-19 and maintains an EMICT\nWeChat group for West China Hospital of Sichuan University. WeChat is the most widely used", "social media app in China. The EMICT releases the latest national and hospital-based\ninformation regarding COVID-19, guidance documents, and other notices from the hospital\nand radiology department in the WeChat group on a daily basis. Staff can also report to the\nEMICT in the WeChat group any time. Protocols for each modality and infection control\ninstructions are posted on the walls in all examination rooms. The EMICT periodically reminds\nstaff to undertake personal measures to reduce infection, such as wearing masks at all instances\nin the radiology department and N95 masks if working in the contaminated area; not touching\nthe mask and the eyes; practicing hand hygiene; facing away from colleagues when eating,\ndrinking, and talking; and not using personal cell phones while on duty.\n In addition, the chief thoracic radiologist provided lectures on all radiologists and\ntechnologists on typical CT findings of COVID-19 infection using materials developed in", "Wuhan, the epicenter of the outbreak in China.\nCT examination procedures\nThere are two sets of procedures for CT examination: the fever-CT procedure and routine CT\nprocedure for those not suspected of COVID-19.\nThe fever-CT procedure for suspected or confirmed COVID-19 (Figure 2)\n8\nBefore the fever-CT technologist operates the equipment, he or she should wear personal\nprotective equipment according to three-level protection standard [8]. Before the CT\nexamination of patients with suspected and confirmed COVID-19 begins, the fever tent or\nisolation ward notifies the radiologist in advance. The fever-CT technologist checks the\nequipment and prepares to disinfect the imaging equipment immediately after the examination.\nThe patient enters the fever-CT waiting area through the fever access area. If the patient\ncan get onto and off the examination table by themselves, the patient is allowed to do so. If the", "patient cannot get onto or off the examination table independently, the person accompanying\nthe patient assists the patient, rather than the technologist. The technologist checks the patient\ninformation and, using an intercom system in the examination room, asks the patient to remove\nany metal ornaments on the neck and chest. Also, by intercom, the technologist trains the\npatient to hold his or her breath during the examination.\nThe technologist uses a low-dose chest CT protocol to scan the patient. After scanning, the\noriginal images are reconstructed as 1 mm-thick layers. The technologist browses the images to\nensure that their quality meets the diagnostic requirements and then guides the patient to leave\nthrough the fever access area. The disposable sheets for patient examination are changed after\neach patient. The equipment is disinfected according to the procedure below.\nTo protect themselves, the technologists assigned to the fever-CT wear N95 mask and", "other personal protection as established by the EMICT.\nThe CT procedure for regular patients (figure.3)\n9\nSome patients with COVID-19 have no symptoms, and they may call at the general clinic for\nother reasons. The following CT procedure is applicable under these circumstances:\nWhen the patient makes an appointment for examination, the staff asks the patient about\ntheir epidemiological history, symptoms, and signs. If suspected criteria are met, the patient\nwill be sent to the fever tent for further screening. When a patient presents to the radiology\ndepartment entrance, his/her temperature is measured. If the temperature is higher than 37.2 , ℃\nthe patient is sent to the fever tent for further investigation.\nThose with no exposure history, suspicious symptoms or fever are screened in one of the\nnon-contaminated CT scanners. The technologists assigned to these scanners wear surgical\nmasks. All patients and the person accompanying them are required to wear surgical masks.", "After the CT examination, the technologist browses the images quickly. If the CT appearance is\ntypical of lung infection, the technologist immediately reports it to the chest radiologist on duty\nand asks the patient to wait in the CT examination room. If the chest radiologist does not\nsuspect COVID-19 infection, the patient can leave the CT examination room. If the chest\nradiologist does suspect COVID-19 infection, the technologist immediately reports it to the\nEMICT and sends the patient to the fever tent. The floor and equipment in the CT examination\nroom are disinfected according to regulations, and air disinfection is conducted for 30 min\nbefore examining other patients. These CT scanners are considered noncontaminated (not\nfever-CTs) after these sterilization procedures.\nFever-DR examination procedure\n10\nThe COVID-19 guideline of the NHC does not recommend chest DR because its ability in\ndiagnosing COVID-19 is limited. At our hospital, we only use mobile DR units to provide", "bedside examination for critically ill patients. The technologist operating the mobile DR\nwears personal protective equipment according to the three-level protection standard and\nsterilizes the mobile DR according to the ward management requirements as described below.\nEquipment and environment disinfection procedures\nRoutine disinfection procedure [9]\n1) Object surface disinfection: Object surface is wiped with 1000mg/L chlorine-containing\ndisinfectant, wipe twice with 75% ethanol for non-corrosion resistance, once /4 hours.\n2) Equipment disinfection: The equipment in the contaminated area are wiped with\n2000mg/L chlorine-containing disinfectant. The DR and CT gantry in the contaminated\narea are wiped with 75% ethanol. The equipment in the buffer area is wiped with\n500-1000mg/L chlorine-containing disinfectant or alcohol-containing disposable\ndisinfectant wipes twice a day.\n3) Air disinfection: Turning off all central air conditioners to prevent air contamination with", "each other. Polluted area: open the door for ventilation, each time more than 30 minutes,\nonce /4 hours; The air sterilizer is continuously sterilized or the ultraviolet ray is\ncontinuously used in the unmanned state for 60 minutes, four times a day, remembered to\nclose the inner shielding door when air disinfection. Other ambient air is sprayed with\n1000mg/L chlorine-containing disinfectant and ventilated twice a day\n4) Ground disinfection: The ground is wiped with 1000mg/L chlorine-containing\ndisinfectant, once /4 hours.\n5) When contaminated, disinfect at any time. In case of visible contamination, disposable\nabsorbent materials should be used first to completely remove the pollutants, and then a\ncloth soaked with 2000mg/L chlorine-containing disinfectant should be used for 30\nminutes before wiping.\n11\nFever-CT disinfection procedures after examination\nIn addition to the above, disinfect the examination bed and ground with chlorinated disinfectant\ncontaining 2000mg/L [10].", "Noncontaminated CT disinfection procedures after suspected COVID-19 case examination\nIn addition to the above routine disinfection procedure, air disinfection is conducted for 30 min\nbefore examining other patients.\nResults\nFrom January 21, 2020 when screening for epidemiological history or symptoms\nsuspicious for COVID-19, to March 9, 2020, our hospital screened a total of 7,203 individuals\nand confirmed 24 cases of COVID-19. Of these, 3,083 people underwent fever-CT\nexaminations. Including the initial examination and reexamination, the total number of fever\nCT examination numbered 3,340. The fever-CT scanned a patient approximately every 21.5\nminutes. As a result of our precautions, none of the staff of the radiology department developed\nsymptoms suspicious for COVID-19. The fever-CT technologist, with the highest probability\nof exposure, remains PCR negative.\nDiscussion\nIt has been 17 years since the severe acute respiratory syndrome (SARS) epidemic, the last", "national spread of severe infectious disease, broke out. Currently, the Chinese people are\npanicking again. The speed and extent by which COVID-19 has spread in 2 months are\n12\nunprecedented, beyond those of SARS, and this has been aided by its contagious nature and\nrapid spread via droplets and contact. The droplet mode of transmission means that a person can\nbe infected easily by means of casual contact or even fomites on contaminated environmental\nsurfaces. Another theory has yet to be proved: aerosol propagation.\nHow radiology departments respond to any infectious disease outbreak is determined\nprimarily by the estimated risk of cross-infection to the staff and other patients. Appropriate\nprecautions taken only by staff in direct contact with patients may be adequate when the risk is\nlow. The strongest measures need to be implemented to limit the spread of the disease when the\nrisk is high. With severe infectious diseases such as COVID-19, the highest level of infection", "control measures must be implemented; these include providing adequate standard protective\nequipment, training staff, and instituting proper emergency plans.\nOnce a contagious infectious disease has been identified, the EMICT must consider four\nmain areas of response: data gathering, collaboration, needs assessment, and expert advice [10].\nData gathering includes dissemination of up-to-date case definitions and information about\nconfirmatory tests to all staff with direct patient contact to allow appropriate barrier precautions\nto be taken. All typical and atypical imaging features of the disease should be made known to\nall radiologists to assist in recognition of the disease on images and to allow accurate reporting\nof these findings. We have stored images of all probable cases of COVID-19 in the PACS so\nthat these images were readily available for any radiologist to review, and images from\nprevious imaging studies are also available for comparison.", "Collaboration with the radiology departments of other hospitals is very important because\npatients may initially present to different centers, depending on geographic location and travel\n13\ndistance. These patients may be few in number at a single hospital, but if data from patients at\nseveral hospitals are available, a more accurate overall understanding of both imaging features\nand epidemiology can be achieved. Dissemination of this information to all healthcare facilities\nwill also lead to early recognition of the disease, and appropriate isolation measures may be\ninstituted.\nThe Internet and social media apps, especially WeChat, have been used for distribution of\nmedical information, and because the exchange of information regarding infectious disease\noutbreaks is almost instantaneous, it is an indispensable tool for radiologists. In fact, within a\nmonth of the outbreak, the hospital that received the most infected patients from the source of", "the outbreak made a PowerPoint presentation of the CT manifestations of COVID-19, which\nwas shared via WeChat and disseminated across the country in a very short time. Subsequently,\nCOVID-19-teaching PowerPoint presentations from various hospitals appeared and were\nquickly shared via WeChat.\nOur diagnostic process is limited as chest CT along is not diagnostic of COVID-19\nbecause of lack of imaging specificity. But when combined with other epidemiological,\nclinical, laboratory and virus nucleic acid information, typical chest CT imaging findings are\nhelpful for making the diagnosis. In our opinion, the major role of chest CT is to understand the\nextent and dynamic evolution of lung lesions induced by COVID-19. The reasons why we\nadopted the low-dose chest CT scan protocol are as follows: low-dose chest CT has been\nwidely used in the screening of early lung cancer. It is well known that many early lung cancers", "are ground-glass opacities (GGO), so we believe that low-dose screening is also applicable for\nCOVID-19. In addition, considering the rapid development of COVID-19, many CT\n14\nexaminations may be conducted in the same individual to monitor disease progress. Low-dose\nscanning can reduce the radiation damage to patients.\nAlthough the processes we established minimized the exposure of hospital staff, ancillary\npersonnel and other patients, it remains limited as follows. Sichuan province is not the center of\nthe epidemic. The number of patients with COVID-19 whom we have treated has not been\nhigh, and most cases are from other provinces of China. However, we believe that our\nexperience in management, the reconfiguration of our radiology department, and the workflow\nchanges implemented in the current COVID-19 situation are useful for other radiology\ndepartments that must prepare for dealing with patients with COVID-19. While no radiology", "personnel developed symptoms suspicious for or were confirmed as having COVID-19, there\nmay be asymptomatic personnel.\nREFERENCES\n1. National Health Commission of the People’s Republic of China.(2020). March 12: Daily briefing\non novel coronavirus cases in China. Retrieved from\nhttp://en.nhc.gov.cn/2020-03/12/c_77618.htm. Accessed March 11, 2020.\n2. World Health Organization. (2020). Coronavirus disease 2019 (COVID-19) Situation Report-52.\nRetrieved from\nhttps://www.who.int/docs/default-source/coronaviruse/20200312-sitrep-52-covid-19.pdf?sfvrsn=e\n2bfc9c0_2 9. Accessed March 11, 2020.\n3. National Health Commission of the People’s Republic of China.(2020). Latest developments in\nepidemic control on Feb 15. Retrieved from http://en.nhc.gov.cn/2020-02/16/c_76622. Accessed\nMarch 11, 2020.\n15\n4. Health Commission of the People’s Republic of China.(2020). The notification of the trial\noperation based on the guideline version 6 in the coronavirus disease diagnosis and treatment.", "Retrieved from\nhttp://www.nhc.gov.cn/xcs/zhengcwj/202002/8334a8326dd94d329df351d7da8aefc2.shtml.\nAccessed March 11, 2020\n5. Health Commission of the People’s Republic of China.(2020). The notification of the trial\noperation based on the guideline version 6 in the coronavirus disease diagnosis and treatment.\nRetrieved from\nhttp://www.nhc.gov.cn/xcs/zhengcwj/202002/8334a8326dd94d329df351d7da8aefc2.shtml.\nAccessed March 11, 2020.\n6. Health Commission of the People’s Republic of China.(2009). The guideline for pathogens\nisolated operations in hospital. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/200904/40116.shtml. Accessed March 11, 2020.\n7. Health Commission of the People’s Republic of China.(2017). The guideline for prevention and\ncontrol of hospital acquired infections of airborne pathogens. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201701/7e0e8fc6725843aabba8f841f2f585d2.shtml. Accessed\nMarch 11, 2020.", "8. Health Commission of the People’s Republic of China.(2017). The guideline for prevention and\ncontrol of hospital acquired infections of airborne pathogens. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201701/7e0e8fc6725843aabba8f841f2f585d2.shtml. Accessed\nMarch 11, 2020.\n9. Health Commission of the People’s Republic of China.(2012). The standardization for\nsterilization techniques in hospital. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201204/54510.shtml. Accessed March 11, 2020.\n10. Health Commission of the People’s Republic of China.(2012). The standardization for\nsterilization techniques in hospital. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201204/54510.shtml. Accessed March 11, 2020.\n11. Katona P. Bioterrorism Preparedness: Generic Blueprint for Health Departments, Hospitals, and\nPhysicians. Infectious Diseases in Clinical Practice. 2002;11(3):115-122. Accessed March 11,\n2020.\n16\nFigure Legends", "Figure 1. Diagram of the layout of our radiology department was divided into four areas: contaminated\n(shaded in black), semicontaminated (shaded in dark gray), buffer (shaded in light gray), and clean areas\n(shaded in white). The contaminated area was separated from other areas by barriers.\nFigure 2. Diagram shows CT protocol for suspected and confirmed patients with COVID-19.\nFigure 3. Diagram shows CT protocol for regular patients.\nAbbreviations:\nCOVID-19: coronavirus disease 2019\nCT: computed tomography\nDR: digital radiography\nEMICT: emergency management and infection control team\nNHC: National Health Commission\nPACS: picture archiving and communication system\nSARS: severe acute respiratory syndrome", "Sentence Summary\nWith severe infectious diseases such as COVID-19, the highest level of infection control\nmeasures must be implemented, collaboration with the radiology departments of other\nhospitals be needed, and social media be employed.\nTake-home points\n1. To response to a community infection emergency, a special emergency management team\nneeds to be setup at the departmental level to implement infection containment and\ncontrol procedures that continues to allow the imaging examination and imaging\ndiagnosis of those with suspected infection, and to prevent intra-departmental spreading\nof infection (EMICT).\n2. Infection control measures, such as reconfiguration of department areas, personal\nprotection and anti-infection training of all staff, standardized procedures including\ncontact minimization for chest CT and DR examinations, and timely disinfection of CT\nand DR examination rooms, should be implemented properly.", "3. If there are more than one scanner in a hospital, only one of them should be assigned to\nsuspected cases." ]	[ 23 ]	3,975	6,764
188	What must be done to assist in recognition of the disease on images and to allow accurate reporting of these findings?	2,459	[ "All typical and atypical imaging features of the disease should be made known to\nall radiologists" ]	[ "The Battle Against Coronavirus Disease 2019 (COVID-19): Emergency Management\nand Infection Control in a Radiology Department\nhttps://www.jacr.org/article/S1546-1440(20)30285-4/pdf\nJournal Pre-proof\nZixing Huang, Shuang Zhao, Zhenlin Li, Weixia Chen, Lihong Zhao, Lipeng Deng, Bin\nSong\nPII: S1546-1440(20)30285-4\nDOI: https://doi.org/10.1016/j.jacr.2020.03.011\nReference: JACR 5139\nTo appear in: Journal of the American College of Radiology\nReceived Date: 24 February 2020\nRevised Date: 13 March 2020\nAccepted Date: 15 March 2020\nPlease cite this article as: Huang Z, Zhao S, Li Z, Chen W, Zhao L, Deng L, Song B, The Battle Against\nCoronavirus Disease 2019 (COVID-19): Emergency Management and Infection Control in a Radiology\nDepartment, Journal of the American College of Radiology (2020), doi: https://doi.org/10.1016/\nj.jacr.2020.03.011.\nThis is a PDF file of an article that has undergone enhancements after acceptance, such as the addition", "of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of\nrecord. This version will undergo additional copyediting, typesetting and review before it is published\nin its final form, but we are providing this version to give early visibility of the article. Please note that,\nduring the production process, errors may be discovered which could affect the content, and all legal\ndisclaimers that apply to the journal pertain.\n© 2020 Published by Elsevier Inc. on behalf of American College of Radiology\nThe Battle Against Coronavirus Disease 2019 (COVID-19): Emergency Management\nand Infection Control in a Radiology Department\nZixing Huang, Shuang Zhao, Zhenlin Li, Weixia Chen, Lihong Zhao, Lipeng Deng,\nBin Song\nDepartment of Radiology, West China Hospital, Sichuan University, Chengdu, China\n*Zixing Huang and Shuang Zhao contributed equally to this work as co-first author.\nCorresponding Author: Bin Song, MD", "Address: Department of Radiology, West China Hospital, Sichuan University.\nNo. 37, GUOXUE Alley, Chengdu, 610041, China\nTel.: (+86)28 85423680, Fax: (+86)28 85582944\nEmail: [email protected].\nAuthors’ contributions\nZXH: conceived the study and drafted the manuscript.\nZS: conceived the study and drafted the manuscript.\nZLL: The member of the emergency management and infection control team (EMICT)\nand was involved in the formulation of the measures.\nWXC: The member of the EMICT and was involved in the formulation of the\nmeasures.\nLHZ: The member of the EMICT and was involved in the formulation of the\nmeasures.\nLPD: The member of the EMICT and was involved in the formulation of the\nmeasures.\nBS: Leader of the EMICT, conceived the study and reviewed the manuscript.\nAll authors read and approved the final manuscript.\nThe authors declare no conflict of interest.\nThe authors declare that they had full access to all of the data in this study and the", "authors take complete responsibility for the integrity of the data and the accuracy of\nthe data analysis\n1\nThe Battle Against Novel Coronavirus Pneumonia (COVID-19): Emergency\nManagement and Infection Control in a Radiology Department\nAbstract\nObjective: To describe the strategy and the emergency management and infection control\nprocedure of our radiology department during the COVID-19 outbreak.\nMethods: We set up emergency management and sensing control teams. The team formulated\nvarious measures: reconfiguration of the radiology department, personal protection and training\nof staff, examination procedures for patients suspected of or confirmed with COVID-19 as well\nas patients without an exposure history or symptoms. Those with suspected or confirmed\nCOVID-19 infection were scanned in the designated fever-CT unit.\nResults: From January 21, 2020 to March 9, 2020, 3,083 people suspected of or confirmed with\nCOVID-19 underwent fever-CT examinations. Including initial examinations and", "reexaminations, the total number of fever-CT examinations numbered 3,340. As a result of our\nprecautions, none of the staff of the radiology department were infected with COVID-19.\nConclusion: Strategic planning and adequate protections can help protect patients and staff\nagainst a highly infectious disease while maintaining function at a high volume capacity.\nKeywords: Coronavirus, COVID-19, novel coronavirus pneumonia, infection control", "2\nIntroduction\nThe whole world has been closely focusing on an outbreak of respiratory disease caused by a\nnovel coronavirus that was first reported in Wuhan, China, on December 31, 2019, and that\ncontinues to spread. On February 11, 2020, the World Health Organization (WHO) named the\ndisease “coronavirus disease 2019” (COVID-19).\nAs of 24:00 on March 11, 2020, the National Health Commission (NHC) had received reports\nof 80,793 confirmed cases and 3,169 deaths on the Chinese mainland. There remain 14,831\nconfirmed cases (including 4,257 in serious condition) and 253 suspected cases still\nhospitalized. To date, 677,243 people have been identified as having had close contact with\ninfected patients of whom13,701 are under medical observation [1]. Outside China, 44,067\nlaboratory-confirmed cases and 1,440 deaths have occurred in 117 countries /territories/areas\naccording to the WHO [2]. COVID-19 poses significant threats to international health. Like the", "flu, COVID-19 is thought to spread mainly from person-to-person between people who are in\nclose contact with one another through respiratory droplets produced when an infected person\ncoughs or sneezes. In light of the infectious nature of this disease, healthcare workers are at\nhigh risk of infection of COVID-19. In China, healthcare workers account for 1,716 confirmed\ncases of COVID-19, including six deaths [3].\n Computed tomography (CT) can play a role in both diagnosing and categorizing\nCOVID-19 on the basis of case definitions issued by the WHO and the treatment guidelines\nfrom the NHC [4]. Suspected patients having the virus may undergo chest CT. Isolation and\nbarrier procedures are necessary to protect both the department staff and other patients in the\nhospital. Note should be made that due to overlap of imaging findings with other respiratory\n3\ndiseases, CT is not helpful as a screening tool. But it can help identify the degree of pulmonary\ninvolvement and disease course.", "Our hospital is a national regional medical center with 4,300 beds and a tertiary referral\ncenter in Sichuan province. The initial response started on January 21, 2020, after transmission\nof COVID-19 was confirmed to be human-to-human on January 20, 2020. The first suspected\ncase of COVID-19 in Sichuan province was reported on January 21, 2020. The Sichuan\nprovincial government immediately launched the first-level response to major public health\nemergencies. On the same day, our hospital was designated to care for Sichuan province\npatients with COVID-19.\nThis article describes the emergency management procedure of our radiology department\nfor situations involving severe infectious diseases, such as COVID-19, and the\ninfection-protection experience of the department staff.\nMethods\nThe hospital provided personal protective equipment (medical protective clothing,\nsurgical cap, N95 mask, gloves, face shields, and goggles) to all its healthcare staff, erected", "three medical tents (fever tents) for screening of fever cases in the parking lot of the emergency\ndepartment, planned an examination route and examination area for patients suspected of\nharboring the virus, and placed confirmed patients in an isolation ward. “Fever” was the\ncolloquial term used to designate suspected COVID-19 based on symptoms such as a fever or\nwith an epidemiological history of a potential exposure as well as those with confirmed\nCOVID-19 referred for treatment. Further, during outbreak, emergency and outpatient patients\n4\nwithout fever were asked for information such as epidemiological history and sent to fever tents\nas long as they met suspected criteria.\nThe radiology department has 65 diagnostic radiologists and 161 other staff members\n(trained technologists, nurses, engineers, and support staff). The equipment of the radiology\ndepartment includes 12 magnetic resonance (MR) scanners, 14 CT scanners, 15 digital", "subtraction angiography (DSA) systems, 32 sets of digital radiography (DR) systems\n(including nine mobile bedside DR sets), and 130 imaging diagnostic workstations for picture\narchiving and communication systems (PACS). Most of the equipment is distributed among\nfour buildings at the hospital main campus. 4 CT scanners, 4 MR scanners, 1 DR are located on\nthe first floor of the first inpatient building, and 9 DR and 8 DSA are located on the second\nfloor. 1 CT and 1 MR scanner are located in the third inpatient building. 1 CT and 1 MR scanner\nare located in the sixth inpatient building. 2 CT scanners, 2 MR scanners and 7 DSA are located\nin the technical building. The rest of the equipment is located in the seventh inpatient building\nin the branch campus.\nThe first inpatient building, located next to the emergency department, was reconfigured to\nhandle cases of COVID-19. Fever tents were set up by the emergency department in the", "emergency department parking lot to separate normal emergency patients from patients with\nsymptoms or exposure history suspicious of COVID-19. We established separate means of\naccess between fever tents and between the fever examination area of the radiology department\nto avoid cross-contamination.\nThe emergency management and infection control measures, as described below and\nimplemented in the radiology department during the outbreak, have been approved by the\n5\ninfection control committee of hospital. These measures are in accordance with relevant laws\nand regulations, in order to protect patients as well as the staff.\nRadiology Emergency Management and Infection Control Team (EMICT)\nThe radiology department director chaired the EMICT. Its members include the deputy\ndirector, chief technologist, head nurse, equipment engineer supervisor, and infection control\nnurse of the radiology department. Team responsibilities included (1) coordination between the", "hospital’s management and planning of infection control and radiology departments; (2)\ncollection of the most up-to-date protection-related information to educate and train staff in the\ndepartment; (3) reallocation of staff according to the actual situation; (4) establishment of the\nCT procedures for patients with COVID-19; and (5) establishment of an emergency\nmanagement plan for the radiology department to ensure that the department would run\nnormally.\nSuspected patients\nThe suspected patients were identified according to the Diagnosis and Treatment Program of\nthe Novel Coronavirus Pneumonia of the NHC [5], mainly based on epidemiological history.\nReconfiguration of the radiology department\nThe radiology department was divided into four areas [6]: contaminated, semicontaminated,\nbuffer, and clean areas (Figure 1). The contaminated area is connected to the fever clinic and\nincludes the fever accessway, the CT examination room, and the DR examination room for\n6", "confirmed and suspected cases. One CT scanner and one DR system closest to the emergency\ndepartment are designated the fever-CT and fever-DR to examine patients with suspected and\nconfirmed COVID-19. There is a separate dedicated access between the contaminated area and\nthe fever screening tents. The semicontaminated area includes the fever-CT control room,\nfever-DR control room, and other patient examination access areas. The buffer zone includes\naccess areas for medical personnel and a dressing area for technologists. The clean area\nincludes the administrative office and the diagnostic room.\nThe contaminated area was isolated from other areas using physical barricades.\nDirectional signs were newly installed to guide patients and staff.\nPersonal protection and training of staff\nFor providing care for patients with confirmed and suspected COVID-19, all hospital staff\nare required to wear complete personal protective equipment [7]: medical protective clothing,", "surgical cap, N95 mask, gloves, face shields, and goggles. Wearing and removing of the\nequipment must be performed in accordance with the procedures and under the supervision of\nthe infection control nurse.\nBecause staff members working in the contaminated area are under much situational\npressure, periodically taking time off could lower their physical and mental stress levels. The\ntechnologists on fever-CT duty shifts are provided a break once a week for four hours. In\naddition, the health of staff in the contaminated area must be monitored closely for the\nsymptoms of COVID-19. Pregnant staff must be assigned to the clean area.\n7\nThe EMICT formulates and continually updates guidelines and educates all staff for West\nChina Hospital of Sichuan University. The EMICT training for staff is mainly involves\ndocuments regarding infection control and CT findings of COVID-19 and maintains an EMICT\nWeChat group for West China Hospital of Sichuan University. WeChat is the most widely used", "social media app in China. The EMICT releases the latest national and hospital-based\ninformation regarding COVID-19, guidance documents, and other notices from the hospital\nand radiology department in the WeChat group on a daily basis. Staff can also report to the\nEMICT in the WeChat group any time. Protocols for each modality and infection control\ninstructions are posted on the walls in all examination rooms. The EMICT periodically reminds\nstaff to undertake personal measures to reduce infection, such as wearing masks at all instances\nin the radiology department and N95 masks if working in the contaminated area; not touching\nthe mask and the eyes; practicing hand hygiene; facing away from colleagues when eating,\ndrinking, and talking; and not using personal cell phones while on duty.\n In addition, the chief thoracic radiologist provided lectures on all radiologists and\ntechnologists on typical CT findings of COVID-19 infection using materials developed in", "Wuhan, the epicenter of the outbreak in China.\nCT examination procedures\nThere are two sets of procedures for CT examination: the fever-CT procedure and routine CT\nprocedure for those not suspected of COVID-19.\nThe fever-CT procedure for suspected or confirmed COVID-19 (Figure 2)\n8\nBefore the fever-CT technologist operates the equipment, he or she should wear personal\nprotective equipment according to three-level protection standard [8]. Before the CT\nexamination of patients with suspected and confirmed COVID-19 begins, the fever tent or\nisolation ward notifies the radiologist in advance. The fever-CT technologist checks the\nequipment and prepares to disinfect the imaging equipment immediately after the examination.\nThe patient enters the fever-CT waiting area through the fever access area. If the patient\ncan get onto and off the examination table by themselves, the patient is allowed to do so. If the", "patient cannot get onto or off the examination table independently, the person accompanying\nthe patient assists the patient, rather than the technologist. The technologist checks the patient\ninformation and, using an intercom system in the examination room, asks the patient to remove\nany metal ornaments on the neck and chest. Also, by intercom, the technologist trains the\npatient to hold his or her breath during the examination.\nThe technologist uses a low-dose chest CT protocol to scan the patient. After scanning, the\noriginal images are reconstructed as 1 mm-thick layers. The technologist browses the images to\nensure that their quality meets the diagnostic requirements and then guides the patient to leave\nthrough the fever access area. The disposable sheets for patient examination are changed after\neach patient. The equipment is disinfected according to the procedure below.\nTo protect themselves, the technologists assigned to the fever-CT wear N95 mask and", "other personal protection as established by the EMICT.\nThe CT procedure for regular patients (figure.3)\n9\nSome patients with COVID-19 have no symptoms, and they may call at the general clinic for\nother reasons. The following CT procedure is applicable under these circumstances:\nWhen the patient makes an appointment for examination, the staff asks the patient about\ntheir epidemiological history, symptoms, and signs. If suspected criteria are met, the patient\nwill be sent to the fever tent for further screening. When a patient presents to the radiology\ndepartment entrance, his/her temperature is measured. If the temperature is higher than 37.2 , ℃\nthe patient is sent to the fever tent for further investigation.\nThose with no exposure history, suspicious symptoms or fever are screened in one of the\nnon-contaminated CT scanners. The technologists assigned to these scanners wear surgical\nmasks. All patients and the person accompanying them are required to wear surgical masks.", "After the CT examination, the technologist browses the images quickly. If the CT appearance is\ntypical of lung infection, the technologist immediately reports it to the chest radiologist on duty\nand asks the patient to wait in the CT examination room. If the chest radiologist does not\nsuspect COVID-19 infection, the patient can leave the CT examination room. If the chest\nradiologist does suspect COVID-19 infection, the technologist immediately reports it to the\nEMICT and sends the patient to the fever tent. The floor and equipment in the CT examination\nroom are disinfected according to regulations, and air disinfection is conducted for 30 min\nbefore examining other patients. These CT scanners are considered noncontaminated (not\nfever-CTs) after these sterilization procedures.\nFever-DR examination procedure\n10\nThe COVID-19 guideline of the NHC does not recommend chest DR because its ability in\ndiagnosing COVID-19 is limited. At our hospital, we only use mobile DR units to provide", "bedside examination for critically ill patients. The technologist operating the mobile DR\nwears personal protective equipment according to the three-level protection standard and\nsterilizes the mobile DR according to the ward management requirements as described below.\nEquipment and environment disinfection procedures\nRoutine disinfection procedure [9]\n1) Object surface disinfection: Object surface is wiped with 1000mg/L chlorine-containing\ndisinfectant, wipe twice with 75% ethanol for non-corrosion resistance, once /4 hours.\n2) Equipment disinfection: The equipment in the contaminated area are wiped with\n2000mg/L chlorine-containing disinfectant. The DR and CT gantry in the contaminated\narea are wiped with 75% ethanol. The equipment in the buffer area is wiped with\n500-1000mg/L chlorine-containing disinfectant or alcohol-containing disposable\ndisinfectant wipes twice a day.\n3) Air disinfection: Turning off all central air conditioners to prevent air contamination with", "each other. Polluted area: open the door for ventilation, each time more than 30 minutes,\nonce /4 hours; The air sterilizer is continuously sterilized or the ultraviolet ray is\ncontinuously used in the unmanned state for 60 minutes, four times a day, remembered to\nclose the inner shielding door when air disinfection. Other ambient air is sprayed with\n1000mg/L chlorine-containing disinfectant and ventilated twice a day\n4) Ground disinfection: The ground is wiped with 1000mg/L chlorine-containing\ndisinfectant, once /4 hours.\n5) When contaminated, disinfect at any time. In case of visible contamination, disposable\nabsorbent materials should be used first to completely remove the pollutants, and then a\ncloth soaked with 2000mg/L chlorine-containing disinfectant should be used for 30\nminutes before wiping.\n11\nFever-CT disinfection procedures after examination\nIn addition to the above, disinfect the examination bed and ground with chlorinated disinfectant\ncontaining 2000mg/L [10].", "Noncontaminated CT disinfection procedures after suspected COVID-19 case examination\nIn addition to the above routine disinfection procedure, air disinfection is conducted for 30 min\nbefore examining other patients.\nResults\nFrom January 21, 2020 when screening for epidemiological history or symptoms\nsuspicious for COVID-19, to March 9, 2020, our hospital screened a total of 7,203 individuals\nand confirmed 24 cases of COVID-19. Of these, 3,083 people underwent fever-CT\nexaminations. Including the initial examination and reexamination, the total number of fever\nCT examination numbered 3,340. The fever-CT scanned a patient approximately every 21.5\nminutes. As a result of our precautions, none of the staff of the radiology department developed\nsymptoms suspicious for COVID-19. The fever-CT technologist, with the highest probability\nof exposure, remains PCR negative.\nDiscussion\nIt has been 17 years since the severe acute respiratory syndrome (SARS) epidemic, the last", "national spread of severe infectious disease, broke out. Currently, the Chinese people are\npanicking again. The speed and extent by which COVID-19 has spread in 2 months are\n12\nunprecedented, beyond those of SARS, and this has been aided by its contagious nature and\nrapid spread via droplets and contact. The droplet mode of transmission means that a person can\nbe infected easily by means of casual contact or even fomites on contaminated environmental\nsurfaces. Another theory has yet to be proved: aerosol propagation.\nHow radiology departments respond to any infectious disease outbreak is determined\nprimarily by the estimated risk of cross-infection to the staff and other patients. Appropriate\nprecautions taken only by staff in direct contact with patients may be adequate when the risk is\nlow. The strongest measures need to be implemented to limit the spread of the disease when the\nrisk is high. With severe infectious diseases such as COVID-19, the highest level of infection", "control measures must be implemented; these include providing adequate standard protective\nequipment, training staff, and instituting proper emergency plans.\nOnce a contagious infectious disease has been identified, the EMICT must consider four\nmain areas of response: data gathering, collaboration, needs assessment, and expert advice [10].\nData gathering includes dissemination of up-to-date case definitions and information about\nconfirmatory tests to all staff with direct patient contact to allow appropriate barrier precautions\nto be taken. All typical and atypical imaging features of the disease should be made known to\nall radiologists to assist in recognition of the disease on images and to allow accurate reporting\nof these findings. We have stored images of all probable cases of COVID-19 in the PACS so\nthat these images were readily available for any radiologist to review, and images from\nprevious imaging studies are also available for comparison.", "Collaboration with the radiology departments of other hospitals is very important because\npatients may initially present to different centers, depending on geographic location and travel\n13\ndistance. These patients may be few in number at a single hospital, but if data from patients at\nseveral hospitals are available, a more accurate overall understanding of both imaging features\nand epidemiology can be achieved. Dissemination of this information to all healthcare facilities\nwill also lead to early recognition of the disease, and appropriate isolation measures may be\ninstituted.\nThe Internet and social media apps, especially WeChat, have been used for distribution of\nmedical information, and because the exchange of information regarding infectious disease\noutbreaks is almost instantaneous, it is an indispensable tool for radiologists. In fact, within a\nmonth of the outbreak, the hospital that received the most infected patients from the source of", "the outbreak made a PowerPoint presentation of the CT manifestations of COVID-19, which\nwas shared via WeChat and disseminated across the country in a very short time. Subsequently,\nCOVID-19-teaching PowerPoint presentations from various hospitals appeared and were\nquickly shared via WeChat.\nOur diagnostic process is limited as chest CT along is not diagnostic of COVID-19\nbecause of lack of imaging specificity. But when combined with other epidemiological,\nclinical, laboratory and virus nucleic acid information, typical chest CT imaging findings are\nhelpful for making the diagnosis. In our opinion, the major role of chest CT is to understand the\nextent and dynamic evolution of lung lesions induced by COVID-19. The reasons why we\nadopted the low-dose chest CT scan protocol are as follows: low-dose chest CT has been\nwidely used in the screening of early lung cancer. It is well known that many early lung cancers", "are ground-glass opacities (GGO), so we believe that low-dose screening is also applicable for\nCOVID-19. In addition, considering the rapid development of COVID-19, many CT\n14\nexaminations may be conducted in the same individual to monitor disease progress. Low-dose\nscanning can reduce the radiation damage to patients.\nAlthough the processes we established minimized the exposure of hospital staff, ancillary\npersonnel and other patients, it remains limited as follows. Sichuan province is not the center of\nthe epidemic. The number of patients with COVID-19 whom we have treated has not been\nhigh, and most cases are from other provinces of China. However, we believe that our\nexperience in management, the reconfiguration of our radiology department, and the workflow\nchanges implemented in the current COVID-19 situation are useful for other radiology\ndepartments that must prepare for dealing with patients with COVID-19. While no radiology", "personnel developed symptoms suspicious for or were confirmed as having COVID-19, there\nmay be asymptomatic personnel.\nREFERENCES\n1. National Health Commission of the People’s Republic of China.(2020). March 12: Daily briefing\non novel coronavirus cases in China. Retrieved from\nhttp://en.nhc.gov.cn/2020-03/12/c_77618.htm. Accessed March 11, 2020.\n2. World Health Organization. (2020). Coronavirus disease 2019 (COVID-19) Situation Report-52.\nRetrieved from\nhttps://www.who.int/docs/default-source/coronaviruse/20200312-sitrep-52-covid-19.pdf?sfvrsn=e\n2bfc9c0_2 9. Accessed March 11, 2020.\n3. National Health Commission of the People’s Republic of China.(2020). Latest developments in\nepidemic control on Feb 15. Retrieved from http://en.nhc.gov.cn/2020-02/16/c_76622. Accessed\nMarch 11, 2020.\n15\n4. Health Commission of the People’s Republic of China.(2020). The notification of the trial\noperation based on the guideline version 6 in the coronavirus disease diagnosis and treatment.", "Retrieved from\nhttp://www.nhc.gov.cn/xcs/zhengcwj/202002/8334a8326dd94d329df351d7da8aefc2.shtml.\nAccessed March 11, 2020\n5. Health Commission of the People’s Republic of China.(2020). The notification of the trial\noperation based on the guideline version 6 in the coronavirus disease diagnosis and treatment.\nRetrieved from\nhttp://www.nhc.gov.cn/xcs/zhengcwj/202002/8334a8326dd94d329df351d7da8aefc2.shtml.\nAccessed March 11, 2020.\n6. Health Commission of the People’s Republic of China.(2009). The guideline for pathogens\nisolated operations in hospital. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/200904/40116.shtml. Accessed March 11, 2020.\n7. Health Commission of the People’s Republic of China.(2017). The guideline for prevention and\ncontrol of hospital acquired infections of airborne pathogens. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201701/7e0e8fc6725843aabba8f841f2f585d2.shtml. Accessed\nMarch 11, 2020.", "8. Health Commission of the People’s Republic of China.(2017). The guideline for prevention and\ncontrol of hospital acquired infections of airborne pathogens. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201701/7e0e8fc6725843aabba8f841f2f585d2.shtml. Accessed\nMarch 11, 2020.\n9. Health Commission of the People’s Republic of China.(2012). The standardization for\nsterilization techniques in hospital. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201204/54510.shtml. Accessed March 11, 2020.\n10. Health Commission of the People’s Republic of China.(2012). The standardization for\nsterilization techniques in hospital. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201204/54510.shtml. Accessed March 11, 2020.\n11. Katona P. Bioterrorism Preparedness: Generic Blueprint for Health Departments, Hospitals, and\nPhysicians. Infectious Diseases in Clinical Practice. 2002;11(3):115-122. Accessed March 11,\n2020.\n16\nFigure Legends", "Figure 1. Diagram of the layout of our radiology department was divided into four areas: contaminated\n(shaded in black), semicontaminated (shaded in dark gray), buffer (shaded in light gray), and clean areas\n(shaded in white). The contaminated area was separated from other areas by barriers.\nFigure 2. Diagram shows CT protocol for suspected and confirmed patients with COVID-19.\nFigure 3. Diagram shows CT protocol for regular patients.\nAbbreviations:\nCOVID-19: coronavirus disease 2019\nCT: computed tomography\nDR: digital radiography\nEMICT: emergency management and infection control team\nNHC: National Health Commission\nPACS: picture archiving and communication system\nSARS: severe acute respiratory syndrome", "Sentence Summary\nWith severe infectious diseases such as COVID-19, the highest level of infection control\nmeasures must be implemented, collaboration with the radiology departments of other\nhospitals be needed, and social media be employed.\nTake-home points\n1. To response to a community infection emergency, a special emergency management team\nneeds to be setup at the departmental level to implement infection containment and\ncontrol procedures that continues to allow the imaging examination and imaging\ndiagnosis of those with suspected infection, and to prevent intra-departmental spreading\nof infection (EMICT).\n2. Infection control measures, such as reconfiguration of department areas, personal\nprotection and anti-infection training of all staff, standardized procedures including\ncontact minimization for chest CT and DR examinations, and timely disinfection of CT\nand DR examination rooms, should be implemented properly.", "3. If there are more than one scanner in a hospital, only one of them should be assigned to\nsuspected cases." ]	[ 23 ]	3,975	6,764
188	What is the major role of chest CT?	2,460	[ "to understand the\nextent and dynamic evolution of lung lesions induced by COVID-19" ]	[ "The Battle Against Coronavirus Disease 2019 (COVID-19): Emergency Management\nand Infection Control in a Radiology Department\nhttps://www.jacr.org/article/S1546-1440(20)30285-4/pdf\nJournal Pre-proof\nZixing Huang, Shuang Zhao, Zhenlin Li, Weixia Chen, Lihong Zhao, Lipeng Deng, Bin\nSong\nPII: S1546-1440(20)30285-4\nDOI: https://doi.org/10.1016/j.jacr.2020.03.011\nReference: JACR 5139\nTo appear in: Journal of the American College of Radiology\nReceived Date: 24 February 2020\nRevised Date: 13 March 2020\nAccepted Date: 15 March 2020\nPlease cite this article as: Huang Z, Zhao S, Li Z, Chen W, Zhao L, Deng L, Song B, The Battle Against\nCoronavirus Disease 2019 (COVID-19): Emergency Management and Infection Control in a Radiology\nDepartment, Journal of the American College of Radiology (2020), doi: https://doi.org/10.1016/\nj.jacr.2020.03.011.\nThis is a PDF file of an article that has undergone enhancements after acceptance, such as the addition", "of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of\nrecord. This version will undergo additional copyediting, typesetting and review before it is published\nin its final form, but we are providing this version to give early visibility of the article. Please note that,\nduring the production process, errors may be discovered which could affect the content, and all legal\ndisclaimers that apply to the journal pertain.\n© 2020 Published by Elsevier Inc. on behalf of American College of Radiology\nThe Battle Against Coronavirus Disease 2019 (COVID-19): Emergency Management\nand Infection Control in a Radiology Department\nZixing Huang, Shuang Zhao, Zhenlin Li, Weixia Chen, Lihong Zhao, Lipeng Deng,\nBin Song\nDepartment of Radiology, West China Hospital, Sichuan University, Chengdu, China\n*Zixing Huang and Shuang Zhao contributed equally to this work as co-first author.\nCorresponding Author: Bin Song, MD", "Address: Department of Radiology, West China Hospital, Sichuan University.\nNo. 37, GUOXUE Alley, Chengdu, 610041, China\nTel.: (+86)28 85423680, Fax: (+86)28 85582944\nEmail: [email protected].\nAuthors’ contributions\nZXH: conceived the study and drafted the manuscript.\nZS: conceived the study and drafted the manuscript.\nZLL: The member of the emergency management and infection control team (EMICT)\nand was involved in the formulation of the measures.\nWXC: The member of the EMICT and was involved in the formulation of the\nmeasures.\nLHZ: The member of the EMICT and was involved in the formulation of the\nmeasures.\nLPD: The member of the EMICT and was involved in the formulation of the\nmeasures.\nBS: Leader of the EMICT, conceived the study and reviewed the manuscript.\nAll authors read and approved the final manuscript.\nThe authors declare no conflict of interest.\nThe authors declare that they had full access to all of the data in this study and the", "authors take complete responsibility for the integrity of the data and the accuracy of\nthe data analysis\n1\nThe Battle Against Novel Coronavirus Pneumonia (COVID-19): Emergency\nManagement and Infection Control in a Radiology Department\nAbstract\nObjective: To describe the strategy and the emergency management and infection control\nprocedure of our radiology department during the COVID-19 outbreak.\nMethods: We set up emergency management and sensing control teams. The team formulated\nvarious measures: reconfiguration of the radiology department, personal protection and training\nof staff, examination procedures for patients suspected of or confirmed with COVID-19 as well\nas patients without an exposure history or symptoms. Those with suspected or confirmed\nCOVID-19 infection were scanned in the designated fever-CT unit.\nResults: From January 21, 2020 to March 9, 2020, 3,083 people suspected of or confirmed with\nCOVID-19 underwent fever-CT examinations. Including initial examinations and", "reexaminations, the total number of fever-CT examinations numbered 3,340. As a result of our\nprecautions, none of the staff of the radiology department were infected with COVID-19.\nConclusion: Strategic planning and adequate protections can help protect patients and staff\nagainst a highly infectious disease while maintaining function at a high volume capacity.\nKeywords: Coronavirus, COVID-19, novel coronavirus pneumonia, infection control", "2\nIntroduction\nThe whole world has been closely focusing on an outbreak of respiratory disease caused by a\nnovel coronavirus that was first reported in Wuhan, China, on December 31, 2019, and that\ncontinues to spread. On February 11, 2020, the World Health Organization (WHO) named the\ndisease “coronavirus disease 2019” (COVID-19).\nAs of 24:00 on March 11, 2020, the National Health Commission (NHC) had received reports\nof 80,793 confirmed cases and 3,169 deaths on the Chinese mainland. There remain 14,831\nconfirmed cases (including 4,257 in serious condition) and 253 suspected cases still\nhospitalized. To date, 677,243 people have been identified as having had close contact with\ninfected patients of whom13,701 are under medical observation [1]. Outside China, 44,067\nlaboratory-confirmed cases and 1,440 deaths have occurred in 117 countries /territories/areas\naccording to the WHO [2]. COVID-19 poses significant threats to international health. Like the", "flu, COVID-19 is thought to spread mainly from person-to-person between people who are in\nclose contact with one another through respiratory droplets produced when an infected person\ncoughs or sneezes. In light of the infectious nature of this disease, healthcare workers are at\nhigh risk of infection of COVID-19. In China, healthcare workers account for 1,716 confirmed\ncases of COVID-19, including six deaths [3].\n Computed tomography (CT) can play a role in both diagnosing and categorizing\nCOVID-19 on the basis of case definitions issued by the WHO and the treatment guidelines\nfrom the NHC [4]. Suspected patients having the virus may undergo chest CT. Isolation and\nbarrier procedures are necessary to protect both the department staff and other patients in the\nhospital. Note should be made that due to overlap of imaging findings with other respiratory\n3\ndiseases, CT is not helpful as a screening tool. But it can help identify the degree of pulmonary\ninvolvement and disease course.", "Our hospital is a national regional medical center with 4,300 beds and a tertiary referral\ncenter in Sichuan province. The initial response started on January 21, 2020, after transmission\nof COVID-19 was confirmed to be human-to-human on January 20, 2020. The first suspected\ncase of COVID-19 in Sichuan province was reported on January 21, 2020. The Sichuan\nprovincial government immediately launched the first-level response to major public health\nemergencies. On the same day, our hospital was designated to care for Sichuan province\npatients with COVID-19.\nThis article describes the emergency management procedure of our radiology department\nfor situations involving severe infectious diseases, such as COVID-19, and the\ninfection-protection experience of the department staff.\nMethods\nThe hospital provided personal protective equipment (medical protective clothing,\nsurgical cap, N95 mask, gloves, face shields, and goggles) to all its healthcare staff, erected", "three medical tents (fever tents) for screening of fever cases in the parking lot of the emergency\ndepartment, planned an examination route and examination area for patients suspected of\nharboring the virus, and placed confirmed patients in an isolation ward. “Fever” was the\ncolloquial term used to designate suspected COVID-19 based on symptoms such as a fever or\nwith an epidemiological history of a potential exposure as well as those with confirmed\nCOVID-19 referred for treatment. Further, during outbreak, emergency and outpatient patients\n4\nwithout fever were asked for information such as epidemiological history and sent to fever tents\nas long as they met suspected criteria.\nThe radiology department has 65 diagnostic radiologists and 161 other staff members\n(trained technologists, nurses, engineers, and support staff). The equipment of the radiology\ndepartment includes 12 magnetic resonance (MR) scanners, 14 CT scanners, 15 digital", "subtraction angiography (DSA) systems, 32 sets of digital radiography (DR) systems\n(including nine mobile bedside DR sets), and 130 imaging diagnostic workstations for picture\narchiving and communication systems (PACS). Most of the equipment is distributed among\nfour buildings at the hospital main campus. 4 CT scanners, 4 MR scanners, 1 DR are located on\nthe first floor of the first inpatient building, and 9 DR and 8 DSA are located on the second\nfloor. 1 CT and 1 MR scanner are located in the third inpatient building. 1 CT and 1 MR scanner\nare located in the sixth inpatient building. 2 CT scanners, 2 MR scanners and 7 DSA are located\nin the technical building. The rest of the equipment is located in the seventh inpatient building\nin the branch campus.\nThe first inpatient building, located next to the emergency department, was reconfigured to\nhandle cases of COVID-19. Fever tents were set up by the emergency department in the", "emergency department parking lot to separate normal emergency patients from patients with\nsymptoms or exposure history suspicious of COVID-19. We established separate means of\naccess between fever tents and between the fever examination area of the radiology department\nto avoid cross-contamination.\nThe emergency management and infection control measures, as described below and\nimplemented in the radiology department during the outbreak, have been approved by the\n5\ninfection control committee of hospital. These measures are in accordance with relevant laws\nand regulations, in order to protect patients as well as the staff.\nRadiology Emergency Management and Infection Control Team (EMICT)\nThe radiology department director chaired the EMICT. Its members include the deputy\ndirector, chief technologist, head nurse, equipment engineer supervisor, and infection control\nnurse of the radiology department. Team responsibilities included (1) coordination between the", "hospital’s management and planning of infection control and radiology departments; (2)\ncollection of the most up-to-date protection-related information to educate and train staff in the\ndepartment; (3) reallocation of staff according to the actual situation; (4) establishment of the\nCT procedures for patients with COVID-19; and (5) establishment of an emergency\nmanagement plan for the radiology department to ensure that the department would run\nnormally.\nSuspected patients\nThe suspected patients were identified according to the Diagnosis and Treatment Program of\nthe Novel Coronavirus Pneumonia of the NHC [5], mainly based on epidemiological history.\nReconfiguration of the radiology department\nThe radiology department was divided into four areas [6]: contaminated, semicontaminated,\nbuffer, and clean areas (Figure 1). The contaminated area is connected to the fever clinic and\nincludes the fever accessway, the CT examination room, and the DR examination room for\n6", "confirmed and suspected cases. One CT scanner and one DR system closest to the emergency\ndepartment are designated the fever-CT and fever-DR to examine patients with suspected and\nconfirmed COVID-19. There is a separate dedicated access between the contaminated area and\nthe fever screening tents. The semicontaminated area includes the fever-CT control room,\nfever-DR control room, and other patient examination access areas. The buffer zone includes\naccess areas for medical personnel and a dressing area for technologists. The clean area\nincludes the administrative office and the diagnostic room.\nThe contaminated area was isolated from other areas using physical barricades.\nDirectional signs were newly installed to guide patients and staff.\nPersonal protection and training of staff\nFor providing care for patients with confirmed and suspected COVID-19, all hospital staff\nare required to wear complete personal protective equipment [7]: medical protective clothing,", "surgical cap, N95 mask, gloves, face shields, and goggles. Wearing and removing of the\nequipment must be performed in accordance with the procedures and under the supervision of\nthe infection control nurse.\nBecause staff members working in the contaminated area are under much situational\npressure, periodically taking time off could lower their physical and mental stress levels. The\ntechnologists on fever-CT duty shifts are provided a break once a week for four hours. In\naddition, the health of staff in the contaminated area must be monitored closely for the\nsymptoms of COVID-19. Pregnant staff must be assigned to the clean area.\n7\nThe EMICT formulates and continually updates guidelines and educates all staff for West\nChina Hospital of Sichuan University. The EMICT training for staff is mainly involves\ndocuments regarding infection control and CT findings of COVID-19 and maintains an EMICT\nWeChat group for West China Hospital of Sichuan University. WeChat is the most widely used", "social media app in China. The EMICT releases the latest national and hospital-based\ninformation regarding COVID-19, guidance documents, and other notices from the hospital\nand radiology department in the WeChat group on a daily basis. Staff can also report to the\nEMICT in the WeChat group any time. Protocols for each modality and infection control\ninstructions are posted on the walls in all examination rooms. The EMICT periodically reminds\nstaff to undertake personal measures to reduce infection, such as wearing masks at all instances\nin the radiology department and N95 masks if working in the contaminated area; not touching\nthe mask and the eyes; practicing hand hygiene; facing away from colleagues when eating,\ndrinking, and talking; and not using personal cell phones while on duty.\n In addition, the chief thoracic radiologist provided lectures on all radiologists and\ntechnologists on typical CT findings of COVID-19 infection using materials developed in", "Wuhan, the epicenter of the outbreak in China.\nCT examination procedures\nThere are two sets of procedures for CT examination: the fever-CT procedure and routine CT\nprocedure for those not suspected of COVID-19.\nThe fever-CT procedure for suspected or confirmed COVID-19 (Figure 2)\n8\nBefore the fever-CT technologist operates the equipment, he or she should wear personal\nprotective equipment according to three-level protection standard [8]. Before the CT\nexamination of patients with suspected and confirmed COVID-19 begins, the fever tent or\nisolation ward notifies the radiologist in advance. The fever-CT technologist checks the\nequipment and prepares to disinfect the imaging equipment immediately after the examination.\nThe patient enters the fever-CT waiting area through the fever access area. If the patient\ncan get onto and off the examination table by themselves, the patient is allowed to do so. If the", "patient cannot get onto or off the examination table independently, the person accompanying\nthe patient assists the patient, rather than the technologist. The technologist checks the patient\ninformation and, using an intercom system in the examination room, asks the patient to remove\nany metal ornaments on the neck and chest. Also, by intercom, the technologist trains the\npatient to hold his or her breath during the examination.\nThe technologist uses a low-dose chest CT protocol to scan the patient. After scanning, the\noriginal images are reconstructed as 1 mm-thick layers. The technologist browses the images to\nensure that their quality meets the diagnostic requirements and then guides the patient to leave\nthrough the fever access area. The disposable sheets for patient examination are changed after\neach patient. The equipment is disinfected according to the procedure below.\nTo protect themselves, the technologists assigned to the fever-CT wear N95 mask and", "other personal protection as established by the EMICT.\nThe CT procedure for regular patients (figure.3)\n9\nSome patients with COVID-19 have no symptoms, and they may call at the general clinic for\nother reasons. The following CT procedure is applicable under these circumstances:\nWhen the patient makes an appointment for examination, the staff asks the patient about\ntheir epidemiological history, symptoms, and signs. If suspected criteria are met, the patient\nwill be sent to the fever tent for further screening. When a patient presents to the radiology\ndepartment entrance, his/her temperature is measured. If the temperature is higher than 37.2 , ℃\nthe patient is sent to the fever tent for further investigation.\nThose with no exposure history, suspicious symptoms or fever are screened in one of the\nnon-contaminated CT scanners. The technologists assigned to these scanners wear surgical\nmasks. All patients and the person accompanying them are required to wear surgical masks.", "After the CT examination, the technologist browses the images quickly. If the CT appearance is\ntypical of lung infection, the technologist immediately reports it to the chest radiologist on duty\nand asks the patient to wait in the CT examination room. If the chest radiologist does not\nsuspect COVID-19 infection, the patient can leave the CT examination room. If the chest\nradiologist does suspect COVID-19 infection, the technologist immediately reports it to the\nEMICT and sends the patient to the fever tent. The floor and equipment in the CT examination\nroom are disinfected according to regulations, and air disinfection is conducted for 30 min\nbefore examining other patients. These CT scanners are considered noncontaminated (not\nfever-CTs) after these sterilization procedures.\nFever-DR examination procedure\n10\nThe COVID-19 guideline of the NHC does not recommend chest DR because its ability in\ndiagnosing COVID-19 is limited. At our hospital, we only use mobile DR units to provide", "bedside examination for critically ill patients. The technologist operating the mobile DR\nwears personal protective equipment according to the three-level protection standard and\nsterilizes the mobile DR according to the ward management requirements as described below.\nEquipment and environment disinfection procedures\nRoutine disinfection procedure [9]\n1) Object surface disinfection: Object surface is wiped with 1000mg/L chlorine-containing\ndisinfectant, wipe twice with 75% ethanol for non-corrosion resistance, once /4 hours.\n2) Equipment disinfection: The equipment in the contaminated area are wiped with\n2000mg/L chlorine-containing disinfectant. The DR and CT gantry in the contaminated\narea are wiped with 75% ethanol. The equipment in the buffer area is wiped with\n500-1000mg/L chlorine-containing disinfectant or alcohol-containing disposable\ndisinfectant wipes twice a day.\n3) Air disinfection: Turning off all central air conditioners to prevent air contamination with", "each other. Polluted area: open the door for ventilation, each time more than 30 minutes,\nonce /4 hours; The air sterilizer is continuously sterilized or the ultraviolet ray is\ncontinuously used in the unmanned state for 60 minutes, four times a day, remembered to\nclose the inner shielding door when air disinfection. Other ambient air is sprayed with\n1000mg/L chlorine-containing disinfectant and ventilated twice a day\n4) Ground disinfection: The ground is wiped with 1000mg/L chlorine-containing\ndisinfectant, once /4 hours.\n5) When contaminated, disinfect at any time. In case of visible contamination, disposable\nabsorbent materials should be used first to completely remove the pollutants, and then a\ncloth soaked with 2000mg/L chlorine-containing disinfectant should be used for 30\nminutes before wiping.\n11\nFever-CT disinfection procedures after examination\nIn addition to the above, disinfect the examination bed and ground with chlorinated disinfectant\ncontaining 2000mg/L [10].", "Noncontaminated CT disinfection procedures after suspected COVID-19 case examination\nIn addition to the above routine disinfection procedure, air disinfection is conducted for 30 min\nbefore examining other patients.\nResults\nFrom January 21, 2020 when screening for epidemiological history or symptoms\nsuspicious for COVID-19, to March 9, 2020, our hospital screened a total of 7,203 individuals\nand confirmed 24 cases of COVID-19. Of these, 3,083 people underwent fever-CT\nexaminations. Including the initial examination and reexamination, the total number of fever\nCT examination numbered 3,340. The fever-CT scanned a patient approximately every 21.5\nminutes. As a result of our precautions, none of the staff of the radiology department developed\nsymptoms suspicious for COVID-19. The fever-CT technologist, with the highest probability\nof exposure, remains PCR negative.\nDiscussion\nIt has been 17 years since the severe acute respiratory syndrome (SARS) epidemic, the last", "national spread of severe infectious disease, broke out. Currently, the Chinese people are\npanicking again. The speed and extent by which COVID-19 has spread in 2 months are\n12\nunprecedented, beyond those of SARS, and this has been aided by its contagious nature and\nrapid spread via droplets and contact. The droplet mode of transmission means that a person can\nbe infected easily by means of casual contact or even fomites on contaminated environmental\nsurfaces. Another theory has yet to be proved: aerosol propagation.\nHow radiology departments respond to any infectious disease outbreak is determined\nprimarily by the estimated risk of cross-infection to the staff and other patients. Appropriate\nprecautions taken only by staff in direct contact with patients may be adequate when the risk is\nlow. The strongest measures need to be implemented to limit the spread of the disease when the\nrisk is high. With severe infectious diseases such as COVID-19, the highest level of infection", "control measures must be implemented; these include providing adequate standard protective\nequipment, training staff, and instituting proper emergency plans.\nOnce a contagious infectious disease has been identified, the EMICT must consider four\nmain areas of response: data gathering, collaboration, needs assessment, and expert advice [10].\nData gathering includes dissemination of up-to-date case definitions and information about\nconfirmatory tests to all staff with direct patient contact to allow appropriate barrier precautions\nto be taken. All typical and atypical imaging features of the disease should be made known to\nall radiologists to assist in recognition of the disease on images and to allow accurate reporting\nof these findings. We have stored images of all probable cases of COVID-19 in the PACS so\nthat these images were readily available for any radiologist to review, and images from\nprevious imaging studies are also available for comparison.", "Collaboration with the radiology departments of other hospitals is very important because\npatients may initially present to different centers, depending on geographic location and travel\n13\ndistance. These patients may be few in number at a single hospital, but if data from patients at\nseveral hospitals are available, a more accurate overall understanding of both imaging features\nand epidemiology can be achieved. Dissemination of this information to all healthcare facilities\nwill also lead to early recognition of the disease, and appropriate isolation measures may be\ninstituted.\nThe Internet and social media apps, especially WeChat, have been used for distribution of\nmedical information, and because the exchange of information regarding infectious disease\noutbreaks is almost instantaneous, it is an indispensable tool for radiologists. In fact, within a\nmonth of the outbreak, the hospital that received the most infected patients from the source of", "the outbreak made a PowerPoint presentation of the CT manifestations of COVID-19, which\nwas shared via WeChat and disseminated across the country in a very short time. Subsequently,\nCOVID-19-teaching PowerPoint presentations from various hospitals appeared and were\nquickly shared via WeChat.\nOur diagnostic process is limited as chest CT along is not diagnostic of COVID-19\nbecause of lack of imaging specificity. But when combined with other epidemiological,\nclinical, laboratory and virus nucleic acid information, typical chest CT imaging findings are\nhelpful for making the diagnosis. In our opinion, the major role of chest CT is to understand the\nextent and dynamic evolution of lung lesions induced by COVID-19. The reasons why we\nadopted the low-dose chest CT scan protocol are as follows: low-dose chest CT has been\nwidely used in the screening of early lung cancer. It is well known that many early lung cancers", "are ground-glass opacities (GGO), so we believe that low-dose screening is also applicable for\nCOVID-19. In addition, considering the rapid development of COVID-19, many CT\n14\nexaminations may be conducted in the same individual to monitor disease progress. Low-dose\nscanning can reduce the radiation damage to patients.\nAlthough the processes we established minimized the exposure of hospital staff, ancillary\npersonnel and other patients, it remains limited as follows. Sichuan province is not the center of\nthe epidemic. The number of patients with COVID-19 whom we have treated has not been\nhigh, and most cases are from other provinces of China. However, we believe that our\nexperience in management, the reconfiguration of our radiology department, and the workflow\nchanges implemented in the current COVID-19 situation are useful for other radiology\ndepartments that must prepare for dealing with patients with COVID-19. While no radiology", "personnel developed symptoms suspicious for or were confirmed as having COVID-19, there\nmay be asymptomatic personnel.\nREFERENCES\n1. National Health Commission of the People’s Republic of China.(2020). March 12: Daily briefing\non novel coronavirus cases in China. Retrieved from\nhttp://en.nhc.gov.cn/2020-03/12/c_77618.htm. Accessed March 11, 2020.\n2. World Health Organization. (2020). Coronavirus disease 2019 (COVID-19) Situation Report-52.\nRetrieved from\nhttps://www.who.int/docs/default-source/coronaviruse/20200312-sitrep-52-covid-19.pdf?sfvrsn=e\n2bfc9c0_2 9. Accessed March 11, 2020.\n3. National Health Commission of the People’s Republic of China.(2020). Latest developments in\nepidemic control on Feb 15. Retrieved from http://en.nhc.gov.cn/2020-02/16/c_76622. Accessed\nMarch 11, 2020.\n15\n4. Health Commission of the People’s Republic of China.(2020). The notification of the trial\noperation based on the guideline version 6 in the coronavirus disease diagnosis and treatment.", "Retrieved from\nhttp://www.nhc.gov.cn/xcs/zhengcwj/202002/8334a8326dd94d329df351d7da8aefc2.shtml.\nAccessed March 11, 2020\n5. Health Commission of the People’s Republic of China.(2020). The notification of the trial\noperation based on the guideline version 6 in the coronavirus disease diagnosis and treatment.\nRetrieved from\nhttp://www.nhc.gov.cn/xcs/zhengcwj/202002/8334a8326dd94d329df351d7da8aefc2.shtml.\nAccessed March 11, 2020.\n6. Health Commission of the People’s Republic of China.(2009). The guideline for pathogens\nisolated operations in hospital. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/200904/40116.shtml. Accessed March 11, 2020.\n7. Health Commission of the People’s Republic of China.(2017). The guideline for prevention and\ncontrol of hospital acquired infections of airborne pathogens. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201701/7e0e8fc6725843aabba8f841f2f585d2.shtml. Accessed\nMarch 11, 2020.", "8. Health Commission of the People’s Republic of China.(2017). The guideline for prevention and\ncontrol of hospital acquired infections of airborne pathogens. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201701/7e0e8fc6725843aabba8f841f2f585d2.shtml. Accessed\nMarch 11, 2020.\n9. Health Commission of the People’s Republic of China.(2012). The standardization for\nsterilization techniques in hospital. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201204/54510.shtml. Accessed March 11, 2020.\n10. Health Commission of the People’s Republic of China.(2012). The standardization for\nsterilization techniques in hospital. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201204/54510.shtml. Accessed March 11, 2020.\n11. Katona P. Bioterrorism Preparedness: Generic Blueprint for Health Departments, Hospitals, and\nPhysicians. Infectious Diseases in Clinical Practice. 2002;11(3):115-122. Accessed March 11,\n2020.\n16\nFigure Legends", "Figure 1. Diagram of the layout of our radiology department was divided into four areas: contaminated\n(shaded in black), semicontaminated (shaded in dark gray), buffer (shaded in light gray), and clean areas\n(shaded in white). The contaminated area was separated from other areas by barriers.\nFigure 2. Diagram shows CT protocol for suspected and confirmed patients with COVID-19.\nFigure 3. Diagram shows CT protocol for regular patients.\nAbbreviations:\nCOVID-19: coronavirus disease 2019\nCT: computed tomography\nDR: digital radiography\nEMICT: emergency management and infection control team\nNHC: National Health Commission\nPACS: picture archiving and communication system\nSARS: severe acute respiratory syndrome", "Sentence Summary\nWith severe infectious diseases such as COVID-19, the highest level of infection control\nmeasures must be implemented, collaboration with the radiology departments of other\nhospitals be needed, and social media be employed.\nTake-home points\n1. To response to a community infection emergency, a special emergency management team\nneeds to be setup at the departmental level to implement infection containment and\ncontrol procedures that continues to allow the imaging examination and imaging\ndiagnosis of those with suspected infection, and to prevent intra-departmental spreading\nof infection (EMICT).\n2. Infection control measures, such as reconfiguration of department areas, personal\nprotection and anti-infection training of all staff, standardized procedures including\ncontact minimization for chest CT and DR examinations, and timely disinfection of CT\nand DR examination rooms, should be implemented properly.", "3. If there are more than one scanner in a hospital, only one of them should be assigned to\nsuspected cases." ]	[ 25 ]	3,975	6,764
188	What is the reason to adopt low-dose CT?	2,461	[ "low-dose chest CT has been\nwidely used in the screening of early lung cancer. It is well known that many early lung cancers\nare ground-glass opacities (GGO), so we believe that low-dose screening is also applicable for\nCOVID-19. In addition, considering the rapid development of COVID-19, many CT\n14\nexaminations may be conducted in the same individual to monitor disease progress. Low-dose\nscanning can reduce the radiation damage to patients." ]	[ "The Battle Against Coronavirus Disease 2019 (COVID-19): Emergency Management\nand Infection Control in a Radiology Department\nhttps://www.jacr.org/article/S1546-1440(20)30285-4/pdf\nJournal Pre-proof\nZixing Huang, Shuang Zhao, Zhenlin Li, Weixia Chen, Lihong Zhao, Lipeng Deng, Bin\nSong\nPII: S1546-1440(20)30285-4\nDOI: https://doi.org/10.1016/j.jacr.2020.03.011\nReference: JACR 5139\nTo appear in: Journal of the American College of Radiology\nReceived Date: 24 February 2020\nRevised Date: 13 March 2020\nAccepted Date: 15 March 2020\nPlease cite this article as: Huang Z, Zhao S, Li Z, Chen W, Zhao L, Deng L, Song B, The Battle Against\nCoronavirus Disease 2019 (COVID-19): Emergency Management and Infection Control in a Radiology\nDepartment, Journal of the American College of Radiology (2020), doi: https://doi.org/10.1016/\nj.jacr.2020.03.011.\nThis is a PDF file of an article that has undergone enhancements after acceptance, such as the addition", "of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of\nrecord. This version will undergo additional copyediting, typesetting and review before it is published\nin its final form, but we are providing this version to give early visibility of the article. Please note that,\nduring the production process, errors may be discovered which could affect the content, and all legal\ndisclaimers that apply to the journal pertain.\n© 2020 Published by Elsevier Inc. on behalf of American College of Radiology\nThe Battle Against Coronavirus Disease 2019 (COVID-19): Emergency Management\nand Infection Control in a Radiology Department\nZixing Huang, Shuang Zhao, Zhenlin Li, Weixia Chen, Lihong Zhao, Lipeng Deng,\nBin Song\nDepartment of Radiology, West China Hospital, Sichuan University, Chengdu, China\n*Zixing Huang and Shuang Zhao contributed equally to this work as co-first author.\nCorresponding Author: Bin Song, MD", "Address: Department of Radiology, West China Hospital, Sichuan University.\nNo. 37, GUOXUE Alley, Chengdu, 610041, China\nTel.: (+86)28 85423680, Fax: (+86)28 85582944\nEmail: [email protected].\nAuthors’ contributions\nZXH: conceived the study and drafted the manuscript.\nZS: conceived the study and drafted the manuscript.\nZLL: The member of the emergency management and infection control team (EMICT)\nand was involved in the formulation of the measures.\nWXC: The member of the EMICT and was involved in the formulation of the\nmeasures.\nLHZ: The member of the EMICT and was involved in the formulation of the\nmeasures.\nLPD: The member of the EMICT and was involved in the formulation of the\nmeasures.\nBS: Leader of the EMICT, conceived the study and reviewed the manuscript.\nAll authors read and approved the final manuscript.\nThe authors declare no conflict of interest.\nThe authors declare that they had full access to all of the data in this study and the", "authors take complete responsibility for the integrity of the data and the accuracy of\nthe data analysis\n1\nThe Battle Against Novel Coronavirus Pneumonia (COVID-19): Emergency\nManagement and Infection Control in a Radiology Department\nAbstract\nObjective: To describe the strategy and the emergency management and infection control\nprocedure of our radiology department during the COVID-19 outbreak.\nMethods: We set up emergency management and sensing control teams. The team formulated\nvarious measures: reconfiguration of the radiology department, personal protection and training\nof staff, examination procedures for patients suspected of or confirmed with COVID-19 as well\nas patients without an exposure history or symptoms. Those with suspected or confirmed\nCOVID-19 infection were scanned in the designated fever-CT unit.\nResults: From January 21, 2020 to March 9, 2020, 3,083 people suspected of or confirmed with\nCOVID-19 underwent fever-CT examinations. Including initial examinations and", "reexaminations, the total number of fever-CT examinations numbered 3,340. As a result of our\nprecautions, none of the staff of the radiology department were infected with COVID-19.\nConclusion: Strategic planning and adequate protections can help protect patients and staff\nagainst a highly infectious disease while maintaining function at a high volume capacity.\nKeywords: Coronavirus, COVID-19, novel coronavirus pneumonia, infection control", "2\nIntroduction\nThe whole world has been closely focusing on an outbreak of respiratory disease caused by a\nnovel coronavirus that was first reported in Wuhan, China, on December 31, 2019, and that\ncontinues to spread. On February 11, 2020, the World Health Organization (WHO) named the\ndisease “coronavirus disease 2019” (COVID-19).\nAs of 24:00 on March 11, 2020, the National Health Commission (NHC) had received reports\nof 80,793 confirmed cases and 3,169 deaths on the Chinese mainland. There remain 14,831\nconfirmed cases (including 4,257 in serious condition) and 253 suspected cases still\nhospitalized. To date, 677,243 people have been identified as having had close contact with\ninfected patients of whom13,701 are under medical observation [1]. Outside China, 44,067\nlaboratory-confirmed cases and 1,440 deaths have occurred in 117 countries /territories/areas\naccording to the WHO [2]. COVID-19 poses significant threats to international health. Like the", "flu, COVID-19 is thought to spread mainly from person-to-person between people who are in\nclose contact with one another through respiratory droplets produced when an infected person\ncoughs or sneezes. In light of the infectious nature of this disease, healthcare workers are at\nhigh risk of infection of COVID-19. In China, healthcare workers account for 1,716 confirmed\ncases of COVID-19, including six deaths [3].\n Computed tomography (CT) can play a role in both diagnosing and categorizing\nCOVID-19 on the basis of case definitions issued by the WHO and the treatment guidelines\nfrom the NHC [4]. Suspected patients having the virus may undergo chest CT. Isolation and\nbarrier procedures are necessary to protect both the department staff and other patients in the\nhospital. Note should be made that due to overlap of imaging findings with other respiratory\n3\ndiseases, CT is not helpful as a screening tool. But it can help identify the degree of pulmonary\ninvolvement and disease course.", "Our hospital is a national regional medical center with 4,300 beds and a tertiary referral\ncenter in Sichuan province. The initial response started on January 21, 2020, after transmission\nof COVID-19 was confirmed to be human-to-human on January 20, 2020. The first suspected\ncase of COVID-19 in Sichuan province was reported on January 21, 2020. The Sichuan\nprovincial government immediately launched the first-level response to major public health\nemergencies. On the same day, our hospital was designated to care for Sichuan province\npatients with COVID-19.\nThis article describes the emergency management procedure of our radiology department\nfor situations involving severe infectious diseases, such as COVID-19, and the\ninfection-protection experience of the department staff.\nMethods\nThe hospital provided personal protective equipment (medical protective clothing,\nsurgical cap, N95 mask, gloves, face shields, and goggles) to all its healthcare staff, erected", "three medical tents (fever tents) for screening of fever cases in the parking lot of the emergency\ndepartment, planned an examination route and examination area for patients suspected of\nharboring the virus, and placed confirmed patients in an isolation ward. “Fever” was the\ncolloquial term used to designate suspected COVID-19 based on symptoms such as a fever or\nwith an epidemiological history of a potential exposure as well as those with confirmed\nCOVID-19 referred for treatment. Further, during outbreak, emergency and outpatient patients\n4\nwithout fever were asked for information such as epidemiological history and sent to fever tents\nas long as they met suspected criteria.\nThe radiology department has 65 diagnostic radiologists and 161 other staff members\n(trained technologists, nurses, engineers, and support staff). The equipment of the radiology\ndepartment includes 12 magnetic resonance (MR) scanners, 14 CT scanners, 15 digital", "subtraction angiography (DSA) systems, 32 sets of digital radiography (DR) systems\n(including nine mobile bedside DR sets), and 130 imaging diagnostic workstations for picture\narchiving and communication systems (PACS). Most of the equipment is distributed among\nfour buildings at the hospital main campus. 4 CT scanners, 4 MR scanners, 1 DR are located on\nthe first floor of the first inpatient building, and 9 DR and 8 DSA are located on the second\nfloor. 1 CT and 1 MR scanner are located in the third inpatient building. 1 CT and 1 MR scanner\nare located in the sixth inpatient building. 2 CT scanners, 2 MR scanners and 7 DSA are located\nin the technical building. The rest of the equipment is located in the seventh inpatient building\nin the branch campus.\nThe first inpatient building, located next to the emergency department, was reconfigured to\nhandle cases of COVID-19. Fever tents were set up by the emergency department in the", "emergency department parking lot to separate normal emergency patients from patients with\nsymptoms or exposure history suspicious of COVID-19. We established separate means of\naccess between fever tents and between the fever examination area of the radiology department\nto avoid cross-contamination.\nThe emergency management and infection control measures, as described below and\nimplemented in the radiology department during the outbreak, have been approved by the\n5\ninfection control committee of hospital. These measures are in accordance with relevant laws\nand regulations, in order to protect patients as well as the staff.\nRadiology Emergency Management and Infection Control Team (EMICT)\nThe radiology department director chaired the EMICT. Its members include the deputy\ndirector, chief technologist, head nurse, equipment engineer supervisor, and infection control\nnurse of the radiology department. Team responsibilities included (1) coordination between the", "hospital’s management and planning of infection control and radiology departments; (2)\ncollection of the most up-to-date protection-related information to educate and train staff in the\ndepartment; (3) reallocation of staff according to the actual situation; (4) establishment of the\nCT procedures for patients with COVID-19; and (5) establishment of an emergency\nmanagement plan for the radiology department to ensure that the department would run\nnormally.\nSuspected patients\nThe suspected patients were identified according to the Diagnosis and Treatment Program of\nthe Novel Coronavirus Pneumonia of the NHC [5], mainly based on epidemiological history.\nReconfiguration of the radiology department\nThe radiology department was divided into four areas [6]: contaminated, semicontaminated,\nbuffer, and clean areas (Figure 1). The contaminated area is connected to the fever clinic and\nincludes the fever accessway, the CT examination room, and the DR examination room for\n6", "confirmed and suspected cases. One CT scanner and one DR system closest to the emergency\ndepartment are designated the fever-CT and fever-DR to examine patients with suspected and\nconfirmed COVID-19. There is a separate dedicated access between the contaminated area and\nthe fever screening tents. The semicontaminated area includes the fever-CT control room,\nfever-DR control room, and other patient examination access areas. The buffer zone includes\naccess areas for medical personnel and a dressing area for technologists. The clean area\nincludes the administrative office and the diagnostic room.\nThe contaminated area was isolated from other areas using physical barricades.\nDirectional signs were newly installed to guide patients and staff.\nPersonal protection and training of staff\nFor providing care for patients with confirmed and suspected COVID-19, all hospital staff\nare required to wear complete personal protective equipment [7]: medical protective clothing,", "surgical cap, N95 mask, gloves, face shields, and goggles. Wearing and removing of the\nequipment must be performed in accordance with the procedures and under the supervision of\nthe infection control nurse.\nBecause staff members working in the contaminated area are under much situational\npressure, periodically taking time off could lower their physical and mental stress levels. The\ntechnologists on fever-CT duty shifts are provided a break once a week for four hours. In\naddition, the health of staff in the contaminated area must be monitored closely for the\nsymptoms of COVID-19. Pregnant staff must be assigned to the clean area.\n7\nThe EMICT formulates and continually updates guidelines and educates all staff for West\nChina Hospital of Sichuan University. The EMICT training for staff is mainly involves\ndocuments regarding infection control and CT findings of COVID-19 and maintains an EMICT\nWeChat group for West China Hospital of Sichuan University. WeChat is the most widely used", "social media app in China. The EMICT releases the latest national and hospital-based\ninformation regarding COVID-19, guidance documents, and other notices from the hospital\nand radiology department in the WeChat group on a daily basis. Staff can also report to the\nEMICT in the WeChat group any time. Protocols for each modality and infection control\ninstructions are posted on the walls in all examination rooms. The EMICT periodically reminds\nstaff to undertake personal measures to reduce infection, such as wearing masks at all instances\nin the radiology department and N95 masks if working in the contaminated area; not touching\nthe mask and the eyes; practicing hand hygiene; facing away from colleagues when eating,\ndrinking, and talking; and not using personal cell phones while on duty.\n In addition, the chief thoracic radiologist provided lectures on all radiologists and\ntechnologists on typical CT findings of COVID-19 infection using materials developed in", "Wuhan, the epicenter of the outbreak in China.\nCT examination procedures\nThere are two sets of procedures for CT examination: the fever-CT procedure and routine CT\nprocedure for those not suspected of COVID-19.\nThe fever-CT procedure for suspected or confirmed COVID-19 (Figure 2)\n8\nBefore the fever-CT technologist operates the equipment, he or she should wear personal\nprotective equipment according to three-level protection standard [8]. Before the CT\nexamination of patients with suspected and confirmed COVID-19 begins, the fever tent or\nisolation ward notifies the radiologist in advance. The fever-CT technologist checks the\nequipment and prepares to disinfect the imaging equipment immediately after the examination.\nThe patient enters the fever-CT waiting area through the fever access area. If the patient\ncan get onto and off the examination table by themselves, the patient is allowed to do so. If the", "patient cannot get onto or off the examination table independently, the person accompanying\nthe patient assists the patient, rather than the technologist. The technologist checks the patient\ninformation and, using an intercom system in the examination room, asks the patient to remove\nany metal ornaments on the neck and chest. Also, by intercom, the technologist trains the\npatient to hold his or her breath during the examination.\nThe technologist uses a low-dose chest CT protocol to scan the patient. After scanning, the\noriginal images are reconstructed as 1 mm-thick layers. The technologist browses the images to\nensure that their quality meets the diagnostic requirements and then guides the patient to leave\nthrough the fever access area. The disposable sheets for patient examination are changed after\neach patient. The equipment is disinfected according to the procedure below.\nTo protect themselves, the technologists assigned to the fever-CT wear N95 mask and", "other personal protection as established by the EMICT.\nThe CT procedure for regular patients (figure.3)\n9\nSome patients with COVID-19 have no symptoms, and they may call at the general clinic for\nother reasons. The following CT procedure is applicable under these circumstances:\nWhen the patient makes an appointment for examination, the staff asks the patient about\ntheir epidemiological history, symptoms, and signs. If suspected criteria are met, the patient\nwill be sent to the fever tent for further screening. When a patient presents to the radiology\ndepartment entrance, his/her temperature is measured. If the temperature is higher than 37.2 , ℃\nthe patient is sent to the fever tent for further investigation.\nThose with no exposure history, suspicious symptoms or fever are screened in one of the\nnon-contaminated CT scanners. The technologists assigned to these scanners wear surgical\nmasks. All patients and the person accompanying them are required to wear surgical masks.", "After the CT examination, the technologist browses the images quickly. If the CT appearance is\ntypical of lung infection, the technologist immediately reports it to the chest radiologist on duty\nand asks the patient to wait in the CT examination room. If the chest radiologist does not\nsuspect COVID-19 infection, the patient can leave the CT examination room. If the chest\nradiologist does suspect COVID-19 infection, the technologist immediately reports it to the\nEMICT and sends the patient to the fever tent. The floor and equipment in the CT examination\nroom are disinfected according to regulations, and air disinfection is conducted for 30 min\nbefore examining other patients. These CT scanners are considered noncontaminated (not\nfever-CTs) after these sterilization procedures.\nFever-DR examination procedure\n10\nThe COVID-19 guideline of the NHC does not recommend chest DR because its ability in\ndiagnosing COVID-19 is limited. At our hospital, we only use mobile DR units to provide", "bedside examination for critically ill patients. The technologist operating the mobile DR\nwears personal protective equipment according to the three-level protection standard and\nsterilizes the mobile DR according to the ward management requirements as described below.\nEquipment and environment disinfection procedures\nRoutine disinfection procedure [9]\n1) Object surface disinfection: Object surface is wiped with 1000mg/L chlorine-containing\ndisinfectant, wipe twice with 75% ethanol for non-corrosion resistance, once /4 hours.\n2) Equipment disinfection: The equipment in the contaminated area are wiped with\n2000mg/L chlorine-containing disinfectant. The DR and CT gantry in the contaminated\narea are wiped with 75% ethanol. The equipment in the buffer area is wiped with\n500-1000mg/L chlorine-containing disinfectant or alcohol-containing disposable\ndisinfectant wipes twice a day.\n3) Air disinfection: Turning off all central air conditioners to prevent air contamination with", "each other. Polluted area: open the door for ventilation, each time more than 30 minutes,\nonce /4 hours; The air sterilizer is continuously sterilized or the ultraviolet ray is\ncontinuously used in the unmanned state for 60 minutes, four times a day, remembered to\nclose the inner shielding door when air disinfection. Other ambient air is sprayed with\n1000mg/L chlorine-containing disinfectant and ventilated twice a day\n4) Ground disinfection: The ground is wiped with 1000mg/L chlorine-containing\ndisinfectant, once /4 hours.\n5) When contaminated, disinfect at any time. In case of visible contamination, disposable\nabsorbent materials should be used first to completely remove the pollutants, and then a\ncloth soaked with 2000mg/L chlorine-containing disinfectant should be used for 30\nminutes before wiping.\n11\nFever-CT disinfection procedures after examination\nIn addition to the above, disinfect the examination bed and ground with chlorinated disinfectant\ncontaining 2000mg/L [10].", "Noncontaminated CT disinfection procedures after suspected COVID-19 case examination\nIn addition to the above routine disinfection procedure, air disinfection is conducted for 30 min\nbefore examining other patients.\nResults\nFrom January 21, 2020 when screening for epidemiological history or symptoms\nsuspicious for COVID-19, to March 9, 2020, our hospital screened a total of 7,203 individuals\nand confirmed 24 cases of COVID-19. Of these, 3,083 people underwent fever-CT\nexaminations. Including the initial examination and reexamination, the total number of fever\nCT examination numbered 3,340. The fever-CT scanned a patient approximately every 21.5\nminutes. As a result of our precautions, none of the staff of the radiology department developed\nsymptoms suspicious for COVID-19. The fever-CT technologist, with the highest probability\nof exposure, remains PCR negative.\nDiscussion\nIt has been 17 years since the severe acute respiratory syndrome (SARS) epidemic, the last", "national spread of severe infectious disease, broke out. Currently, the Chinese people are\npanicking again. The speed and extent by which COVID-19 has spread in 2 months are\n12\nunprecedented, beyond those of SARS, and this has been aided by its contagious nature and\nrapid spread via droplets and contact. The droplet mode of transmission means that a person can\nbe infected easily by means of casual contact or even fomites on contaminated environmental\nsurfaces. Another theory has yet to be proved: aerosol propagation.\nHow radiology departments respond to any infectious disease outbreak is determined\nprimarily by the estimated risk of cross-infection to the staff and other patients. Appropriate\nprecautions taken only by staff in direct contact with patients may be adequate when the risk is\nlow. The strongest measures need to be implemented to limit the spread of the disease when the\nrisk is high. With severe infectious diseases such as COVID-19, the highest level of infection", "control measures must be implemented; these include providing adequate standard protective\nequipment, training staff, and instituting proper emergency plans.\nOnce a contagious infectious disease has been identified, the EMICT must consider four\nmain areas of response: data gathering, collaboration, needs assessment, and expert advice [10].\nData gathering includes dissemination of up-to-date case definitions and information about\nconfirmatory tests to all staff with direct patient contact to allow appropriate barrier precautions\nto be taken. All typical and atypical imaging features of the disease should be made known to\nall radiologists to assist in recognition of the disease on images and to allow accurate reporting\nof these findings. We have stored images of all probable cases of COVID-19 in the PACS so\nthat these images were readily available for any radiologist to review, and images from\nprevious imaging studies are also available for comparison.", "Collaboration with the radiology departments of other hospitals is very important because\npatients may initially present to different centers, depending on geographic location and travel\n13\ndistance. These patients may be few in number at a single hospital, but if data from patients at\nseveral hospitals are available, a more accurate overall understanding of both imaging features\nand epidemiology can be achieved. Dissemination of this information to all healthcare facilities\nwill also lead to early recognition of the disease, and appropriate isolation measures may be\ninstituted.\nThe Internet and social media apps, especially WeChat, have been used for distribution of\nmedical information, and because the exchange of information regarding infectious disease\noutbreaks is almost instantaneous, it is an indispensable tool for radiologists. In fact, within a\nmonth of the outbreak, the hospital that received the most infected patients from the source of", "the outbreak made a PowerPoint presentation of the CT manifestations of COVID-19, which\nwas shared via WeChat and disseminated across the country in a very short time. Subsequently,\nCOVID-19-teaching PowerPoint presentations from various hospitals appeared and were\nquickly shared via WeChat.\nOur diagnostic process is limited as chest CT along is not diagnostic of COVID-19\nbecause of lack of imaging specificity. But when combined with other epidemiological,\nclinical, laboratory and virus nucleic acid information, typical chest CT imaging findings are\nhelpful for making the diagnosis. In our opinion, the major role of chest CT is to understand the\nextent and dynamic evolution of lung lesions induced by COVID-19. The reasons why we\nadopted the low-dose chest CT scan protocol are as follows: low-dose chest CT has been\nwidely used in the screening of early lung cancer. It is well known that many early lung cancers", "are ground-glass opacities (GGO), so we believe that low-dose screening is also applicable for\nCOVID-19. In addition, considering the rapid development of COVID-19, many CT\n14\nexaminations may be conducted in the same individual to monitor disease progress. Low-dose\nscanning can reduce the radiation damage to patients.\nAlthough the processes we established minimized the exposure of hospital staff, ancillary\npersonnel and other patients, it remains limited as follows. Sichuan province is not the center of\nthe epidemic. The number of patients with COVID-19 whom we have treated has not been\nhigh, and most cases are from other provinces of China. However, we believe that our\nexperience in management, the reconfiguration of our radiology department, and the workflow\nchanges implemented in the current COVID-19 situation are useful for other radiology\ndepartments that must prepare for dealing with patients with COVID-19. While no radiology", "personnel developed symptoms suspicious for or were confirmed as having COVID-19, there\nmay be asymptomatic personnel.\nREFERENCES\n1. National Health Commission of the People’s Republic of China.(2020). March 12: Daily briefing\non novel coronavirus cases in China. Retrieved from\nhttp://en.nhc.gov.cn/2020-03/12/c_77618.htm. Accessed March 11, 2020.\n2. World Health Organization. (2020). Coronavirus disease 2019 (COVID-19) Situation Report-52.\nRetrieved from\nhttps://www.who.int/docs/default-source/coronaviruse/20200312-sitrep-52-covid-19.pdf?sfvrsn=e\n2bfc9c0_2 9. Accessed March 11, 2020.\n3. National Health Commission of the People’s Republic of China.(2020). Latest developments in\nepidemic control on Feb 15. Retrieved from http://en.nhc.gov.cn/2020-02/16/c_76622. Accessed\nMarch 11, 2020.\n15\n4. Health Commission of the People’s Republic of China.(2020). The notification of the trial\noperation based on the guideline version 6 in the coronavirus disease diagnosis and treatment.", "Retrieved from\nhttp://www.nhc.gov.cn/xcs/zhengcwj/202002/8334a8326dd94d329df351d7da8aefc2.shtml.\nAccessed March 11, 2020\n5. Health Commission of the People’s Republic of China.(2020). The notification of the trial\noperation based on the guideline version 6 in the coronavirus disease diagnosis and treatment.\nRetrieved from\nhttp://www.nhc.gov.cn/xcs/zhengcwj/202002/8334a8326dd94d329df351d7da8aefc2.shtml.\nAccessed March 11, 2020.\n6. Health Commission of the People’s Republic of China.(2009). The guideline for pathogens\nisolated operations in hospital. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/200904/40116.shtml. Accessed March 11, 2020.\n7. Health Commission of the People’s Republic of China.(2017). The guideline for prevention and\ncontrol of hospital acquired infections of airborne pathogens. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201701/7e0e8fc6725843aabba8f841f2f585d2.shtml. Accessed\nMarch 11, 2020.", "8. Health Commission of the People’s Republic of China.(2017). The guideline for prevention and\ncontrol of hospital acquired infections of airborne pathogens. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201701/7e0e8fc6725843aabba8f841f2f585d2.shtml. Accessed\nMarch 11, 2020.\n9. Health Commission of the People’s Republic of China.(2012). The standardization for\nsterilization techniques in hospital. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201204/54510.shtml. Accessed March 11, 2020.\n10. Health Commission of the People’s Republic of China.(2012). The standardization for\nsterilization techniques in hospital. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201204/54510.shtml. Accessed March 11, 2020.\n11. Katona P. Bioterrorism Preparedness: Generic Blueprint for Health Departments, Hospitals, and\nPhysicians. Infectious Diseases in Clinical Practice. 2002;11(3):115-122. Accessed March 11,\n2020.\n16\nFigure Legends", "Figure 1. Diagram of the layout of our radiology department was divided into four areas: contaminated\n(shaded in black), semicontaminated (shaded in dark gray), buffer (shaded in light gray), and clean areas\n(shaded in white). The contaminated area was separated from other areas by barriers.\nFigure 2. Diagram shows CT protocol for suspected and confirmed patients with COVID-19.\nFigure 3. Diagram shows CT protocol for regular patients.\nAbbreviations:\nCOVID-19: coronavirus disease 2019\nCT: computed tomography\nDR: digital radiography\nEMICT: emergency management and infection control team\nNHC: National Health Commission\nPACS: picture archiving and communication system\nSARS: severe acute respiratory syndrome", "Sentence Summary\nWith severe infectious diseases such as COVID-19, the highest level of infection control\nmeasures must be implemented, collaboration with the radiology departments of other\nhospitals be needed, and social media be employed.\nTake-home points\n1. To response to a community infection emergency, a special emergency management team\nneeds to be setup at the departmental level to implement infection containment and\ncontrol procedures that continues to allow the imaging examination and imaging\ndiagnosis of those with suspected infection, and to prevent intra-departmental spreading\nof infection (EMICT).\n2. Infection control measures, such as reconfiguration of department areas, personal\nprotection and anti-infection training of all staff, standardized procedures including\ncontact minimization for chest CT and DR examinations, and timely disinfection of CT\nand DR examination rooms, should be implemented properly.", "3. If there are more than one scanner in a hospital, only one of them should be assigned to\nsuspected cases." ]	[]	3,975	6,764
188	What did the EMICT responsibilities include?	2,448	[ "(1) coordination between the\nhospital’s management and planning of infection control and radiology departments; (2)\ncollection of the most up-to-date protection-related information to educate and train staff in the\ndepartment; (3) reallocation of staff according to the actual situation; (4) establishment of the\nCT procedures for patients with COVID-19; and (5) establishment of an emergency\nmanagement plan for the radiology department to ensure that the department would run\nnormally." ]	[ "The Battle Against Coronavirus Disease 2019 (COVID-19): Emergency Management\nand Infection Control in a Radiology Department\nhttps://www.jacr.org/article/S1546-1440(20)30285-4/pdf\nJournal Pre-proof\nZixing Huang, Shuang Zhao, Zhenlin Li, Weixia Chen, Lihong Zhao, Lipeng Deng, Bin\nSong\nPII: S1546-1440(20)30285-4\nDOI: https://doi.org/10.1016/j.jacr.2020.03.011\nReference: JACR 5139\nTo appear in: Journal of the American College of Radiology\nReceived Date: 24 February 2020\nRevised Date: 13 March 2020\nAccepted Date: 15 March 2020\nPlease cite this article as: Huang Z, Zhao S, Li Z, Chen W, Zhao L, Deng L, Song B, The Battle Against\nCoronavirus Disease 2019 (COVID-19): Emergency Management and Infection Control in a Radiology\nDepartment, Journal of the American College of Radiology (2020), doi: https://doi.org/10.1016/\nj.jacr.2020.03.011.\nThis is a PDF file of an article that has undergone enhancements after acceptance, such as the addition", "of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of\nrecord. This version will undergo additional copyediting, typesetting and review before it is published\nin its final form, but we are providing this version to give early visibility of the article. Please note that,\nduring the production process, errors may be discovered which could affect the content, and all legal\ndisclaimers that apply to the journal pertain.\n© 2020 Published by Elsevier Inc. on behalf of American College of Radiology\nThe Battle Against Coronavirus Disease 2019 (COVID-19): Emergency Management\nand Infection Control in a Radiology Department\nZixing Huang, Shuang Zhao, Zhenlin Li, Weixia Chen, Lihong Zhao, Lipeng Deng,\nBin Song\nDepartment of Radiology, West China Hospital, Sichuan University, Chengdu, China\n*Zixing Huang and Shuang Zhao contributed equally to this work as co-first author.\nCorresponding Author: Bin Song, MD", "Address: Department of Radiology, West China Hospital, Sichuan University.\nNo. 37, GUOXUE Alley, Chengdu, 610041, China\nTel.: (+86)28 85423680, Fax: (+86)28 85582944\nEmail: [email protected].\nAuthors’ contributions\nZXH: conceived the study and drafted the manuscript.\nZS: conceived the study and drafted the manuscript.\nZLL: The member of the emergency management and infection control team (EMICT)\nand was involved in the formulation of the measures.\nWXC: The member of the EMICT and was involved in the formulation of the\nmeasures.\nLHZ: The member of the EMICT and was involved in the formulation of the\nmeasures.\nLPD: The member of the EMICT and was involved in the formulation of the\nmeasures.\nBS: Leader of the EMICT, conceived the study and reviewed the manuscript.\nAll authors read and approved the final manuscript.\nThe authors declare no conflict of interest.\nThe authors declare that they had full access to all of the data in this study and the", "authors take complete responsibility for the integrity of the data and the accuracy of\nthe data analysis\n1\nThe Battle Against Novel Coronavirus Pneumonia (COVID-19): Emergency\nManagement and Infection Control in a Radiology Department\nAbstract\nObjective: To describe the strategy and the emergency management and infection control\nprocedure of our radiology department during the COVID-19 outbreak.\nMethods: We set up emergency management and sensing control teams. The team formulated\nvarious measures: reconfiguration of the radiology department, personal protection and training\nof staff, examination procedures for patients suspected of or confirmed with COVID-19 as well\nas patients without an exposure history or symptoms. Those with suspected or confirmed\nCOVID-19 infection were scanned in the designated fever-CT unit.\nResults: From January 21, 2020 to March 9, 2020, 3,083 people suspected of or confirmed with\nCOVID-19 underwent fever-CT examinations. Including initial examinations and", "reexaminations, the total number of fever-CT examinations numbered 3,340. As a result of our\nprecautions, none of the staff of the radiology department were infected with COVID-19.\nConclusion: Strategic planning and adequate protections can help protect patients and staff\nagainst a highly infectious disease while maintaining function at a high volume capacity.\nKeywords: Coronavirus, COVID-19, novel coronavirus pneumonia, infection control", "2\nIntroduction\nThe whole world has been closely focusing on an outbreak of respiratory disease caused by a\nnovel coronavirus that was first reported in Wuhan, China, on December 31, 2019, and that\ncontinues to spread. On February 11, 2020, the World Health Organization (WHO) named the\ndisease “coronavirus disease 2019” (COVID-19).\nAs of 24:00 on March 11, 2020, the National Health Commission (NHC) had received reports\nof 80,793 confirmed cases and 3,169 deaths on the Chinese mainland. There remain 14,831\nconfirmed cases (including 4,257 in serious condition) and 253 suspected cases still\nhospitalized. To date, 677,243 people have been identified as having had close contact with\ninfected patients of whom13,701 are under medical observation [1]. Outside China, 44,067\nlaboratory-confirmed cases and 1,440 deaths have occurred in 117 countries /territories/areas\naccording to the WHO [2]. COVID-19 poses significant threats to international health. Like the", "flu, COVID-19 is thought to spread mainly from person-to-person between people who are in\nclose contact with one another through respiratory droplets produced when an infected person\ncoughs or sneezes. In light of the infectious nature of this disease, healthcare workers are at\nhigh risk of infection of COVID-19. In China, healthcare workers account for 1,716 confirmed\ncases of COVID-19, including six deaths [3].\n Computed tomography (CT) can play a role in both diagnosing and categorizing\nCOVID-19 on the basis of case definitions issued by the WHO and the treatment guidelines\nfrom the NHC [4]. Suspected patients having the virus may undergo chest CT. Isolation and\nbarrier procedures are necessary to protect both the department staff and other patients in the\nhospital. Note should be made that due to overlap of imaging findings with other respiratory\n3\ndiseases, CT is not helpful as a screening tool. But it can help identify the degree of pulmonary\ninvolvement and disease course.", "Our hospital is a national regional medical center with 4,300 beds and a tertiary referral\ncenter in Sichuan province. The initial response started on January 21, 2020, after transmission\nof COVID-19 was confirmed to be human-to-human on January 20, 2020. The first suspected\ncase of COVID-19 in Sichuan province was reported on January 21, 2020. The Sichuan\nprovincial government immediately launched the first-level response to major public health\nemergencies. On the same day, our hospital was designated to care for Sichuan province\npatients with COVID-19.\nThis article describes the emergency management procedure of our radiology department\nfor situations involving severe infectious diseases, such as COVID-19, and the\ninfection-protection experience of the department staff.\nMethods\nThe hospital provided personal protective equipment (medical protective clothing,\nsurgical cap, N95 mask, gloves, face shields, and goggles) to all its healthcare staff, erected", "three medical tents (fever tents) for screening of fever cases in the parking lot of the emergency\ndepartment, planned an examination route and examination area for patients suspected of\nharboring the virus, and placed confirmed patients in an isolation ward. “Fever” was the\ncolloquial term used to designate suspected COVID-19 based on symptoms such as a fever or\nwith an epidemiological history of a potential exposure as well as those with confirmed\nCOVID-19 referred for treatment. Further, during outbreak, emergency and outpatient patients\n4\nwithout fever were asked for information such as epidemiological history and sent to fever tents\nas long as they met suspected criteria.\nThe radiology department has 65 diagnostic radiologists and 161 other staff members\n(trained technologists, nurses, engineers, and support staff). The equipment of the radiology\ndepartment includes 12 magnetic resonance (MR) scanners, 14 CT scanners, 15 digital", "subtraction angiography (DSA) systems, 32 sets of digital radiography (DR) systems\n(including nine mobile bedside DR sets), and 130 imaging diagnostic workstations for picture\narchiving and communication systems (PACS). Most of the equipment is distributed among\nfour buildings at the hospital main campus. 4 CT scanners, 4 MR scanners, 1 DR are located on\nthe first floor of the first inpatient building, and 9 DR and 8 DSA are located on the second\nfloor. 1 CT and 1 MR scanner are located in the third inpatient building. 1 CT and 1 MR scanner\nare located in the sixth inpatient building. 2 CT scanners, 2 MR scanners and 7 DSA are located\nin the technical building. The rest of the equipment is located in the seventh inpatient building\nin the branch campus.\nThe first inpatient building, located next to the emergency department, was reconfigured to\nhandle cases of COVID-19. Fever tents were set up by the emergency department in the", "emergency department parking lot to separate normal emergency patients from patients with\nsymptoms or exposure history suspicious of COVID-19. We established separate means of\naccess between fever tents and between the fever examination area of the radiology department\nto avoid cross-contamination.\nThe emergency management and infection control measures, as described below and\nimplemented in the radiology department during the outbreak, have been approved by the\n5\ninfection control committee of hospital. These measures are in accordance with relevant laws\nand regulations, in order to protect patients as well as the staff.\nRadiology Emergency Management and Infection Control Team (EMICT)\nThe radiology department director chaired the EMICT. Its members include the deputy\ndirector, chief technologist, head nurse, equipment engineer supervisor, and infection control\nnurse of the radiology department. Team responsibilities included (1) coordination between the", "hospital’s management and planning of infection control and radiology departments; (2)\ncollection of the most up-to-date protection-related information to educate and train staff in the\ndepartment; (3) reallocation of staff according to the actual situation; (4) establishment of the\nCT procedures for patients with COVID-19; and (5) establishment of an emergency\nmanagement plan for the radiology department to ensure that the department would run\nnormally.\nSuspected patients\nThe suspected patients were identified according to the Diagnosis and Treatment Program of\nthe Novel Coronavirus Pneumonia of the NHC [5], mainly based on epidemiological history.\nReconfiguration of the radiology department\nThe radiology department was divided into four areas [6]: contaminated, semicontaminated,\nbuffer, and clean areas (Figure 1). The contaminated area is connected to the fever clinic and\nincludes the fever accessway, the CT examination room, and the DR examination room for\n6", "confirmed and suspected cases. One CT scanner and one DR system closest to the emergency\ndepartment are designated the fever-CT and fever-DR to examine patients with suspected and\nconfirmed COVID-19. There is a separate dedicated access between the contaminated area and\nthe fever screening tents. The semicontaminated area includes the fever-CT control room,\nfever-DR control room, and other patient examination access areas. The buffer zone includes\naccess areas for medical personnel and a dressing area for technologists. The clean area\nincludes the administrative office and the diagnostic room.\nThe contaminated area was isolated from other areas using physical barricades.\nDirectional signs were newly installed to guide patients and staff.\nPersonal protection and training of staff\nFor providing care for patients with confirmed and suspected COVID-19, all hospital staff\nare required to wear complete personal protective equipment [7]: medical protective clothing,", "surgical cap, N95 mask, gloves, face shields, and goggles. Wearing and removing of the\nequipment must be performed in accordance with the procedures and under the supervision of\nthe infection control nurse.\nBecause staff members working in the contaminated area are under much situational\npressure, periodically taking time off could lower their physical and mental stress levels. The\ntechnologists on fever-CT duty shifts are provided a break once a week for four hours. In\naddition, the health of staff in the contaminated area must be monitored closely for the\nsymptoms of COVID-19. Pregnant staff must be assigned to the clean area.\n7\nThe EMICT formulates and continually updates guidelines and educates all staff for West\nChina Hospital of Sichuan University. The EMICT training for staff is mainly involves\ndocuments regarding infection control and CT findings of COVID-19 and maintains an EMICT\nWeChat group for West China Hospital of Sichuan University. WeChat is the most widely used", "social media app in China. The EMICT releases the latest national and hospital-based\ninformation regarding COVID-19, guidance documents, and other notices from the hospital\nand radiology department in the WeChat group on a daily basis. Staff can also report to the\nEMICT in the WeChat group any time. Protocols for each modality and infection control\ninstructions are posted on the walls in all examination rooms. The EMICT periodically reminds\nstaff to undertake personal measures to reduce infection, such as wearing masks at all instances\nin the radiology department and N95 masks if working in the contaminated area; not touching\nthe mask and the eyes; practicing hand hygiene; facing away from colleagues when eating,\ndrinking, and talking; and not using personal cell phones while on duty.\n In addition, the chief thoracic radiologist provided lectures on all radiologists and\ntechnologists on typical CT findings of COVID-19 infection using materials developed in", "Wuhan, the epicenter of the outbreak in China.\nCT examination procedures\nThere are two sets of procedures for CT examination: the fever-CT procedure and routine CT\nprocedure for those not suspected of COVID-19.\nThe fever-CT procedure for suspected or confirmed COVID-19 (Figure 2)\n8\nBefore the fever-CT technologist operates the equipment, he or she should wear personal\nprotective equipment according to three-level protection standard [8]. Before the CT\nexamination of patients with suspected and confirmed COVID-19 begins, the fever tent or\nisolation ward notifies the radiologist in advance. The fever-CT technologist checks the\nequipment and prepares to disinfect the imaging equipment immediately after the examination.\nThe patient enters the fever-CT waiting area through the fever access area. If the patient\ncan get onto and off the examination table by themselves, the patient is allowed to do so. If the", "patient cannot get onto or off the examination table independently, the person accompanying\nthe patient assists the patient, rather than the technologist. The technologist checks the patient\ninformation and, using an intercom system in the examination room, asks the patient to remove\nany metal ornaments on the neck and chest. Also, by intercom, the technologist trains the\npatient to hold his or her breath during the examination.\nThe technologist uses a low-dose chest CT protocol to scan the patient. After scanning, the\noriginal images are reconstructed as 1 mm-thick layers. The technologist browses the images to\nensure that their quality meets the diagnostic requirements and then guides the patient to leave\nthrough the fever access area. The disposable sheets for patient examination are changed after\neach patient. The equipment is disinfected according to the procedure below.\nTo protect themselves, the technologists assigned to the fever-CT wear N95 mask and", "other personal protection as established by the EMICT.\nThe CT procedure for regular patients (figure.3)\n9\nSome patients with COVID-19 have no symptoms, and they may call at the general clinic for\nother reasons. The following CT procedure is applicable under these circumstances:\nWhen the patient makes an appointment for examination, the staff asks the patient about\ntheir epidemiological history, symptoms, and signs. If suspected criteria are met, the patient\nwill be sent to the fever tent for further screening. When a patient presents to the radiology\ndepartment entrance, his/her temperature is measured. If the temperature is higher than 37.2 , ℃\nthe patient is sent to the fever tent for further investigation.\nThose with no exposure history, suspicious symptoms or fever are screened in one of the\nnon-contaminated CT scanners. The technologists assigned to these scanners wear surgical\nmasks. All patients and the person accompanying them are required to wear surgical masks.", "After the CT examination, the technologist browses the images quickly. If the CT appearance is\ntypical of lung infection, the technologist immediately reports it to the chest radiologist on duty\nand asks the patient to wait in the CT examination room. If the chest radiologist does not\nsuspect COVID-19 infection, the patient can leave the CT examination room. If the chest\nradiologist does suspect COVID-19 infection, the technologist immediately reports it to the\nEMICT and sends the patient to the fever tent. The floor and equipment in the CT examination\nroom are disinfected according to regulations, and air disinfection is conducted for 30 min\nbefore examining other patients. These CT scanners are considered noncontaminated (not\nfever-CTs) after these sterilization procedures.\nFever-DR examination procedure\n10\nThe COVID-19 guideline of the NHC does not recommend chest DR because its ability in\ndiagnosing COVID-19 is limited. At our hospital, we only use mobile DR units to provide", "bedside examination for critically ill patients. The technologist operating the mobile DR\nwears personal protective equipment according to the three-level protection standard and\nsterilizes the mobile DR according to the ward management requirements as described below.\nEquipment and environment disinfection procedures\nRoutine disinfection procedure [9]\n1) Object surface disinfection: Object surface is wiped with 1000mg/L chlorine-containing\ndisinfectant, wipe twice with 75% ethanol for non-corrosion resistance, once /4 hours.\n2) Equipment disinfection: The equipment in the contaminated area are wiped with\n2000mg/L chlorine-containing disinfectant. The DR and CT gantry in the contaminated\narea are wiped with 75% ethanol. The equipment in the buffer area is wiped with\n500-1000mg/L chlorine-containing disinfectant or alcohol-containing disposable\ndisinfectant wipes twice a day.\n3) Air disinfection: Turning off all central air conditioners to prevent air contamination with", "each other. Polluted area: open the door for ventilation, each time more than 30 minutes,\nonce /4 hours; The air sterilizer is continuously sterilized or the ultraviolet ray is\ncontinuously used in the unmanned state for 60 minutes, four times a day, remembered to\nclose the inner shielding door when air disinfection. Other ambient air is sprayed with\n1000mg/L chlorine-containing disinfectant and ventilated twice a day\n4) Ground disinfection: The ground is wiped with 1000mg/L chlorine-containing\ndisinfectant, once /4 hours.\n5) When contaminated, disinfect at any time. In case of visible contamination, disposable\nabsorbent materials should be used first to completely remove the pollutants, and then a\ncloth soaked with 2000mg/L chlorine-containing disinfectant should be used for 30\nminutes before wiping.\n11\nFever-CT disinfection procedures after examination\nIn addition to the above, disinfect the examination bed and ground with chlorinated disinfectant\ncontaining 2000mg/L [10].", "Noncontaminated CT disinfection procedures after suspected COVID-19 case examination\nIn addition to the above routine disinfection procedure, air disinfection is conducted for 30 min\nbefore examining other patients.\nResults\nFrom January 21, 2020 when screening for epidemiological history or symptoms\nsuspicious for COVID-19, to March 9, 2020, our hospital screened a total of 7,203 individuals\nand confirmed 24 cases of COVID-19. Of these, 3,083 people underwent fever-CT\nexaminations. Including the initial examination and reexamination, the total number of fever\nCT examination numbered 3,340. The fever-CT scanned a patient approximately every 21.5\nminutes. As a result of our precautions, none of the staff of the radiology department developed\nsymptoms suspicious for COVID-19. The fever-CT technologist, with the highest probability\nof exposure, remains PCR negative.\nDiscussion\nIt has been 17 years since the severe acute respiratory syndrome (SARS) epidemic, the last", "national spread of severe infectious disease, broke out. Currently, the Chinese people are\npanicking again. The speed and extent by which COVID-19 has spread in 2 months are\n12\nunprecedented, beyond those of SARS, and this has been aided by its contagious nature and\nrapid spread via droplets and contact. The droplet mode of transmission means that a person can\nbe infected easily by means of casual contact or even fomites on contaminated environmental\nsurfaces. Another theory has yet to be proved: aerosol propagation.\nHow radiology departments respond to any infectious disease outbreak is determined\nprimarily by the estimated risk of cross-infection to the staff and other patients. Appropriate\nprecautions taken only by staff in direct contact with patients may be adequate when the risk is\nlow. The strongest measures need to be implemented to limit the spread of the disease when the\nrisk is high. With severe infectious diseases such as COVID-19, the highest level of infection", "control measures must be implemented; these include providing adequate standard protective\nequipment, training staff, and instituting proper emergency plans.\nOnce a contagious infectious disease has been identified, the EMICT must consider four\nmain areas of response: data gathering, collaboration, needs assessment, and expert advice [10].\nData gathering includes dissemination of up-to-date case definitions and information about\nconfirmatory tests to all staff with direct patient contact to allow appropriate barrier precautions\nto be taken. All typical and atypical imaging features of the disease should be made known to\nall radiologists to assist in recognition of the disease on images and to allow accurate reporting\nof these findings. We have stored images of all probable cases of COVID-19 in the PACS so\nthat these images were readily available for any radiologist to review, and images from\nprevious imaging studies are also available for comparison.", "Collaboration with the radiology departments of other hospitals is very important because\npatients may initially present to different centers, depending on geographic location and travel\n13\ndistance. These patients may be few in number at a single hospital, but if data from patients at\nseveral hospitals are available, a more accurate overall understanding of both imaging features\nand epidemiology can be achieved. Dissemination of this information to all healthcare facilities\nwill also lead to early recognition of the disease, and appropriate isolation measures may be\ninstituted.\nThe Internet and social media apps, especially WeChat, have been used for distribution of\nmedical information, and because the exchange of information regarding infectious disease\noutbreaks is almost instantaneous, it is an indispensable tool for radiologists. In fact, within a\nmonth of the outbreak, the hospital that received the most infected patients from the source of", "the outbreak made a PowerPoint presentation of the CT manifestations of COVID-19, which\nwas shared via WeChat and disseminated across the country in a very short time. Subsequently,\nCOVID-19-teaching PowerPoint presentations from various hospitals appeared and were\nquickly shared via WeChat.\nOur diagnostic process is limited as chest CT along is not diagnostic of COVID-19\nbecause of lack of imaging specificity. But when combined with other epidemiological,\nclinical, laboratory and virus nucleic acid information, typical chest CT imaging findings are\nhelpful for making the diagnosis. In our opinion, the major role of chest CT is to understand the\nextent and dynamic evolution of lung lesions induced by COVID-19. The reasons why we\nadopted the low-dose chest CT scan protocol are as follows: low-dose chest CT has been\nwidely used in the screening of early lung cancer. It is well known that many early lung cancers", "are ground-glass opacities (GGO), so we believe that low-dose screening is also applicable for\nCOVID-19. In addition, considering the rapid development of COVID-19, many CT\n14\nexaminations may be conducted in the same individual to monitor disease progress. Low-dose\nscanning can reduce the radiation damage to patients.\nAlthough the processes we established minimized the exposure of hospital staff, ancillary\npersonnel and other patients, it remains limited as follows. Sichuan province is not the center of\nthe epidemic. The number of patients with COVID-19 whom we have treated has not been\nhigh, and most cases are from other provinces of China. However, we believe that our\nexperience in management, the reconfiguration of our radiology department, and the workflow\nchanges implemented in the current COVID-19 situation are useful for other radiology\ndepartments that must prepare for dealing with patients with COVID-19. While no radiology", "personnel developed symptoms suspicious for or were confirmed as having COVID-19, there\nmay be asymptomatic personnel.\nREFERENCES\n1. National Health Commission of the People’s Republic of China.(2020). March 12: Daily briefing\non novel coronavirus cases in China. Retrieved from\nhttp://en.nhc.gov.cn/2020-03/12/c_77618.htm. Accessed March 11, 2020.\n2. World Health Organization. (2020). Coronavirus disease 2019 (COVID-19) Situation Report-52.\nRetrieved from\nhttps://www.who.int/docs/default-source/coronaviruse/20200312-sitrep-52-covid-19.pdf?sfvrsn=e\n2bfc9c0_2 9. Accessed March 11, 2020.\n3. National Health Commission of the People’s Republic of China.(2020). Latest developments in\nepidemic control on Feb 15. Retrieved from http://en.nhc.gov.cn/2020-02/16/c_76622. Accessed\nMarch 11, 2020.\n15\n4. Health Commission of the People’s Republic of China.(2020). The notification of the trial\noperation based on the guideline version 6 in the coronavirus disease diagnosis and treatment.", "Retrieved from\nhttp://www.nhc.gov.cn/xcs/zhengcwj/202002/8334a8326dd94d329df351d7da8aefc2.shtml.\nAccessed March 11, 2020\n5. Health Commission of the People’s Republic of China.(2020). The notification of the trial\noperation based on the guideline version 6 in the coronavirus disease diagnosis and treatment.\nRetrieved from\nhttp://www.nhc.gov.cn/xcs/zhengcwj/202002/8334a8326dd94d329df351d7da8aefc2.shtml.\nAccessed March 11, 2020.\n6. Health Commission of the People’s Republic of China.(2009). The guideline for pathogens\nisolated operations in hospital. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/200904/40116.shtml. Accessed March 11, 2020.\n7. Health Commission of the People’s Republic of China.(2017). The guideline for prevention and\ncontrol of hospital acquired infections of airborne pathogens. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201701/7e0e8fc6725843aabba8f841f2f585d2.shtml. Accessed\nMarch 11, 2020.", "8. Health Commission of the People’s Republic of China.(2017). The guideline for prevention and\ncontrol of hospital acquired infections of airborne pathogens. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201701/7e0e8fc6725843aabba8f841f2f585d2.shtml. Accessed\nMarch 11, 2020.\n9. Health Commission of the People’s Republic of China.(2012). The standardization for\nsterilization techniques in hospital. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201204/54510.shtml. Accessed March 11, 2020.\n10. Health Commission of the People’s Republic of China.(2012). The standardization for\nsterilization techniques in hospital. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201204/54510.shtml. Accessed March 11, 2020.\n11. Katona P. Bioterrorism Preparedness: Generic Blueprint for Health Departments, Hospitals, and\nPhysicians. Infectious Diseases in Clinical Practice. 2002;11(3):115-122. Accessed March 11,\n2020.\n16\nFigure Legends", "Figure 1. Diagram of the layout of our radiology department was divided into four areas: contaminated\n(shaded in black), semicontaminated (shaded in dark gray), buffer (shaded in light gray), and clean areas\n(shaded in white). The contaminated area was separated from other areas by barriers.\nFigure 2. Diagram shows CT protocol for suspected and confirmed patients with COVID-19.\nFigure 3. Diagram shows CT protocol for regular patients.\nAbbreviations:\nCOVID-19: coronavirus disease 2019\nCT: computed tomography\nDR: digital radiography\nEMICT: emergency management and infection control team\nNHC: National Health Commission\nPACS: picture archiving and communication system\nSARS: severe acute respiratory syndrome", "Sentence Summary\nWith severe infectious diseases such as COVID-19, the highest level of infection control\nmeasures must be implemented, collaboration with the radiology departments of other\nhospitals be needed, and social media be employed.\nTake-home points\n1. To response to a community infection emergency, a special emergency management team\nneeds to be setup at the departmental level to implement infection containment and\ncontrol procedures that continues to allow the imaging examination and imaging\ndiagnosis of those with suspected infection, and to prevent intra-departmental spreading\nof infection (EMICT).\n2. Infection control measures, such as reconfiguration of department areas, personal\nprotection and anti-infection training of all staff, standardized procedures including\ncontact minimization for chest CT and DR examinations, and timely disinfection of CT\nand DR examination rooms, should be implemented properly.", "3. If there are more than one scanner in a hospital, only one of them should be assigned to\nsuspected cases." ]	[]	3,975	6,764
188	How were the radiology department areas divided?	2,449	[ "contaminated, semicontaminated,\nbuffer, and clean areas" ]	[ "The Battle Against Coronavirus Disease 2019 (COVID-19): Emergency Management\nand Infection Control in a Radiology Department\nhttps://www.jacr.org/article/S1546-1440(20)30285-4/pdf\nJournal Pre-proof\nZixing Huang, Shuang Zhao, Zhenlin Li, Weixia Chen, Lihong Zhao, Lipeng Deng, Bin\nSong\nPII: S1546-1440(20)30285-4\nDOI: https://doi.org/10.1016/j.jacr.2020.03.011\nReference: JACR 5139\nTo appear in: Journal of the American College of Radiology\nReceived Date: 24 February 2020\nRevised Date: 13 March 2020\nAccepted Date: 15 March 2020\nPlease cite this article as: Huang Z, Zhao S, Li Z, Chen W, Zhao L, Deng L, Song B, The Battle Against\nCoronavirus Disease 2019 (COVID-19): Emergency Management and Infection Control in a Radiology\nDepartment, Journal of the American College of Radiology (2020), doi: https://doi.org/10.1016/\nj.jacr.2020.03.011.\nThis is a PDF file of an article that has undergone enhancements after acceptance, such as the addition", "of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of\nrecord. This version will undergo additional copyediting, typesetting and review before it is published\nin its final form, but we are providing this version to give early visibility of the article. Please note that,\nduring the production process, errors may be discovered which could affect the content, and all legal\ndisclaimers that apply to the journal pertain.\n© 2020 Published by Elsevier Inc. on behalf of American College of Radiology\nThe Battle Against Coronavirus Disease 2019 (COVID-19): Emergency Management\nand Infection Control in a Radiology Department\nZixing Huang, Shuang Zhao, Zhenlin Li, Weixia Chen, Lihong Zhao, Lipeng Deng,\nBin Song\nDepartment of Radiology, West China Hospital, Sichuan University, Chengdu, China\n*Zixing Huang and Shuang Zhao contributed equally to this work as co-first author.\nCorresponding Author: Bin Song, MD", "Address: Department of Radiology, West China Hospital, Sichuan University.\nNo. 37, GUOXUE Alley, Chengdu, 610041, China\nTel.: (+86)28 85423680, Fax: (+86)28 85582944\nEmail: [email protected].\nAuthors’ contributions\nZXH: conceived the study and drafted the manuscript.\nZS: conceived the study and drafted the manuscript.\nZLL: The member of the emergency management and infection control team (EMICT)\nand was involved in the formulation of the measures.\nWXC: The member of the EMICT and was involved in the formulation of the\nmeasures.\nLHZ: The member of the EMICT and was involved in the formulation of the\nmeasures.\nLPD: The member of the EMICT and was involved in the formulation of the\nmeasures.\nBS: Leader of the EMICT, conceived the study and reviewed the manuscript.\nAll authors read and approved the final manuscript.\nThe authors declare no conflict of interest.\nThe authors declare that they had full access to all of the data in this study and the", "authors take complete responsibility for the integrity of the data and the accuracy of\nthe data analysis\n1\nThe Battle Against Novel Coronavirus Pneumonia (COVID-19): Emergency\nManagement and Infection Control in a Radiology Department\nAbstract\nObjective: To describe the strategy and the emergency management and infection control\nprocedure of our radiology department during the COVID-19 outbreak.\nMethods: We set up emergency management and sensing control teams. The team formulated\nvarious measures: reconfiguration of the radiology department, personal protection and training\nof staff, examination procedures for patients suspected of or confirmed with COVID-19 as well\nas patients without an exposure history or symptoms. Those with suspected or confirmed\nCOVID-19 infection were scanned in the designated fever-CT unit.\nResults: From January 21, 2020 to March 9, 2020, 3,083 people suspected of or confirmed with\nCOVID-19 underwent fever-CT examinations. Including initial examinations and", "reexaminations, the total number of fever-CT examinations numbered 3,340. As a result of our\nprecautions, none of the staff of the radiology department were infected with COVID-19.\nConclusion: Strategic planning and adequate protections can help protect patients and staff\nagainst a highly infectious disease while maintaining function at a high volume capacity.\nKeywords: Coronavirus, COVID-19, novel coronavirus pneumonia, infection control", "2\nIntroduction\nThe whole world has been closely focusing on an outbreak of respiratory disease caused by a\nnovel coronavirus that was first reported in Wuhan, China, on December 31, 2019, and that\ncontinues to spread. On February 11, 2020, the World Health Organization (WHO) named the\ndisease “coronavirus disease 2019” (COVID-19).\nAs of 24:00 on March 11, 2020, the National Health Commission (NHC) had received reports\nof 80,793 confirmed cases and 3,169 deaths on the Chinese mainland. There remain 14,831\nconfirmed cases (including 4,257 in serious condition) and 253 suspected cases still\nhospitalized. To date, 677,243 people have been identified as having had close contact with\ninfected patients of whom13,701 are under medical observation [1]. Outside China, 44,067\nlaboratory-confirmed cases and 1,440 deaths have occurred in 117 countries /territories/areas\naccording to the WHO [2]. COVID-19 poses significant threats to international health. Like the", "flu, COVID-19 is thought to spread mainly from person-to-person between people who are in\nclose contact with one another through respiratory droplets produced when an infected person\ncoughs or sneezes. In light of the infectious nature of this disease, healthcare workers are at\nhigh risk of infection of COVID-19. In China, healthcare workers account for 1,716 confirmed\ncases of COVID-19, including six deaths [3].\n Computed tomography (CT) can play a role in both diagnosing and categorizing\nCOVID-19 on the basis of case definitions issued by the WHO and the treatment guidelines\nfrom the NHC [4]. Suspected patients having the virus may undergo chest CT. Isolation and\nbarrier procedures are necessary to protect both the department staff and other patients in the\nhospital. Note should be made that due to overlap of imaging findings with other respiratory\n3\ndiseases, CT is not helpful as a screening tool. But it can help identify the degree of pulmonary\ninvolvement and disease course.", "Our hospital is a national regional medical center with 4,300 beds and a tertiary referral\ncenter in Sichuan province. The initial response started on January 21, 2020, after transmission\nof COVID-19 was confirmed to be human-to-human on January 20, 2020. The first suspected\ncase of COVID-19 in Sichuan province was reported on January 21, 2020. The Sichuan\nprovincial government immediately launched the first-level response to major public health\nemergencies. On the same day, our hospital was designated to care for Sichuan province\npatients with COVID-19.\nThis article describes the emergency management procedure of our radiology department\nfor situations involving severe infectious diseases, such as COVID-19, and the\ninfection-protection experience of the department staff.\nMethods\nThe hospital provided personal protective equipment (medical protective clothing,\nsurgical cap, N95 mask, gloves, face shields, and goggles) to all its healthcare staff, erected", "three medical tents (fever tents) for screening of fever cases in the parking lot of the emergency\ndepartment, planned an examination route and examination area for patients suspected of\nharboring the virus, and placed confirmed patients in an isolation ward. “Fever” was the\ncolloquial term used to designate suspected COVID-19 based on symptoms such as a fever or\nwith an epidemiological history of a potential exposure as well as those with confirmed\nCOVID-19 referred for treatment. Further, during outbreak, emergency and outpatient patients\n4\nwithout fever were asked for information such as epidemiological history and sent to fever tents\nas long as they met suspected criteria.\nThe radiology department has 65 diagnostic radiologists and 161 other staff members\n(trained technologists, nurses, engineers, and support staff). The equipment of the radiology\ndepartment includes 12 magnetic resonance (MR) scanners, 14 CT scanners, 15 digital", "subtraction angiography (DSA) systems, 32 sets of digital radiography (DR) systems\n(including nine mobile bedside DR sets), and 130 imaging diagnostic workstations for picture\narchiving and communication systems (PACS). Most of the equipment is distributed among\nfour buildings at the hospital main campus. 4 CT scanners, 4 MR scanners, 1 DR are located on\nthe first floor of the first inpatient building, and 9 DR and 8 DSA are located on the second\nfloor. 1 CT and 1 MR scanner are located in the third inpatient building. 1 CT and 1 MR scanner\nare located in the sixth inpatient building. 2 CT scanners, 2 MR scanners and 7 DSA are located\nin the technical building. The rest of the equipment is located in the seventh inpatient building\nin the branch campus.\nThe first inpatient building, located next to the emergency department, was reconfigured to\nhandle cases of COVID-19. Fever tents were set up by the emergency department in the", "emergency department parking lot to separate normal emergency patients from patients with\nsymptoms or exposure history suspicious of COVID-19. We established separate means of\naccess between fever tents and between the fever examination area of the radiology department\nto avoid cross-contamination.\nThe emergency management and infection control measures, as described below and\nimplemented in the radiology department during the outbreak, have been approved by the\n5\ninfection control committee of hospital. These measures are in accordance with relevant laws\nand regulations, in order to protect patients as well as the staff.\nRadiology Emergency Management and Infection Control Team (EMICT)\nThe radiology department director chaired the EMICT. Its members include the deputy\ndirector, chief technologist, head nurse, equipment engineer supervisor, and infection control\nnurse of the radiology department. Team responsibilities included (1) coordination between the", "hospital’s management and planning of infection control and radiology departments; (2)\ncollection of the most up-to-date protection-related information to educate and train staff in the\ndepartment; (3) reallocation of staff according to the actual situation; (4) establishment of the\nCT procedures for patients with COVID-19; and (5) establishment of an emergency\nmanagement plan for the radiology department to ensure that the department would run\nnormally.\nSuspected patients\nThe suspected patients were identified according to the Diagnosis and Treatment Program of\nthe Novel Coronavirus Pneumonia of the NHC [5], mainly based on epidemiological history.\nReconfiguration of the radiology department\nThe radiology department was divided into four areas [6]: contaminated, semicontaminated,\nbuffer, and clean areas (Figure 1). The contaminated area is connected to the fever clinic and\nincludes the fever accessway, the CT examination room, and the DR examination room for\n6", "confirmed and suspected cases. One CT scanner and one DR system closest to the emergency\ndepartment are designated the fever-CT and fever-DR to examine patients with suspected and\nconfirmed COVID-19. There is a separate dedicated access between the contaminated area and\nthe fever screening tents. The semicontaminated area includes the fever-CT control room,\nfever-DR control room, and other patient examination access areas. The buffer zone includes\naccess areas for medical personnel and a dressing area for technologists. The clean area\nincludes the administrative office and the diagnostic room.\nThe contaminated area was isolated from other areas using physical barricades.\nDirectional signs were newly installed to guide patients and staff.\nPersonal protection and training of staff\nFor providing care for patients with confirmed and suspected COVID-19, all hospital staff\nare required to wear complete personal protective equipment [7]: medical protective clothing,", "surgical cap, N95 mask, gloves, face shields, and goggles. Wearing and removing of the\nequipment must be performed in accordance with the procedures and under the supervision of\nthe infection control nurse.\nBecause staff members working in the contaminated area are under much situational\npressure, periodically taking time off could lower their physical and mental stress levels. The\ntechnologists on fever-CT duty shifts are provided a break once a week for four hours. In\naddition, the health of staff in the contaminated area must be monitored closely for the\nsymptoms of COVID-19. Pregnant staff must be assigned to the clean area.\n7\nThe EMICT formulates and continually updates guidelines and educates all staff for West\nChina Hospital of Sichuan University. The EMICT training for staff is mainly involves\ndocuments regarding infection control and CT findings of COVID-19 and maintains an EMICT\nWeChat group for West China Hospital of Sichuan University. WeChat is the most widely used", "social media app in China. The EMICT releases the latest national and hospital-based\ninformation regarding COVID-19, guidance documents, and other notices from the hospital\nand radiology department in the WeChat group on a daily basis. Staff can also report to the\nEMICT in the WeChat group any time. Protocols for each modality and infection control\ninstructions are posted on the walls in all examination rooms. The EMICT periodically reminds\nstaff to undertake personal measures to reduce infection, such as wearing masks at all instances\nin the radiology department and N95 masks if working in the contaminated area; not touching\nthe mask and the eyes; practicing hand hygiene; facing away from colleagues when eating,\ndrinking, and talking; and not using personal cell phones while on duty.\n In addition, the chief thoracic radiologist provided lectures on all radiologists and\ntechnologists on typical CT findings of COVID-19 infection using materials developed in", "Wuhan, the epicenter of the outbreak in China.\nCT examination procedures\nThere are two sets of procedures for CT examination: the fever-CT procedure and routine CT\nprocedure for those not suspected of COVID-19.\nThe fever-CT procedure for suspected or confirmed COVID-19 (Figure 2)\n8\nBefore the fever-CT technologist operates the equipment, he or she should wear personal\nprotective equipment according to three-level protection standard [8]. Before the CT\nexamination of patients with suspected and confirmed COVID-19 begins, the fever tent or\nisolation ward notifies the radiologist in advance. The fever-CT technologist checks the\nequipment and prepares to disinfect the imaging equipment immediately after the examination.\nThe patient enters the fever-CT waiting area through the fever access area. If the patient\ncan get onto and off the examination table by themselves, the patient is allowed to do so. If the", "patient cannot get onto or off the examination table independently, the person accompanying\nthe patient assists the patient, rather than the technologist. The technologist checks the patient\ninformation and, using an intercom system in the examination room, asks the patient to remove\nany metal ornaments on the neck and chest. Also, by intercom, the technologist trains the\npatient to hold his or her breath during the examination.\nThe technologist uses a low-dose chest CT protocol to scan the patient. After scanning, the\noriginal images are reconstructed as 1 mm-thick layers. The technologist browses the images to\nensure that their quality meets the diagnostic requirements and then guides the patient to leave\nthrough the fever access area. The disposable sheets for patient examination are changed after\neach patient. The equipment is disinfected according to the procedure below.\nTo protect themselves, the technologists assigned to the fever-CT wear N95 mask and", "other personal protection as established by the EMICT.\nThe CT procedure for regular patients (figure.3)\n9\nSome patients with COVID-19 have no symptoms, and they may call at the general clinic for\nother reasons. The following CT procedure is applicable under these circumstances:\nWhen the patient makes an appointment for examination, the staff asks the patient about\ntheir epidemiological history, symptoms, and signs. If suspected criteria are met, the patient\nwill be sent to the fever tent for further screening. When a patient presents to the radiology\ndepartment entrance, his/her temperature is measured. If the temperature is higher than 37.2 , ℃\nthe patient is sent to the fever tent for further investigation.\nThose with no exposure history, suspicious symptoms or fever are screened in one of the\nnon-contaminated CT scanners. The technologists assigned to these scanners wear surgical\nmasks. All patients and the person accompanying them are required to wear surgical masks.", "After the CT examination, the technologist browses the images quickly. If the CT appearance is\ntypical of lung infection, the technologist immediately reports it to the chest radiologist on duty\nand asks the patient to wait in the CT examination room. If the chest radiologist does not\nsuspect COVID-19 infection, the patient can leave the CT examination room. If the chest\nradiologist does suspect COVID-19 infection, the technologist immediately reports it to the\nEMICT and sends the patient to the fever tent. The floor and equipment in the CT examination\nroom are disinfected according to regulations, and air disinfection is conducted for 30 min\nbefore examining other patients. These CT scanners are considered noncontaminated (not\nfever-CTs) after these sterilization procedures.\nFever-DR examination procedure\n10\nThe COVID-19 guideline of the NHC does not recommend chest DR because its ability in\ndiagnosing COVID-19 is limited. At our hospital, we only use mobile DR units to provide", "bedside examination for critically ill patients. The technologist operating the mobile DR\nwears personal protective equipment according to the three-level protection standard and\nsterilizes the mobile DR according to the ward management requirements as described below.\nEquipment and environment disinfection procedures\nRoutine disinfection procedure [9]\n1) Object surface disinfection: Object surface is wiped with 1000mg/L chlorine-containing\ndisinfectant, wipe twice with 75% ethanol for non-corrosion resistance, once /4 hours.\n2) Equipment disinfection: The equipment in the contaminated area are wiped with\n2000mg/L chlorine-containing disinfectant. The DR and CT gantry in the contaminated\narea are wiped with 75% ethanol. The equipment in the buffer area is wiped with\n500-1000mg/L chlorine-containing disinfectant or alcohol-containing disposable\ndisinfectant wipes twice a day.\n3) Air disinfection: Turning off all central air conditioners to prevent air contamination with", "each other. Polluted area: open the door for ventilation, each time more than 30 minutes,\nonce /4 hours; The air sterilizer is continuously sterilized or the ultraviolet ray is\ncontinuously used in the unmanned state for 60 minutes, four times a day, remembered to\nclose the inner shielding door when air disinfection. Other ambient air is sprayed with\n1000mg/L chlorine-containing disinfectant and ventilated twice a day\n4) Ground disinfection: The ground is wiped with 1000mg/L chlorine-containing\ndisinfectant, once /4 hours.\n5) When contaminated, disinfect at any time. In case of visible contamination, disposable\nabsorbent materials should be used first to completely remove the pollutants, and then a\ncloth soaked with 2000mg/L chlorine-containing disinfectant should be used for 30\nminutes before wiping.\n11\nFever-CT disinfection procedures after examination\nIn addition to the above, disinfect the examination bed and ground with chlorinated disinfectant\ncontaining 2000mg/L [10].", "Noncontaminated CT disinfection procedures after suspected COVID-19 case examination\nIn addition to the above routine disinfection procedure, air disinfection is conducted for 30 min\nbefore examining other patients.\nResults\nFrom January 21, 2020 when screening for epidemiological history or symptoms\nsuspicious for COVID-19, to March 9, 2020, our hospital screened a total of 7,203 individuals\nand confirmed 24 cases of COVID-19. Of these, 3,083 people underwent fever-CT\nexaminations. Including the initial examination and reexamination, the total number of fever\nCT examination numbered 3,340. The fever-CT scanned a patient approximately every 21.5\nminutes. As a result of our precautions, none of the staff of the radiology department developed\nsymptoms suspicious for COVID-19. The fever-CT technologist, with the highest probability\nof exposure, remains PCR negative.\nDiscussion\nIt has been 17 years since the severe acute respiratory syndrome (SARS) epidemic, the last", "national spread of severe infectious disease, broke out. Currently, the Chinese people are\npanicking again. The speed and extent by which COVID-19 has spread in 2 months are\n12\nunprecedented, beyond those of SARS, and this has been aided by its contagious nature and\nrapid spread via droplets and contact. The droplet mode of transmission means that a person can\nbe infected easily by means of casual contact or even fomites on contaminated environmental\nsurfaces. Another theory has yet to be proved: aerosol propagation.\nHow radiology departments respond to any infectious disease outbreak is determined\nprimarily by the estimated risk of cross-infection to the staff and other patients. Appropriate\nprecautions taken only by staff in direct contact with patients may be adequate when the risk is\nlow. The strongest measures need to be implemented to limit the spread of the disease when the\nrisk is high. With severe infectious diseases such as COVID-19, the highest level of infection", "control measures must be implemented; these include providing adequate standard protective\nequipment, training staff, and instituting proper emergency plans.\nOnce a contagious infectious disease has been identified, the EMICT must consider four\nmain areas of response: data gathering, collaboration, needs assessment, and expert advice [10].\nData gathering includes dissemination of up-to-date case definitions and information about\nconfirmatory tests to all staff with direct patient contact to allow appropriate barrier precautions\nto be taken. All typical and atypical imaging features of the disease should be made known to\nall radiologists to assist in recognition of the disease on images and to allow accurate reporting\nof these findings. We have stored images of all probable cases of COVID-19 in the PACS so\nthat these images were readily available for any radiologist to review, and images from\nprevious imaging studies are also available for comparison.", "Collaboration with the radiology departments of other hospitals is very important because\npatients may initially present to different centers, depending on geographic location and travel\n13\ndistance. These patients may be few in number at a single hospital, but if data from patients at\nseveral hospitals are available, a more accurate overall understanding of both imaging features\nand epidemiology can be achieved. Dissemination of this information to all healthcare facilities\nwill also lead to early recognition of the disease, and appropriate isolation measures may be\ninstituted.\nThe Internet and social media apps, especially WeChat, have been used for distribution of\nmedical information, and because the exchange of information regarding infectious disease\noutbreaks is almost instantaneous, it is an indispensable tool for radiologists. In fact, within a\nmonth of the outbreak, the hospital that received the most infected patients from the source of", "the outbreak made a PowerPoint presentation of the CT manifestations of COVID-19, which\nwas shared via WeChat and disseminated across the country in a very short time. Subsequently,\nCOVID-19-teaching PowerPoint presentations from various hospitals appeared and were\nquickly shared via WeChat.\nOur diagnostic process is limited as chest CT along is not diagnostic of COVID-19\nbecause of lack of imaging specificity. But when combined with other epidemiological,\nclinical, laboratory and virus nucleic acid information, typical chest CT imaging findings are\nhelpful for making the diagnosis. In our opinion, the major role of chest CT is to understand the\nextent and dynamic evolution of lung lesions induced by COVID-19. The reasons why we\nadopted the low-dose chest CT scan protocol are as follows: low-dose chest CT has been\nwidely used in the screening of early lung cancer. It is well known that many early lung cancers", "are ground-glass opacities (GGO), so we believe that low-dose screening is also applicable for\nCOVID-19. In addition, considering the rapid development of COVID-19, many CT\n14\nexaminations may be conducted in the same individual to monitor disease progress. Low-dose\nscanning can reduce the radiation damage to patients.\nAlthough the processes we established minimized the exposure of hospital staff, ancillary\npersonnel and other patients, it remains limited as follows. Sichuan province is not the center of\nthe epidemic. The number of patients with COVID-19 whom we have treated has not been\nhigh, and most cases are from other provinces of China. However, we believe that our\nexperience in management, the reconfiguration of our radiology department, and the workflow\nchanges implemented in the current COVID-19 situation are useful for other radiology\ndepartments that must prepare for dealing with patients with COVID-19. While no radiology", "personnel developed symptoms suspicious for or were confirmed as having COVID-19, there\nmay be asymptomatic personnel.\nREFERENCES\n1. National Health Commission of the People’s Republic of China.(2020). March 12: Daily briefing\non novel coronavirus cases in China. Retrieved from\nhttp://en.nhc.gov.cn/2020-03/12/c_77618.htm. Accessed March 11, 2020.\n2. World Health Organization. (2020). Coronavirus disease 2019 (COVID-19) Situation Report-52.\nRetrieved from\nhttps://www.who.int/docs/default-source/coronaviruse/20200312-sitrep-52-covid-19.pdf?sfvrsn=e\n2bfc9c0_2 9. Accessed March 11, 2020.\n3. National Health Commission of the People’s Republic of China.(2020). Latest developments in\nepidemic control on Feb 15. Retrieved from http://en.nhc.gov.cn/2020-02/16/c_76622. Accessed\nMarch 11, 2020.\n15\n4. Health Commission of the People’s Republic of China.(2020). The notification of the trial\noperation based on the guideline version 6 in the coronavirus disease diagnosis and treatment.", "Retrieved from\nhttp://www.nhc.gov.cn/xcs/zhengcwj/202002/8334a8326dd94d329df351d7da8aefc2.shtml.\nAccessed March 11, 2020\n5. Health Commission of the People’s Republic of China.(2020). The notification of the trial\noperation based on the guideline version 6 in the coronavirus disease diagnosis and treatment.\nRetrieved from\nhttp://www.nhc.gov.cn/xcs/zhengcwj/202002/8334a8326dd94d329df351d7da8aefc2.shtml.\nAccessed March 11, 2020.\n6. Health Commission of the People’s Republic of China.(2009). The guideline for pathogens\nisolated operations in hospital. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/200904/40116.shtml. Accessed March 11, 2020.\n7. Health Commission of the People’s Republic of China.(2017). The guideline for prevention and\ncontrol of hospital acquired infections of airborne pathogens. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201701/7e0e8fc6725843aabba8f841f2f585d2.shtml. Accessed\nMarch 11, 2020.", "8. Health Commission of the People’s Republic of China.(2017). The guideline for prevention and\ncontrol of hospital acquired infections of airborne pathogens. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201701/7e0e8fc6725843aabba8f841f2f585d2.shtml. Accessed\nMarch 11, 2020.\n9. Health Commission of the People’s Republic of China.(2012). The standardization for\nsterilization techniques in hospital. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201204/54510.shtml. Accessed March 11, 2020.\n10. Health Commission of the People’s Republic of China.(2012). The standardization for\nsterilization techniques in hospital. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201204/54510.shtml. Accessed March 11, 2020.\n11. Katona P. Bioterrorism Preparedness: Generic Blueprint for Health Departments, Hospitals, and\nPhysicians. Infectious Diseases in Clinical Practice. 2002;11(3):115-122. Accessed March 11,\n2020.\n16\nFigure Legends", "Figure 1. Diagram of the layout of our radiology department was divided into four areas: contaminated\n(shaded in black), semicontaminated (shaded in dark gray), buffer (shaded in light gray), and clean areas\n(shaded in white). The contaminated area was separated from other areas by barriers.\nFigure 2. Diagram shows CT protocol for suspected and confirmed patients with COVID-19.\nFigure 3. Diagram shows CT protocol for regular patients.\nAbbreviations:\nCOVID-19: coronavirus disease 2019\nCT: computed tomography\nDR: digital radiography\nEMICT: emergency management and infection control team\nNHC: National Health Commission\nPACS: picture archiving and communication system\nSARS: severe acute respiratory syndrome", "Sentence Summary\nWith severe infectious diseases such as COVID-19, the highest level of infection control\nmeasures must be implemented, collaboration with the radiology departments of other\nhospitals be needed, and social media be employed.\nTake-home points\n1. To response to a community infection emergency, a special emergency management team\nneeds to be setup at the departmental level to implement infection containment and\ncontrol procedures that continues to allow the imaging examination and imaging\ndiagnosis of those with suspected infection, and to prevent intra-departmental spreading\nof infection (EMICT).\n2. Infection control measures, such as reconfiguration of department areas, personal\nprotection and anti-infection training of all staff, standardized procedures including\ncontact minimization for chest CT and DR examinations, and timely disinfection of CT\nand DR examination rooms, should be implemented properly.", "3. If there are more than one scanner in a hospital, only one of them should be assigned to\nsuspected cases." ]	[ 11 ]	3,975	6,764
188	How was the contaminated area connected to the CT room and other facilities?	2,450	[ "connected to the fever clinic and\nincludes the fever accessway, the CT examination room, and the DR examination room for\n6\nconfirmed and suspected cases. One CT scanner and one DR system closest to the emergency\ndepartment are designated the fever-CT and fever-DR to examine patients with suspected and\nconfirmed COVID-19. There is a separate dedicated access between the contaminated area and\nthe fever screening tents." ]	[ "The Battle Against Coronavirus Disease 2019 (COVID-19): Emergency Management\nand Infection Control in a Radiology Department\nhttps://www.jacr.org/article/S1546-1440(20)30285-4/pdf\nJournal Pre-proof\nZixing Huang, Shuang Zhao, Zhenlin Li, Weixia Chen, Lihong Zhao, Lipeng Deng, Bin\nSong\nPII: S1546-1440(20)30285-4\nDOI: https://doi.org/10.1016/j.jacr.2020.03.011\nReference: JACR 5139\nTo appear in: Journal of the American College of Radiology\nReceived Date: 24 February 2020\nRevised Date: 13 March 2020\nAccepted Date: 15 March 2020\nPlease cite this article as: Huang Z, Zhao S, Li Z, Chen W, Zhao L, Deng L, Song B, The Battle Against\nCoronavirus Disease 2019 (COVID-19): Emergency Management and Infection Control in a Radiology\nDepartment, Journal of the American College of Radiology (2020), doi: https://doi.org/10.1016/\nj.jacr.2020.03.011.\nThis is a PDF file of an article that has undergone enhancements after acceptance, such as the addition", "of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of\nrecord. This version will undergo additional copyediting, typesetting and review before it is published\nin its final form, but we are providing this version to give early visibility of the article. Please note that,\nduring the production process, errors may be discovered which could affect the content, and all legal\ndisclaimers that apply to the journal pertain.\n© 2020 Published by Elsevier Inc. on behalf of American College of Radiology\nThe Battle Against Coronavirus Disease 2019 (COVID-19): Emergency Management\nand Infection Control in a Radiology Department\nZixing Huang, Shuang Zhao, Zhenlin Li, Weixia Chen, Lihong Zhao, Lipeng Deng,\nBin Song\nDepartment of Radiology, West China Hospital, Sichuan University, Chengdu, China\n*Zixing Huang and Shuang Zhao contributed equally to this work as co-first author.\nCorresponding Author: Bin Song, MD", "Address: Department of Radiology, West China Hospital, Sichuan University.\nNo. 37, GUOXUE Alley, Chengdu, 610041, China\nTel.: (+86)28 85423680, Fax: (+86)28 85582944\nEmail: [email protected].\nAuthors’ contributions\nZXH: conceived the study and drafted the manuscript.\nZS: conceived the study and drafted the manuscript.\nZLL: The member of the emergency management and infection control team (EMICT)\nand was involved in the formulation of the measures.\nWXC: The member of the EMICT and was involved in the formulation of the\nmeasures.\nLHZ: The member of the EMICT and was involved in the formulation of the\nmeasures.\nLPD: The member of the EMICT and was involved in the formulation of the\nmeasures.\nBS: Leader of the EMICT, conceived the study and reviewed the manuscript.\nAll authors read and approved the final manuscript.\nThe authors declare no conflict of interest.\nThe authors declare that they had full access to all of the data in this study and the", "authors take complete responsibility for the integrity of the data and the accuracy of\nthe data analysis\n1\nThe Battle Against Novel Coronavirus Pneumonia (COVID-19): Emergency\nManagement and Infection Control in a Radiology Department\nAbstract\nObjective: To describe the strategy and the emergency management and infection control\nprocedure of our radiology department during the COVID-19 outbreak.\nMethods: We set up emergency management and sensing control teams. The team formulated\nvarious measures: reconfiguration of the radiology department, personal protection and training\nof staff, examination procedures for patients suspected of or confirmed with COVID-19 as well\nas patients without an exposure history or symptoms. Those with suspected or confirmed\nCOVID-19 infection were scanned in the designated fever-CT unit.\nResults: From January 21, 2020 to March 9, 2020, 3,083 people suspected of or confirmed with\nCOVID-19 underwent fever-CT examinations. Including initial examinations and", "reexaminations, the total number of fever-CT examinations numbered 3,340. As a result of our\nprecautions, none of the staff of the radiology department were infected with COVID-19.\nConclusion: Strategic planning and adequate protections can help protect patients and staff\nagainst a highly infectious disease while maintaining function at a high volume capacity.\nKeywords: Coronavirus, COVID-19, novel coronavirus pneumonia, infection control", "2\nIntroduction\nThe whole world has been closely focusing on an outbreak of respiratory disease caused by a\nnovel coronavirus that was first reported in Wuhan, China, on December 31, 2019, and that\ncontinues to spread. On February 11, 2020, the World Health Organization (WHO) named the\ndisease “coronavirus disease 2019” (COVID-19).\nAs of 24:00 on March 11, 2020, the National Health Commission (NHC) had received reports\nof 80,793 confirmed cases and 3,169 deaths on the Chinese mainland. There remain 14,831\nconfirmed cases (including 4,257 in serious condition) and 253 suspected cases still\nhospitalized. To date, 677,243 people have been identified as having had close contact with\ninfected patients of whom13,701 are under medical observation [1]. Outside China, 44,067\nlaboratory-confirmed cases and 1,440 deaths have occurred in 117 countries /territories/areas\naccording to the WHO [2]. COVID-19 poses significant threats to international health. Like the", "flu, COVID-19 is thought to spread mainly from person-to-person between people who are in\nclose contact with one another through respiratory droplets produced when an infected person\ncoughs or sneezes. In light of the infectious nature of this disease, healthcare workers are at\nhigh risk of infection of COVID-19. In China, healthcare workers account for 1,716 confirmed\ncases of COVID-19, including six deaths [3].\n Computed tomography (CT) can play a role in both diagnosing and categorizing\nCOVID-19 on the basis of case definitions issued by the WHO and the treatment guidelines\nfrom the NHC [4]. Suspected patients having the virus may undergo chest CT. Isolation and\nbarrier procedures are necessary to protect both the department staff and other patients in the\nhospital. Note should be made that due to overlap of imaging findings with other respiratory\n3\ndiseases, CT is not helpful as a screening tool. But it can help identify the degree of pulmonary\ninvolvement and disease course.", "Our hospital is a national regional medical center with 4,300 beds and a tertiary referral\ncenter in Sichuan province. The initial response started on January 21, 2020, after transmission\nof COVID-19 was confirmed to be human-to-human on January 20, 2020. The first suspected\ncase of COVID-19 in Sichuan province was reported on January 21, 2020. The Sichuan\nprovincial government immediately launched the first-level response to major public health\nemergencies. On the same day, our hospital was designated to care for Sichuan province\npatients with COVID-19.\nThis article describes the emergency management procedure of our radiology department\nfor situations involving severe infectious diseases, such as COVID-19, and the\ninfection-protection experience of the department staff.\nMethods\nThe hospital provided personal protective equipment (medical protective clothing,\nsurgical cap, N95 mask, gloves, face shields, and goggles) to all its healthcare staff, erected", "three medical tents (fever tents) for screening of fever cases in the parking lot of the emergency\ndepartment, planned an examination route and examination area for patients suspected of\nharboring the virus, and placed confirmed patients in an isolation ward. “Fever” was the\ncolloquial term used to designate suspected COVID-19 based on symptoms such as a fever or\nwith an epidemiological history of a potential exposure as well as those with confirmed\nCOVID-19 referred for treatment. Further, during outbreak, emergency and outpatient patients\n4\nwithout fever were asked for information such as epidemiological history and sent to fever tents\nas long as they met suspected criteria.\nThe radiology department has 65 diagnostic radiologists and 161 other staff members\n(trained technologists, nurses, engineers, and support staff). The equipment of the radiology\ndepartment includes 12 magnetic resonance (MR) scanners, 14 CT scanners, 15 digital", "subtraction angiography (DSA) systems, 32 sets of digital radiography (DR) systems\n(including nine mobile bedside DR sets), and 130 imaging diagnostic workstations for picture\narchiving and communication systems (PACS). Most of the equipment is distributed among\nfour buildings at the hospital main campus. 4 CT scanners, 4 MR scanners, 1 DR are located on\nthe first floor of the first inpatient building, and 9 DR and 8 DSA are located on the second\nfloor. 1 CT and 1 MR scanner are located in the third inpatient building. 1 CT and 1 MR scanner\nare located in the sixth inpatient building. 2 CT scanners, 2 MR scanners and 7 DSA are located\nin the technical building. The rest of the equipment is located in the seventh inpatient building\nin the branch campus.\nThe first inpatient building, located next to the emergency department, was reconfigured to\nhandle cases of COVID-19. Fever tents were set up by the emergency department in the", "emergency department parking lot to separate normal emergency patients from patients with\nsymptoms or exposure history suspicious of COVID-19. We established separate means of\naccess between fever tents and between the fever examination area of the radiology department\nto avoid cross-contamination.\nThe emergency management and infection control measures, as described below and\nimplemented in the radiology department during the outbreak, have been approved by the\n5\ninfection control committee of hospital. These measures are in accordance with relevant laws\nand regulations, in order to protect patients as well as the staff.\nRadiology Emergency Management and Infection Control Team (EMICT)\nThe radiology department director chaired the EMICT. Its members include the deputy\ndirector, chief technologist, head nurse, equipment engineer supervisor, and infection control\nnurse of the radiology department. Team responsibilities included (1) coordination between the", "hospital’s management and planning of infection control and radiology departments; (2)\ncollection of the most up-to-date protection-related information to educate and train staff in the\ndepartment; (3) reallocation of staff according to the actual situation; (4) establishment of the\nCT procedures for patients with COVID-19; and (5) establishment of an emergency\nmanagement plan for the radiology department to ensure that the department would run\nnormally.\nSuspected patients\nThe suspected patients were identified according to the Diagnosis and Treatment Program of\nthe Novel Coronavirus Pneumonia of the NHC [5], mainly based on epidemiological history.\nReconfiguration of the radiology department\nThe radiology department was divided into four areas [6]: contaminated, semicontaminated,\nbuffer, and clean areas (Figure 1). The contaminated area is connected to the fever clinic and\nincludes the fever accessway, the CT examination room, and the DR examination room for\n6", "confirmed and suspected cases. One CT scanner and one DR system closest to the emergency\ndepartment are designated the fever-CT and fever-DR to examine patients with suspected and\nconfirmed COVID-19. There is a separate dedicated access between the contaminated area and\nthe fever screening tents. The semicontaminated area includes the fever-CT control room,\nfever-DR control room, and other patient examination access areas. The buffer zone includes\naccess areas for medical personnel and a dressing area for technologists. The clean area\nincludes the administrative office and the diagnostic room.\nThe contaminated area was isolated from other areas using physical barricades.\nDirectional signs were newly installed to guide patients and staff.\nPersonal protection and training of staff\nFor providing care for patients with confirmed and suspected COVID-19, all hospital staff\nare required to wear complete personal protective equipment [7]: medical protective clothing,", "surgical cap, N95 mask, gloves, face shields, and goggles. Wearing and removing of the\nequipment must be performed in accordance with the procedures and under the supervision of\nthe infection control nurse.\nBecause staff members working in the contaminated area are under much situational\npressure, periodically taking time off could lower their physical and mental stress levels. The\ntechnologists on fever-CT duty shifts are provided a break once a week for four hours. In\naddition, the health of staff in the contaminated area must be monitored closely for the\nsymptoms of COVID-19. Pregnant staff must be assigned to the clean area.\n7\nThe EMICT formulates and continually updates guidelines and educates all staff for West\nChina Hospital of Sichuan University. The EMICT training for staff is mainly involves\ndocuments regarding infection control and CT findings of COVID-19 and maintains an EMICT\nWeChat group for West China Hospital of Sichuan University. WeChat is the most widely used", "social media app in China. The EMICT releases the latest national and hospital-based\ninformation regarding COVID-19, guidance documents, and other notices from the hospital\nand radiology department in the WeChat group on a daily basis. Staff can also report to the\nEMICT in the WeChat group any time. Protocols for each modality and infection control\ninstructions are posted on the walls in all examination rooms. The EMICT periodically reminds\nstaff to undertake personal measures to reduce infection, such as wearing masks at all instances\nin the radiology department and N95 masks if working in the contaminated area; not touching\nthe mask and the eyes; practicing hand hygiene; facing away from colleagues when eating,\ndrinking, and talking; and not using personal cell phones while on duty.\n In addition, the chief thoracic radiologist provided lectures on all radiologists and\ntechnologists on typical CT findings of COVID-19 infection using materials developed in", "Wuhan, the epicenter of the outbreak in China.\nCT examination procedures\nThere are two sets of procedures for CT examination: the fever-CT procedure and routine CT\nprocedure for those not suspected of COVID-19.\nThe fever-CT procedure for suspected or confirmed COVID-19 (Figure 2)\n8\nBefore the fever-CT technologist operates the equipment, he or she should wear personal\nprotective equipment according to three-level protection standard [8]. Before the CT\nexamination of patients with suspected and confirmed COVID-19 begins, the fever tent or\nisolation ward notifies the radiologist in advance. The fever-CT technologist checks the\nequipment and prepares to disinfect the imaging equipment immediately after the examination.\nThe patient enters the fever-CT waiting area through the fever access area. If the patient\ncan get onto and off the examination table by themselves, the patient is allowed to do so. If the", "patient cannot get onto or off the examination table independently, the person accompanying\nthe patient assists the patient, rather than the technologist. The technologist checks the patient\ninformation and, using an intercom system in the examination room, asks the patient to remove\nany metal ornaments on the neck and chest. Also, by intercom, the technologist trains the\npatient to hold his or her breath during the examination.\nThe technologist uses a low-dose chest CT protocol to scan the patient. After scanning, the\noriginal images are reconstructed as 1 mm-thick layers. The technologist browses the images to\nensure that their quality meets the diagnostic requirements and then guides the patient to leave\nthrough the fever access area. The disposable sheets for patient examination are changed after\neach patient. The equipment is disinfected according to the procedure below.\nTo protect themselves, the technologists assigned to the fever-CT wear N95 mask and", "other personal protection as established by the EMICT.\nThe CT procedure for regular patients (figure.3)\n9\nSome patients with COVID-19 have no symptoms, and they may call at the general clinic for\nother reasons. The following CT procedure is applicable under these circumstances:\nWhen the patient makes an appointment for examination, the staff asks the patient about\ntheir epidemiological history, symptoms, and signs. If suspected criteria are met, the patient\nwill be sent to the fever tent for further screening. When a patient presents to the radiology\ndepartment entrance, his/her temperature is measured. If the temperature is higher than 37.2 , ℃\nthe patient is sent to the fever tent for further investigation.\nThose with no exposure history, suspicious symptoms or fever are screened in one of the\nnon-contaminated CT scanners. The technologists assigned to these scanners wear surgical\nmasks. All patients and the person accompanying them are required to wear surgical masks.", "After the CT examination, the technologist browses the images quickly. If the CT appearance is\ntypical of lung infection, the technologist immediately reports it to the chest radiologist on duty\nand asks the patient to wait in the CT examination room. If the chest radiologist does not\nsuspect COVID-19 infection, the patient can leave the CT examination room. If the chest\nradiologist does suspect COVID-19 infection, the technologist immediately reports it to the\nEMICT and sends the patient to the fever tent. The floor and equipment in the CT examination\nroom are disinfected according to regulations, and air disinfection is conducted for 30 min\nbefore examining other patients. These CT scanners are considered noncontaminated (not\nfever-CTs) after these sterilization procedures.\nFever-DR examination procedure\n10\nThe COVID-19 guideline of the NHC does not recommend chest DR because its ability in\ndiagnosing COVID-19 is limited. At our hospital, we only use mobile DR units to provide", "bedside examination for critically ill patients. The technologist operating the mobile DR\nwears personal protective equipment according to the three-level protection standard and\nsterilizes the mobile DR according to the ward management requirements as described below.\nEquipment and environment disinfection procedures\nRoutine disinfection procedure [9]\n1) Object surface disinfection: Object surface is wiped with 1000mg/L chlorine-containing\ndisinfectant, wipe twice with 75% ethanol for non-corrosion resistance, once /4 hours.\n2) Equipment disinfection: The equipment in the contaminated area are wiped with\n2000mg/L chlorine-containing disinfectant. The DR and CT gantry in the contaminated\narea are wiped with 75% ethanol. The equipment in the buffer area is wiped with\n500-1000mg/L chlorine-containing disinfectant or alcohol-containing disposable\ndisinfectant wipes twice a day.\n3) Air disinfection: Turning off all central air conditioners to prevent air contamination with", "each other. Polluted area: open the door for ventilation, each time more than 30 minutes,\nonce /4 hours; The air sterilizer is continuously sterilized or the ultraviolet ray is\ncontinuously used in the unmanned state for 60 minutes, four times a day, remembered to\nclose the inner shielding door when air disinfection. Other ambient air is sprayed with\n1000mg/L chlorine-containing disinfectant and ventilated twice a day\n4) Ground disinfection: The ground is wiped with 1000mg/L chlorine-containing\ndisinfectant, once /4 hours.\n5) When contaminated, disinfect at any time. In case of visible contamination, disposable\nabsorbent materials should be used first to completely remove the pollutants, and then a\ncloth soaked with 2000mg/L chlorine-containing disinfectant should be used for 30\nminutes before wiping.\n11\nFever-CT disinfection procedures after examination\nIn addition to the above, disinfect the examination bed and ground with chlorinated disinfectant\ncontaining 2000mg/L [10].", "Noncontaminated CT disinfection procedures after suspected COVID-19 case examination\nIn addition to the above routine disinfection procedure, air disinfection is conducted for 30 min\nbefore examining other patients.\nResults\nFrom January 21, 2020 when screening for epidemiological history or symptoms\nsuspicious for COVID-19, to March 9, 2020, our hospital screened a total of 7,203 individuals\nand confirmed 24 cases of COVID-19. Of these, 3,083 people underwent fever-CT\nexaminations. Including the initial examination and reexamination, the total number of fever\nCT examination numbered 3,340. The fever-CT scanned a patient approximately every 21.5\nminutes. As a result of our precautions, none of the staff of the radiology department developed\nsymptoms suspicious for COVID-19. The fever-CT technologist, with the highest probability\nof exposure, remains PCR negative.\nDiscussion\nIt has been 17 years since the severe acute respiratory syndrome (SARS) epidemic, the last", "national spread of severe infectious disease, broke out. Currently, the Chinese people are\npanicking again. The speed and extent by which COVID-19 has spread in 2 months are\n12\nunprecedented, beyond those of SARS, and this has been aided by its contagious nature and\nrapid spread via droplets and contact. The droplet mode of transmission means that a person can\nbe infected easily by means of casual contact or even fomites on contaminated environmental\nsurfaces. Another theory has yet to be proved: aerosol propagation.\nHow radiology departments respond to any infectious disease outbreak is determined\nprimarily by the estimated risk of cross-infection to the staff and other patients. Appropriate\nprecautions taken only by staff in direct contact with patients may be adequate when the risk is\nlow. The strongest measures need to be implemented to limit the spread of the disease when the\nrisk is high. With severe infectious diseases such as COVID-19, the highest level of infection", "control measures must be implemented; these include providing adequate standard protective\nequipment, training staff, and instituting proper emergency plans.\nOnce a contagious infectious disease has been identified, the EMICT must consider four\nmain areas of response: data gathering, collaboration, needs assessment, and expert advice [10].\nData gathering includes dissemination of up-to-date case definitions and information about\nconfirmatory tests to all staff with direct patient contact to allow appropriate barrier precautions\nto be taken. All typical and atypical imaging features of the disease should be made known to\nall radiologists to assist in recognition of the disease on images and to allow accurate reporting\nof these findings. We have stored images of all probable cases of COVID-19 in the PACS so\nthat these images were readily available for any radiologist to review, and images from\nprevious imaging studies are also available for comparison.", "Collaboration with the radiology departments of other hospitals is very important because\npatients may initially present to different centers, depending on geographic location and travel\n13\ndistance. These patients may be few in number at a single hospital, but if data from patients at\nseveral hospitals are available, a more accurate overall understanding of both imaging features\nand epidemiology can be achieved. Dissemination of this information to all healthcare facilities\nwill also lead to early recognition of the disease, and appropriate isolation measures may be\ninstituted.\nThe Internet and social media apps, especially WeChat, have been used for distribution of\nmedical information, and because the exchange of information regarding infectious disease\noutbreaks is almost instantaneous, it is an indispensable tool for radiologists. In fact, within a\nmonth of the outbreak, the hospital that received the most infected patients from the source of", "the outbreak made a PowerPoint presentation of the CT manifestations of COVID-19, which\nwas shared via WeChat and disseminated across the country in a very short time. Subsequently,\nCOVID-19-teaching PowerPoint presentations from various hospitals appeared and were\nquickly shared via WeChat.\nOur diagnostic process is limited as chest CT along is not diagnostic of COVID-19\nbecause of lack of imaging specificity. But when combined with other epidemiological,\nclinical, laboratory and virus nucleic acid information, typical chest CT imaging findings are\nhelpful for making the diagnosis. In our opinion, the major role of chest CT is to understand the\nextent and dynamic evolution of lung lesions induced by COVID-19. The reasons why we\nadopted the low-dose chest CT scan protocol are as follows: low-dose chest CT has been\nwidely used in the screening of early lung cancer. It is well known that many early lung cancers", "are ground-glass opacities (GGO), so we believe that low-dose screening is also applicable for\nCOVID-19. In addition, considering the rapid development of COVID-19, many CT\n14\nexaminations may be conducted in the same individual to monitor disease progress. Low-dose\nscanning can reduce the radiation damage to patients.\nAlthough the processes we established minimized the exposure of hospital staff, ancillary\npersonnel and other patients, it remains limited as follows. Sichuan province is not the center of\nthe epidemic. The number of patients with COVID-19 whom we have treated has not been\nhigh, and most cases are from other provinces of China. However, we believe that our\nexperience in management, the reconfiguration of our radiology department, and the workflow\nchanges implemented in the current COVID-19 situation are useful for other radiology\ndepartments that must prepare for dealing with patients with COVID-19. While no radiology", "personnel developed symptoms suspicious for or were confirmed as having COVID-19, there\nmay be asymptomatic personnel.\nREFERENCES\n1. National Health Commission of the People’s Republic of China.(2020). March 12: Daily briefing\non novel coronavirus cases in China. Retrieved from\nhttp://en.nhc.gov.cn/2020-03/12/c_77618.htm. Accessed March 11, 2020.\n2. World Health Organization. (2020). Coronavirus disease 2019 (COVID-19) Situation Report-52.\nRetrieved from\nhttps://www.who.int/docs/default-source/coronaviruse/20200312-sitrep-52-covid-19.pdf?sfvrsn=e\n2bfc9c0_2 9. Accessed March 11, 2020.\n3. National Health Commission of the People’s Republic of China.(2020). Latest developments in\nepidemic control on Feb 15. Retrieved from http://en.nhc.gov.cn/2020-02/16/c_76622. Accessed\nMarch 11, 2020.\n15\n4. Health Commission of the People’s Republic of China.(2020). The notification of the trial\noperation based on the guideline version 6 in the coronavirus disease diagnosis and treatment.", "Retrieved from\nhttp://www.nhc.gov.cn/xcs/zhengcwj/202002/8334a8326dd94d329df351d7da8aefc2.shtml.\nAccessed March 11, 2020\n5. Health Commission of the People’s Republic of China.(2020). The notification of the trial\noperation based on the guideline version 6 in the coronavirus disease diagnosis and treatment.\nRetrieved from\nhttp://www.nhc.gov.cn/xcs/zhengcwj/202002/8334a8326dd94d329df351d7da8aefc2.shtml.\nAccessed March 11, 2020.\n6. Health Commission of the People’s Republic of China.(2009). The guideline for pathogens\nisolated operations in hospital. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/200904/40116.shtml. Accessed March 11, 2020.\n7. Health Commission of the People’s Republic of China.(2017). The guideline for prevention and\ncontrol of hospital acquired infections of airborne pathogens. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201701/7e0e8fc6725843aabba8f841f2f585d2.shtml. Accessed\nMarch 11, 2020.", "8. Health Commission of the People’s Republic of China.(2017). The guideline for prevention and\ncontrol of hospital acquired infections of airborne pathogens. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201701/7e0e8fc6725843aabba8f841f2f585d2.shtml. Accessed\nMarch 11, 2020.\n9. Health Commission of the People’s Republic of China.(2012). The standardization for\nsterilization techniques in hospital. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201204/54510.shtml. Accessed March 11, 2020.\n10. Health Commission of the People’s Republic of China.(2012). The standardization for\nsterilization techniques in hospital. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201204/54510.shtml. Accessed March 11, 2020.\n11. Katona P. Bioterrorism Preparedness: Generic Blueprint for Health Departments, Hospitals, and\nPhysicians. Infectious Diseases in Clinical Practice. 2002;11(3):115-122. Accessed March 11,\n2020.\n16\nFigure Legends", "Figure 1. Diagram of the layout of our radiology department was divided into four areas: contaminated\n(shaded in black), semicontaminated (shaded in dark gray), buffer (shaded in light gray), and clean areas\n(shaded in white). The contaminated area was separated from other areas by barriers.\nFigure 2. Diagram shows CT protocol for suspected and confirmed patients with COVID-19.\nFigure 3. Diagram shows CT protocol for regular patients.\nAbbreviations:\nCOVID-19: coronavirus disease 2019\nCT: computed tomography\nDR: digital radiography\nEMICT: emergency management and infection control team\nNHC: National Health Commission\nPACS: picture archiving and communication system\nSARS: severe acute respiratory syndrome", "Sentence Summary\nWith severe infectious diseases such as COVID-19, the highest level of infection control\nmeasures must be implemented, collaboration with the radiology departments of other\nhospitals be needed, and social media be employed.\nTake-home points\n1. To response to a community infection emergency, a special emergency management team\nneeds to be setup at the departmental level to implement infection containment and\ncontrol procedures that continues to allow the imaging examination and imaging\ndiagnosis of those with suspected infection, and to prevent intra-departmental spreading\nof infection (EMICT).\n2. Infection control measures, such as reconfiguration of department areas, personal\nprotection and anti-infection training of all staff, standardized procedures including\ncontact minimization for chest CT and DR examinations, and timely disinfection of CT\nand DR examination rooms, should be implemented properly.", "3. If there are more than one scanner in a hospital, only one of them should be assigned to\nsuspected cases." ]	[]	3,975	6,764
188	What does the clean area include?	2,453	[ "he clean area\nincludes the administrative office and the diagnostic room." ]	[ "The Battle Against Coronavirus Disease 2019 (COVID-19): Emergency Management\nand Infection Control in a Radiology Department\nhttps://www.jacr.org/article/S1546-1440(20)30285-4/pdf\nJournal Pre-proof\nZixing Huang, Shuang Zhao, Zhenlin Li, Weixia Chen, Lihong Zhao, Lipeng Deng, Bin\nSong\nPII: S1546-1440(20)30285-4\nDOI: https://doi.org/10.1016/j.jacr.2020.03.011\nReference: JACR 5139\nTo appear in: Journal of the American College of Radiology\nReceived Date: 24 February 2020\nRevised Date: 13 March 2020\nAccepted Date: 15 March 2020\nPlease cite this article as: Huang Z, Zhao S, Li Z, Chen W, Zhao L, Deng L, Song B, The Battle Against\nCoronavirus Disease 2019 (COVID-19): Emergency Management and Infection Control in a Radiology\nDepartment, Journal of the American College of Radiology (2020), doi: https://doi.org/10.1016/\nj.jacr.2020.03.011.\nThis is a PDF file of an article that has undergone enhancements after acceptance, such as the addition", "of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of\nrecord. This version will undergo additional copyediting, typesetting and review before it is published\nin its final form, but we are providing this version to give early visibility of the article. Please note that,\nduring the production process, errors may be discovered which could affect the content, and all legal\ndisclaimers that apply to the journal pertain.\n© 2020 Published by Elsevier Inc. on behalf of American College of Radiology\nThe Battle Against Coronavirus Disease 2019 (COVID-19): Emergency Management\nand Infection Control in a Radiology Department\nZixing Huang, Shuang Zhao, Zhenlin Li, Weixia Chen, Lihong Zhao, Lipeng Deng,\nBin Song\nDepartment of Radiology, West China Hospital, Sichuan University, Chengdu, China\n*Zixing Huang and Shuang Zhao contributed equally to this work as co-first author.\nCorresponding Author: Bin Song, MD", "Address: Department of Radiology, West China Hospital, Sichuan University.\nNo. 37, GUOXUE Alley, Chengdu, 610041, China\nTel.: (+86)28 85423680, Fax: (+86)28 85582944\nEmail: [email protected].\nAuthors’ contributions\nZXH: conceived the study and drafted the manuscript.\nZS: conceived the study and drafted the manuscript.\nZLL: The member of the emergency management and infection control team (EMICT)\nand was involved in the formulation of the measures.\nWXC: The member of the EMICT and was involved in the formulation of the\nmeasures.\nLHZ: The member of the EMICT and was involved in the formulation of the\nmeasures.\nLPD: The member of the EMICT and was involved in the formulation of the\nmeasures.\nBS: Leader of the EMICT, conceived the study and reviewed the manuscript.\nAll authors read and approved the final manuscript.\nThe authors declare no conflict of interest.\nThe authors declare that they had full access to all of the data in this study and the", "authors take complete responsibility for the integrity of the data and the accuracy of\nthe data analysis\n1\nThe Battle Against Novel Coronavirus Pneumonia (COVID-19): Emergency\nManagement and Infection Control in a Radiology Department\nAbstract\nObjective: To describe the strategy and the emergency management and infection control\nprocedure of our radiology department during the COVID-19 outbreak.\nMethods: We set up emergency management and sensing control teams. The team formulated\nvarious measures: reconfiguration of the radiology department, personal protection and training\nof staff, examination procedures for patients suspected of or confirmed with COVID-19 as well\nas patients without an exposure history or symptoms. Those with suspected or confirmed\nCOVID-19 infection were scanned in the designated fever-CT unit.\nResults: From January 21, 2020 to March 9, 2020, 3,083 people suspected of or confirmed with\nCOVID-19 underwent fever-CT examinations. Including initial examinations and", "reexaminations, the total number of fever-CT examinations numbered 3,340. As a result of our\nprecautions, none of the staff of the radiology department were infected with COVID-19.\nConclusion: Strategic planning and adequate protections can help protect patients and staff\nagainst a highly infectious disease while maintaining function at a high volume capacity.\nKeywords: Coronavirus, COVID-19, novel coronavirus pneumonia, infection control", "2\nIntroduction\nThe whole world has been closely focusing on an outbreak of respiratory disease caused by a\nnovel coronavirus that was first reported in Wuhan, China, on December 31, 2019, and that\ncontinues to spread. On February 11, 2020, the World Health Organization (WHO) named the\ndisease “coronavirus disease 2019” (COVID-19).\nAs of 24:00 on March 11, 2020, the National Health Commission (NHC) had received reports\nof 80,793 confirmed cases and 3,169 deaths on the Chinese mainland. There remain 14,831\nconfirmed cases (including 4,257 in serious condition) and 253 suspected cases still\nhospitalized. To date, 677,243 people have been identified as having had close contact with\ninfected patients of whom13,701 are under medical observation [1]. Outside China, 44,067\nlaboratory-confirmed cases and 1,440 deaths have occurred in 117 countries /territories/areas\naccording to the WHO [2]. COVID-19 poses significant threats to international health. Like the", "flu, COVID-19 is thought to spread mainly from person-to-person between people who are in\nclose contact with one another through respiratory droplets produced when an infected person\ncoughs or sneezes. In light of the infectious nature of this disease, healthcare workers are at\nhigh risk of infection of COVID-19. In China, healthcare workers account for 1,716 confirmed\ncases of COVID-19, including six deaths [3].\n Computed tomography (CT) can play a role in both diagnosing and categorizing\nCOVID-19 on the basis of case definitions issued by the WHO and the treatment guidelines\nfrom the NHC [4]. Suspected patients having the virus may undergo chest CT. Isolation and\nbarrier procedures are necessary to protect both the department staff and other patients in the\nhospital. Note should be made that due to overlap of imaging findings with other respiratory\n3\ndiseases, CT is not helpful as a screening tool. But it can help identify the degree of pulmonary\ninvolvement and disease course.", "Our hospital is a national regional medical center with 4,300 beds and a tertiary referral\ncenter in Sichuan province. The initial response started on January 21, 2020, after transmission\nof COVID-19 was confirmed to be human-to-human on January 20, 2020. The first suspected\ncase of COVID-19 in Sichuan province was reported on January 21, 2020. The Sichuan\nprovincial government immediately launched the first-level response to major public health\nemergencies. On the same day, our hospital was designated to care for Sichuan province\npatients with COVID-19.\nThis article describes the emergency management procedure of our radiology department\nfor situations involving severe infectious diseases, such as COVID-19, and the\ninfection-protection experience of the department staff.\nMethods\nThe hospital provided personal protective equipment (medical protective clothing,\nsurgical cap, N95 mask, gloves, face shields, and goggles) to all its healthcare staff, erected", "three medical tents (fever tents) for screening of fever cases in the parking lot of the emergency\ndepartment, planned an examination route and examination area for patients suspected of\nharboring the virus, and placed confirmed patients in an isolation ward. “Fever” was the\ncolloquial term used to designate suspected COVID-19 based on symptoms such as a fever or\nwith an epidemiological history of a potential exposure as well as those with confirmed\nCOVID-19 referred for treatment. Further, during outbreak, emergency and outpatient patients\n4\nwithout fever were asked for information such as epidemiological history and sent to fever tents\nas long as they met suspected criteria.\nThe radiology department has 65 diagnostic radiologists and 161 other staff members\n(trained technologists, nurses, engineers, and support staff). The equipment of the radiology\ndepartment includes 12 magnetic resonance (MR) scanners, 14 CT scanners, 15 digital", "subtraction angiography (DSA) systems, 32 sets of digital radiography (DR) systems\n(including nine mobile bedside DR sets), and 130 imaging diagnostic workstations for picture\narchiving and communication systems (PACS). Most of the equipment is distributed among\nfour buildings at the hospital main campus. 4 CT scanners, 4 MR scanners, 1 DR are located on\nthe first floor of the first inpatient building, and 9 DR and 8 DSA are located on the second\nfloor. 1 CT and 1 MR scanner are located in the third inpatient building. 1 CT and 1 MR scanner\nare located in the sixth inpatient building. 2 CT scanners, 2 MR scanners and 7 DSA are located\nin the technical building. The rest of the equipment is located in the seventh inpatient building\nin the branch campus.\nThe first inpatient building, located next to the emergency department, was reconfigured to\nhandle cases of COVID-19. Fever tents were set up by the emergency department in the", "emergency department parking lot to separate normal emergency patients from patients with\nsymptoms or exposure history suspicious of COVID-19. We established separate means of\naccess between fever tents and between the fever examination area of the radiology department\nto avoid cross-contamination.\nThe emergency management and infection control measures, as described below and\nimplemented in the radiology department during the outbreak, have been approved by the\n5\ninfection control committee of hospital. These measures are in accordance with relevant laws\nand regulations, in order to protect patients as well as the staff.\nRadiology Emergency Management and Infection Control Team (EMICT)\nThe radiology department director chaired the EMICT. Its members include the deputy\ndirector, chief technologist, head nurse, equipment engineer supervisor, and infection control\nnurse of the radiology department. Team responsibilities included (1) coordination between the", "hospital’s management and planning of infection control and radiology departments; (2)\ncollection of the most up-to-date protection-related information to educate and train staff in the\ndepartment; (3) reallocation of staff according to the actual situation; (4) establishment of the\nCT procedures for patients with COVID-19; and (5) establishment of an emergency\nmanagement plan for the radiology department to ensure that the department would run\nnormally.\nSuspected patients\nThe suspected patients were identified according to the Diagnosis and Treatment Program of\nthe Novel Coronavirus Pneumonia of the NHC [5], mainly based on epidemiological history.\nReconfiguration of the radiology department\nThe radiology department was divided into four areas [6]: contaminated, semicontaminated,\nbuffer, and clean areas (Figure 1). The contaminated area is connected to the fever clinic and\nincludes the fever accessway, the CT examination room, and the DR examination room for\n6", "confirmed and suspected cases. One CT scanner and one DR system closest to the emergency\ndepartment are designated the fever-CT and fever-DR to examine patients with suspected and\nconfirmed COVID-19. There is a separate dedicated access between the contaminated area and\nthe fever screening tents. The semicontaminated area includes the fever-CT control room,\nfever-DR control room, and other patient examination access areas. The buffer zone includes\naccess areas for medical personnel and a dressing area for technologists. The clean area\nincludes the administrative office and the diagnostic room.\nThe contaminated area was isolated from other areas using physical barricades.\nDirectional signs were newly installed to guide patients and staff.\nPersonal protection and training of staff\nFor providing care for patients with confirmed and suspected COVID-19, all hospital staff\nare required to wear complete personal protective equipment [7]: medical protective clothing,", "surgical cap, N95 mask, gloves, face shields, and goggles. Wearing and removing of the\nequipment must be performed in accordance with the procedures and under the supervision of\nthe infection control nurse.\nBecause staff members working in the contaminated area are under much situational\npressure, periodically taking time off could lower their physical and mental stress levels. The\ntechnologists on fever-CT duty shifts are provided a break once a week for four hours. In\naddition, the health of staff in the contaminated area must be monitored closely for the\nsymptoms of COVID-19. Pregnant staff must be assigned to the clean area.\n7\nThe EMICT formulates and continually updates guidelines and educates all staff for West\nChina Hospital of Sichuan University. The EMICT training for staff is mainly involves\ndocuments regarding infection control and CT findings of COVID-19 and maintains an EMICT\nWeChat group for West China Hospital of Sichuan University. WeChat is the most widely used", "social media app in China. The EMICT releases the latest national and hospital-based\ninformation regarding COVID-19, guidance documents, and other notices from the hospital\nand radiology department in the WeChat group on a daily basis. Staff can also report to the\nEMICT in the WeChat group any time. Protocols for each modality and infection control\ninstructions are posted on the walls in all examination rooms. The EMICT periodically reminds\nstaff to undertake personal measures to reduce infection, such as wearing masks at all instances\nin the radiology department and N95 masks if working in the contaminated area; not touching\nthe mask and the eyes; practicing hand hygiene; facing away from colleagues when eating,\ndrinking, and talking; and not using personal cell phones while on duty.\n In addition, the chief thoracic radiologist provided lectures on all radiologists and\ntechnologists on typical CT findings of COVID-19 infection using materials developed in", "Wuhan, the epicenter of the outbreak in China.\nCT examination procedures\nThere are two sets of procedures for CT examination: the fever-CT procedure and routine CT\nprocedure for those not suspected of COVID-19.\nThe fever-CT procedure for suspected or confirmed COVID-19 (Figure 2)\n8\nBefore the fever-CT technologist operates the equipment, he or she should wear personal\nprotective equipment according to three-level protection standard [8]. Before the CT\nexamination of patients with suspected and confirmed COVID-19 begins, the fever tent or\nisolation ward notifies the radiologist in advance. The fever-CT technologist checks the\nequipment and prepares to disinfect the imaging equipment immediately after the examination.\nThe patient enters the fever-CT waiting area through the fever access area. If the patient\ncan get onto and off the examination table by themselves, the patient is allowed to do so. If the", "patient cannot get onto or off the examination table independently, the person accompanying\nthe patient assists the patient, rather than the technologist. The technologist checks the patient\ninformation and, using an intercom system in the examination room, asks the patient to remove\nany metal ornaments on the neck and chest. Also, by intercom, the technologist trains the\npatient to hold his or her breath during the examination.\nThe technologist uses a low-dose chest CT protocol to scan the patient. After scanning, the\noriginal images are reconstructed as 1 mm-thick layers. The technologist browses the images to\nensure that their quality meets the diagnostic requirements and then guides the patient to leave\nthrough the fever access area. The disposable sheets for patient examination are changed after\neach patient. The equipment is disinfected according to the procedure below.\nTo protect themselves, the technologists assigned to the fever-CT wear N95 mask and", "other personal protection as established by the EMICT.\nThe CT procedure for regular patients (figure.3)\n9\nSome patients with COVID-19 have no symptoms, and they may call at the general clinic for\nother reasons. The following CT procedure is applicable under these circumstances:\nWhen the patient makes an appointment for examination, the staff asks the patient about\ntheir epidemiological history, symptoms, and signs. If suspected criteria are met, the patient\nwill be sent to the fever tent for further screening. When a patient presents to the radiology\ndepartment entrance, his/her temperature is measured. If the temperature is higher than 37.2 , ℃\nthe patient is sent to the fever tent for further investigation.\nThose with no exposure history, suspicious symptoms or fever are screened in one of the\nnon-contaminated CT scanners. The technologists assigned to these scanners wear surgical\nmasks. All patients and the person accompanying them are required to wear surgical masks.", "After the CT examination, the technologist browses the images quickly. If the CT appearance is\ntypical of lung infection, the technologist immediately reports it to the chest radiologist on duty\nand asks the patient to wait in the CT examination room. If the chest radiologist does not\nsuspect COVID-19 infection, the patient can leave the CT examination room. If the chest\nradiologist does suspect COVID-19 infection, the technologist immediately reports it to the\nEMICT and sends the patient to the fever tent. The floor and equipment in the CT examination\nroom are disinfected according to regulations, and air disinfection is conducted for 30 min\nbefore examining other patients. These CT scanners are considered noncontaminated (not\nfever-CTs) after these sterilization procedures.\nFever-DR examination procedure\n10\nThe COVID-19 guideline of the NHC does not recommend chest DR because its ability in\ndiagnosing COVID-19 is limited. At our hospital, we only use mobile DR units to provide", "bedside examination for critically ill patients. The technologist operating the mobile DR\nwears personal protective equipment according to the three-level protection standard and\nsterilizes the mobile DR according to the ward management requirements as described below.\nEquipment and environment disinfection procedures\nRoutine disinfection procedure [9]\n1) Object surface disinfection: Object surface is wiped with 1000mg/L chlorine-containing\ndisinfectant, wipe twice with 75% ethanol for non-corrosion resistance, once /4 hours.\n2) Equipment disinfection: The equipment in the contaminated area are wiped with\n2000mg/L chlorine-containing disinfectant. The DR and CT gantry in the contaminated\narea are wiped with 75% ethanol. The equipment in the buffer area is wiped with\n500-1000mg/L chlorine-containing disinfectant or alcohol-containing disposable\ndisinfectant wipes twice a day.\n3) Air disinfection: Turning off all central air conditioners to prevent air contamination with", "each other. Polluted area: open the door for ventilation, each time more than 30 minutes,\nonce /4 hours; The air sterilizer is continuously sterilized or the ultraviolet ray is\ncontinuously used in the unmanned state for 60 minutes, four times a day, remembered to\nclose the inner shielding door when air disinfection. Other ambient air is sprayed with\n1000mg/L chlorine-containing disinfectant and ventilated twice a day\n4) Ground disinfection: The ground is wiped with 1000mg/L chlorine-containing\ndisinfectant, once /4 hours.\n5) When contaminated, disinfect at any time. In case of visible contamination, disposable\nabsorbent materials should be used first to completely remove the pollutants, and then a\ncloth soaked with 2000mg/L chlorine-containing disinfectant should be used for 30\nminutes before wiping.\n11\nFever-CT disinfection procedures after examination\nIn addition to the above, disinfect the examination bed and ground with chlorinated disinfectant\ncontaining 2000mg/L [10].", "Noncontaminated CT disinfection procedures after suspected COVID-19 case examination\nIn addition to the above routine disinfection procedure, air disinfection is conducted for 30 min\nbefore examining other patients.\nResults\nFrom January 21, 2020 when screening for epidemiological history or symptoms\nsuspicious for COVID-19, to March 9, 2020, our hospital screened a total of 7,203 individuals\nand confirmed 24 cases of COVID-19. Of these, 3,083 people underwent fever-CT\nexaminations. Including the initial examination and reexamination, the total number of fever\nCT examination numbered 3,340. The fever-CT scanned a patient approximately every 21.5\nminutes. As a result of our precautions, none of the staff of the radiology department developed\nsymptoms suspicious for COVID-19. The fever-CT technologist, with the highest probability\nof exposure, remains PCR negative.\nDiscussion\nIt has been 17 years since the severe acute respiratory syndrome (SARS) epidemic, the last", "national spread of severe infectious disease, broke out. Currently, the Chinese people are\npanicking again. The speed and extent by which COVID-19 has spread in 2 months are\n12\nunprecedented, beyond those of SARS, and this has been aided by its contagious nature and\nrapid spread via droplets and contact. The droplet mode of transmission means that a person can\nbe infected easily by means of casual contact or even fomites on contaminated environmental\nsurfaces. Another theory has yet to be proved: aerosol propagation.\nHow radiology departments respond to any infectious disease outbreak is determined\nprimarily by the estimated risk of cross-infection to the staff and other patients. Appropriate\nprecautions taken only by staff in direct contact with patients may be adequate when the risk is\nlow. The strongest measures need to be implemented to limit the spread of the disease when the\nrisk is high. With severe infectious diseases such as COVID-19, the highest level of infection", "control measures must be implemented; these include providing adequate standard protective\nequipment, training staff, and instituting proper emergency plans.\nOnce a contagious infectious disease has been identified, the EMICT must consider four\nmain areas of response: data gathering, collaboration, needs assessment, and expert advice [10].\nData gathering includes dissemination of up-to-date case definitions and information about\nconfirmatory tests to all staff with direct patient contact to allow appropriate barrier precautions\nto be taken. All typical and atypical imaging features of the disease should be made known to\nall radiologists to assist in recognition of the disease on images and to allow accurate reporting\nof these findings. We have stored images of all probable cases of COVID-19 in the PACS so\nthat these images were readily available for any radiologist to review, and images from\nprevious imaging studies are also available for comparison.", "Collaboration with the radiology departments of other hospitals is very important because\npatients may initially present to different centers, depending on geographic location and travel\n13\ndistance. These patients may be few in number at a single hospital, but if data from patients at\nseveral hospitals are available, a more accurate overall understanding of both imaging features\nand epidemiology can be achieved. Dissemination of this information to all healthcare facilities\nwill also lead to early recognition of the disease, and appropriate isolation measures may be\ninstituted.\nThe Internet and social media apps, especially WeChat, have been used for distribution of\nmedical information, and because the exchange of information regarding infectious disease\noutbreaks is almost instantaneous, it is an indispensable tool for radiologists. In fact, within a\nmonth of the outbreak, the hospital that received the most infected patients from the source of", "the outbreak made a PowerPoint presentation of the CT manifestations of COVID-19, which\nwas shared via WeChat and disseminated across the country in a very short time. Subsequently,\nCOVID-19-teaching PowerPoint presentations from various hospitals appeared and were\nquickly shared via WeChat.\nOur diagnostic process is limited as chest CT along is not diagnostic of COVID-19\nbecause of lack of imaging specificity. But when combined with other epidemiological,\nclinical, laboratory and virus nucleic acid information, typical chest CT imaging findings are\nhelpful for making the diagnosis. In our opinion, the major role of chest CT is to understand the\nextent and dynamic evolution of lung lesions induced by COVID-19. The reasons why we\nadopted the low-dose chest CT scan protocol are as follows: low-dose chest CT has been\nwidely used in the screening of early lung cancer. It is well known that many early lung cancers", "are ground-glass opacities (GGO), so we believe that low-dose screening is also applicable for\nCOVID-19. In addition, considering the rapid development of COVID-19, many CT\n14\nexaminations may be conducted in the same individual to monitor disease progress. Low-dose\nscanning can reduce the radiation damage to patients.\nAlthough the processes we established minimized the exposure of hospital staff, ancillary\npersonnel and other patients, it remains limited as follows. Sichuan province is not the center of\nthe epidemic. The number of patients with COVID-19 whom we have treated has not been\nhigh, and most cases are from other provinces of China. However, we believe that our\nexperience in management, the reconfiguration of our radiology department, and the workflow\nchanges implemented in the current COVID-19 situation are useful for other radiology\ndepartments that must prepare for dealing with patients with COVID-19. While no radiology", "personnel developed symptoms suspicious for or were confirmed as having COVID-19, there\nmay be asymptomatic personnel.\nREFERENCES\n1. National Health Commission of the People’s Republic of China.(2020). March 12: Daily briefing\non novel coronavirus cases in China. Retrieved from\nhttp://en.nhc.gov.cn/2020-03/12/c_77618.htm. Accessed March 11, 2020.\n2. World Health Organization. (2020). Coronavirus disease 2019 (COVID-19) Situation Report-52.\nRetrieved from\nhttps://www.who.int/docs/default-source/coronaviruse/20200312-sitrep-52-covid-19.pdf?sfvrsn=e\n2bfc9c0_2 9. Accessed March 11, 2020.\n3. National Health Commission of the People’s Republic of China.(2020). Latest developments in\nepidemic control on Feb 15. Retrieved from http://en.nhc.gov.cn/2020-02/16/c_76622. Accessed\nMarch 11, 2020.\n15\n4. Health Commission of the People’s Republic of China.(2020). The notification of the trial\noperation based on the guideline version 6 in the coronavirus disease diagnosis and treatment.", "Retrieved from\nhttp://www.nhc.gov.cn/xcs/zhengcwj/202002/8334a8326dd94d329df351d7da8aefc2.shtml.\nAccessed March 11, 2020\n5. Health Commission of the People’s Republic of China.(2020). The notification of the trial\noperation based on the guideline version 6 in the coronavirus disease diagnosis and treatment.\nRetrieved from\nhttp://www.nhc.gov.cn/xcs/zhengcwj/202002/8334a8326dd94d329df351d7da8aefc2.shtml.\nAccessed March 11, 2020.\n6. Health Commission of the People’s Republic of China.(2009). The guideline for pathogens\nisolated operations in hospital. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/200904/40116.shtml. Accessed March 11, 2020.\n7. Health Commission of the People’s Republic of China.(2017). The guideline for prevention and\ncontrol of hospital acquired infections of airborne pathogens. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201701/7e0e8fc6725843aabba8f841f2f585d2.shtml. Accessed\nMarch 11, 2020.", "8. Health Commission of the People’s Republic of China.(2017). The guideline for prevention and\ncontrol of hospital acquired infections of airborne pathogens. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201701/7e0e8fc6725843aabba8f841f2f585d2.shtml. Accessed\nMarch 11, 2020.\n9. Health Commission of the People’s Republic of China.(2012). The standardization for\nsterilization techniques in hospital. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201204/54510.shtml. Accessed March 11, 2020.\n10. Health Commission of the People’s Republic of China.(2012). The standardization for\nsterilization techniques in hospital. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201204/54510.shtml. Accessed March 11, 2020.\n11. Katona P. Bioterrorism Preparedness: Generic Blueprint for Health Departments, Hospitals, and\nPhysicians. Infectious Diseases in Clinical Practice. 2002;11(3):115-122. Accessed March 11,\n2020.\n16\nFigure Legends", "Figure 1. Diagram of the layout of our radiology department was divided into four areas: contaminated\n(shaded in black), semicontaminated (shaded in dark gray), buffer (shaded in light gray), and clean areas\n(shaded in white). The contaminated area was separated from other areas by barriers.\nFigure 2. Diagram shows CT protocol for suspected and confirmed patients with COVID-19.\nFigure 3. Diagram shows CT protocol for regular patients.\nAbbreviations:\nCOVID-19: coronavirus disease 2019\nCT: computed tomography\nDR: digital radiography\nEMICT: emergency management and infection control team\nNHC: National Health Commission\nPACS: picture archiving and communication system\nSARS: severe acute respiratory syndrome", "Sentence Summary\nWith severe infectious diseases such as COVID-19, the highest level of infection control\nmeasures must be implemented, collaboration with the radiology departments of other\nhospitals be needed, and social media be employed.\nTake-home points\n1. To response to a community infection emergency, a special emergency management team\nneeds to be setup at the departmental level to implement infection containment and\ncontrol procedures that continues to allow the imaging examination and imaging\ndiagnosis of those with suspected infection, and to prevent intra-departmental spreading\nof infection (EMICT).\n2. Infection control measures, such as reconfiguration of department areas, personal\nprotection and anti-infection training of all staff, standardized procedures including\ncontact minimization for chest CT and DR examinations, and timely disinfection of CT\nand DR examination rooms, should be implemented properly.", "3. If there are more than one scanner in a hospital, only one of them should be assigned to\nsuspected cases." ]	[ 12 ]	3,975	6,764
188	What does the semicontaminated area include?	2,451	[ "the fever-CT control room,\nfever-DR control room, and other patient examination access areas." ]	[ "The Battle Against Coronavirus Disease 2019 (COVID-19): Emergency Management\nand Infection Control in a Radiology Department\nhttps://www.jacr.org/article/S1546-1440(20)30285-4/pdf\nJournal Pre-proof\nZixing Huang, Shuang Zhao, Zhenlin Li, Weixia Chen, Lihong Zhao, Lipeng Deng, Bin\nSong\nPII: S1546-1440(20)30285-4\nDOI: https://doi.org/10.1016/j.jacr.2020.03.011\nReference: JACR 5139\nTo appear in: Journal of the American College of Radiology\nReceived Date: 24 February 2020\nRevised Date: 13 March 2020\nAccepted Date: 15 March 2020\nPlease cite this article as: Huang Z, Zhao S, Li Z, Chen W, Zhao L, Deng L, Song B, The Battle Against\nCoronavirus Disease 2019 (COVID-19): Emergency Management and Infection Control in a Radiology\nDepartment, Journal of the American College of Radiology (2020), doi: https://doi.org/10.1016/\nj.jacr.2020.03.011.\nThis is a PDF file of an article that has undergone enhancements after acceptance, such as the addition", "of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of\nrecord. This version will undergo additional copyediting, typesetting and review before it is published\nin its final form, but we are providing this version to give early visibility of the article. Please note that,\nduring the production process, errors may be discovered which could affect the content, and all legal\ndisclaimers that apply to the journal pertain.\n© 2020 Published by Elsevier Inc. on behalf of American College of Radiology\nThe Battle Against Coronavirus Disease 2019 (COVID-19): Emergency Management\nand Infection Control in a Radiology Department\nZixing Huang, Shuang Zhao, Zhenlin Li, Weixia Chen, Lihong Zhao, Lipeng Deng,\nBin Song\nDepartment of Radiology, West China Hospital, Sichuan University, Chengdu, China\n*Zixing Huang and Shuang Zhao contributed equally to this work as co-first author.\nCorresponding Author: Bin Song, MD", "Address: Department of Radiology, West China Hospital, Sichuan University.\nNo. 37, GUOXUE Alley, Chengdu, 610041, China\nTel.: (+86)28 85423680, Fax: (+86)28 85582944\nEmail: [email protected].\nAuthors’ contributions\nZXH: conceived the study and drafted the manuscript.\nZS: conceived the study and drafted the manuscript.\nZLL: The member of the emergency management and infection control team (EMICT)\nand was involved in the formulation of the measures.\nWXC: The member of the EMICT and was involved in the formulation of the\nmeasures.\nLHZ: The member of the EMICT and was involved in the formulation of the\nmeasures.\nLPD: The member of the EMICT and was involved in the formulation of the\nmeasures.\nBS: Leader of the EMICT, conceived the study and reviewed the manuscript.\nAll authors read and approved the final manuscript.\nThe authors declare no conflict of interest.\nThe authors declare that they had full access to all of the data in this study and the", "authors take complete responsibility for the integrity of the data and the accuracy of\nthe data analysis\n1\nThe Battle Against Novel Coronavirus Pneumonia (COVID-19): Emergency\nManagement and Infection Control in a Radiology Department\nAbstract\nObjective: To describe the strategy and the emergency management and infection control\nprocedure of our radiology department during the COVID-19 outbreak.\nMethods: We set up emergency management and sensing control teams. The team formulated\nvarious measures: reconfiguration of the radiology department, personal protection and training\nof staff, examination procedures for patients suspected of or confirmed with COVID-19 as well\nas patients without an exposure history or symptoms. Those with suspected or confirmed\nCOVID-19 infection were scanned in the designated fever-CT unit.\nResults: From January 21, 2020 to March 9, 2020, 3,083 people suspected of or confirmed with\nCOVID-19 underwent fever-CT examinations. Including initial examinations and", "reexaminations, the total number of fever-CT examinations numbered 3,340. As a result of our\nprecautions, none of the staff of the radiology department were infected with COVID-19.\nConclusion: Strategic planning and adequate protections can help protect patients and staff\nagainst a highly infectious disease while maintaining function at a high volume capacity.\nKeywords: Coronavirus, COVID-19, novel coronavirus pneumonia, infection control", "2\nIntroduction\nThe whole world has been closely focusing on an outbreak of respiratory disease caused by a\nnovel coronavirus that was first reported in Wuhan, China, on December 31, 2019, and that\ncontinues to spread. On February 11, 2020, the World Health Organization (WHO) named the\ndisease “coronavirus disease 2019” (COVID-19).\nAs of 24:00 on March 11, 2020, the National Health Commission (NHC) had received reports\nof 80,793 confirmed cases and 3,169 deaths on the Chinese mainland. There remain 14,831\nconfirmed cases (including 4,257 in serious condition) and 253 suspected cases still\nhospitalized. To date, 677,243 people have been identified as having had close contact with\ninfected patients of whom13,701 are under medical observation [1]. Outside China, 44,067\nlaboratory-confirmed cases and 1,440 deaths have occurred in 117 countries /territories/areas\naccording to the WHO [2]. COVID-19 poses significant threats to international health. Like the", "flu, COVID-19 is thought to spread mainly from person-to-person between people who are in\nclose contact with one another through respiratory droplets produced when an infected person\ncoughs or sneezes. In light of the infectious nature of this disease, healthcare workers are at\nhigh risk of infection of COVID-19. In China, healthcare workers account for 1,716 confirmed\ncases of COVID-19, including six deaths [3].\n Computed tomography (CT) can play a role in both diagnosing and categorizing\nCOVID-19 on the basis of case definitions issued by the WHO and the treatment guidelines\nfrom the NHC [4]. Suspected patients having the virus may undergo chest CT. Isolation and\nbarrier procedures are necessary to protect both the department staff and other patients in the\nhospital. Note should be made that due to overlap of imaging findings with other respiratory\n3\ndiseases, CT is not helpful as a screening tool. But it can help identify the degree of pulmonary\ninvolvement and disease course.", "Our hospital is a national regional medical center with 4,300 beds and a tertiary referral\ncenter in Sichuan province. The initial response started on January 21, 2020, after transmission\nof COVID-19 was confirmed to be human-to-human on January 20, 2020. The first suspected\ncase of COVID-19 in Sichuan province was reported on January 21, 2020. The Sichuan\nprovincial government immediately launched the first-level response to major public health\nemergencies. On the same day, our hospital was designated to care for Sichuan province\npatients with COVID-19.\nThis article describes the emergency management procedure of our radiology department\nfor situations involving severe infectious diseases, such as COVID-19, and the\ninfection-protection experience of the department staff.\nMethods\nThe hospital provided personal protective equipment (medical protective clothing,\nsurgical cap, N95 mask, gloves, face shields, and goggles) to all its healthcare staff, erected", "three medical tents (fever tents) for screening of fever cases in the parking lot of the emergency\ndepartment, planned an examination route and examination area for patients suspected of\nharboring the virus, and placed confirmed patients in an isolation ward. “Fever” was the\ncolloquial term used to designate suspected COVID-19 based on symptoms such as a fever or\nwith an epidemiological history of a potential exposure as well as those with confirmed\nCOVID-19 referred for treatment. Further, during outbreak, emergency and outpatient patients\n4\nwithout fever were asked for information such as epidemiological history and sent to fever tents\nas long as they met suspected criteria.\nThe radiology department has 65 diagnostic radiologists and 161 other staff members\n(trained technologists, nurses, engineers, and support staff). The equipment of the radiology\ndepartment includes 12 magnetic resonance (MR) scanners, 14 CT scanners, 15 digital", "subtraction angiography (DSA) systems, 32 sets of digital radiography (DR) systems\n(including nine mobile bedside DR sets), and 130 imaging diagnostic workstations for picture\narchiving and communication systems (PACS). Most of the equipment is distributed among\nfour buildings at the hospital main campus. 4 CT scanners, 4 MR scanners, 1 DR are located on\nthe first floor of the first inpatient building, and 9 DR and 8 DSA are located on the second\nfloor. 1 CT and 1 MR scanner are located in the third inpatient building. 1 CT and 1 MR scanner\nare located in the sixth inpatient building. 2 CT scanners, 2 MR scanners and 7 DSA are located\nin the technical building. The rest of the equipment is located in the seventh inpatient building\nin the branch campus.\nThe first inpatient building, located next to the emergency department, was reconfigured to\nhandle cases of COVID-19. Fever tents were set up by the emergency department in the", "emergency department parking lot to separate normal emergency patients from patients with\nsymptoms or exposure history suspicious of COVID-19. We established separate means of\naccess between fever tents and between the fever examination area of the radiology department\nto avoid cross-contamination.\nThe emergency management and infection control measures, as described below and\nimplemented in the radiology department during the outbreak, have been approved by the\n5\ninfection control committee of hospital. These measures are in accordance with relevant laws\nand regulations, in order to protect patients as well as the staff.\nRadiology Emergency Management and Infection Control Team (EMICT)\nThe radiology department director chaired the EMICT. Its members include the deputy\ndirector, chief technologist, head nurse, equipment engineer supervisor, and infection control\nnurse of the radiology department. Team responsibilities included (1) coordination between the", "hospital’s management and planning of infection control and radiology departments; (2)\ncollection of the most up-to-date protection-related information to educate and train staff in the\ndepartment; (3) reallocation of staff according to the actual situation; (4) establishment of the\nCT procedures for patients with COVID-19; and (5) establishment of an emergency\nmanagement plan for the radiology department to ensure that the department would run\nnormally.\nSuspected patients\nThe suspected patients were identified according to the Diagnosis and Treatment Program of\nthe Novel Coronavirus Pneumonia of the NHC [5], mainly based on epidemiological history.\nReconfiguration of the radiology department\nThe radiology department was divided into four areas [6]: contaminated, semicontaminated,\nbuffer, and clean areas (Figure 1). The contaminated area is connected to the fever clinic and\nincludes the fever accessway, the CT examination room, and the DR examination room for\n6", "confirmed and suspected cases. One CT scanner and one DR system closest to the emergency\ndepartment are designated the fever-CT and fever-DR to examine patients with suspected and\nconfirmed COVID-19. There is a separate dedicated access between the contaminated area and\nthe fever screening tents. The semicontaminated area includes the fever-CT control room,\nfever-DR control room, and other patient examination access areas. The buffer zone includes\naccess areas for medical personnel and a dressing area for technologists. The clean area\nincludes the administrative office and the diagnostic room.\nThe contaminated area was isolated from other areas using physical barricades.\nDirectional signs were newly installed to guide patients and staff.\nPersonal protection and training of staff\nFor providing care for patients with confirmed and suspected COVID-19, all hospital staff\nare required to wear complete personal protective equipment [7]: medical protective clothing,", "surgical cap, N95 mask, gloves, face shields, and goggles. Wearing and removing of the\nequipment must be performed in accordance with the procedures and under the supervision of\nthe infection control nurse.\nBecause staff members working in the contaminated area are under much situational\npressure, periodically taking time off could lower their physical and mental stress levels. The\ntechnologists on fever-CT duty shifts are provided a break once a week for four hours. In\naddition, the health of staff in the contaminated area must be monitored closely for the\nsymptoms of COVID-19. Pregnant staff must be assigned to the clean area.\n7\nThe EMICT formulates and continually updates guidelines and educates all staff for West\nChina Hospital of Sichuan University. The EMICT training for staff is mainly involves\ndocuments regarding infection control and CT findings of COVID-19 and maintains an EMICT\nWeChat group for West China Hospital of Sichuan University. WeChat is the most widely used", "social media app in China. The EMICT releases the latest national and hospital-based\ninformation regarding COVID-19, guidance documents, and other notices from the hospital\nand radiology department in the WeChat group on a daily basis. Staff can also report to the\nEMICT in the WeChat group any time. Protocols for each modality and infection control\ninstructions are posted on the walls in all examination rooms. The EMICT periodically reminds\nstaff to undertake personal measures to reduce infection, such as wearing masks at all instances\nin the radiology department and N95 masks if working in the contaminated area; not touching\nthe mask and the eyes; practicing hand hygiene; facing away from colleagues when eating,\ndrinking, and talking; and not using personal cell phones while on duty.\n In addition, the chief thoracic radiologist provided lectures on all radiologists and\ntechnologists on typical CT findings of COVID-19 infection using materials developed in", "Wuhan, the epicenter of the outbreak in China.\nCT examination procedures\nThere are two sets of procedures for CT examination: the fever-CT procedure and routine CT\nprocedure for those not suspected of COVID-19.\nThe fever-CT procedure for suspected or confirmed COVID-19 (Figure 2)\n8\nBefore the fever-CT technologist operates the equipment, he or she should wear personal\nprotective equipment according to three-level protection standard [8]. Before the CT\nexamination of patients with suspected and confirmed COVID-19 begins, the fever tent or\nisolation ward notifies the radiologist in advance. The fever-CT technologist checks the\nequipment and prepares to disinfect the imaging equipment immediately after the examination.\nThe patient enters the fever-CT waiting area through the fever access area. If the patient\ncan get onto and off the examination table by themselves, the patient is allowed to do so. If the", "patient cannot get onto or off the examination table independently, the person accompanying\nthe patient assists the patient, rather than the technologist. The technologist checks the patient\ninformation and, using an intercom system in the examination room, asks the patient to remove\nany metal ornaments on the neck and chest. Also, by intercom, the technologist trains the\npatient to hold his or her breath during the examination.\nThe technologist uses a low-dose chest CT protocol to scan the patient. After scanning, the\noriginal images are reconstructed as 1 mm-thick layers. The technologist browses the images to\nensure that their quality meets the diagnostic requirements and then guides the patient to leave\nthrough the fever access area. The disposable sheets for patient examination are changed after\neach patient. The equipment is disinfected according to the procedure below.\nTo protect themselves, the technologists assigned to the fever-CT wear N95 mask and", "other personal protection as established by the EMICT.\nThe CT procedure for regular patients (figure.3)\n9\nSome patients with COVID-19 have no symptoms, and they may call at the general clinic for\nother reasons. The following CT procedure is applicable under these circumstances:\nWhen the patient makes an appointment for examination, the staff asks the patient about\ntheir epidemiological history, symptoms, and signs. If suspected criteria are met, the patient\nwill be sent to the fever tent for further screening. When a patient presents to the radiology\ndepartment entrance, his/her temperature is measured. If the temperature is higher than 37.2 , ℃\nthe patient is sent to the fever tent for further investigation.\nThose with no exposure history, suspicious symptoms or fever are screened in one of the\nnon-contaminated CT scanners. The technologists assigned to these scanners wear surgical\nmasks. All patients and the person accompanying them are required to wear surgical masks.", "After the CT examination, the technologist browses the images quickly. If the CT appearance is\ntypical of lung infection, the technologist immediately reports it to the chest radiologist on duty\nand asks the patient to wait in the CT examination room. If the chest radiologist does not\nsuspect COVID-19 infection, the patient can leave the CT examination room. If the chest\nradiologist does suspect COVID-19 infection, the technologist immediately reports it to the\nEMICT and sends the patient to the fever tent. The floor and equipment in the CT examination\nroom are disinfected according to regulations, and air disinfection is conducted for 30 min\nbefore examining other patients. These CT scanners are considered noncontaminated (not\nfever-CTs) after these sterilization procedures.\nFever-DR examination procedure\n10\nThe COVID-19 guideline of the NHC does not recommend chest DR because its ability in\ndiagnosing COVID-19 is limited. At our hospital, we only use mobile DR units to provide", "bedside examination for critically ill patients. The technologist operating the mobile DR\nwears personal protective equipment according to the three-level protection standard and\nsterilizes the mobile DR according to the ward management requirements as described below.\nEquipment and environment disinfection procedures\nRoutine disinfection procedure [9]\n1) Object surface disinfection: Object surface is wiped with 1000mg/L chlorine-containing\ndisinfectant, wipe twice with 75% ethanol for non-corrosion resistance, once /4 hours.\n2) Equipment disinfection: The equipment in the contaminated area are wiped with\n2000mg/L chlorine-containing disinfectant. The DR and CT gantry in the contaminated\narea are wiped with 75% ethanol. The equipment in the buffer area is wiped with\n500-1000mg/L chlorine-containing disinfectant or alcohol-containing disposable\ndisinfectant wipes twice a day.\n3) Air disinfection: Turning off all central air conditioners to prevent air contamination with", "each other. Polluted area: open the door for ventilation, each time more than 30 minutes,\nonce /4 hours; The air sterilizer is continuously sterilized or the ultraviolet ray is\ncontinuously used in the unmanned state for 60 minutes, four times a day, remembered to\nclose the inner shielding door when air disinfection. Other ambient air is sprayed with\n1000mg/L chlorine-containing disinfectant and ventilated twice a day\n4) Ground disinfection: The ground is wiped with 1000mg/L chlorine-containing\ndisinfectant, once /4 hours.\n5) When contaminated, disinfect at any time. In case of visible contamination, disposable\nabsorbent materials should be used first to completely remove the pollutants, and then a\ncloth soaked with 2000mg/L chlorine-containing disinfectant should be used for 30\nminutes before wiping.\n11\nFever-CT disinfection procedures after examination\nIn addition to the above, disinfect the examination bed and ground with chlorinated disinfectant\ncontaining 2000mg/L [10].", "Noncontaminated CT disinfection procedures after suspected COVID-19 case examination\nIn addition to the above routine disinfection procedure, air disinfection is conducted for 30 min\nbefore examining other patients.\nResults\nFrom January 21, 2020 when screening for epidemiological history or symptoms\nsuspicious for COVID-19, to March 9, 2020, our hospital screened a total of 7,203 individuals\nand confirmed 24 cases of COVID-19. Of these, 3,083 people underwent fever-CT\nexaminations. Including the initial examination and reexamination, the total number of fever\nCT examination numbered 3,340. The fever-CT scanned a patient approximately every 21.5\nminutes. As a result of our precautions, none of the staff of the radiology department developed\nsymptoms suspicious for COVID-19. The fever-CT technologist, with the highest probability\nof exposure, remains PCR negative.\nDiscussion\nIt has been 17 years since the severe acute respiratory syndrome (SARS) epidemic, the last", "national spread of severe infectious disease, broke out. Currently, the Chinese people are\npanicking again. The speed and extent by which COVID-19 has spread in 2 months are\n12\nunprecedented, beyond those of SARS, and this has been aided by its contagious nature and\nrapid spread via droplets and contact. The droplet mode of transmission means that a person can\nbe infected easily by means of casual contact or even fomites on contaminated environmental\nsurfaces. Another theory has yet to be proved: aerosol propagation.\nHow radiology departments respond to any infectious disease outbreak is determined\nprimarily by the estimated risk of cross-infection to the staff and other patients. Appropriate\nprecautions taken only by staff in direct contact with patients may be adequate when the risk is\nlow. The strongest measures need to be implemented to limit the spread of the disease when the\nrisk is high. With severe infectious diseases such as COVID-19, the highest level of infection", "control measures must be implemented; these include providing adequate standard protective\nequipment, training staff, and instituting proper emergency plans.\nOnce a contagious infectious disease has been identified, the EMICT must consider four\nmain areas of response: data gathering, collaboration, needs assessment, and expert advice [10].\nData gathering includes dissemination of up-to-date case definitions and information about\nconfirmatory tests to all staff with direct patient contact to allow appropriate barrier precautions\nto be taken. All typical and atypical imaging features of the disease should be made known to\nall radiologists to assist in recognition of the disease on images and to allow accurate reporting\nof these findings. We have stored images of all probable cases of COVID-19 in the PACS so\nthat these images were readily available for any radiologist to review, and images from\nprevious imaging studies are also available for comparison.", "Collaboration with the radiology departments of other hospitals is very important because\npatients may initially present to different centers, depending on geographic location and travel\n13\ndistance. These patients may be few in number at a single hospital, but if data from patients at\nseveral hospitals are available, a more accurate overall understanding of both imaging features\nand epidemiology can be achieved. Dissemination of this information to all healthcare facilities\nwill also lead to early recognition of the disease, and appropriate isolation measures may be\ninstituted.\nThe Internet and social media apps, especially WeChat, have been used for distribution of\nmedical information, and because the exchange of information regarding infectious disease\noutbreaks is almost instantaneous, it is an indispensable tool for radiologists. In fact, within a\nmonth of the outbreak, the hospital that received the most infected patients from the source of", "the outbreak made a PowerPoint presentation of the CT manifestations of COVID-19, which\nwas shared via WeChat and disseminated across the country in a very short time. Subsequently,\nCOVID-19-teaching PowerPoint presentations from various hospitals appeared and were\nquickly shared via WeChat.\nOur diagnostic process is limited as chest CT along is not diagnostic of COVID-19\nbecause of lack of imaging specificity. But when combined with other epidemiological,\nclinical, laboratory and virus nucleic acid information, typical chest CT imaging findings are\nhelpful for making the diagnosis. In our opinion, the major role of chest CT is to understand the\nextent and dynamic evolution of lung lesions induced by COVID-19. The reasons why we\nadopted the low-dose chest CT scan protocol are as follows: low-dose chest CT has been\nwidely used in the screening of early lung cancer. It is well known that many early lung cancers", "are ground-glass opacities (GGO), so we believe that low-dose screening is also applicable for\nCOVID-19. In addition, considering the rapid development of COVID-19, many CT\n14\nexaminations may be conducted in the same individual to monitor disease progress. Low-dose\nscanning can reduce the radiation damage to patients.\nAlthough the processes we established minimized the exposure of hospital staff, ancillary\npersonnel and other patients, it remains limited as follows. Sichuan province is not the center of\nthe epidemic. The number of patients with COVID-19 whom we have treated has not been\nhigh, and most cases are from other provinces of China. However, we believe that our\nexperience in management, the reconfiguration of our radiology department, and the workflow\nchanges implemented in the current COVID-19 situation are useful for other radiology\ndepartments that must prepare for dealing with patients with COVID-19. While no radiology", "personnel developed symptoms suspicious for or were confirmed as having COVID-19, there\nmay be asymptomatic personnel.\nREFERENCES\n1. National Health Commission of the People’s Republic of China.(2020). March 12: Daily briefing\non novel coronavirus cases in China. Retrieved from\nhttp://en.nhc.gov.cn/2020-03/12/c_77618.htm. Accessed March 11, 2020.\n2. World Health Organization. (2020). Coronavirus disease 2019 (COVID-19) Situation Report-52.\nRetrieved from\nhttps://www.who.int/docs/default-source/coronaviruse/20200312-sitrep-52-covid-19.pdf?sfvrsn=e\n2bfc9c0_2 9. Accessed March 11, 2020.\n3. National Health Commission of the People’s Republic of China.(2020). Latest developments in\nepidemic control on Feb 15. Retrieved from http://en.nhc.gov.cn/2020-02/16/c_76622. Accessed\nMarch 11, 2020.\n15\n4. Health Commission of the People’s Republic of China.(2020). The notification of the trial\noperation based on the guideline version 6 in the coronavirus disease diagnosis and treatment.", "Retrieved from\nhttp://www.nhc.gov.cn/xcs/zhengcwj/202002/8334a8326dd94d329df351d7da8aefc2.shtml.\nAccessed March 11, 2020\n5. Health Commission of the People’s Republic of China.(2020). The notification of the trial\noperation based on the guideline version 6 in the coronavirus disease diagnosis and treatment.\nRetrieved from\nhttp://www.nhc.gov.cn/xcs/zhengcwj/202002/8334a8326dd94d329df351d7da8aefc2.shtml.\nAccessed March 11, 2020.\n6. Health Commission of the People’s Republic of China.(2009). The guideline for pathogens\nisolated operations in hospital. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/200904/40116.shtml. Accessed March 11, 2020.\n7. Health Commission of the People’s Republic of China.(2017). The guideline for prevention and\ncontrol of hospital acquired infections of airborne pathogens. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201701/7e0e8fc6725843aabba8f841f2f585d2.shtml. Accessed\nMarch 11, 2020.", "8. Health Commission of the People’s Republic of China.(2017). The guideline for prevention and\ncontrol of hospital acquired infections of airborne pathogens. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201701/7e0e8fc6725843aabba8f841f2f585d2.shtml. Accessed\nMarch 11, 2020.\n9. Health Commission of the People’s Republic of China.(2012). The standardization for\nsterilization techniques in hospital. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201204/54510.shtml. Accessed March 11, 2020.\n10. Health Commission of the People’s Republic of China.(2012). The standardization for\nsterilization techniques in hospital. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201204/54510.shtml. Accessed March 11, 2020.\n11. Katona P. Bioterrorism Preparedness: Generic Blueprint for Health Departments, Hospitals, and\nPhysicians. Infectious Diseases in Clinical Practice. 2002;11(3):115-122. Accessed March 11,\n2020.\n16\nFigure Legends", "Figure 1. Diagram of the layout of our radiology department was divided into four areas: contaminated\n(shaded in black), semicontaminated (shaded in dark gray), buffer (shaded in light gray), and clean areas\n(shaded in white). The contaminated area was separated from other areas by barriers.\nFigure 2. Diagram shows CT protocol for suspected and confirmed patients with COVID-19.\nFigure 3. Diagram shows CT protocol for regular patients.\nAbbreviations:\nCOVID-19: coronavirus disease 2019\nCT: computed tomography\nDR: digital radiography\nEMICT: emergency management and infection control team\nNHC: National Health Commission\nPACS: picture archiving and communication system\nSARS: severe acute respiratory syndrome", "Sentence Summary\nWith severe infectious diseases such as COVID-19, the highest level of infection control\nmeasures must be implemented, collaboration with the radiology departments of other\nhospitals be needed, and social media be employed.\nTake-home points\n1. To response to a community infection emergency, a special emergency management team\nneeds to be setup at the departmental level to implement infection containment and\ncontrol procedures that continues to allow the imaging examination and imaging\ndiagnosis of those with suspected infection, and to prevent intra-departmental spreading\nof infection (EMICT).\n2. Infection control measures, such as reconfiguration of department areas, personal\nprotection and anti-infection training of all staff, standardized procedures including\ncontact minimization for chest CT and DR examinations, and timely disinfection of CT\nand DR examination rooms, should be implemented properly.", "3. If there are more than one scanner in a hospital, only one of them should be assigned to\nsuspected cases." ]	[ 12 ]	3,975	6,764
188	What does the buffer area include?	2,452	[ "access areas for medical personnel and a dressing area for technologists." ]	[ "The Battle Against Coronavirus Disease 2019 (COVID-19): Emergency Management\nand Infection Control in a Radiology Department\nhttps://www.jacr.org/article/S1546-1440(20)30285-4/pdf\nJournal Pre-proof\nZixing Huang, Shuang Zhao, Zhenlin Li, Weixia Chen, Lihong Zhao, Lipeng Deng, Bin\nSong\nPII: S1546-1440(20)30285-4\nDOI: https://doi.org/10.1016/j.jacr.2020.03.011\nReference: JACR 5139\nTo appear in: Journal of the American College of Radiology\nReceived Date: 24 February 2020\nRevised Date: 13 March 2020\nAccepted Date: 15 March 2020\nPlease cite this article as: Huang Z, Zhao S, Li Z, Chen W, Zhao L, Deng L, Song B, The Battle Against\nCoronavirus Disease 2019 (COVID-19): Emergency Management and Infection Control in a Radiology\nDepartment, Journal of the American College of Radiology (2020), doi: https://doi.org/10.1016/\nj.jacr.2020.03.011.\nThis is a PDF file of an article that has undergone enhancements after acceptance, such as the addition", "of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of\nrecord. This version will undergo additional copyediting, typesetting and review before it is published\nin its final form, but we are providing this version to give early visibility of the article. Please note that,\nduring the production process, errors may be discovered which could affect the content, and all legal\ndisclaimers that apply to the journal pertain.\n© 2020 Published by Elsevier Inc. on behalf of American College of Radiology\nThe Battle Against Coronavirus Disease 2019 (COVID-19): Emergency Management\nand Infection Control in a Radiology Department\nZixing Huang, Shuang Zhao, Zhenlin Li, Weixia Chen, Lihong Zhao, Lipeng Deng,\nBin Song\nDepartment of Radiology, West China Hospital, Sichuan University, Chengdu, China\n*Zixing Huang and Shuang Zhao contributed equally to this work as co-first author.\nCorresponding Author: Bin Song, MD", "Address: Department of Radiology, West China Hospital, Sichuan University.\nNo. 37, GUOXUE Alley, Chengdu, 610041, China\nTel.: (+86)28 85423680, Fax: (+86)28 85582944\nEmail: [email protected].\nAuthors’ contributions\nZXH: conceived the study and drafted the manuscript.\nZS: conceived the study and drafted the manuscript.\nZLL: The member of the emergency management and infection control team (EMICT)\nand was involved in the formulation of the measures.\nWXC: The member of the EMICT and was involved in the formulation of the\nmeasures.\nLHZ: The member of the EMICT and was involved in the formulation of the\nmeasures.\nLPD: The member of the EMICT and was involved in the formulation of the\nmeasures.\nBS: Leader of the EMICT, conceived the study and reviewed the manuscript.\nAll authors read and approved the final manuscript.\nThe authors declare no conflict of interest.\nThe authors declare that they had full access to all of the data in this study and the", "authors take complete responsibility for the integrity of the data and the accuracy of\nthe data analysis\n1\nThe Battle Against Novel Coronavirus Pneumonia (COVID-19): Emergency\nManagement and Infection Control in a Radiology Department\nAbstract\nObjective: To describe the strategy and the emergency management and infection control\nprocedure of our radiology department during the COVID-19 outbreak.\nMethods: We set up emergency management and sensing control teams. The team formulated\nvarious measures: reconfiguration of the radiology department, personal protection and training\nof staff, examination procedures for patients suspected of or confirmed with COVID-19 as well\nas patients without an exposure history or symptoms. Those with suspected or confirmed\nCOVID-19 infection were scanned in the designated fever-CT unit.\nResults: From January 21, 2020 to March 9, 2020, 3,083 people suspected of or confirmed with\nCOVID-19 underwent fever-CT examinations. Including initial examinations and", "reexaminations, the total number of fever-CT examinations numbered 3,340. As a result of our\nprecautions, none of the staff of the radiology department were infected with COVID-19.\nConclusion: Strategic planning and adequate protections can help protect patients and staff\nagainst a highly infectious disease while maintaining function at a high volume capacity.\nKeywords: Coronavirus, COVID-19, novel coronavirus pneumonia, infection control", "2\nIntroduction\nThe whole world has been closely focusing on an outbreak of respiratory disease caused by a\nnovel coronavirus that was first reported in Wuhan, China, on December 31, 2019, and that\ncontinues to spread. On February 11, 2020, the World Health Organization (WHO) named the\ndisease “coronavirus disease 2019” (COVID-19).\nAs of 24:00 on March 11, 2020, the National Health Commission (NHC) had received reports\nof 80,793 confirmed cases and 3,169 deaths on the Chinese mainland. There remain 14,831\nconfirmed cases (including 4,257 in serious condition) and 253 suspected cases still\nhospitalized. To date, 677,243 people have been identified as having had close contact with\ninfected patients of whom13,701 are under medical observation [1]. Outside China, 44,067\nlaboratory-confirmed cases and 1,440 deaths have occurred in 117 countries /territories/areas\naccording to the WHO [2]. COVID-19 poses significant threats to international health. Like the", "flu, COVID-19 is thought to spread mainly from person-to-person between people who are in\nclose contact with one another through respiratory droplets produced when an infected person\ncoughs or sneezes. In light of the infectious nature of this disease, healthcare workers are at\nhigh risk of infection of COVID-19. In China, healthcare workers account for 1,716 confirmed\ncases of COVID-19, including six deaths [3].\n Computed tomography (CT) can play a role in both diagnosing and categorizing\nCOVID-19 on the basis of case definitions issued by the WHO and the treatment guidelines\nfrom the NHC [4]. Suspected patients having the virus may undergo chest CT. Isolation and\nbarrier procedures are necessary to protect both the department staff and other patients in the\nhospital. Note should be made that due to overlap of imaging findings with other respiratory\n3\ndiseases, CT is not helpful as a screening tool. But it can help identify the degree of pulmonary\ninvolvement and disease course.", "Our hospital is a national regional medical center with 4,300 beds and a tertiary referral\ncenter in Sichuan province. The initial response started on January 21, 2020, after transmission\nof COVID-19 was confirmed to be human-to-human on January 20, 2020. The first suspected\ncase of COVID-19 in Sichuan province was reported on January 21, 2020. The Sichuan\nprovincial government immediately launched the first-level response to major public health\nemergencies. On the same day, our hospital was designated to care for Sichuan province\npatients with COVID-19.\nThis article describes the emergency management procedure of our radiology department\nfor situations involving severe infectious diseases, such as COVID-19, and the\ninfection-protection experience of the department staff.\nMethods\nThe hospital provided personal protective equipment (medical protective clothing,\nsurgical cap, N95 mask, gloves, face shields, and goggles) to all its healthcare staff, erected", "three medical tents (fever tents) for screening of fever cases in the parking lot of the emergency\ndepartment, planned an examination route and examination area for patients suspected of\nharboring the virus, and placed confirmed patients in an isolation ward. “Fever” was the\ncolloquial term used to designate suspected COVID-19 based on symptoms such as a fever or\nwith an epidemiological history of a potential exposure as well as those with confirmed\nCOVID-19 referred for treatment. Further, during outbreak, emergency and outpatient patients\n4\nwithout fever were asked for information such as epidemiological history and sent to fever tents\nas long as they met suspected criteria.\nThe radiology department has 65 diagnostic radiologists and 161 other staff members\n(trained technologists, nurses, engineers, and support staff). The equipment of the radiology\ndepartment includes 12 magnetic resonance (MR) scanners, 14 CT scanners, 15 digital", "subtraction angiography (DSA) systems, 32 sets of digital radiography (DR) systems\n(including nine mobile bedside DR sets), and 130 imaging diagnostic workstations for picture\narchiving and communication systems (PACS). Most of the equipment is distributed among\nfour buildings at the hospital main campus. 4 CT scanners, 4 MR scanners, 1 DR are located on\nthe first floor of the first inpatient building, and 9 DR and 8 DSA are located on the second\nfloor. 1 CT and 1 MR scanner are located in the third inpatient building. 1 CT and 1 MR scanner\nare located in the sixth inpatient building. 2 CT scanners, 2 MR scanners and 7 DSA are located\nin the technical building. The rest of the equipment is located in the seventh inpatient building\nin the branch campus.\nThe first inpatient building, located next to the emergency department, was reconfigured to\nhandle cases of COVID-19. Fever tents were set up by the emergency department in the", "emergency department parking lot to separate normal emergency patients from patients with\nsymptoms or exposure history suspicious of COVID-19. We established separate means of\naccess between fever tents and between the fever examination area of the radiology department\nto avoid cross-contamination.\nThe emergency management and infection control measures, as described below and\nimplemented in the radiology department during the outbreak, have been approved by the\n5\ninfection control committee of hospital. These measures are in accordance with relevant laws\nand regulations, in order to protect patients as well as the staff.\nRadiology Emergency Management and Infection Control Team (EMICT)\nThe radiology department director chaired the EMICT. Its members include the deputy\ndirector, chief technologist, head nurse, equipment engineer supervisor, and infection control\nnurse of the radiology department. Team responsibilities included (1) coordination between the", "hospital’s management and planning of infection control and radiology departments; (2)\ncollection of the most up-to-date protection-related information to educate and train staff in the\ndepartment; (3) reallocation of staff according to the actual situation; (4) establishment of the\nCT procedures for patients with COVID-19; and (5) establishment of an emergency\nmanagement plan for the radiology department to ensure that the department would run\nnormally.\nSuspected patients\nThe suspected patients were identified according to the Diagnosis and Treatment Program of\nthe Novel Coronavirus Pneumonia of the NHC [5], mainly based on epidemiological history.\nReconfiguration of the radiology department\nThe radiology department was divided into four areas [6]: contaminated, semicontaminated,\nbuffer, and clean areas (Figure 1). The contaminated area is connected to the fever clinic and\nincludes the fever accessway, the CT examination room, and the DR examination room for\n6", "confirmed and suspected cases. One CT scanner and one DR system closest to the emergency\ndepartment are designated the fever-CT and fever-DR to examine patients with suspected and\nconfirmed COVID-19. There is a separate dedicated access between the contaminated area and\nthe fever screening tents. The semicontaminated area includes the fever-CT control room,\nfever-DR control room, and other patient examination access areas. The buffer zone includes\naccess areas for medical personnel and a dressing area for technologists. The clean area\nincludes the administrative office and the diagnostic room.\nThe contaminated area was isolated from other areas using physical barricades.\nDirectional signs were newly installed to guide patients and staff.\nPersonal protection and training of staff\nFor providing care for patients with confirmed and suspected COVID-19, all hospital staff\nare required to wear complete personal protective equipment [7]: medical protective clothing,", "surgical cap, N95 mask, gloves, face shields, and goggles. Wearing and removing of the\nequipment must be performed in accordance with the procedures and under the supervision of\nthe infection control nurse.\nBecause staff members working in the contaminated area are under much situational\npressure, periodically taking time off could lower their physical and mental stress levels. The\ntechnologists on fever-CT duty shifts are provided a break once a week for four hours. In\naddition, the health of staff in the contaminated area must be monitored closely for the\nsymptoms of COVID-19. Pregnant staff must be assigned to the clean area.\n7\nThe EMICT formulates and continually updates guidelines and educates all staff for West\nChina Hospital of Sichuan University. The EMICT training for staff is mainly involves\ndocuments regarding infection control and CT findings of COVID-19 and maintains an EMICT\nWeChat group for West China Hospital of Sichuan University. WeChat is the most widely used", "social media app in China. The EMICT releases the latest national and hospital-based\ninformation regarding COVID-19, guidance documents, and other notices from the hospital\nand radiology department in the WeChat group on a daily basis. Staff can also report to the\nEMICT in the WeChat group any time. Protocols for each modality and infection control\ninstructions are posted on the walls in all examination rooms. The EMICT periodically reminds\nstaff to undertake personal measures to reduce infection, such as wearing masks at all instances\nin the radiology department and N95 masks if working in the contaminated area; not touching\nthe mask and the eyes; practicing hand hygiene; facing away from colleagues when eating,\ndrinking, and talking; and not using personal cell phones while on duty.\n In addition, the chief thoracic radiologist provided lectures on all radiologists and\ntechnologists on typical CT findings of COVID-19 infection using materials developed in", "Wuhan, the epicenter of the outbreak in China.\nCT examination procedures\nThere are two sets of procedures for CT examination: the fever-CT procedure and routine CT\nprocedure for those not suspected of COVID-19.\nThe fever-CT procedure for suspected or confirmed COVID-19 (Figure 2)\n8\nBefore the fever-CT technologist operates the equipment, he or she should wear personal\nprotective equipment according to three-level protection standard [8]. Before the CT\nexamination of patients with suspected and confirmed COVID-19 begins, the fever tent or\nisolation ward notifies the radiologist in advance. The fever-CT technologist checks the\nequipment and prepares to disinfect the imaging equipment immediately after the examination.\nThe patient enters the fever-CT waiting area through the fever access area. If the patient\ncan get onto and off the examination table by themselves, the patient is allowed to do so. If the", "patient cannot get onto or off the examination table independently, the person accompanying\nthe patient assists the patient, rather than the technologist. The technologist checks the patient\ninformation and, using an intercom system in the examination room, asks the patient to remove\nany metal ornaments on the neck and chest. Also, by intercom, the technologist trains the\npatient to hold his or her breath during the examination.\nThe technologist uses a low-dose chest CT protocol to scan the patient. After scanning, the\noriginal images are reconstructed as 1 mm-thick layers. The technologist browses the images to\nensure that their quality meets the diagnostic requirements and then guides the patient to leave\nthrough the fever access area. The disposable sheets for patient examination are changed after\neach patient. The equipment is disinfected according to the procedure below.\nTo protect themselves, the technologists assigned to the fever-CT wear N95 mask and", "other personal protection as established by the EMICT.\nThe CT procedure for regular patients (figure.3)\n9\nSome patients with COVID-19 have no symptoms, and they may call at the general clinic for\nother reasons. The following CT procedure is applicable under these circumstances:\nWhen the patient makes an appointment for examination, the staff asks the patient about\ntheir epidemiological history, symptoms, and signs. If suspected criteria are met, the patient\nwill be sent to the fever tent for further screening. When a patient presents to the radiology\ndepartment entrance, his/her temperature is measured. If the temperature is higher than 37.2 , ℃\nthe patient is sent to the fever tent for further investigation.\nThose with no exposure history, suspicious symptoms or fever are screened in one of the\nnon-contaminated CT scanners. The technologists assigned to these scanners wear surgical\nmasks. All patients and the person accompanying them are required to wear surgical masks.", "After the CT examination, the technologist browses the images quickly. If the CT appearance is\ntypical of lung infection, the technologist immediately reports it to the chest radiologist on duty\nand asks the patient to wait in the CT examination room. If the chest radiologist does not\nsuspect COVID-19 infection, the patient can leave the CT examination room. If the chest\nradiologist does suspect COVID-19 infection, the technologist immediately reports it to the\nEMICT and sends the patient to the fever tent. The floor and equipment in the CT examination\nroom are disinfected according to regulations, and air disinfection is conducted for 30 min\nbefore examining other patients. These CT scanners are considered noncontaminated (not\nfever-CTs) after these sterilization procedures.\nFever-DR examination procedure\n10\nThe COVID-19 guideline of the NHC does not recommend chest DR because its ability in\ndiagnosing COVID-19 is limited. At our hospital, we only use mobile DR units to provide", "bedside examination for critically ill patients. The technologist operating the mobile DR\nwears personal protective equipment according to the three-level protection standard and\nsterilizes the mobile DR according to the ward management requirements as described below.\nEquipment and environment disinfection procedures\nRoutine disinfection procedure [9]\n1) Object surface disinfection: Object surface is wiped with 1000mg/L chlorine-containing\ndisinfectant, wipe twice with 75% ethanol for non-corrosion resistance, once /4 hours.\n2) Equipment disinfection: The equipment in the contaminated area are wiped with\n2000mg/L chlorine-containing disinfectant. The DR and CT gantry in the contaminated\narea are wiped with 75% ethanol. The equipment in the buffer area is wiped with\n500-1000mg/L chlorine-containing disinfectant or alcohol-containing disposable\ndisinfectant wipes twice a day.\n3) Air disinfection: Turning off all central air conditioners to prevent air contamination with", "each other. Polluted area: open the door for ventilation, each time more than 30 minutes,\nonce /4 hours; The air sterilizer is continuously sterilized or the ultraviolet ray is\ncontinuously used in the unmanned state for 60 minutes, four times a day, remembered to\nclose the inner shielding door when air disinfection. Other ambient air is sprayed with\n1000mg/L chlorine-containing disinfectant and ventilated twice a day\n4) Ground disinfection: The ground is wiped with 1000mg/L chlorine-containing\ndisinfectant, once /4 hours.\n5) When contaminated, disinfect at any time. In case of visible contamination, disposable\nabsorbent materials should be used first to completely remove the pollutants, and then a\ncloth soaked with 2000mg/L chlorine-containing disinfectant should be used for 30\nminutes before wiping.\n11\nFever-CT disinfection procedures after examination\nIn addition to the above, disinfect the examination bed and ground with chlorinated disinfectant\ncontaining 2000mg/L [10].", "Noncontaminated CT disinfection procedures after suspected COVID-19 case examination\nIn addition to the above routine disinfection procedure, air disinfection is conducted for 30 min\nbefore examining other patients.\nResults\nFrom January 21, 2020 when screening for epidemiological history or symptoms\nsuspicious for COVID-19, to March 9, 2020, our hospital screened a total of 7,203 individuals\nand confirmed 24 cases of COVID-19. Of these, 3,083 people underwent fever-CT\nexaminations. Including the initial examination and reexamination, the total number of fever\nCT examination numbered 3,340. The fever-CT scanned a patient approximately every 21.5\nminutes. As a result of our precautions, none of the staff of the radiology department developed\nsymptoms suspicious for COVID-19. The fever-CT technologist, with the highest probability\nof exposure, remains PCR negative.\nDiscussion\nIt has been 17 years since the severe acute respiratory syndrome (SARS) epidemic, the last", "national spread of severe infectious disease, broke out. Currently, the Chinese people are\npanicking again. The speed and extent by which COVID-19 has spread in 2 months are\n12\nunprecedented, beyond those of SARS, and this has been aided by its contagious nature and\nrapid spread via droplets and contact. The droplet mode of transmission means that a person can\nbe infected easily by means of casual contact or even fomites on contaminated environmental\nsurfaces. Another theory has yet to be proved: aerosol propagation.\nHow radiology departments respond to any infectious disease outbreak is determined\nprimarily by the estimated risk of cross-infection to the staff and other patients. Appropriate\nprecautions taken only by staff in direct contact with patients may be adequate when the risk is\nlow. The strongest measures need to be implemented to limit the spread of the disease when the\nrisk is high. With severe infectious diseases such as COVID-19, the highest level of infection", "control measures must be implemented; these include providing adequate standard protective\nequipment, training staff, and instituting proper emergency plans.\nOnce a contagious infectious disease has been identified, the EMICT must consider four\nmain areas of response: data gathering, collaboration, needs assessment, and expert advice [10].\nData gathering includes dissemination of up-to-date case definitions and information about\nconfirmatory tests to all staff with direct patient contact to allow appropriate barrier precautions\nto be taken. All typical and atypical imaging features of the disease should be made known to\nall radiologists to assist in recognition of the disease on images and to allow accurate reporting\nof these findings. We have stored images of all probable cases of COVID-19 in the PACS so\nthat these images were readily available for any radiologist to review, and images from\nprevious imaging studies are also available for comparison.", "Collaboration with the radiology departments of other hospitals is very important because\npatients may initially present to different centers, depending on geographic location and travel\n13\ndistance. These patients may be few in number at a single hospital, but if data from patients at\nseveral hospitals are available, a more accurate overall understanding of both imaging features\nand epidemiology can be achieved. Dissemination of this information to all healthcare facilities\nwill also lead to early recognition of the disease, and appropriate isolation measures may be\ninstituted.\nThe Internet and social media apps, especially WeChat, have been used for distribution of\nmedical information, and because the exchange of information regarding infectious disease\noutbreaks is almost instantaneous, it is an indispensable tool for radiologists. In fact, within a\nmonth of the outbreak, the hospital that received the most infected patients from the source of", "the outbreak made a PowerPoint presentation of the CT manifestations of COVID-19, which\nwas shared via WeChat and disseminated across the country in a very short time. Subsequently,\nCOVID-19-teaching PowerPoint presentations from various hospitals appeared and were\nquickly shared via WeChat.\nOur diagnostic process is limited as chest CT along is not diagnostic of COVID-19\nbecause of lack of imaging specificity. But when combined with other epidemiological,\nclinical, laboratory and virus nucleic acid information, typical chest CT imaging findings are\nhelpful for making the diagnosis. In our opinion, the major role of chest CT is to understand the\nextent and dynamic evolution of lung lesions induced by COVID-19. The reasons why we\nadopted the low-dose chest CT scan protocol are as follows: low-dose chest CT has been\nwidely used in the screening of early lung cancer. It is well known that many early lung cancers", "are ground-glass opacities (GGO), so we believe that low-dose screening is also applicable for\nCOVID-19. In addition, considering the rapid development of COVID-19, many CT\n14\nexaminations may be conducted in the same individual to monitor disease progress. Low-dose\nscanning can reduce the radiation damage to patients.\nAlthough the processes we established minimized the exposure of hospital staff, ancillary\npersonnel and other patients, it remains limited as follows. Sichuan province is not the center of\nthe epidemic. The number of patients with COVID-19 whom we have treated has not been\nhigh, and most cases are from other provinces of China. However, we believe that our\nexperience in management, the reconfiguration of our radiology department, and the workflow\nchanges implemented in the current COVID-19 situation are useful for other radiology\ndepartments that must prepare for dealing with patients with COVID-19. While no radiology", "personnel developed symptoms suspicious for or were confirmed as having COVID-19, there\nmay be asymptomatic personnel.\nREFERENCES\n1. National Health Commission of the People’s Republic of China.(2020). March 12: Daily briefing\non novel coronavirus cases in China. Retrieved from\nhttp://en.nhc.gov.cn/2020-03/12/c_77618.htm. Accessed March 11, 2020.\n2. World Health Organization. (2020). Coronavirus disease 2019 (COVID-19) Situation Report-52.\nRetrieved from\nhttps://www.who.int/docs/default-source/coronaviruse/20200312-sitrep-52-covid-19.pdf?sfvrsn=e\n2bfc9c0_2 9. Accessed March 11, 2020.\n3. National Health Commission of the People’s Republic of China.(2020). Latest developments in\nepidemic control on Feb 15. Retrieved from http://en.nhc.gov.cn/2020-02/16/c_76622. Accessed\nMarch 11, 2020.\n15\n4. Health Commission of the People’s Republic of China.(2020). The notification of the trial\noperation based on the guideline version 6 in the coronavirus disease diagnosis and treatment.", "Retrieved from\nhttp://www.nhc.gov.cn/xcs/zhengcwj/202002/8334a8326dd94d329df351d7da8aefc2.shtml.\nAccessed March 11, 2020\n5. Health Commission of the People’s Republic of China.(2020). The notification of the trial\noperation based on the guideline version 6 in the coronavirus disease diagnosis and treatment.\nRetrieved from\nhttp://www.nhc.gov.cn/xcs/zhengcwj/202002/8334a8326dd94d329df351d7da8aefc2.shtml.\nAccessed March 11, 2020.\n6. Health Commission of the People’s Republic of China.(2009). The guideline for pathogens\nisolated operations in hospital. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/200904/40116.shtml. Accessed March 11, 2020.\n7. Health Commission of the People’s Republic of China.(2017). The guideline for prevention and\ncontrol of hospital acquired infections of airborne pathogens. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201701/7e0e8fc6725843aabba8f841f2f585d2.shtml. Accessed\nMarch 11, 2020.", "8. Health Commission of the People’s Republic of China.(2017). The guideline for prevention and\ncontrol of hospital acquired infections of airborne pathogens. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201701/7e0e8fc6725843aabba8f841f2f585d2.shtml. Accessed\nMarch 11, 2020.\n9. Health Commission of the People’s Republic of China.(2012). The standardization for\nsterilization techniques in hospital. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201204/54510.shtml. Accessed March 11, 2020.\n10. Health Commission of the People’s Republic of China.(2012). The standardization for\nsterilization techniques in hospital. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201204/54510.shtml. Accessed March 11, 2020.\n11. Katona P. Bioterrorism Preparedness: Generic Blueprint for Health Departments, Hospitals, and\nPhysicians. Infectious Diseases in Clinical Practice. 2002;11(3):115-122. Accessed March 11,\n2020.\n16\nFigure Legends", "Figure 1. Diagram of the layout of our radiology department was divided into four areas: contaminated\n(shaded in black), semicontaminated (shaded in dark gray), buffer (shaded in light gray), and clean areas\n(shaded in white). The contaminated area was separated from other areas by barriers.\nFigure 2. Diagram shows CT protocol for suspected and confirmed patients with COVID-19.\nFigure 3. Diagram shows CT protocol for regular patients.\nAbbreviations:\nCOVID-19: coronavirus disease 2019\nCT: computed tomography\nDR: digital radiography\nEMICT: emergency management and infection control team\nNHC: National Health Commission\nPACS: picture archiving and communication system\nSARS: severe acute respiratory syndrome", "Sentence Summary\nWith severe infectious diseases such as COVID-19, the highest level of infection control\nmeasures must be implemented, collaboration with the radiology departments of other\nhospitals be needed, and social media be employed.\nTake-home points\n1. To response to a community infection emergency, a special emergency management team\nneeds to be setup at the departmental level to implement infection containment and\ncontrol procedures that continues to allow the imaging examination and imaging\ndiagnosis of those with suspected infection, and to prevent intra-departmental spreading\nof infection (EMICT).\n2. Infection control measures, such as reconfiguration of department areas, personal\nprotection and anti-infection training of all staff, standardized procedures including\ncontact minimization for chest CT and DR examinations, and timely disinfection of CT\nand DR examination rooms, should be implemented properly.", "3. If there are more than one scanner in a hospital, only one of them should be assigned to\nsuspected cases." ]	[ 12 ]	3,975	6,764
188	How was the wearing and removing of the equipment performed?	2,454	[ "under the supervision of\nthe infection control nurse." ]	[ "The Battle Against Coronavirus Disease 2019 (COVID-19): Emergency Management\nand Infection Control in a Radiology Department\nhttps://www.jacr.org/article/S1546-1440(20)30285-4/pdf\nJournal Pre-proof\nZixing Huang, Shuang Zhao, Zhenlin Li, Weixia Chen, Lihong Zhao, Lipeng Deng, Bin\nSong\nPII: S1546-1440(20)30285-4\nDOI: https://doi.org/10.1016/j.jacr.2020.03.011\nReference: JACR 5139\nTo appear in: Journal of the American College of Radiology\nReceived Date: 24 February 2020\nRevised Date: 13 March 2020\nAccepted Date: 15 March 2020\nPlease cite this article as: Huang Z, Zhao S, Li Z, Chen W, Zhao L, Deng L, Song B, The Battle Against\nCoronavirus Disease 2019 (COVID-19): Emergency Management and Infection Control in a Radiology\nDepartment, Journal of the American College of Radiology (2020), doi: https://doi.org/10.1016/\nj.jacr.2020.03.011.\nThis is a PDF file of an article that has undergone enhancements after acceptance, such as the addition", "of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of\nrecord. This version will undergo additional copyediting, typesetting and review before it is published\nin its final form, but we are providing this version to give early visibility of the article. Please note that,\nduring the production process, errors may be discovered which could affect the content, and all legal\ndisclaimers that apply to the journal pertain.\n© 2020 Published by Elsevier Inc. on behalf of American College of Radiology\nThe Battle Against Coronavirus Disease 2019 (COVID-19): Emergency Management\nand Infection Control in a Radiology Department\nZixing Huang, Shuang Zhao, Zhenlin Li, Weixia Chen, Lihong Zhao, Lipeng Deng,\nBin Song\nDepartment of Radiology, West China Hospital, Sichuan University, Chengdu, China\n*Zixing Huang and Shuang Zhao contributed equally to this work as co-first author.\nCorresponding Author: Bin Song, MD", "Address: Department of Radiology, West China Hospital, Sichuan University.\nNo. 37, GUOXUE Alley, Chengdu, 610041, China\nTel.: (+86)28 85423680, Fax: (+86)28 85582944\nEmail: [email protected].\nAuthors’ contributions\nZXH: conceived the study and drafted the manuscript.\nZS: conceived the study and drafted the manuscript.\nZLL: The member of the emergency management and infection control team (EMICT)\nand was involved in the formulation of the measures.\nWXC: The member of the EMICT and was involved in the formulation of the\nmeasures.\nLHZ: The member of the EMICT and was involved in the formulation of the\nmeasures.\nLPD: The member of the EMICT and was involved in the formulation of the\nmeasures.\nBS: Leader of the EMICT, conceived the study and reviewed the manuscript.\nAll authors read and approved the final manuscript.\nThe authors declare no conflict of interest.\nThe authors declare that they had full access to all of the data in this study and the", "authors take complete responsibility for the integrity of the data and the accuracy of\nthe data analysis\n1\nThe Battle Against Novel Coronavirus Pneumonia (COVID-19): Emergency\nManagement and Infection Control in a Radiology Department\nAbstract\nObjective: To describe the strategy and the emergency management and infection control\nprocedure of our radiology department during the COVID-19 outbreak.\nMethods: We set up emergency management and sensing control teams. The team formulated\nvarious measures: reconfiguration of the radiology department, personal protection and training\nof staff, examination procedures for patients suspected of or confirmed with COVID-19 as well\nas patients without an exposure history or symptoms. Those with suspected or confirmed\nCOVID-19 infection were scanned in the designated fever-CT unit.\nResults: From January 21, 2020 to March 9, 2020, 3,083 people suspected of or confirmed with\nCOVID-19 underwent fever-CT examinations. Including initial examinations and", "reexaminations, the total number of fever-CT examinations numbered 3,340. As a result of our\nprecautions, none of the staff of the radiology department were infected with COVID-19.\nConclusion: Strategic planning and adequate protections can help protect patients and staff\nagainst a highly infectious disease while maintaining function at a high volume capacity.\nKeywords: Coronavirus, COVID-19, novel coronavirus pneumonia, infection control", "2\nIntroduction\nThe whole world has been closely focusing on an outbreak of respiratory disease caused by a\nnovel coronavirus that was first reported in Wuhan, China, on December 31, 2019, and that\ncontinues to spread. On February 11, 2020, the World Health Organization (WHO) named the\ndisease “coronavirus disease 2019” (COVID-19).\nAs of 24:00 on March 11, 2020, the National Health Commission (NHC) had received reports\nof 80,793 confirmed cases and 3,169 deaths on the Chinese mainland. There remain 14,831\nconfirmed cases (including 4,257 in serious condition) and 253 suspected cases still\nhospitalized. To date, 677,243 people have been identified as having had close contact with\ninfected patients of whom13,701 are under medical observation [1]. Outside China, 44,067\nlaboratory-confirmed cases and 1,440 deaths have occurred in 117 countries /territories/areas\naccording to the WHO [2]. COVID-19 poses significant threats to international health. Like the", "flu, COVID-19 is thought to spread mainly from person-to-person between people who are in\nclose contact with one another through respiratory droplets produced when an infected person\ncoughs or sneezes. In light of the infectious nature of this disease, healthcare workers are at\nhigh risk of infection of COVID-19. In China, healthcare workers account for 1,716 confirmed\ncases of COVID-19, including six deaths [3].\n Computed tomography (CT) can play a role in both diagnosing and categorizing\nCOVID-19 on the basis of case definitions issued by the WHO and the treatment guidelines\nfrom the NHC [4]. Suspected patients having the virus may undergo chest CT. Isolation and\nbarrier procedures are necessary to protect both the department staff and other patients in the\nhospital. Note should be made that due to overlap of imaging findings with other respiratory\n3\ndiseases, CT is not helpful as a screening tool. But it can help identify the degree of pulmonary\ninvolvement and disease course.", "Our hospital is a national regional medical center with 4,300 beds and a tertiary referral\ncenter in Sichuan province. The initial response started on January 21, 2020, after transmission\nof COVID-19 was confirmed to be human-to-human on January 20, 2020. The first suspected\ncase of COVID-19 in Sichuan province was reported on January 21, 2020. The Sichuan\nprovincial government immediately launched the first-level response to major public health\nemergencies. On the same day, our hospital was designated to care for Sichuan province\npatients with COVID-19.\nThis article describes the emergency management procedure of our radiology department\nfor situations involving severe infectious diseases, such as COVID-19, and the\ninfection-protection experience of the department staff.\nMethods\nThe hospital provided personal protective equipment (medical protective clothing,\nsurgical cap, N95 mask, gloves, face shields, and goggles) to all its healthcare staff, erected", "three medical tents (fever tents) for screening of fever cases in the parking lot of the emergency\ndepartment, planned an examination route and examination area for patients suspected of\nharboring the virus, and placed confirmed patients in an isolation ward. “Fever” was the\ncolloquial term used to designate suspected COVID-19 based on symptoms such as a fever or\nwith an epidemiological history of a potential exposure as well as those with confirmed\nCOVID-19 referred for treatment. Further, during outbreak, emergency and outpatient patients\n4\nwithout fever were asked for information such as epidemiological history and sent to fever tents\nas long as they met suspected criteria.\nThe radiology department has 65 diagnostic radiologists and 161 other staff members\n(trained technologists, nurses, engineers, and support staff). The equipment of the radiology\ndepartment includes 12 magnetic resonance (MR) scanners, 14 CT scanners, 15 digital", "subtraction angiography (DSA) systems, 32 sets of digital radiography (DR) systems\n(including nine mobile bedside DR sets), and 130 imaging diagnostic workstations for picture\narchiving and communication systems (PACS). Most of the equipment is distributed among\nfour buildings at the hospital main campus. 4 CT scanners, 4 MR scanners, 1 DR are located on\nthe first floor of the first inpatient building, and 9 DR and 8 DSA are located on the second\nfloor. 1 CT and 1 MR scanner are located in the third inpatient building. 1 CT and 1 MR scanner\nare located in the sixth inpatient building. 2 CT scanners, 2 MR scanners and 7 DSA are located\nin the technical building. The rest of the equipment is located in the seventh inpatient building\nin the branch campus.\nThe first inpatient building, located next to the emergency department, was reconfigured to\nhandle cases of COVID-19. Fever tents were set up by the emergency department in the", "emergency department parking lot to separate normal emergency patients from patients with\nsymptoms or exposure history suspicious of COVID-19. We established separate means of\naccess between fever tents and between the fever examination area of the radiology department\nto avoid cross-contamination.\nThe emergency management and infection control measures, as described below and\nimplemented in the radiology department during the outbreak, have been approved by the\n5\ninfection control committee of hospital. These measures are in accordance with relevant laws\nand regulations, in order to protect patients as well as the staff.\nRadiology Emergency Management and Infection Control Team (EMICT)\nThe radiology department director chaired the EMICT. Its members include the deputy\ndirector, chief technologist, head nurse, equipment engineer supervisor, and infection control\nnurse of the radiology department. Team responsibilities included (1) coordination between the", "hospital’s management and planning of infection control and radiology departments; (2)\ncollection of the most up-to-date protection-related information to educate and train staff in the\ndepartment; (3) reallocation of staff according to the actual situation; (4) establishment of the\nCT procedures for patients with COVID-19; and (5) establishment of an emergency\nmanagement plan for the radiology department to ensure that the department would run\nnormally.\nSuspected patients\nThe suspected patients were identified according to the Diagnosis and Treatment Program of\nthe Novel Coronavirus Pneumonia of the NHC [5], mainly based on epidemiological history.\nReconfiguration of the radiology department\nThe radiology department was divided into four areas [6]: contaminated, semicontaminated,\nbuffer, and clean areas (Figure 1). The contaminated area is connected to the fever clinic and\nincludes the fever accessway, the CT examination room, and the DR examination room for\n6", "confirmed and suspected cases. One CT scanner and one DR system closest to the emergency\ndepartment are designated the fever-CT and fever-DR to examine patients with suspected and\nconfirmed COVID-19. There is a separate dedicated access between the contaminated area and\nthe fever screening tents. The semicontaminated area includes the fever-CT control room,\nfever-DR control room, and other patient examination access areas. The buffer zone includes\naccess areas for medical personnel and a dressing area for technologists. The clean area\nincludes the administrative office and the diagnostic room.\nThe contaminated area was isolated from other areas using physical barricades.\nDirectional signs were newly installed to guide patients and staff.\nPersonal protection and training of staff\nFor providing care for patients with confirmed and suspected COVID-19, all hospital staff\nare required to wear complete personal protective equipment [7]: medical protective clothing,", "surgical cap, N95 mask, gloves, face shields, and goggles. Wearing and removing of the\nequipment must be performed in accordance with the procedures and under the supervision of\nthe infection control nurse.\nBecause staff members working in the contaminated area are under much situational\npressure, periodically taking time off could lower their physical and mental stress levels. The\ntechnologists on fever-CT duty shifts are provided a break once a week for four hours. In\naddition, the health of staff in the contaminated area must be monitored closely for the\nsymptoms of COVID-19. Pregnant staff must be assigned to the clean area.\n7\nThe EMICT formulates and continually updates guidelines and educates all staff for West\nChina Hospital of Sichuan University. The EMICT training for staff is mainly involves\ndocuments regarding infection control and CT findings of COVID-19 and maintains an EMICT\nWeChat group for West China Hospital of Sichuan University. WeChat is the most widely used", "social media app in China. The EMICT releases the latest national and hospital-based\ninformation regarding COVID-19, guidance documents, and other notices from the hospital\nand radiology department in the WeChat group on a daily basis. Staff can also report to the\nEMICT in the WeChat group any time. Protocols for each modality and infection control\ninstructions are posted on the walls in all examination rooms. The EMICT periodically reminds\nstaff to undertake personal measures to reduce infection, such as wearing masks at all instances\nin the radiology department and N95 masks if working in the contaminated area; not touching\nthe mask and the eyes; practicing hand hygiene; facing away from colleagues when eating,\ndrinking, and talking; and not using personal cell phones while on duty.\n In addition, the chief thoracic radiologist provided lectures on all radiologists and\ntechnologists on typical CT findings of COVID-19 infection using materials developed in", "Wuhan, the epicenter of the outbreak in China.\nCT examination procedures\nThere are two sets of procedures for CT examination: the fever-CT procedure and routine CT\nprocedure for those not suspected of COVID-19.\nThe fever-CT procedure for suspected or confirmed COVID-19 (Figure 2)\n8\nBefore the fever-CT technologist operates the equipment, he or she should wear personal\nprotective equipment according to three-level protection standard [8]. Before the CT\nexamination of patients with suspected and confirmed COVID-19 begins, the fever tent or\nisolation ward notifies the radiologist in advance. The fever-CT technologist checks the\nequipment and prepares to disinfect the imaging equipment immediately after the examination.\nThe patient enters the fever-CT waiting area through the fever access area. If the patient\ncan get onto and off the examination table by themselves, the patient is allowed to do so. If the", "patient cannot get onto or off the examination table independently, the person accompanying\nthe patient assists the patient, rather than the technologist. The technologist checks the patient\ninformation and, using an intercom system in the examination room, asks the patient to remove\nany metal ornaments on the neck and chest. Also, by intercom, the technologist trains the\npatient to hold his or her breath during the examination.\nThe technologist uses a low-dose chest CT protocol to scan the patient. After scanning, the\noriginal images are reconstructed as 1 mm-thick layers. The technologist browses the images to\nensure that their quality meets the diagnostic requirements and then guides the patient to leave\nthrough the fever access area. The disposable sheets for patient examination are changed after\neach patient. The equipment is disinfected according to the procedure below.\nTo protect themselves, the technologists assigned to the fever-CT wear N95 mask and", "other personal protection as established by the EMICT.\nThe CT procedure for regular patients (figure.3)\n9\nSome patients with COVID-19 have no symptoms, and they may call at the general clinic for\nother reasons. The following CT procedure is applicable under these circumstances:\nWhen the patient makes an appointment for examination, the staff asks the patient about\ntheir epidemiological history, symptoms, and signs. If suspected criteria are met, the patient\nwill be sent to the fever tent for further screening. When a patient presents to the radiology\ndepartment entrance, his/her temperature is measured. If the temperature is higher than 37.2 , ℃\nthe patient is sent to the fever tent for further investigation.\nThose with no exposure history, suspicious symptoms or fever are screened in one of the\nnon-contaminated CT scanners. The technologists assigned to these scanners wear surgical\nmasks. All patients and the person accompanying them are required to wear surgical masks.", "After the CT examination, the technologist browses the images quickly. If the CT appearance is\ntypical of lung infection, the technologist immediately reports it to the chest radiologist on duty\nand asks the patient to wait in the CT examination room. If the chest radiologist does not\nsuspect COVID-19 infection, the patient can leave the CT examination room. If the chest\nradiologist does suspect COVID-19 infection, the technologist immediately reports it to the\nEMICT and sends the patient to the fever tent. The floor and equipment in the CT examination\nroom are disinfected according to regulations, and air disinfection is conducted for 30 min\nbefore examining other patients. These CT scanners are considered noncontaminated (not\nfever-CTs) after these sterilization procedures.\nFever-DR examination procedure\n10\nThe COVID-19 guideline of the NHC does not recommend chest DR because its ability in\ndiagnosing COVID-19 is limited. At our hospital, we only use mobile DR units to provide", "bedside examination for critically ill patients. The technologist operating the mobile DR\nwears personal protective equipment according to the three-level protection standard and\nsterilizes the mobile DR according to the ward management requirements as described below.\nEquipment and environment disinfection procedures\nRoutine disinfection procedure [9]\n1) Object surface disinfection: Object surface is wiped with 1000mg/L chlorine-containing\ndisinfectant, wipe twice with 75% ethanol for non-corrosion resistance, once /4 hours.\n2) Equipment disinfection: The equipment in the contaminated area are wiped with\n2000mg/L chlorine-containing disinfectant. The DR and CT gantry in the contaminated\narea are wiped with 75% ethanol. The equipment in the buffer area is wiped with\n500-1000mg/L chlorine-containing disinfectant or alcohol-containing disposable\ndisinfectant wipes twice a day.\n3) Air disinfection: Turning off all central air conditioners to prevent air contamination with", "each other. Polluted area: open the door for ventilation, each time more than 30 minutes,\nonce /4 hours; The air sterilizer is continuously sterilized or the ultraviolet ray is\ncontinuously used in the unmanned state for 60 minutes, four times a day, remembered to\nclose the inner shielding door when air disinfection. Other ambient air is sprayed with\n1000mg/L chlorine-containing disinfectant and ventilated twice a day\n4) Ground disinfection: The ground is wiped with 1000mg/L chlorine-containing\ndisinfectant, once /4 hours.\n5) When contaminated, disinfect at any time. In case of visible contamination, disposable\nabsorbent materials should be used first to completely remove the pollutants, and then a\ncloth soaked with 2000mg/L chlorine-containing disinfectant should be used for 30\nminutes before wiping.\n11\nFever-CT disinfection procedures after examination\nIn addition to the above, disinfect the examination bed and ground with chlorinated disinfectant\ncontaining 2000mg/L [10].", "Noncontaminated CT disinfection procedures after suspected COVID-19 case examination\nIn addition to the above routine disinfection procedure, air disinfection is conducted for 30 min\nbefore examining other patients.\nResults\nFrom January 21, 2020 when screening for epidemiological history or symptoms\nsuspicious for COVID-19, to March 9, 2020, our hospital screened a total of 7,203 individuals\nand confirmed 24 cases of COVID-19. Of these, 3,083 people underwent fever-CT\nexaminations. Including the initial examination and reexamination, the total number of fever\nCT examination numbered 3,340. The fever-CT scanned a patient approximately every 21.5\nminutes. As a result of our precautions, none of the staff of the radiology department developed\nsymptoms suspicious for COVID-19. The fever-CT technologist, with the highest probability\nof exposure, remains PCR negative.\nDiscussion\nIt has been 17 years since the severe acute respiratory syndrome (SARS) epidemic, the last", "national spread of severe infectious disease, broke out. Currently, the Chinese people are\npanicking again. The speed and extent by which COVID-19 has spread in 2 months are\n12\nunprecedented, beyond those of SARS, and this has been aided by its contagious nature and\nrapid spread via droplets and contact. The droplet mode of transmission means that a person can\nbe infected easily by means of casual contact or even fomites on contaminated environmental\nsurfaces. Another theory has yet to be proved: aerosol propagation.\nHow radiology departments respond to any infectious disease outbreak is determined\nprimarily by the estimated risk of cross-infection to the staff and other patients. Appropriate\nprecautions taken only by staff in direct contact with patients may be adequate when the risk is\nlow. The strongest measures need to be implemented to limit the spread of the disease when the\nrisk is high. With severe infectious diseases such as COVID-19, the highest level of infection", "control measures must be implemented; these include providing adequate standard protective\nequipment, training staff, and instituting proper emergency plans.\nOnce a contagious infectious disease has been identified, the EMICT must consider four\nmain areas of response: data gathering, collaboration, needs assessment, and expert advice [10].\nData gathering includes dissemination of up-to-date case definitions and information about\nconfirmatory tests to all staff with direct patient contact to allow appropriate barrier precautions\nto be taken. All typical and atypical imaging features of the disease should be made known to\nall radiologists to assist in recognition of the disease on images and to allow accurate reporting\nof these findings. We have stored images of all probable cases of COVID-19 in the PACS so\nthat these images were readily available for any radiologist to review, and images from\nprevious imaging studies are also available for comparison.", "Collaboration with the radiology departments of other hospitals is very important because\npatients may initially present to different centers, depending on geographic location and travel\n13\ndistance. These patients may be few in number at a single hospital, but if data from patients at\nseveral hospitals are available, a more accurate overall understanding of both imaging features\nand epidemiology can be achieved. Dissemination of this information to all healthcare facilities\nwill also lead to early recognition of the disease, and appropriate isolation measures may be\ninstituted.\nThe Internet and social media apps, especially WeChat, have been used for distribution of\nmedical information, and because the exchange of information regarding infectious disease\noutbreaks is almost instantaneous, it is an indispensable tool for radiologists. In fact, within a\nmonth of the outbreak, the hospital that received the most infected patients from the source of", "the outbreak made a PowerPoint presentation of the CT manifestations of COVID-19, which\nwas shared via WeChat and disseminated across the country in a very short time. Subsequently,\nCOVID-19-teaching PowerPoint presentations from various hospitals appeared and were\nquickly shared via WeChat.\nOur diagnostic process is limited as chest CT along is not diagnostic of COVID-19\nbecause of lack of imaging specificity. But when combined with other epidemiological,\nclinical, laboratory and virus nucleic acid information, typical chest CT imaging findings are\nhelpful for making the diagnosis. In our opinion, the major role of chest CT is to understand the\nextent and dynamic evolution of lung lesions induced by COVID-19. The reasons why we\nadopted the low-dose chest CT scan protocol are as follows: low-dose chest CT has been\nwidely used in the screening of early lung cancer. It is well known that many early lung cancers", "are ground-glass opacities (GGO), so we believe that low-dose screening is also applicable for\nCOVID-19. In addition, considering the rapid development of COVID-19, many CT\n14\nexaminations may be conducted in the same individual to monitor disease progress. Low-dose\nscanning can reduce the radiation damage to patients.\nAlthough the processes we established minimized the exposure of hospital staff, ancillary\npersonnel and other patients, it remains limited as follows. Sichuan province is not the center of\nthe epidemic. The number of patients with COVID-19 whom we have treated has not been\nhigh, and most cases are from other provinces of China. However, we believe that our\nexperience in management, the reconfiguration of our radiology department, and the workflow\nchanges implemented in the current COVID-19 situation are useful for other radiology\ndepartments that must prepare for dealing with patients with COVID-19. While no radiology", "personnel developed symptoms suspicious for or were confirmed as having COVID-19, there\nmay be asymptomatic personnel.\nREFERENCES\n1. National Health Commission of the People’s Republic of China.(2020). March 12: Daily briefing\non novel coronavirus cases in China. Retrieved from\nhttp://en.nhc.gov.cn/2020-03/12/c_77618.htm. Accessed March 11, 2020.\n2. World Health Organization. (2020). Coronavirus disease 2019 (COVID-19) Situation Report-52.\nRetrieved from\nhttps://www.who.int/docs/default-source/coronaviruse/20200312-sitrep-52-covid-19.pdf?sfvrsn=e\n2bfc9c0_2 9. Accessed March 11, 2020.\n3. National Health Commission of the People’s Republic of China.(2020). Latest developments in\nepidemic control on Feb 15. Retrieved from http://en.nhc.gov.cn/2020-02/16/c_76622. Accessed\nMarch 11, 2020.\n15\n4. Health Commission of the People’s Republic of China.(2020). The notification of the trial\noperation based on the guideline version 6 in the coronavirus disease diagnosis and treatment.", "Retrieved from\nhttp://www.nhc.gov.cn/xcs/zhengcwj/202002/8334a8326dd94d329df351d7da8aefc2.shtml.\nAccessed March 11, 2020\n5. Health Commission of the People’s Republic of China.(2020). The notification of the trial\noperation based on the guideline version 6 in the coronavirus disease diagnosis and treatment.\nRetrieved from\nhttp://www.nhc.gov.cn/xcs/zhengcwj/202002/8334a8326dd94d329df351d7da8aefc2.shtml.\nAccessed March 11, 2020.\n6. Health Commission of the People’s Republic of China.(2009). The guideline for pathogens\nisolated operations in hospital. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/200904/40116.shtml. Accessed March 11, 2020.\n7. Health Commission of the People’s Republic of China.(2017). The guideline for prevention and\ncontrol of hospital acquired infections of airborne pathogens. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201701/7e0e8fc6725843aabba8f841f2f585d2.shtml. Accessed\nMarch 11, 2020.", "8. Health Commission of the People’s Republic of China.(2017). The guideline for prevention and\ncontrol of hospital acquired infections of airborne pathogens. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201701/7e0e8fc6725843aabba8f841f2f585d2.shtml. Accessed\nMarch 11, 2020.\n9. Health Commission of the People’s Republic of China.(2012). The standardization for\nsterilization techniques in hospital. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201204/54510.shtml. Accessed March 11, 2020.\n10. Health Commission of the People’s Republic of China.(2012). The standardization for\nsterilization techniques in hospital. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201204/54510.shtml. Accessed March 11, 2020.\n11. Katona P. Bioterrorism Preparedness: Generic Blueprint for Health Departments, Hospitals, and\nPhysicians. Infectious Diseases in Clinical Practice. 2002;11(3):115-122. Accessed March 11,\n2020.\n16\nFigure Legends", "Figure 1. Diagram of the layout of our radiology department was divided into four areas: contaminated\n(shaded in black), semicontaminated (shaded in dark gray), buffer (shaded in light gray), and clean areas\n(shaded in white). The contaminated area was separated from other areas by barriers.\nFigure 2. Diagram shows CT protocol for suspected and confirmed patients with COVID-19.\nFigure 3. Diagram shows CT protocol for regular patients.\nAbbreviations:\nCOVID-19: coronavirus disease 2019\nCT: computed tomography\nDR: digital radiography\nEMICT: emergency management and infection control team\nNHC: National Health Commission\nPACS: picture archiving and communication system\nSARS: severe acute respiratory syndrome", "Sentence Summary\nWith severe infectious diseases such as COVID-19, the highest level of infection control\nmeasures must be implemented, collaboration with the radiology departments of other\nhospitals be needed, and social media be employed.\nTake-home points\n1. To response to a community infection emergency, a special emergency management team\nneeds to be setup at the departmental level to implement infection containment and\ncontrol procedures that continues to allow the imaging examination and imaging\ndiagnosis of those with suspected infection, and to prevent intra-departmental spreading\nof infection (EMICT).\n2. Infection control measures, such as reconfiguration of department areas, personal\nprotection and anti-infection training of all staff, standardized procedures including\ncontact minimization for chest CT and DR examinations, and timely disinfection of CT\nand DR examination rooms, should be implemented properly.", "3. If there are more than one scanner in a hospital, only one of them should be assigned to\nsuspected cases." ]	[ 13 ]	3,975	6,764
188	What can lower the physical and mental stress levels of staff members?	2,455	[ "periodically taking time off" ]	[ "The Battle Against Coronavirus Disease 2019 (COVID-19): Emergency Management\nand Infection Control in a Radiology Department\nhttps://www.jacr.org/article/S1546-1440(20)30285-4/pdf\nJournal Pre-proof\nZixing Huang, Shuang Zhao, Zhenlin Li, Weixia Chen, Lihong Zhao, Lipeng Deng, Bin\nSong\nPII: S1546-1440(20)30285-4\nDOI: https://doi.org/10.1016/j.jacr.2020.03.011\nReference: JACR 5139\nTo appear in: Journal of the American College of Radiology\nReceived Date: 24 February 2020\nRevised Date: 13 March 2020\nAccepted Date: 15 March 2020\nPlease cite this article as: Huang Z, Zhao S, Li Z, Chen W, Zhao L, Deng L, Song B, The Battle Against\nCoronavirus Disease 2019 (COVID-19): Emergency Management and Infection Control in a Radiology\nDepartment, Journal of the American College of Radiology (2020), doi: https://doi.org/10.1016/\nj.jacr.2020.03.011.\nThis is a PDF file of an article that has undergone enhancements after acceptance, such as the addition", "of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of\nrecord. This version will undergo additional copyediting, typesetting and review before it is published\nin its final form, but we are providing this version to give early visibility of the article. Please note that,\nduring the production process, errors may be discovered which could affect the content, and all legal\ndisclaimers that apply to the journal pertain.\n© 2020 Published by Elsevier Inc. on behalf of American College of Radiology\nThe Battle Against Coronavirus Disease 2019 (COVID-19): Emergency Management\nand Infection Control in a Radiology Department\nZixing Huang, Shuang Zhao, Zhenlin Li, Weixia Chen, Lihong Zhao, Lipeng Deng,\nBin Song\nDepartment of Radiology, West China Hospital, Sichuan University, Chengdu, China\n*Zixing Huang and Shuang Zhao contributed equally to this work as co-first author.\nCorresponding Author: Bin Song, MD", "Address: Department of Radiology, West China Hospital, Sichuan University.\nNo. 37, GUOXUE Alley, Chengdu, 610041, China\nTel.: (+86)28 85423680, Fax: (+86)28 85582944\nEmail: [email protected].\nAuthors’ contributions\nZXH: conceived the study and drafted the manuscript.\nZS: conceived the study and drafted the manuscript.\nZLL: The member of the emergency management and infection control team (EMICT)\nand was involved in the formulation of the measures.\nWXC: The member of the EMICT and was involved in the formulation of the\nmeasures.\nLHZ: The member of the EMICT and was involved in the formulation of the\nmeasures.\nLPD: The member of the EMICT and was involved in the formulation of the\nmeasures.\nBS: Leader of the EMICT, conceived the study and reviewed the manuscript.\nAll authors read and approved the final manuscript.\nThe authors declare no conflict of interest.\nThe authors declare that they had full access to all of the data in this study and the", "authors take complete responsibility for the integrity of the data and the accuracy of\nthe data analysis\n1\nThe Battle Against Novel Coronavirus Pneumonia (COVID-19): Emergency\nManagement and Infection Control in a Radiology Department\nAbstract\nObjective: To describe the strategy and the emergency management and infection control\nprocedure of our radiology department during the COVID-19 outbreak.\nMethods: We set up emergency management and sensing control teams. The team formulated\nvarious measures: reconfiguration of the radiology department, personal protection and training\nof staff, examination procedures for patients suspected of or confirmed with COVID-19 as well\nas patients without an exposure history or symptoms. Those with suspected or confirmed\nCOVID-19 infection were scanned in the designated fever-CT unit.\nResults: From January 21, 2020 to March 9, 2020, 3,083 people suspected of or confirmed with\nCOVID-19 underwent fever-CT examinations. Including initial examinations and", "reexaminations, the total number of fever-CT examinations numbered 3,340. As a result of our\nprecautions, none of the staff of the radiology department were infected with COVID-19.\nConclusion: Strategic planning and adequate protections can help protect patients and staff\nagainst a highly infectious disease while maintaining function at a high volume capacity.\nKeywords: Coronavirus, COVID-19, novel coronavirus pneumonia, infection control", "2\nIntroduction\nThe whole world has been closely focusing on an outbreak of respiratory disease caused by a\nnovel coronavirus that was first reported in Wuhan, China, on December 31, 2019, and that\ncontinues to spread. On February 11, 2020, the World Health Organization (WHO) named the\ndisease “coronavirus disease 2019” (COVID-19).\nAs of 24:00 on March 11, 2020, the National Health Commission (NHC) had received reports\nof 80,793 confirmed cases and 3,169 deaths on the Chinese mainland. There remain 14,831\nconfirmed cases (including 4,257 in serious condition) and 253 suspected cases still\nhospitalized. To date, 677,243 people have been identified as having had close contact with\ninfected patients of whom13,701 are under medical observation [1]. Outside China, 44,067\nlaboratory-confirmed cases and 1,440 deaths have occurred in 117 countries /territories/areas\naccording to the WHO [2]. COVID-19 poses significant threats to international health. Like the", "flu, COVID-19 is thought to spread mainly from person-to-person between people who are in\nclose contact with one another through respiratory droplets produced when an infected person\ncoughs or sneezes. In light of the infectious nature of this disease, healthcare workers are at\nhigh risk of infection of COVID-19. In China, healthcare workers account for 1,716 confirmed\ncases of COVID-19, including six deaths [3].\n Computed tomography (CT) can play a role in both diagnosing and categorizing\nCOVID-19 on the basis of case definitions issued by the WHO and the treatment guidelines\nfrom the NHC [4]. Suspected patients having the virus may undergo chest CT. Isolation and\nbarrier procedures are necessary to protect both the department staff and other patients in the\nhospital. Note should be made that due to overlap of imaging findings with other respiratory\n3\ndiseases, CT is not helpful as a screening tool. But it can help identify the degree of pulmonary\ninvolvement and disease course.", "Our hospital is a national regional medical center with 4,300 beds and a tertiary referral\ncenter in Sichuan province. The initial response started on January 21, 2020, after transmission\nof COVID-19 was confirmed to be human-to-human on January 20, 2020. The first suspected\ncase of COVID-19 in Sichuan province was reported on January 21, 2020. The Sichuan\nprovincial government immediately launched the first-level response to major public health\nemergencies. On the same day, our hospital was designated to care for Sichuan province\npatients with COVID-19.\nThis article describes the emergency management procedure of our radiology department\nfor situations involving severe infectious diseases, such as COVID-19, and the\ninfection-protection experience of the department staff.\nMethods\nThe hospital provided personal protective equipment (medical protective clothing,\nsurgical cap, N95 mask, gloves, face shields, and goggles) to all its healthcare staff, erected", "three medical tents (fever tents) for screening of fever cases in the parking lot of the emergency\ndepartment, planned an examination route and examination area for patients suspected of\nharboring the virus, and placed confirmed patients in an isolation ward. “Fever” was the\ncolloquial term used to designate suspected COVID-19 based on symptoms such as a fever or\nwith an epidemiological history of a potential exposure as well as those with confirmed\nCOVID-19 referred for treatment. Further, during outbreak, emergency and outpatient patients\n4\nwithout fever were asked for information such as epidemiological history and sent to fever tents\nas long as they met suspected criteria.\nThe radiology department has 65 diagnostic radiologists and 161 other staff members\n(trained technologists, nurses, engineers, and support staff). The equipment of the radiology\ndepartment includes 12 magnetic resonance (MR) scanners, 14 CT scanners, 15 digital", "subtraction angiography (DSA) systems, 32 sets of digital radiography (DR) systems\n(including nine mobile bedside DR sets), and 130 imaging diagnostic workstations for picture\narchiving and communication systems (PACS). Most of the equipment is distributed among\nfour buildings at the hospital main campus. 4 CT scanners, 4 MR scanners, 1 DR are located on\nthe first floor of the first inpatient building, and 9 DR and 8 DSA are located on the second\nfloor. 1 CT and 1 MR scanner are located in the third inpatient building. 1 CT and 1 MR scanner\nare located in the sixth inpatient building. 2 CT scanners, 2 MR scanners and 7 DSA are located\nin the technical building. The rest of the equipment is located in the seventh inpatient building\nin the branch campus.\nThe first inpatient building, located next to the emergency department, was reconfigured to\nhandle cases of COVID-19. Fever tents were set up by the emergency department in the", "emergency department parking lot to separate normal emergency patients from patients with\nsymptoms or exposure history suspicious of COVID-19. We established separate means of\naccess between fever tents and between the fever examination area of the radiology department\nto avoid cross-contamination.\nThe emergency management and infection control measures, as described below and\nimplemented in the radiology department during the outbreak, have been approved by the\n5\ninfection control committee of hospital. These measures are in accordance with relevant laws\nand regulations, in order to protect patients as well as the staff.\nRadiology Emergency Management and Infection Control Team (EMICT)\nThe radiology department director chaired the EMICT. Its members include the deputy\ndirector, chief technologist, head nurse, equipment engineer supervisor, and infection control\nnurse of the radiology department. Team responsibilities included (1) coordination between the", "hospital’s management and planning of infection control and radiology departments; (2)\ncollection of the most up-to-date protection-related information to educate and train staff in the\ndepartment; (3) reallocation of staff according to the actual situation; (4) establishment of the\nCT procedures for patients with COVID-19; and (5) establishment of an emergency\nmanagement plan for the radiology department to ensure that the department would run\nnormally.\nSuspected patients\nThe suspected patients were identified according to the Diagnosis and Treatment Program of\nthe Novel Coronavirus Pneumonia of the NHC [5], mainly based on epidemiological history.\nReconfiguration of the radiology department\nThe radiology department was divided into four areas [6]: contaminated, semicontaminated,\nbuffer, and clean areas (Figure 1). The contaminated area is connected to the fever clinic and\nincludes the fever accessway, the CT examination room, and the DR examination room for\n6", "confirmed and suspected cases. One CT scanner and one DR system closest to the emergency\ndepartment are designated the fever-CT and fever-DR to examine patients with suspected and\nconfirmed COVID-19. There is a separate dedicated access between the contaminated area and\nthe fever screening tents. The semicontaminated area includes the fever-CT control room,\nfever-DR control room, and other patient examination access areas. The buffer zone includes\naccess areas for medical personnel and a dressing area for technologists. The clean area\nincludes the administrative office and the diagnostic room.\nThe contaminated area was isolated from other areas using physical barricades.\nDirectional signs were newly installed to guide patients and staff.\nPersonal protection and training of staff\nFor providing care for patients with confirmed and suspected COVID-19, all hospital staff\nare required to wear complete personal protective equipment [7]: medical protective clothing,", "surgical cap, N95 mask, gloves, face shields, and goggles. Wearing and removing of the\nequipment must be performed in accordance with the procedures and under the supervision of\nthe infection control nurse.\nBecause staff members working in the contaminated area are under much situational\npressure, periodically taking time off could lower their physical and mental stress levels. The\ntechnologists on fever-CT duty shifts are provided a break once a week for four hours. In\naddition, the health of staff in the contaminated area must be monitored closely for the\nsymptoms of COVID-19. Pregnant staff must be assigned to the clean area.\n7\nThe EMICT formulates and continually updates guidelines and educates all staff for West\nChina Hospital of Sichuan University. The EMICT training for staff is mainly involves\ndocuments regarding infection control and CT findings of COVID-19 and maintains an EMICT\nWeChat group for West China Hospital of Sichuan University. WeChat is the most widely used", "social media app in China. The EMICT releases the latest national and hospital-based\ninformation regarding COVID-19, guidance documents, and other notices from the hospital\nand radiology department in the WeChat group on a daily basis. Staff can also report to the\nEMICT in the WeChat group any time. Protocols for each modality and infection control\ninstructions are posted on the walls in all examination rooms. The EMICT periodically reminds\nstaff to undertake personal measures to reduce infection, such as wearing masks at all instances\nin the radiology department and N95 masks if working in the contaminated area; not touching\nthe mask and the eyes; practicing hand hygiene; facing away from colleagues when eating,\ndrinking, and talking; and not using personal cell phones while on duty.\n In addition, the chief thoracic radiologist provided lectures on all radiologists and\ntechnologists on typical CT findings of COVID-19 infection using materials developed in", "Wuhan, the epicenter of the outbreak in China.\nCT examination procedures\nThere are two sets of procedures for CT examination: the fever-CT procedure and routine CT\nprocedure for those not suspected of COVID-19.\nThe fever-CT procedure for suspected or confirmed COVID-19 (Figure 2)\n8\nBefore the fever-CT technologist operates the equipment, he or she should wear personal\nprotective equipment according to three-level protection standard [8]. Before the CT\nexamination of patients with suspected and confirmed COVID-19 begins, the fever tent or\nisolation ward notifies the radiologist in advance. The fever-CT technologist checks the\nequipment and prepares to disinfect the imaging equipment immediately after the examination.\nThe patient enters the fever-CT waiting area through the fever access area. If the patient\ncan get onto and off the examination table by themselves, the patient is allowed to do so. If the", "patient cannot get onto or off the examination table independently, the person accompanying\nthe patient assists the patient, rather than the technologist. The technologist checks the patient\ninformation and, using an intercom system in the examination room, asks the patient to remove\nany metal ornaments on the neck and chest. Also, by intercom, the technologist trains the\npatient to hold his or her breath during the examination.\nThe technologist uses a low-dose chest CT protocol to scan the patient. After scanning, the\noriginal images are reconstructed as 1 mm-thick layers. The technologist browses the images to\nensure that their quality meets the diagnostic requirements and then guides the patient to leave\nthrough the fever access area. The disposable sheets for patient examination are changed after\neach patient. The equipment is disinfected according to the procedure below.\nTo protect themselves, the technologists assigned to the fever-CT wear N95 mask and", "other personal protection as established by the EMICT.\nThe CT procedure for regular patients (figure.3)\n9\nSome patients with COVID-19 have no symptoms, and they may call at the general clinic for\nother reasons. The following CT procedure is applicable under these circumstances:\nWhen the patient makes an appointment for examination, the staff asks the patient about\ntheir epidemiological history, symptoms, and signs. If suspected criteria are met, the patient\nwill be sent to the fever tent for further screening. When a patient presents to the radiology\ndepartment entrance, his/her temperature is measured. If the temperature is higher than 37.2 , ℃\nthe patient is sent to the fever tent for further investigation.\nThose with no exposure history, suspicious symptoms or fever are screened in one of the\nnon-contaminated CT scanners. The technologists assigned to these scanners wear surgical\nmasks. All patients and the person accompanying them are required to wear surgical masks.", "After the CT examination, the technologist browses the images quickly. If the CT appearance is\ntypical of lung infection, the technologist immediately reports it to the chest radiologist on duty\nand asks the patient to wait in the CT examination room. If the chest radiologist does not\nsuspect COVID-19 infection, the patient can leave the CT examination room. If the chest\nradiologist does suspect COVID-19 infection, the technologist immediately reports it to the\nEMICT and sends the patient to the fever tent. The floor and equipment in the CT examination\nroom are disinfected according to regulations, and air disinfection is conducted for 30 min\nbefore examining other patients. These CT scanners are considered noncontaminated (not\nfever-CTs) after these sterilization procedures.\nFever-DR examination procedure\n10\nThe COVID-19 guideline of the NHC does not recommend chest DR because its ability in\ndiagnosing COVID-19 is limited. At our hospital, we only use mobile DR units to provide", "bedside examination for critically ill patients. The technologist operating the mobile DR\nwears personal protective equipment according to the three-level protection standard and\nsterilizes the mobile DR according to the ward management requirements as described below.\nEquipment and environment disinfection procedures\nRoutine disinfection procedure [9]\n1) Object surface disinfection: Object surface is wiped with 1000mg/L chlorine-containing\ndisinfectant, wipe twice with 75% ethanol for non-corrosion resistance, once /4 hours.\n2) Equipment disinfection: The equipment in the contaminated area are wiped with\n2000mg/L chlorine-containing disinfectant. The DR and CT gantry in the contaminated\narea are wiped with 75% ethanol. The equipment in the buffer area is wiped with\n500-1000mg/L chlorine-containing disinfectant or alcohol-containing disposable\ndisinfectant wipes twice a day.\n3) Air disinfection: Turning off all central air conditioners to prevent air contamination with", "each other. Polluted area: open the door for ventilation, each time more than 30 minutes,\nonce /4 hours; The air sterilizer is continuously sterilized or the ultraviolet ray is\ncontinuously used in the unmanned state for 60 minutes, four times a day, remembered to\nclose the inner shielding door when air disinfection. Other ambient air is sprayed with\n1000mg/L chlorine-containing disinfectant and ventilated twice a day\n4) Ground disinfection: The ground is wiped with 1000mg/L chlorine-containing\ndisinfectant, once /4 hours.\n5) When contaminated, disinfect at any time. In case of visible contamination, disposable\nabsorbent materials should be used first to completely remove the pollutants, and then a\ncloth soaked with 2000mg/L chlorine-containing disinfectant should be used for 30\nminutes before wiping.\n11\nFever-CT disinfection procedures after examination\nIn addition to the above, disinfect the examination bed and ground with chlorinated disinfectant\ncontaining 2000mg/L [10].", "Noncontaminated CT disinfection procedures after suspected COVID-19 case examination\nIn addition to the above routine disinfection procedure, air disinfection is conducted for 30 min\nbefore examining other patients.\nResults\nFrom January 21, 2020 when screening for epidemiological history or symptoms\nsuspicious for COVID-19, to March 9, 2020, our hospital screened a total of 7,203 individuals\nand confirmed 24 cases of COVID-19. Of these, 3,083 people underwent fever-CT\nexaminations. Including the initial examination and reexamination, the total number of fever\nCT examination numbered 3,340. The fever-CT scanned a patient approximately every 21.5\nminutes. As a result of our precautions, none of the staff of the radiology department developed\nsymptoms suspicious for COVID-19. The fever-CT technologist, with the highest probability\nof exposure, remains PCR negative.\nDiscussion\nIt has been 17 years since the severe acute respiratory syndrome (SARS) epidemic, the last", "national spread of severe infectious disease, broke out. Currently, the Chinese people are\npanicking again. The speed and extent by which COVID-19 has spread in 2 months are\n12\nunprecedented, beyond those of SARS, and this has been aided by its contagious nature and\nrapid spread via droplets and contact. The droplet mode of transmission means that a person can\nbe infected easily by means of casual contact or even fomites on contaminated environmental\nsurfaces. Another theory has yet to be proved: aerosol propagation.\nHow radiology departments respond to any infectious disease outbreak is determined\nprimarily by the estimated risk of cross-infection to the staff and other patients. Appropriate\nprecautions taken only by staff in direct contact with patients may be adequate when the risk is\nlow. The strongest measures need to be implemented to limit the spread of the disease when the\nrisk is high. With severe infectious diseases such as COVID-19, the highest level of infection", "control measures must be implemented; these include providing adequate standard protective\nequipment, training staff, and instituting proper emergency plans.\nOnce a contagious infectious disease has been identified, the EMICT must consider four\nmain areas of response: data gathering, collaboration, needs assessment, and expert advice [10].\nData gathering includes dissemination of up-to-date case definitions and information about\nconfirmatory tests to all staff with direct patient contact to allow appropriate barrier precautions\nto be taken. All typical and atypical imaging features of the disease should be made known to\nall radiologists to assist in recognition of the disease on images and to allow accurate reporting\nof these findings. We have stored images of all probable cases of COVID-19 in the PACS so\nthat these images were readily available for any radiologist to review, and images from\nprevious imaging studies are also available for comparison.", "Collaboration with the radiology departments of other hospitals is very important because\npatients may initially present to different centers, depending on geographic location and travel\n13\ndistance. These patients may be few in number at a single hospital, but if data from patients at\nseveral hospitals are available, a more accurate overall understanding of both imaging features\nand epidemiology can be achieved. Dissemination of this information to all healthcare facilities\nwill also lead to early recognition of the disease, and appropriate isolation measures may be\ninstituted.\nThe Internet and social media apps, especially WeChat, have been used for distribution of\nmedical information, and because the exchange of information regarding infectious disease\noutbreaks is almost instantaneous, it is an indispensable tool for radiologists. In fact, within a\nmonth of the outbreak, the hospital that received the most infected patients from the source of", "the outbreak made a PowerPoint presentation of the CT manifestations of COVID-19, which\nwas shared via WeChat and disseminated across the country in a very short time. Subsequently,\nCOVID-19-teaching PowerPoint presentations from various hospitals appeared and were\nquickly shared via WeChat.\nOur diagnostic process is limited as chest CT along is not diagnostic of COVID-19\nbecause of lack of imaging specificity. But when combined with other epidemiological,\nclinical, laboratory and virus nucleic acid information, typical chest CT imaging findings are\nhelpful for making the diagnosis. In our opinion, the major role of chest CT is to understand the\nextent and dynamic evolution of lung lesions induced by COVID-19. The reasons why we\nadopted the low-dose chest CT scan protocol are as follows: low-dose chest CT has been\nwidely used in the screening of early lung cancer. It is well known that many early lung cancers", "are ground-glass opacities (GGO), so we believe that low-dose screening is also applicable for\nCOVID-19. In addition, considering the rapid development of COVID-19, many CT\n14\nexaminations may be conducted in the same individual to monitor disease progress. Low-dose\nscanning can reduce the radiation damage to patients.\nAlthough the processes we established minimized the exposure of hospital staff, ancillary\npersonnel and other patients, it remains limited as follows. Sichuan province is not the center of\nthe epidemic. The number of patients with COVID-19 whom we have treated has not been\nhigh, and most cases are from other provinces of China. However, we believe that our\nexperience in management, the reconfiguration of our radiology department, and the workflow\nchanges implemented in the current COVID-19 situation are useful for other radiology\ndepartments that must prepare for dealing with patients with COVID-19. While no radiology", "personnel developed symptoms suspicious for or were confirmed as having COVID-19, there\nmay be asymptomatic personnel.\nREFERENCES\n1. National Health Commission of the People’s Republic of China.(2020). March 12: Daily briefing\non novel coronavirus cases in China. Retrieved from\nhttp://en.nhc.gov.cn/2020-03/12/c_77618.htm. Accessed March 11, 2020.\n2. World Health Organization. (2020). Coronavirus disease 2019 (COVID-19) Situation Report-52.\nRetrieved from\nhttps://www.who.int/docs/default-source/coronaviruse/20200312-sitrep-52-covid-19.pdf?sfvrsn=e\n2bfc9c0_2 9. Accessed March 11, 2020.\n3. National Health Commission of the People’s Republic of China.(2020). Latest developments in\nepidemic control on Feb 15. Retrieved from http://en.nhc.gov.cn/2020-02/16/c_76622. Accessed\nMarch 11, 2020.\n15\n4. Health Commission of the People’s Republic of China.(2020). The notification of the trial\noperation based on the guideline version 6 in the coronavirus disease diagnosis and treatment.", "Retrieved from\nhttp://www.nhc.gov.cn/xcs/zhengcwj/202002/8334a8326dd94d329df351d7da8aefc2.shtml.\nAccessed March 11, 2020\n5. Health Commission of the People’s Republic of China.(2020). The notification of the trial\noperation based on the guideline version 6 in the coronavirus disease diagnosis and treatment.\nRetrieved from\nhttp://www.nhc.gov.cn/xcs/zhengcwj/202002/8334a8326dd94d329df351d7da8aefc2.shtml.\nAccessed March 11, 2020.\n6. Health Commission of the People’s Republic of China.(2009). The guideline for pathogens\nisolated operations in hospital. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/200904/40116.shtml. Accessed March 11, 2020.\n7. Health Commission of the People’s Republic of China.(2017). The guideline for prevention and\ncontrol of hospital acquired infections of airborne pathogens. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201701/7e0e8fc6725843aabba8f841f2f585d2.shtml. Accessed\nMarch 11, 2020.", "8. Health Commission of the People’s Republic of China.(2017). The guideline for prevention and\ncontrol of hospital acquired infections of airborne pathogens. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201701/7e0e8fc6725843aabba8f841f2f585d2.shtml. Accessed\nMarch 11, 2020.\n9. Health Commission of the People’s Republic of China.(2012). The standardization for\nsterilization techniques in hospital. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201204/54510.shtml. Accessed March 11, 2020.\n10. Health Commission of the People’s Republic of China.(2012). The standardization for\nsterilization techniques in hospital. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201204/54510.shtml. Accessed March 11, 2020.\n11. Katona P. Bioterrorism Preparedness: Generic Blueprint for Health Departments, Hospitals, and\nPhysicians. Infectious Diseases in Clinical Practice. 2002;11(3):115-122. Accessed March 11,\n2020.\n16\nFigure Legends", "Figure 1. Diagram of the layout of our radiology department was divided into four areas: contaminated\n(shaded in black), semicontaminated (shaded in dark gray), buffer (shaded in light gray), and clean areas\n(shaded in white). The contaminated area was separated from other areas by barriers.\nFigure 2. Diagram shows CT protocol for suspected and confirmed patients with COVID-19.\nFigure 3. Diagram shows CT protocol for regular patients.\nAbbreviations:\nCOVID-19: coronavirus disease 2019\nCT: computed tomography\nDR: digital radiography\nEMICT: emergency management and infection control team\nNHC: National Health Commission\nPACS: picture archiving and communication system\nSARS: severe acute respiratory syndrome", "Sentence Summary\nWith severe infectious diseases such as COVID-19, the highest level of infection control\nmeasures must be implemented, collaboration with the radiology departments of other\nhospitals be needed, and social media be employed.\nTake-home points\n1. To response to a community infection emergency, a special emergency management team\nneeds to be setup at the departmental level to implement infection containment and\ncontrol procedures that continues to allow the imaging examination and imaging\ndiagnosis of those with suspected infection, and to prevent intra-departmental spreading\nof infection (EMICT).\n2. Infection control measures, such as reconfiguration of department areas, personal\nprotection and anti-infection training of all staff, standardized procedures including\ncontact minimization for chest CT and DR examinations, and timely disinfection of CT\nand DR examination rooms, should be implemented properly.", "3. If there are more than one scanner in a hospital, only one of them should be assigned to\nsuspected cases." ]	[ 13 ]	3,975	6,764
188	Who must be assigned to the clean area?	2,456	[ "Pregnant staff" ]	[ "The Battle Against Coronavirus Disease 2019 (COVID-19): Emergency Management\nand Infection Control in a Radiology Department\nhttps://www.jacr.org/article/S1546-1440(20)30285-4/pdf\nJournal Pre-proof\nZixing Huang, Shuang Zhao, Zhenlin Li, Weixia Chen, Lihong Zhao, Lipeng Deng, Bin\nSong\nPII: S1546-1440(20)30285-4\nDOI: https://doi.org/10.1016/j.jacr.2020.03.011\nReference: JACR 5139\nTo appear in: Journal of the American College of Radiology\nReceived Date: 24 February 2020\nRevised Date: 13 March 2020\nAccepted Date: 15 March 2020\nPlease cite this article as: Huang Z, Zhao S, Li Z, Chen W, Zhao L, Deng L, Song B, The Battle Against\nCoronavirus Disease 2019 (COVID-19): Emergency Management and Infection Control in a Radiology\nDepartment, Journal of the American College of Radiology (2020), doi: https://doi.org/10.1016/\nj.jacr.2020.03.011.\nThis is a PDF file of an article that has undergone enhancements after acceptance, such as the addition", "of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of\nrecord. This version will undergo additional copyediting, typesetting and review before it is published\nin its final form, but we are providing this version to give early visibility of the article. Please note that,\nduring the production process, errors may be discovered which could affect the content, and all legal\ndisclaimers that apply to the journal pertain.\n© 2020 Published by Elsevier Inc. on behalf of American College of Radiology\nThe Battle Against Coronavirus Disease 2019 (COVID-19): Emergency Management\nand Infection Control in a Radiology Department\nZixing Huang, Shuang Zhao, Zhenlin Li, Weixia Chen, Lihong Zhao, Lipeng Deng,\nBin Song\nDepartment of Radiology, West China Hospital, Sichuan University, Chengdu, China\n*Zixing Huang and Shuang Zhao contributed equally to this work as co-first author.\nCorresponding Author: Bin Song, MD", "Address: Department of Radiology, West China Hospital, Sichuan University.\nNo. 37, GUOXUE Alley, Chengdu, 610041, China\nTel.: (+86)28 85423680, Fax: (+86)28 85582944\nEmail: [email protected].\nAuthors’ contributions\nZXH: conceived the study and drafted the manuscript.\nZS: conceived the study and drafted the manuscript.\nZLL: The member of the emergency management and infection control team (EMICT)\nand was involved in the formulation of the measures.\nWXC: The member of the EMICT and was involved in the formulation of the\nmeasures.\nLHZ: The member of the EMICT and was involved in the formulation of the\nmeasures.\nLPD: The member of the EMICT and was involved in the formulation of the\nmeasures.\nBS: Leader of the EMICT, conceived the study and reviewed the manuscript.\nAll authors read and approved the final manuscript.\nThe authors declare no conflict of interest.\nThe authors declare that they had full access to all of the data in this study and the", "authors take complete responsibility for the integrity of the data and the accuracy of\nthe data analysis\n1\nThe Battle Against Novel Coronavirus Pneumonia (COVID-19): Emergency\nManagement and Infection Control in a Radiology Department\nAbstract\nObjective: To describe the strategy and the emergency management and infection control\nprocedure of our radiology department during the COVID-19 outbreak.\nMethods: We set up emergency management and sensing control teams. The team formulated\nvarious measures: reconfiguration of the radiology department, personal protection and training\nof staff, examination procedures for patients suspected of or confirmed with COVID-19 as well\nas patients without an exposure history or symptoms. Those with suspected or confirmed\nCOVID-19 infection were scanned in the designated fever-CT unit.\nResults: From January 21, 2020 to March 9, 2020, 3,083 people suspected of or confirmed with\nCOVID-19 underwent fever-CT examinations. Including initial examinations and", "reexaminations, the total number of fever-CT examinations numbered 3,340. As a result of our\nprecautions, none of the staff of the radiology department were infected with COVID-19.\nConclusion: Strategic planning and adequate protections can help protect patients and staff\nagainst a highly infectious disease while maintaining function at a high volume capacity.\nKeywords: Coronavirus, COVID-19, novel coronavirus pneumonia, infection control", "2\nIntroduction\nThe whole world has been closely focusing on an outbreak of respiratory disease caused by a\nnovel coronavirus that was first reported in Wuhan, China, on December 31, 2019, and that\ncontinues to spread. On February 11, 2020, the World Health Organization (WHO) named the\ndisease “coronavirus disease 2019” (COVID-19).\nAs of 24:00 on March 11, 2020, the National Health Commission (NHC) had received reports\nof 80,793 confirmed cases and 3,169 deaths on the Chinese mainland. There remain 14,831\nconfirmed cases (including 4,257 in serious condition) and 253 suspected cases still\nhospitalized. To date, 677,243 people have been identified as having had close contact with\ninfected patients of whom13,701 are under medical observation [1]. Outside China, 44,067\nlaboratory-confirmed cases and 1,440 deaths have occurred in 117 countries /territories/areas\naccording to the WHO [2]. COVID-19 poses significant threats to international health. Like the", "flu, COVID-19 is thought to spread mainly from person-to-person between people who are in\nclose contact with one another through respiratory droplets produced when an infected person\ncoughs or sneezes. In light of the infectious nature of this disease, healthcare workers are at\nhigh risk of infection of COVID-19. In China, healthcare workers account for 1,716 confirmed\ncases of COVID-19, including six deaths [3].\n Computed tomography (CT) can play a role in both diagnosing and categorizing\nCOVID-19 on the basis of case definitions issued by the WHO and the treatment guidelines\nfrom the NHC [4]. Suspected patients having the virus may undergo chest CT. Isolation and\nbarrier procedures are necessary to protect both the department staff and other patients in the\nhospital. Note should be made that due to overlap of imaging findings with other respiratory\n3\ndiseases, CT is not helpful as a screening tool. But it can help identify the degree of pulmonary\ninvolvement and disease course.", "Our hospital is a national regional medical center with 4,300 beds and a tertiary referral\ncenter in Sichuan province. The initial response started on January 21, 2020, after transmission\nof COVID-19 was confirmed to be human-to-human on January 20, 2020. The first suspected\ncase of COVID-19 in Sichuan province was reported on January 21, 2020. The Sichuan\nprovincial government immediately launched the first-level response to major public health\nemergencies. On the same day, our hospital was designated to care for Sichuan province\npatients with COVID-19.\nThis article describes the emergency management procedure of our radiology department\nfor situations involving severe infectious diseases, such as COVID-19, and the\ninfection-protection experience of the department staff.\nMethods\nThe hospital provided personal protective equipment (medical protective clothing,\nsurgical cap, N95 mask, gloves, face shields, and goggles) to all its healthcare staff, erected", "three medical tents (fever tents) for screening of fever cases in the parking lot of the emergency\ndepartment, planned an examination route and examination area for patients suspected of\nharboring the virus, and placed confirmed patients in an isolation ward. “Fever” was the\ncolloquial term used to designate suspected COVID-19 based on symptoms such as a fever or\nwith an epidemiological history of a potential exposure as well as those with confirmed\nCOVID-19 referred for treatment. Further, during outbreak, emergency and outpatient patients\n4\nwithout fever were asked for information such as epidemiological history and sent to fever tents\nas long as they met suspected criteria.\nThe radiology department has 65 diagnostic radiologists and 161 other staff members\n(trained technologists, nurses, engineers, and support staff). The equipment of the radiology\ndepartment includes 12 magnetic resonance (MR) scanners, 14 CT scanners, 15 digital", "subtraction angiography (DSA) systems, 32 sets of digital radiography (DR) systems\n(including nine mobile bedside DR sets), and 130 imaging diagnostic workstations for picture\narchiving and communication systems (PACS). Most of the equipment is distributed among\nfour buildings at the hospital main campus. 4 CT scanners, 4 MR scanners, 1 DR are located on\nthe first floor of the first inpatient building, and 9 DR and 8 DSA are located on the second\nfloor. 1 CT and 1 MR scanner are located in the third inpatient building. 1 CT and 1 MR scanner\nare located in the sixth inpatient building. 2 CT scanners, 2 MR scanners and 7 DSA are located\nin the technical building. The rest of the equipment is located in the seventh inpatient building\nin the branch campus.\nThe first inpatient building, located next to the emergency department, was reconfigured to\nhandle cases of COVID-19. Fever tents were set up by the emergency department in the", "emergency department parking lot to separate normal emergency patients from patients with\nsymptoms or exposure history suspicious of COVID-19. We established separate means of\naccess between fever tents and between the fever examination area of the radiology department\nto avoid cross-contamination.\nThe emergency management and infection control measures, as described below and\nimplemented in the radiology department during the outbreak, have been approved by the\n5\ninfection control committee of hospital. These measures are in accordance with relevant laws\nand regulations, in order to protect patients as well as the staff.\nRadiology Emergency Management and Infection Control Team (EMICT)\nThe radiology department director chaired the EMICT. Its members include the deputy\ndirector, chief technologist, head nurse, equipment engineer supervisor, and infection control\nnurse of the radiology department. Team responsibilities included (1) coordination between the", "hospital’s management and planning of infection control and radiology departments; (2)\ncollection of the most up-to-date protection-related information to educate and train staff in the\ndepartment; (3) reallocation of staff according to the actual situation; (4) establishment of the\nCT procedures for patients with COVID-19; and (5) establishment of an emergency\nmanagement plan for the radiology department to ensure that the department would run\nnormally.\nSuspected patients\nThe suspected patients were identified according to the Diagnosis and Treatment Program of\nthe Novel Coronavirus Pneumonia of the NHC [5], mainly based on epidemiological history.\nReconfiguration of the radiology department\nThe radiology department was divided into four areas [6]: contaminated, semicontaminated,\nbuffer, and clean areas (Figure 1). The contaminated area is connected to the fever clinic and\nincludes the fever accessway, the CT examination room, and the DR examination room for\n6", "confirmed and suspected cases. One CT scanner and one DR system closest to the emergency\ndepartment are designated the fever-CT and fever-DR to examine patients with suspected and\nconfirmed COVID-19. There is a separate dedicated access between the contaminated area and\nthe fever screening tents. The semicontaminated area includes the fever-CT control room,\nfever-DR control room, and other patient examination access areas. The buffer zone includes\naccess areas for medical personnel and a dressing area for technologists. The clean area\nincludes the administrative office and the diagnostic room.\nThe contaminated area was isolated from other areas using physical barricades.\nDirectional signs were newly installed to guide patients and staff.\nPersonal protection and training of staff\nFor providing care for patients with confirmed and suspected COVID-19, all hospital staff\nare required to wear complete personal protective equipment [7]: medical protective clothing,", "surgical cap, N95 mask, gloves, face shields, and goggles. Wearing and removing of the\nequipment must be performed in accordance with the procedures and under the supervision of\nthe infection control nurse.\nBecause staff members working in the contaminated area are under much situational\npressure, periodically taking time off could lower their physical and mental stress levels. The\ntechnologists on fever-CT duty shifts are provided a break once a week for four hours. In\naddition, the health of staff in the contaminated area must be monitored closely for the\nsymptoms of COVID-19. Pregnant staff must be assigned to the clean area.\n7\nThe EMICT formulates and continually updates guidelines and educates all staff for West\nChina Hospital of Sichuan University. The EMICT training for staff is mainly involves\ndocuments regarding infection control and CT findings of COVID-19 and maintains an EMICT\nWeChat group for West China Hospital of Sichuan University. WeChat is the most widely used", "social media app in China. The EMICT releases the latest national and hospital-based\ninformation regarding COVID-19, guidance documents, and other notices from the hospital\nand radiology department in the WeChat group on a daily basis. Staff can also report to the\nEMICT in the WeChat group any time. Protocols for each modality and infection control\ninstructions are posted on the walls in all examination rooms. The EMICT periodically reminds\nstaff to undertake personal measures to reduce infection, such as wearing masks at all instances\nin the radiology department and N95 masks if working in the contaminated area; not touching\nthe mask and the eyes; practicing hand hygiene; facing away from colleagues when eating,\ndrinking, and talking; and not using personal cell phones while on duty.\n In addition, the chief thoracic radiologist provided lectures on all radiologists and\ntechnologists on typical CT findings of COVID-19 infection using materials developed in", "Wuhan, the epicenter of the outbreak in China.\nCT examination procedures\nThere are two sets of procedures for CT examination: the fever-CT procedure and routine CT\nprocedure for those not suspected of COVID-19.\nThe fever-CT procedure for suspected or confirmed COVID-19 (Figure 2)\n8\nBefore the fever-CT technologist operates the equipment, he or she should wear personal\nprotective equipment according to three-level protection standard [8]. Before the CT\nexamination of patients with suspected and confirmed COVID-19 begins, the fever tent or\nisolation ward notifies the radiologist in advance. The fever-CT technologist checks the\nequipment and prepares to disinfect the imaging equipment immediately after the examination.\nThe patient enters the fever-CT waiting area through the fever access area. If the patient\ncan get onto and off the examination table by themselves, the patient is allowed to do so. If the", "patient cannot get onto or off the examination table independently, the person accompanying\nthe patient assists the patient, rather than the technologist. The technologist checks the patient\ninformation and, using an intercom system in the examination room, asks the patient to remove\nany metal ornaments on the neck and chest. Also, by intercom, the technologist trains the\npatient to hold his or her breath during the examination.\nThe technologist uses a low-dose chest CT protocol to scan the patient. After scanning, the\noriginal images are reconstructed as 1 mm-thick layers. The technologist browses the images to\nensure that their quality meets the diagnostic requirements and then guides the patient to leave\nthrough the fever access area. The disposable sheets for patient examination are changed after\neach patient. The equipment is disinfected according to the procedure below.\nTo protect themselves, the technologists assigned to the fever-CT wear N95 mask and", "other personal protection as established by the EMICT.\nThe CT procedure for regular patients (figure.3)\n9\nSome patients with COVID-19 have no symptoms, and they may call at the general clinic for\nother reasons. The following CT procedure is applicable under these circumstances:\nWhen the patient makes an appointment for examination, the staff asks the patient about\ntheir epidemiological history, symptoms, and signs. If suspected criteria are met, the patient\nwill be sent to the fever tent for further screening. When a patient presents to the radiology\ndepartment entrance, his/her temperature is measured. If the temperature is higher than 37.2 , ℃\nthe patient is sent to the fever tent for further investigation.\nThose with no exposure history, suspicious symptoms or fever are screened in one of the\nnon-contaminated CT scanners. The technologists assigned to these scanners wear surgical\nmasks. All patients and the person accompanying them are required to wear surgical masks.", "After the CT examination, the technologist browses the images quickly. If the CT appearance is\ntypical of lung infection, the technologist immediately reports it to the chest radiologist on duty\nand asks the patient to wait in the CT examination room. If the chest radiologist does not\nsuspect COVID-19 infection, the patient can leave the CT examination room. If the chest\nradiologist does suspect COVID-19 infection, the technologist immediately reports it to the\nEMICT and sends the patient to the fever tent. The floor and equipment in the CT examination\nroom are disinfected according to regulations, and air disinfection is conducted for 30 min\nbefore examining other patients. These CT scanners are considered noncontaminated (not\nfever-CTs) after these sterilization procedures.\nFever-DR examination procedure\n10\nThe COVID-19 guideline of the NHC does not recommend chest DR because its ability in\ndiagnosing COVID-19 is limited. At our hospital, we only use mobile DR units to provide", "bedside examination for critically ill patients. The technologist operating the mobile DR\nwears personal protective equipment according to the three-level protection standard and\nsterilizes the mobile DR according to the ward management requirements as described below.\nEquipment and environment disinfection procedures\nRoutine disinfection procedure [9]\n1) Object surface disinfection: Object surface is wiped with 1000mg/L chlorine-containing\ndisinfectant, wipe twice with 75% ethanol for non-corrosion resistance, once /4 hours.\n2) Equipment disinfection: The equipment in the contaminated area are wiped with\n2000mg/L chlorine-containing disinfectant. The DR and CT gantry in the contaminated\narea are wiped with 75% ethanol. The equipment in the buffer area is wiped with\n500-1000mg/L chlorine-containing disinfectant or alcohol-containing disposable\ndisinfectant wipes twice a day.\n3) Air disinfection: Turning off all central air conditioners to prevent air contamination with", "each other. Polluted area: open the door for ventilation, each time more than 30 minutes,\nonce /4 hours; The air sterilizer is continuously sterilized or the ultraviolet ray is\ncontinuously used in the unmanned state for 60 minutes, four times a day, remembered to\nclose the inner shielding door when air disinfection. Other ambient air is sprayed with\n1000mg/L chlorine-containing disinfectant and ventilated twice a day\n4) Ground disinfection: The ground is wiped with 1000mg/L chlorine-containing\ndisinfectant, once /4 hours.\n5) When contaminated, disinfect at any time. In case of visible contamination, disposable\nabsorbent materials should be used first to completely remove the pollutants, and then a\ncloth soaked with 2000mg/L chlorine-containing disinfectant should be used for 30\nminutes before wiping.\n11\nFever-CT disinfection procedures after examination\nIn addition to the above, disinfect the examination bed and ground with chlorinated disinfectant\ncontaining 2000mg/L [10].", "Noncontaminated CT disinfection procedures after suspected COVID-19 case examination\nIn addition to the above routine disinfection procedure, air disinfection is conducted for 30 min\nbefore examining other patients.\nResults\nFrom January 21, 2020 when screening for epidemiological history or symptoms\nsuspicious for COVID-19, to March 9, 2020, our hospital screened a total of 7,203 individuals\nand confirmed 24 cases of COVID-19. Of these, 3,083 people underwent fever-CT\nexaminations. Including the initial examination and reexamination, the total number of fever\nCT examination numbered 3,340. The fever-CT scanned a patient approximately every 21.5\nminutes. As a result of our precautions, none of the staff of the radiology department developed\nsymptoms suspicious for COVID-19. The fever-CT technologist, with the highest probability\nof exposure, remains PCR negative.\nDiscussion\nIt has been 17 years since the severe acute respiratory syndrome (SARS) epidemic, the last", "national spread of severe infectious disease, broke out. Currently, the Chinese people are\npanicking again. The speed and extent by which COVID-19 has spread in 2 months are\n12\nunprecedented, beyond those of SARS, and this has been aided by its contagious nature and\nrapid spread via droplets and contact. The droplet mode of transmission means that a person can\nbe infected easily by means of casual contact or even fomites on contaminated environmental\nsurfaces. Another theory has yet to be proved: aerosol propagation.\nHow radiology departments respond to any infectious disease outbreak is determined\nprimarily by the estimated risk of cross-infection to the staff and other patients. Appropriate\nprecautions taken only by staff in direct contact with patients may be adequate when the risk is\nlow. The strongest measures need to be implemented to limit the spread of the disease when the\nrisk is high. With severe infectious diseases such as COVID-19, the highest level of infection", "control measures must be implemented; these include providing adequate standard protective\nequipment, training staff, and instituting proper emergency plans.\nOnce a contagious infectious disease has been identified, the EMICT must consider four\nmain areas of response: data gathering, collaboration, needs assessment, and expert advice [10].\nData gathering includes dissemination of up-to-date case definitions and information about\nconfirmatory tests to all staff with direct patient contact to allow appropriate barrier precautions\nto be taken. All typical and atypical imaging features of the disease should be made known to\nall radiologists to assist in recognition of the disease on images and to allow accurate reporting\nof these findings. We have stored images of all probable cases of COVID-19 in the PACS so\nthat these images were readily available for any radiologist to review, and images from\nprevious imaging studies are also available for comparison.", "Collaboration with the radiology departments of other hospitals is very important because\npatients may initially present to different centers, depending on geographic location and travel\n13\ndistance. These patients may be few in number at a single hospital, but if data from patients at\nseveral hospitals are available, a more accurate overall understanding of both imaging features\nand epidemiology can be achieved. Dissemination of this information to all healthcare facilities\nwill also lead to early recognition of the disease, and appropriate isolation measures may be\ninstituted.\nThe Internet and social media apps, especially WeChat, have been used for distribution of\nmedical information, and because the exchange of information regarding infectious disease\noutbreaks is almost instantaneous, it is an indispensable tool for radiologists. In fact, within a\nmonth of the outbreak, the hospital that received the most infected patients from the source of", "the outbreak made a PowerPoint presentation of the CT manifestations of COVID-19, which\nwas shared via WeChat and disseminated across the country in a very short time. Subsequently,\nCOVID-19-teaching PowerPoint presentations from various hospitals appeared and were\nquickly shared via WeChat.\nOur diagnostic process is limited as chest CT along is not diagnostic of COVID-19\nbecause of lack of imaging specificity. But when combined with other epidemiological,\nclinical, laboratory and virus nucleic acid information, typical chest CT imaging findings are\nhelpful for making the diagnosis. In our opinion, the major role of chest CT is to understand the\nextent and dynamic evolution of lung lesions induced by COVID-19. The reasons why we\nadopted the low-dose chest CT scan protocol are as follows: low-dose chest CT has been\nwidely used in the screening of early lung cancer. It is well known that many early lung cancers", "are ground-glass opacities (GGO), so we believe that low-dose screening is also applicable for\nCOVID-19. In addition, considering the rapid development of COVID-19, many CT\n14\nexaminations may be conducted in the same individual to monitor disease progress. Low-dose\nscanning can reduce the radiation damage to patients.\nAlthough the processes we established minimized the exposure of hospital staff, ancillary\npersonnel and other patients, it remains limited as follows. Sichuan province is not the center of\nthe epidemic. The number of patients with COVID-19 whom we have treated has not been\nhigh, and most cases are from other provinces of China. However, we believe that our\nexperience in management, the reconfiguration of our radiology department, and the workflow\nchanges implemented in the current COVID-19 situation are useful for other radiology\ndepartments that must prepare for dealing with patients with COVID-19. While no radiology", "personnel developed symptoms suspicious for or were confirmed as having COVID-19, there\nmay be asymptomatic personnel.\nREFERENCES\n1. National Health Commission of the People’s Republic of China.(2020). March 12: Daily briefing\non novel coronavirus cases in China. Retrieved from\nhttp://en.nhc.gov.cn/2020-03/12/c_77618.htm. Accessed March 11, 2020.\n2. World Health Organization. (2020). Coronavirus disease 2019 (COVID-19) Situation Report-52.\nRetrieved from\nhttps://www.who.int/docs/default-source/coronaviruse/20200312-sitrep-52-covid-19.pdf?sfvrsn=e\n2bfc9c0_2 9. Accessed March 11, 2020.\n3. National Health Commission of the People’s Republic of China.(2020). Latest developments in\nepidemic control on Feb 15. Retrieved from http://en.nhc.gov.cn/2020-02/16/c_76622. Accessed\nMarch 11, 2020.\n15\n4. Health Commission of the People’s Republic of China.(2020). The notification of the trial\noperation based on the guideline version 6 in the coronavirus disease diagnosis and treatment.", "Retrieved from\nhttp://www.nhc.gov.cn/xcs/zhengcwj/202002/8334a8326dd94d329df351d7da8aefc2.shtml.\nAccessed March 11, 2020\n5. Health Commission of the People’s Republic of China.(2020). The notification of the trial\noperation based on the guideline version 6 in the coronavirus disease diagnosis and treatment.\nRetrieved from\nhttp://www.nhc.gov.cn/xcs/zhengcwj/202002/8334a8326dd94d329df351d7da8aefc2.shtml.\nAccessed March 11, 2020.\n6. Health Commission of the People’s Republic of China.(2009). The guideline for pathogens\nisolated operations in hospital. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/200904/40116.shtml. Accessed March 11, 2020.\n7. Health Commission of the People’s Republic of China.(2017). The guideline for prevention and\ncontrol of hospital acquired infections of airborne pathogens. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201701/7e0e8fc6725843aabba8f841f2f585d2.shtml. Accessed\nMarch 11, 2020.", "8. Health Commission of the People’s Republic of China.(2017). The guideline for prevention and\ncontrol of hospital acquired infections of airborne pathogens. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201701/7e0e8fc6725843aabba8f841f2f585d2.shtml. Accessed\nMarch 11, 2020.\n9. Health Commission of the People’s Republic of China.(2012). The standardization for\nsterilization techniques in hospital. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201204/54510.shtml. Accessed March 11, 2020.\n10. Health Commission of the People’s Republic of China.(2012). The standardization for\nsterilization techniques in hospital. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201204/54510.shtml. Accessed March 11, 2020.\n11. Katona P. Bioterrorism Preparedness: Generic Blueprint for Health Departments, Hospitals, and\nPhysicians. Infectious Diseases in Clinical Practice. 2002;11(3):115-122. Accessed March 11,\n2020.\n16\nFigure Legends", "Figure 1. Diagram of the layout of our radiology department was divided into four areas: contaminated\n(shaded in black), semicontaminated (shaded in dark gray), buffer (shaded in light gray), and clean areas\n(shaded in white). The contaminated area was separated from other areas by barriers.\nFigure 2. Diagram shows CT protocol for suspected and confirmed patients with COVID-19.\nFigure 3. Diagram shows CT protocol for regular patients.\nAbbreviations:\nCOVID-19: coronavirus disease 2019\nCT: computed tomography\nDR: digital radiography\nEMICT: emergency management and infection control team\nNHC: National Health Commission\nPACS: picture archiving and communication system\nSARS: severe acute respiratory syndrome", "Sentence Summary\nWith severe infectious diseases such as COVID-19, the highest level of infection control\nmeasures must be implemented, collaboration with the radiology departments of other\nhospitals be needed, and social media be employed.\nTake-home points\n1. To response to a community infection emergency, a special emergency management team\nneeds to be setup at the departmental level to implement infection containment and\ncontrol procedures that continues to allow the imaging examination and imaging\ndiagnosis of those with suspected infection, and to prevent intra-departmental spreading\nof infection (EMICT).\n2. Infection control measures, such as reconfiguration of department areas, personal\nprotection and anti-infection training of all staff, standardized procedures including\ncontact minimization for chest CT and DR examinations, and timely disinfection of CT\nand DR examination rooms, should be implemented properly.", "3. If there are more than one scanner in a hospital, only one of them should be assigned to\nsuspected cases." ]	[ 13 ]	3,975	6,764
188	What responses must EMICT consider once a disease has been identified?	2,457	[ "data gathering, collaboration, needs assessment, and expert advice" ]	[ "The Battle Against Coronavirus Disease 2019 (COVID-19): Emergency Management\nand Infection Control in a Radiology Department\nhttps://www.jacr.org/article/S1546-1440(20)30285-4/pdf\nJournal Pre-proof\nZixing Huang, Shuang Zhao, Zhenlin Li, Weixia Chen, Lihong Zhao, Lipeng Deng, Bin\nSong\nPII: S1546-1440(20)30285-4\nDOI: https://doi.org/10.1016/j.jacr.2020.03.011\nReference: JACR 5139\nTo appear in: Journal of the American College of Radiology\nReceived Date: 24 February 2020\nRevised Date: 13 March 2020\nAccepted Date: 15 March 2020\nPlease cite this article as: Huang Z, Zhao S, Li Z, Chen W, Zhao L, Deng L, Song B, The Battle Against\nCoronavirus Disease 2019 (COVID-19): Emergency Management and Infection Control in a Radiology\nDepartment, Journal of the American College of Radiology (2020), doi: https://doi.org/10.1016/\nj.jacr.2020.03.011.\nThis is a PDF file of an article that has undergone enhancements after acceptance, such as the addition", "of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of\nrecord. This version will undergo additional copyediting, typesetting and review before it is published\nin its final form, but we are providing this version to give early visibility of the article. Please note that,\nduring the production process, errors may be discovered which could affect the content, and all legal\ndisclaimers that apply to the journal pertain.\n© 2020 Published by Elsevier Inc. on behalf of American College of Radiology\nThe Battle Against Coronavirus Disease 2019 (COVID-19): Emergency Management\nand Infection Control in a Radiology Department\nZixing Huang, Shuang Zhao, Zhenlin Li, Weixia Chen, Lihong Zhao, Lipeng Deng,\nBin Song\nDepartment of Radiology, West China Hospital, Sichuan University, Chengdu, China\n*Zixing Huang and Shuang Zhao contributed equally to this work as co-first author.\nCorresponding Author: Bin Song, MD", "Address: Department of Radiology, West China Hospital, Sichuan University.\nNo. 37, GUOXUE Alley, Chengdu, 610041, China\nTel.: (+86)28 85423680, Fax: (+86)28 85582944\nEmail: [email protected].\nAuthors’ contributions\nZXH: conceived the study and drafted the manuscript.\nZS: conceived the study and drafted the manuscript.\nZLL: The member of the emergency management and infection control team (EMICT)\nand was involved in the formulation of the measures.\nWXC: The member of the EMICT and was involved in the formulation of the\nmeasures.\nLHZ: The member of the EMICT and was involved in the formulation of the\nmeasures.\nLPD: The member of the EMICT and was involved in the formulation of the\nmeasures.\nBS: Leader of the EMICT, conceived the study and reviewed the manuscript.\nAll authors read and approved the final manuscript.\nThe authors declare no conflict of interest.\nThe authors declare that they had full access to all of the data in this study and the", "authors take complete responsibility for the integrity of the data and the accuracy of\nthe data analysis\n1\nThe Battle Against Novel Coronavirus Pneumonia (COVID-19): Emergency\nManagement and Infection Control in a Radiology Department\nAbstract\nObjective: To describe the strategy and the emergency management and infection control\nprocedure of our radiology department during the COVID-19 outbreak.\nMethods: We set up emergency management and sensing control teams. The team formulated\nvarious measures: reconfiguration of the radiology department, personal protection and training\nof staff, examination procedures for patients suspected of or confirmed with COVID-19 as well\nas patients without an exposure history or symptoms. Those with suspected or confirmed\nCOVID-19 infection were scanned in the designated fever-CT unit.\nResults: From January 21, 2020 to March 9, 2020, 3,083 people suspected of or confirmed with\nCOVID-19 underwent fever-CT examinations. Including initial examinations and", "reexaminations, the total number of fever-CT examinations numbered 3,340. As a result of our\nprecautions, none of the staff of the radiology department were infected with COVID-19.\nConclusion: Strategic planning and adequate protections can help protect patients and staff\nagainst a highly infectious disease while maintaining function at a high volume capacity.\nKeywords: Coronavirus, COVID-19, novel coronavirus pneumonia, infection control", "2\nIntroduction\nThe whole world has been closely focusing on an outbreak of respiratory disease caused by a\nnovel coronavirus that was first reported in Wuhan, China, on December 31, 2019, and that\ncontinues to spread. On February 11, 2020, the World Health Organization (WHO) named the\ndisease “coronavirus disease 2019” (COVID-19).\nAs of 24:00 on March 11, 2020, the National Health Commission (NHC) had received reports\nof 80,793 confirmed cases and 3,169 deaths on the Chinese mainland. There remain 14,831\nconfirmed cases (including 4,257 in serious condition) and 253 suspected cases still\nhospitalized. To date, 677,243 people have been identified as having had close contact with\ninfected patients of whom13,701 are under medical observation [1]. Outside China, 44,067\nlaboratory-confirmed cases and 1,440 deaths have occurred in 117 countries /territories/areas\naccording to the WHO [2]. COVID-19 poses significant threats to international health. Like the", "flu, COVID-19 is thought to spread mainly from person-to-person between people who are in\nclose contact with one another through respiratory droplets produced when an infected person\ncoughs or sneezes. In light of the infectious nature of this disease, healthcare workers are at\nhigh risk of infection of COVID-19. In China, healthcare workers account for 1,716 confirmed\ncases of COVID-19, including six deaths [3].\n Computed tomography (CT) can play a role in both diagnosing and categorizing\nCOVID-19 on the basis of case definitions issued by the WHO and the treatment guidelines\nfrom the NHC [4]. Suspected patients having the virus may undergo chest CT. Isolation and\nbarrier procedures are necessary to protect both the department staff and other patients in the\nhospital. Note should be made that due to overlap of imaging findings with other respiratory\n3\ndiseases, CT is not helpful as a screening tool. But it can help identify the degree of pulmonary\ninvolvement and disease course.", "Our hospital is a national regional medical center with 4,300 beds and a tertiary referral\ncenter in Sichuan province. The initial response started on January 21, 2020, after transmission\nof COVID-19 was confirmed to be human-to-human on January 20, 2020. The first suspected\ncase of COVID-19 in Sichuan province was reported on January 21, 2020. The Sichuan\nprovincial government immediately launched the first-level response to major public health\nemergencies. On the same day, our hospital was designated to care for Sichuan province\npatients with COVID-19.\nThis article describes the emergency management procedure of our radiology department\nfor situations involving severe infectious diseases, such as COVID-19, and the\ninfection-protection experience of the department staff.\nMethods\nThe hospital provided personal protective equipment (medical protective clothing,\nsurgical cap, N95 mask, gloves, face shields, and goggles) to all its healthcare staff, erected", "three medical tents (fever tents) for screening of fever cases in the parking lot of the emergency\ndepartment, planned an examination route and examination area for patients suspected of\nharboring the virus, and placed confirmed patients in an isolation ward. “Fever” was the\ncolloquial term used to designate suspected COVID-19 based on symptoms such as a fever or\nwith an epidemiological history of a potential exposure as well as those with confirmed\nCOVID-19 referred for treatment. Further, during outbreak, emergency and outpatient patients\n4\nwithout fever were asked for information such as epidemiological history and sent to fever tents\nas long as they met suspected criteria.\nThe radiology department has 65 diagnostic radiologists and 161 other staff members\n(trained technologists, nurses, engineers, and support staff). The equipment of the radiology\ndepartment includes 12 magnetic resonance (MR) scanners, 14 CT scanners, 15 digital", "subtraction angiography (DSA) systems, 32 sets of digital radiography (DR) systems\n(including nine mobile bedside DR sets), and 130 imaging diagnostic workstations for picture\narchiving and communication systems (PACS). Most of the equipment is distributed among\nfour buildings at the hospital main campus. 4 CT scanners, 4 MR scanners, 1 DR are located on\nthe first floor of the first inpatient building, and 9 DR and 8 DSA are located on the second\nfloor. 1 CT and 1 MR scanner are located in the third inpatient building. 1 CT and 1 MR scanner\nare located in the sixth inpatient building. 2 CT scanners, 2 MR scanners and 7 DSA are located\nin the technical building. The rest of the equipment is located in the seventh inpatient building\nin the branch campus.\nThe first inpatient building, located next to the emergency department, was reconfigured to\nhandle cases of COVID-19. Fever tents were set up by the emergency department in the", "emergency department parking lot to separate normal emergency patients from patients with\nsymptoms or exposure history suspicious of COVID-19. We established separate means of\naccess between fever tents and between the fever examination area of the radiology department\nto avoid cross-contamination.\nThe emergency management and infection control measures, as described below and\nimplemented in the radiology department during the outbreak, have been approved by the\n5\ninfection control committee of hospital. These measures are in accordance with relevant laws\nand regulations, in order to protect patients as well as the staff.\nRadiology Emergency Management and Infection Control Team (EMICT)\nThe radiology department director chaired the EMICT. Its members include the deputy\ndirector, chief technologist, head nurse, equipment engineer supervisor, and infection control\nnurse of the radiology department. Team responsibilities included (1) coordination between the", "hospital’s management and planning of infection control and radiology departments; (2)\ncollection of the most up-to-date protection-related information to educate and train staff in the\ndepartment; (3) reallocation of staff according to the actual situation; (4) establishment of the\nCT procedures for patients with COVID-19; and (5) establishment of an emergency\nmanagement plan for the radiology department to ensure that the department would run\nnormally.\nSuspected patients\nThe suspected patients were identified according to the Diagnosis and Treatment Program of\nthe Novel Coronavirus Pneumonia of the NHC [5], mainly based on epidemiological history.\nReconfiguration of the radiology department\nThe radiology department was divided into four areas [6]: contaminated, semicontaminated,\nbuffer, and clean areas (Figure 1). The contaminated area is connected to the fever clinic and\nincludes the fever accessway, the CT examination room, and the DR examination room for\n6", "confirmed and suspected cases. One CT scanner and one DR system closest to the emergency\ndepartment are designated the fever-CT and fever-DR to examine patients with suspected and\nconfirmed COVID-19. There is a separate dedicated access between the contaminated area and\nthe fever screening tents. The semicontaminated area includes the fever-CT control room,\nfever-DR control room, and other patient examination access areas. The buffer zone includes\naccess areas for medical personnel and a dressing area for technologists. The clean area\nincludes the administrative office and the diagnostic room.\nThe contaminated area was isolated from other areas using physical barricades.\nDirectional signs were newly installed to guide patients and staff.\nPersonal protection and training of staff\nFor providing care for patients with confirmed and suspected COVID-19, all hospital staff\nare required to wear complete personal protective equipment [7]: medical protective clothing,", "surgical cap, N95 mask, gloves, face shields, and goggles. Wearing and removing of the\nequipment must be performed in accordance with the procedures and under the supervision of\nthe infection control nurse.\nBecause staff members working in the contaminated area are under much situational\npressure, periodically taking time off could lower their physical and mental stress levels. The\ntechnologists on fever-CT duty shifts are provided a break once a week for four hours. In\naddition, the health of staff in the contaminated area must be monitored closely for the\nsymptoms of COVID-19. Pregnant staff must be assigned to the clean area.\n7\nThe EMICT formulates and continually updates guidelines and educates all staff for West\nChina Hospital of Sichuan University. The EMICT training for staff is mainly involves\ndocuments regarding infection control and CT findings of COVID-19 and maintains an EMICT\nWeChat group for West China Hospital of Sichuan University. WeChat is the most widely used", "social media app in China. The EMICT releases the latest national and hospital-based\ninformation regarding COVID-19, guidance documents, and other notices from the hospital\nand radiology department in the WeChat group on a daily basis. Staff can also report to the\nEMICT in the WeChat group any time. Protocols for each modality and infection control\ninstructions are posted on the walls in all examination rooms. The EMICT periodically reminds\nstaff to undertake personal measures to reduce infection, such as wearing masks at all instances\nin the radiology department and N95 masks if working in the contaminated area; not touching\nthe mask and the eyes; practicing hand hygiene; facing away from colleagues when eating,\ndrinking, and talking; and not using personal cell phones while on duty.\n In addition, the chief thoracic radiologist provided lectures on all radiologists and\ntechnologists on typical CT findings of COVID-19 infection using materials developed in", "Wuhan, the epicenter of the outbreak in China.\nCT examination procedures\nThere are two sets of procedures for CT examination: the fever-CT procedure and routine CT\nprocedure for those not suspected of COVID-19.\nThe fever-CT procedure for suspected or confirmed COVID-19 (Figure 2)\n8\nBefore the fever-CT technologist operates the equipment, he or she should wear personal\nprotective equipment according to three-level protection standard [8]. Before the CT\nexamination of patients with suspected and confirmed COVID-19 begins, the fever tent or\nisolation ward notifies the radiologist in advance. The fever-CT technologist checks the\nequipment and prepares to disinfect the imaging equipment immediately after the examination.\nThe patient enters the fever-CT waiting area through the fever access area. If the patient\ncan get onto and off the examination table by themselves, the patient is allowed to do so. If the", "patient cannot get onto or off the examination table independently, the person accompanying\nthe patient assists the patient, rather than the technologist. The technologist checks the patient\ninformation and, using an intercom system in the examination room, asks the patient to remove\nany metal ornaments on the neck and chest. Also, by intercom, the technologist trains the\npatient to hold his or her breath during the examination.\nThe technologist uses a low-dose chest CT protocol to scan the patient. After scanning, the\noriginal images are reconstructed as 1 mm-thick layers. The technologist browses the images to\nensure that their quality meets the diagnostic requirements and then guides the patient to leave\nthrough the fever access area. The disposable sheets for patient examination are changed after\neach patient. The equipment is disinfected according to the procedure below.\nTo protect themselves, the technologists assigned to the fever-CT wear N95 mask and", "other personal protection as established by the EMICT.\nThe CT procedure for regular patients (figure.3)\n9\nSome patients with COVID-19 have no symptoms, and they may call at the general clinic for\nother reasons. The following CT procedure is applicable under these circumstances:\nWhen the patient makes an appointment for examination, the staff asks the patient about\ntheir epidemiological history, symptoms, and signs. If suspected criteria are met, the patient\nwill be sent to the fever tent for further screening. When a patient presents to the radiology\ndepartment entrance, his/her temperature is measured. If the temperature is higher than 37.2 , ℃\nthe patient is sent to the fever tent for further investigation.\nThose with no exposure history, suspicious symptoms or fever are screened in one of the\nnon-contaminated CT scanners. The technologists assigned to these scanners wear surgical\nmasks. All patients and the person accompanying them are required to wear surgical masks.", "After the CT examination, the technologist browses the images quickly. If the CT appearance is\ntypical of lung infection, the technologist immediately reports it to the chest radiologist on duty\nand asks the patient to wait in the CT examination room. If the chest radiologist does not\nsuspect COVID-19 infection, the patient can leave the CT examination room. If the chest\nradiologist does suspect COVID-19 infection, the technologist immediately reports it to the\nEMICT and sends the patient to the fever tent. The floor and equipment in the CT examination\nroom are disinfected according to regulations, and air disinfection is conducted for 30 min\nbefore examining other patients. These CT scanners are considered noncontaminated (not\nfever-CTs) after these sterilization procedures.\nFever-DR examination procedure\n10\nThe COVID-19 guideline of the NHC does not recommend chest DR because its ability in\ndiagnosing COVID-19 is limited. At our hospital, we only use mobile DR units to provide", "bedside examination for critically ill patients. The technologist operating the mobile DR\nwears personal protective equipment according to the three-level protection standard and\nsterilizes the mobile DR according to the ward management requirements as described below.\nEquipment and environment disinfection procedures\nRoutine disinfection procedure [9]\n1) Object surface disinfection: Object surface is wiped with 1000mg/L chlorine-containing\ndisinfectant, wipe twice with 75% ethanol for non-corrosion resistance, once /4 hours.\n2) Equipment disinfection: The equipment in the contaminated area are wiped with\n2000mg/L chlorine-containing disinfectant. The DR and CT gantry in the contaminated\narea are wiped with 75% ethanol. The equipment in the buffer area is wiped with\n500-1000mg/L chlorine-containing disinfectant or alcohol-containing disposable\ndisinfectant wipes twice a day.\n3) Air disinfection: Turning off all central air conditioners to prevent air contamination with", "each other. Polluted area: open the door for ventilation, each time more than 30 minutes,\nonce /4 hours; The air sterilizer is continuously sterilized or the ultraviolet ray is\ncontinuously used in the unmanned state for 60 minutes, four times a day, remembered to\nclose the inner shielding door when air disinfection. Other ambient air is sprayed with\n1000mg/L chlorine-containing disinfectant and ventilated twice a day\n4) Ground disinfection: The ground is wiped with 1000mg/L chlorine-containing\ndisinfectant, once /4 hours.\n5) When contaminated, disinfect at any time. In case of visible contamination, disposable\nabsorbent materials should be used first to completely remove the pollutants, and then a\ncloth soaked with 2000mg/L chlorine-containing disinfectant should be used for 30\nminutes before wiping.\n11\nFever-CT disinfection procedures after examination\nIn addition to the above, disinfect the examination bed and ground with chlorinated disinfectant\ncontaining 2000mg/L [10].", "Noncontaminated CT disinfection procedures after suspected COVID-19 case examination\nIn addition to the above routine disinfection procedure, air disinfection is conducted for 30 min\nbefore examining other patients.\nResults\nFrom January 21, 2020 when screening for epidemiological history or symptoms\nsuspicious for COVID-19, to March 9, 2020, our hospital screened a total of 7,203 individuals\nand confirmed 24 cases of COVID-19. Of these, 3,083 people underwent fever-CT\nexaminations. Including the initial examination and reexamination, the total number of fever\nCT examination numbered 3,340. The fever-CT scanned a patient approximately every 21.5\nminutes. As a result of our precautions, none of the staff of the radiology department developed\nsymptoms suspicious for COVID-19. The fever-CT technologist, with the highest probability\nof exposure, remains PCR negative.\nDiscussion\nIt has been 17 years since the severe acute respiratory syndrome (SARS) epidemic, the last", "national spread of severe infectious disease, broke out. Currently, the Chinese people are\npanicking again. The speed and extent by which COVID-19 has spread in 2 months are\n12\nunprecedented, beyond those of SARS, and this has been aided by its contagious nature and\nrapid spread via droplets and contact. The droplet mode of transmission means that a person can\nbe infected easily by means of casual contact or even fomites on contaminated environmental\nsurfaces. Another theory has yet to be proved: aerosol propagation.\nHow radiology departments respond to any infectious disease outbreak is determined\nprimarily by the estimated risk of cross-infection to the staff and other patients. Appropriate\nprecautions taken only by staff in direct contact with patients may be adequate when the risk is\nlow. The strongest measures need to be implemented to limit the spread of the disease when the\nrisk is high. With severe infectious diseases such as COVID-19, the highest level of infection", "control measures must be implemented; these include providing adequate standard protective\nequipment, training staff, and instituting proper emergency plans.\nOnce a contagious infectious disease has been identified, the EMICT must consider four\nmain areas of response: data gathering, collaboration, needs assessment, and expert advice [10].\nData gathering includes dissemination of up-to-date case definitions and information about\nconfirmatory tests to all staff with direct patient contact to allow appropriate barrier precautions\nto be taken. All typical and atypical imaging features of the disease should be made known to\nall radiologists to assist in recognition of the disease on images and to allow accurate reporting\nof these findings. We have stored images of all probable cases of COVID-19 in the PACS so\nthat these images were readily available for any radiologist to review, and images from\nprevious imaging studies are also available for comparison.", "Collaboration with the radiology departments of other hospitals is very important because\npatients may initially present to different centers, depending on geographic location and travel\n13\ndistance. These patients may be few in number at a single hospital, but if data from patients at\nseveral hospitals are available, a more accurate overall understanding of both imaging features\nand epidemiology can be achieved. Dissemination of this information to all healthcare facilities\nwill also lead to early recognition of the disease, and appropriate isolation measures may be\ninstituted.\nThe Internet and social media apps, especially WeChat, have been used for distribution of\nmedical information, and because the exchange of information regarding infectious disease\noutbreaks is almost instantaneous, it is an indispensable tool for radiologists. In fact, within a\nmonth of the outbreak, the hospital that received the most infected patients from the source of", "the outbreak made a PowerPoint presentation of the CT manifestations of COVID-19, which\nwas shared via WeChat and disseminated across the country in a very short time. Subsequently,\nCOVID-19-teaching PowerPoint presentations from various hospitals appeared and were\nquickly shared via WeChat.\nOur diagnostic process is limited as chest CT along is not diagnostic of COVID-19\nbecause of lack of imaging specificity. But when combined with other epidemiological,\nclinical, laboratory and virus nucleic acid information, typical chest CT imaging findings are\nhelpful for making the diagnosis. In our opinion, the major role of chest CT is to understand the\nextent and dynamic evolution of lung lesions induced by COVID-19. The reasons why we\nadopted the low-dose chest CT scan protocol are as follows: low-dose chest CT has been\nwidely used in the screening of early lung cancer. It is well known that many early lung cancers", "are ground-glass opacities (GGO), so we believe that low-dose screening is also applicable for\nCOVID-19. In addition, considering the rapid development of COVID-19, many CT\n14\nexaminations may be conducted in the same individual to monitor disease progress. Low-dose\nscanning can reduce the radiation damage to patients.\nAlthough the processes we established minimized the exposure of hospital staff, ancillary\npersonnel and other patients, it remains limited as follows. Sichuan province is not the center of\nthe epidemic. The number of patients with COVID-19 whom we have treated has not been\nhigh, and most cases are from other provinces of China. However, we believe that our\nexperience in management, the reconfiguration of our radiology department, and the workflow\nchanges implemented in the current COVID-19 situation are useful for other radiology\ndepartments that must prepare for dealing with patients with COVID-19. While no radiology", "personnel developed symptoms suspicious for or were confirmed as having COVID-19, there\nmay be asymptomatic personnel.\nREFERENCES\n1. National Health Commission of the People’s Republic of China.(2020). March 12: Daily briefing\non novel coronavirus cases in China. Retrieved from\nhttp://en.nhc.gov.cn/2020-03/12/c_77618.htm. Accessed March 11, 2020.\n2. World Health Organization. (2020). Coronavirus disease 2019 (COVID-19) Situation Report-52.\nRetrieved from\nhttps://www.who.int/docs/default-source/coronaviruse/20200312-sitrep-52-covid-19.pdf?sfvrsn=e\n2bfc9c0_2 9. Accessed March 11, 2020.\n3. National Health Commission of the People’s Republic of China.(2020). Latest developments in\nepidemic control on Feb 15. Retrieved from http://en.nhc.gov.cn/2020-02/16/c_76622. Accessed\nMarch 11, 2020.\n15\n4. Health Commission of the People’s Republic of China.(2020). The notification of the trial\noperation based on the guideline version 6 in the coronavirus disease diagnosis and treatment.", "Retrieved from\nhttp://www.nhc.gov.cn/xcs/zhengcwj/202002/8334a8326dd94d329df351d7da8aefc2.shtml.\nAccessed March 11, 2020\n5. Health Commission of the People’s Republic of China.(2020). The notification of the trial\noperation based on the guideline version 6 in the coronavirus disease diagnosis and treatment.\nRetrieved from\nhttp://www.nhc.gov.cn/xcs/zhengcwj/202002/8334a8326dd94d329df351d7da8aefc2.shtml.\nAccessed March 11, 2020.\n6. Health Commission of the People’s Republic of China.(2009). The guideline for pathogens\nisolated operations in hospital. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/200904/40116.shtml. Accessed March 11, 2020.\n7. Health Commission of the People’s Republic of China.(2017). The guideline for prevention and\ncontrol of hospital acquired infections of airborne pathogens. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201701/7e0e8fc6725843aabba8f841f2f585d2.shtml. Accessed\nMarch 11, 2020.", "8. Health Commission of the People’s Republic of China.(2017). The guideline for prevention and\ncontrol of hospital acquired infections of airborne pathogens. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201701/7e0e8fc6725843aabba8f841f2f585d2.shtml. Accessed\nMarch 11, 2020.\n9. Health Commission of the People’s Republic of China.(2012). The standardization for\nsterilization techniques in hospital. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201204/54510.shtml. Accessed March 11, 2020.\n10. Health Commission of the People’s Republic of China.(2012). The standardization for\nsterilization techniques in hospital. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201204/54510.shtml. Accessed March 11, 2020.\n11. Katona P. Bioterrorism Preparedness: Generic Blueprint for Health Departments, Hospitals, and\nPhysicians. Infectious Diseases in Clinical Practice. 2002;11(3):115-122. Accessed March 11,\n2020.\n16\nFigure Legends", "Figure 1. Diagram of the layout of our radiology department was divided into four areas: contaminated\n(shaded in black), semicontaminated (shaded in dark gray), buffer (shaded in light gray), and clean areas\n(shaded in white). The contaminated area was separated from other areas by barriers.\nFigure 2. Diagram shows CT protocol for suspected and confirmed patients with COVID-19.\nFigure 3. Diagram shows CT protocol for regular patients.\nAbbreviations:\nCOVID-19: coronavirus disease 2019\nCT: computed tomography\nDR: digital radiography\nEMICT: emergency management and infection control team\nNHC: National Health Commission\nPACS: picture archiving and communication system\nSARS: severe acute respiratory syndrome", "Sentence Summary\nWith severe infectious diseases such as COVID-19, the highest level of infection control\nmeasures must be implemented, collaboration with the radiology departments of other\nhospitals be needed, and social media be employed.\nTake-home points\n1. To response to a community infection emergency, a special emergency management team\nneeds to be setup at the departmental level to implement infection containment and\ncontrol procedures that continues to allow the imaging examination and imaging\ndiagnosis of those with suspected infection, and to prevent intra-departmental spreading\nof infection (EMICT).\n2. Infection control measures, such as reconfiguration of department areas, personal\nprotection and anti-infection training of all staff, standardized procedures including\ncontact minimization for chest CT and DR examinations, and timely disinfection of CT\nand DR examination rooms, should be implemented properly.", "3. If there are more than one scanner in a hospital, only one of them should be assigned to\nsuspected cases." ]	[ 23 ]	3,975	6,764
188	What is the conclusion of the report?	2,462	[ "Strategic planning and adequate protections can help protect patients and staff\nagainst a highly infectious disease while maintaining function at a high volume capacity.\nKeywords: Coronavirus, COVID-19, novel coronavirus pneumonia, infection control" ]	[ "The Battle Against Coronavirus Disease 2019 (COVID-19): Emergency Management\nand Infection Control in a Radiology Department\nhttps://www.jacr.org/article/S1546-1440(20)30285-4/pdf\nJournal Pre-proof\nZixing Huang, Shuang Zhao, Zhenlin Li, Weixia Chen, Lihong Zhao, Lipeng Deng, Bin\nSong\nPII: S1546-1440(20)30285-4\nDOI: https://doi.org/10.1016/j.jacr.2020.03.011\nReference: JACR 5139\nTo appear in: Journal of the American College of Radiology\nReceived Date: 24 February 2020\nRevised Date: 13 March 2020\nAccepted Date: 15 March 2020\nPlease cite this article as: Huang Z, Zhao S, Li Z, Chen W, Zhao L, Deng L, Song B, The Battle Against\nCoronavirus Disease 2019 (COVID-19): Emergency Management and Infection Control in a Radiology\nDepartment, Journal of the American College of Radiology (2020), doi: https://doi.org/10.1016/\nj.jacr.2020.03.011.\nThis is a PDF file of an article that has undergone enhancements after acceptance, such as the addition", "of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of\nrecord. This version will undergo additional copyediting, typesetting and review before it is published\nin its final form, but we are providing this version to give early visibility of the article. Please note that,\nduring the production process, errors may be discovered which could affect the content, and all legal\ndisclaimers that apply to the journal pertain.\n© 2020 Published by Elsevier Inc. on behalf of American College of Radiology\nThe Battle Against Coronavirus Disease 2019 (COVID-19): Emergency Management\nand Infection Control in a Radiology Department\nZixing Huang, Shuang Zhao, Zhenlin Li, Weixia Chen, Lihong Zhao, Lipeng Deng,\nBin Song\nDepartment of Radiology, West China Hospital, Sichuan University, Chengdu, China\n*Zixing Huang and Shuang Zhao contributed equally to this work as co-first author.\nCorresponding Author: Bin Song, MD", "Address: Department of Radiology, West China Hospital, Sichuan University.\nNo. 37, GUOXUE Alley, Chengdu, 610041, China\nTel.: (+86)28 85423680, Fax: (+86)28 85582944\nEmail: [email protected].\nAuthors’ contributions\nZXH: conceived the study and drafted the manuscript.\nZS: conceived the study and drafted the manuscript.\nZLL: The member of the emergency management and infection control team (EMICT)\nand was involved in the formulation of the measures.\nWXC: The member of the EMICT and was involved in the formulation of the\nmeasures.\nLHZ: The member of the EMICT and was involved in the formulation of the\nmeasures.\nLPD: The member of the EMICT and was involved in the formulation of the\nmeasures.\nBS: Leader of the EMICT, conceived the study and reviewed the manuscript.\nAll authors read and approved the final manuscript.\nThe authors declare no conflict of interest.\nThe authors declare that they had full access to all of the data in this study and the", "authors take complete responsibility for the integrity of the data and the accuracy of\nthe data analysis\n1\nThe Battle Against Novel Coronavirus Pneumonia (COVID-19): Emergency\nManagement and Infection Control in a Radiology Department\nAbstract\nObjective: To describe the strategy and the emergency management and infection control\nprocedure of our radiology department during the COVID-19 outbreak.\nMethods: We set up emergency management and sensing control teams. The team formulated\nvarious measures: reconfiguration of the radiology department, personal protection and training\nof staff, examination procedures for patients suspected of or confirmed with COVID-19 as well\nas patients without an exposure history or symptoms. Those with suspected or confirmed\nCOVID-19 infection were scanned in the designated fever-CT unit.\nResults: From January 21, 2020 to March 9, 2020, 3,083 people suspected of or confirmed with\nCOVID-19 underwent fever-CT examinations. Including initial examinations and", "reexaminations, the total number of fever-CT examinations numbered 3,340. As a result of our\nprecautions, none of the staff of the radiology department were infected with COVID-19.\nConclusion: Strategic planning and adequate protections can help protect patients and staff\nagainst a highly infectious disease while maintaining function at a high volume capacity.\nKeywords: Coronavirus, COVID-19, novel coronavirus pneumonia, infection control", "2\nIntroduction\nThe whole world has been closely focusing on an outbreak of respiratory disease caused by a\nnovel coronavirus that was first reported in Wuhan, China, on December 31, 2019, and that\ncontinues to spread. On February 11, 2020, the World Health Organization (WHO) named the\ndisease “coronavirus disease 2019” (COVID-19).\nAs of 24:00 on March 11, 2020, the National Health Commission (NHC) had received reports\nof 80,793 confirmed cases and 3,169 deaths on the Chinese mainland. There remain 14,831\nconfirmed cases (including 4,257 in serious condition) and 253 suspected cases still\nhospitalized. To date, 677,243 people have been identified as having had close contact with\ninfected patients of whom13,701 are under medical observation [1]. Outside China, 44,067\nlaboratory-confirmed cases and 1,440 deaths have occurred in 117 countries /territories/areas\naccording to the WHO [2]. COVID-19 poses significant threats to international health. Like the", "flu, COVID-19 is thought to spread mainly from person-to-person between people who are in\nclose contact with one another through respiratory droplets produced when an infected person\ncoughs or sneezes. In light of the infectious nature of this disease, healthcare workers are at\nhigh risk of infection of COVID-19. In China, healthcare workers account for 1,716 confirmed\ncases of COVID-19, including six deaths [3].\n Computed tomography (CT) can play a role in both diagnosing and categorizing\nCOVID-19 on the basis of case definitions issued by the WHO and the treatment guidelines\nfrom the NHC [4]. Suspected patients having the virus may undergo chest CT. Isolation and\nbarrier procedures are necessary to protect both the department staff and other patients in the\nhospital. Note should be made that due to overlap of imaging findings with other respiratory\n3\ndiseases, CT is not helpful as a screening tool. But it can help identify the degree of pulmonary\ninvolvement and disease course.", "Our hospital is a national regional medical center with 4,300 beds and a tertiary referral\ncenter in Sichuan province. The initial response started on January 21, 2020, after transmission\nof COVID-19 was confirmed to be human-to-human on January 20, 2020. The first suspected\ncase of COVID-19 in Sichuan province was reported on January 21, 2020. The Sichuan\nprovincial government immediately launched the first-level response to major public health\nemergencies. On the same day, our hospital was designated to care for Sichuan province\npatients with COVID-19.\nThis article describes the emergency management procedure of our radiology department\nfor situations involving severe infectious diseases, such as COVID-19, and the\ninfection-protection experience of the department staff.\nMethods\nThe hospital provided personal protective equipment (medical protective clothing,\nsurgical cap, N95 mask, gloves, face shields, and goggles) to all its healthcare staff, erected", "three medical tents (fever tents) for screening of fever cases in the parking lot of the emergency\ndepartment, planned an examination route and examination area for patients suspected of\nharboring the virus, and placed confirmed patients in an isolation ward. “Fever” was the\ncolloquial term used to designate suspected COVID-19 based on symptoms such as a fever or\nwith an epidemiological history of a potential exposure as well as those with confirmed\nCOVID-19 referred for treatment. Further, during outbreak, emergency and outpatient patients\n4\nwithout fever were asked for information such as epidemiological history and sent to fever tents\nas long as they met suspected criteria.\nThe radiology department has 65 diagnostic radiologists and 161 other staff members\n(trained technologists, nurses, engineers, and support staff). The equipment of the radiology\ndepartment includes 12 magnetic resonance (MR) scanners, 14 CT scanners, 15 digital", "subtraction angiography (DSA) systems, 32 sets of digital radiography (DR) systems\n(including nine mobile bedside DR sets), and 130 imaging diagnostic workstations for picture\narchiving and communication systems (PACS). Most of the equipment is distributed among\nfour buildings at the hospital main campus. 4 CT scanners, 4 MR scanners, 1 DR are located on\nthe first floor of the first inpatient building, and 9 DR and 8 DSA are located on the second\nfloor. 1 CT and 1 MR scanner are located in the third inpatient building. 1 CT and 1 MR scanner\nare located in the sixth inpatient building. 2 CT scanners, 2 MR scanners and 7 DSA are located\nin the technical building. The rest of the equipment is located in the seventh inpatient building\nin the branch campus.\nThe first inpatient building, located next to the emergency department, was reconfigured to\nhandle cases of COVID-19. Fever tents were set up by the emergency department in the", "emergency department parking lot to separate normal emergency patients from patients with\nsymptoms or exposure history suspicious of COVID-19. We established separate means of\naccess between fever tents and between the fever examination area of the radiology department\nto avoid cross-contamination.\nThe emergency management and infection control measures, as described below and\nimplemented in the radiology department during the outbreak, have been approved by the\n5\ninfection control committee of hospital. These measures are in accordance with relevant laws\nand regulations, in order to protect patients as well as the staff.\nRadiology Emergency Management and Infection Control Team (EMICT)\nThe radiology department director chaired the EMICT. Its members include the deputy\ndirector, chief technologist, head nurse, equipment engineer supervisor, and infection control\nnurse of the radiology department. Team responsibilities included (1) coordination between the", "hospital’s management and planning of infection control and radiology departments; (2)\ncollection of the most up-to-date protection-related information to educate and train staff in the\ndepartment; (3) reallocation of staff according to the actual situation; (4) establishment of the\nCT procedures for patients with COVID-19; and (5) establishment of an emergency\nmanagement plan for the radiology department to ensure that the department would run\nnormally.\nSuspected patients\nThe suspected patients were identified according to the Diagnosis and Treatment Program of\nthe Novel Coronavirus Pneumonia of the NHC [5], mainly based on epidemiological history.\nReconfiguration of the radiology department\nThe radiology department was divided into four areas [6]: contaminated, semicontaminated,\nbuffer, and clean areas (Figure 1). The contaminated area is connected to the fever clinic and\nincludes the fever accessway, the CT examination room, and the DR examination room for\n6", "confirmed and suspected cases. One CT scanner and one DR system closest to the emergency\ndepartment are designated the fever-CT and fever-DR to examine patients with suspected and\nconfirmed COVID-19. There is a separate dedicated access between the contaminated area and\nthe fever screening tents. The semicontaminated area includes the fever-CT control room,\nfever-DR control room, and other patient examination access areas. The buffer zone includes\naccess areas for medical personnel and a dressing area for technologists. The clean area\nincludes the administrative office and the diagnostic room.\nThe contaminated area was isolated from other areas using physical barricades.\nDirectional signs were newly installed to guide patients and staff.\nPersonal protection and training of staff\nFor providing care for patients with confirmed and suspected COVID-19, all hospital staff\nare required to wear complete personal protective equipment [7]: medical protective clothing,", "surgical cap, N95 mask, gloves, face shields, and goggles. Wearing and removing of the\nequipment must be performed in accordance with the procedures and under the supervision of\nthe infection control nurse.\nBecause staff members working in the contaminated area are under much situational\npressure, periodically taking time off could lower their physical and mental stress levels. The\ntechnologists on fever-CT duty shifts are provided a break once a week for four hours. In\naddition, the health of staff in the contaminated area must be monitored closely for the\nsymptoms of COVID-19. Pregnant staff must be assigned to the clean area.\n7\nThe EMICT formulates and continually updates guidelines and educates all staff for West\nChina Hospital of Sichuan University. The EMICT training for staff is mainly involves\ndocuments regarding infection control and CT findings of COVID-19 and maintains an EMICT\nWeChat group for West China Hospital of Sichuan University. WeChat is the most widely used", "social media app in China. The EMICT releases the latest national and hospital-based\ninformation regarding COVID-19, guidance documents, and other notices from the hospital\nand radiology department in the WeChat group on a daily basis. Staff can also report to the\nEMICT in the WeChat group any time. Protocols for each modality and infection control\ninstructions are posted on the walls in all examination rooms. The EMICT periodically reminds\nstaff to undertake personal measures to reduce infection, such as wearing masks at all instances\nin the radiology department and N95 masks if working in the contaminated area; not touching\nthe mask and the eyes; practicing hand hygiene; facing away from colleagues when eating,\ndrinking, and talking; and not using personal cell phones while on duty.\n In addition, the chief thoracic radiologist provided lectures on all radiologists and\ntechnologists on typical CT findings of COVID-19 infection using materials developed in", "Wuhan, the epicenter of the outbreak in China.\nCT examination procedures\nThere are two sets of procedures for CT examination: the fever-CT procedure and routine CT\nprocedure for those not suspected of COVID-19.\nThe fever-CT procedure for suspected or confirmed COVID-19 (Figure 2)\n8\nBefore the fever-CT technologist operates the equipment, he or she should wear personal\nprotective equipment according to three-level protection standard [8]. Before the CT\nexamination of patients with suspected and confirmed COVID-19 begins, the fever tent or\nisolation ward notifies the radiologist in advance. The fever-CT technologist checks the\nequipment and prepares to disinfect the imaging equipment immediately after the examination.\nThe patient enters the fever-CT waiting area through the fever access area. If the patient\ncan get onto and off the examination table by themselves, the patient is allowed to do so. If the", "patient cannot get onto or off the examination table independently, the person accompanying\nthe patient assists the patient, rather than the technologist. The technologist checks the patient\ninformation and, using an intercom system in the examination room, asks the patient to remove\nany metal ornaments on the neck and chest. Also, by intercom, the technologist trains the\npatient to hold his or her breath during the examination.\nThe technologist uses a low-dose chest CT protocol to scan the patient. After scanning, the\noriginal images are reconstructed as 1 mm-thick layers. The technologist browses the images to\nensure that their quality meets the diagnostic requirements and then guides the patient to leave\nthrough the fever access area. The disposable sheets for patient examination are changed after\neach patient. The equipment is disinfected according to the procedure below.\nTo protect themselves, the technologists assigned to the fever-CT wear N95 mask and", "other personal protection as established by the EMICT.\nThe CT procedure for regular patients (figure.3)\n9\nSome patients with COVID-19 have no symptoms, and they may call at the general clinic for\nother reasons. The following CT procedure is applicable under these circumstances:\nWhen the patient makes an appointment for examination, the staff asks the patient about\ntheir epidemiological history, symptoms, and signs. If suspected criteria are met, the patient\nwill be sent to the fever tent for further screening. When a patient presents to the radiology\ndepartment entrance, his/her temperature is measured. If the temperature is higher than 37.2 , ℃\nthe patient is sent to the fever tent for further investigation.\nThose with no exposure history, suspicious symptoms or fever are screened in one of the\nnon-contaminated CT scanners. The technologists assigned to these scanners wear surgical\nmasks. All patients and the person accompanying them are required to wear surgical masks.", "After the CT examination, the technologist browses the images quickly. If the CT appearance is\ntypical of lung infection, the technologist immediately reports it to the chest radiologist on duty\nand asks the patient to wait in the CT examination room. If the chest radiologist does not\nsuspect COVID-19 infection, the patient can leave the CT examination room. If the chest\nradiologist does suspect COVID-19 infection, the technologist immediately reports it to the\nEMICT and sends the patient to the fever tent. The floor and equipment in the CT examination\nroom are disinfected according to regulations, and air disinfection is conducted for 30 min\nbefore examining other patients. These CT scanners are considered noncontaminated (not\nfever-CTs) after these sterilization procedures.\nFever-DR examination procedure\n10\nThe COVID-19 guideline of the NHC does not recommend chest DR because its ability in\ndiagnosing COVID-19 is limited. At our hospital, we only use mobile DR units to provide", "bedside examination for critically ill patients. The technologist operating the mobile DR\nwears personal protective equipment according to the three-level protection standard and\nsterilizes the mobile DR according to the ward management requirements as described below.\nEquipment and environment disinfection procedures\nRoutine disinfection procedure [9]\n1) Object surface disinfection: Object surface is wiped with 1000mg/L chlorine-containing\ndisinfectant, wipe twice with 75% ethanol for non-corrosion resistance, once /4 hours.\n2) Equipment disinfection: The equipment in the contaminated area are wiped with\n2000mg/L chlorine-containing disinfectant. The DR and CT gantry in the contaminated\narea are wiped with 75% ethanol. The equipment in the buffer area is wiped with\n500-1000mg/L chlorine-containing disinfectant or alcohol-containing disposable\ndisinfectant wipes twice a day.\n3) Air disinfection: Turning off all central air conditioners to prevent air contamination with", "each other. Polluted area: open the door for ventilation, each time more than 30 minutes,\nonce /4 hours; The air sterilizer is continuously sterilized or the ultraviolet ray is\ncontinuously used in the unmanned state for 60 minutes, four times a day, remembered to\nclose the inner shielding door when air disinfection. Other ambient air is sprayed with\n1000mg/L chlorine-containing disinfectant and ventilated twice a day\n4) Ground disinfection: The ground is wiped with 1000mg/L chlorine-containing\ndisinfectant, once /4 hours.\n5) When contaminated, disinfect at any time. In case of visible contamination, disposable\nabsorbent materials should be used first to completely remove the pollutants, and then a\ncloth soaked with 2000mg/L chlorine-containing disinfectant should be used for 30\nminutes before wiping.\n11\nFever-CT disinfection procedures after examination\nIn addition to the above, disinfect the examination bed and ground with chlorinated disinfectant\ncontaining 2000mg/L [10].", "Noncontaminated CT disinfection procedures after suspected COVID-19 case examination\nIn addition to the above routine disinfection procedure, air disinfection is conducted for 30 min\nbefore examining other patients.\nResults\nFrom January 21, 2020 when screening for epidemiological history or symptoms\nsuspicious for COVID-19, to March 9, 2020, our hospital screened a total of 7,203 individuals\nand confirmed 24 cases of COVID-19. Of these, 3,083 people underwent fever-CT\nexaminations. Including the initial examination and reexamination, the total number of fever\nCT examination numbered 3,340. The fever-CT scanned a patient approximately every 21.5\nminutes. As a result of our precautions, none of the staff of the radiology department developed\nsymptoms suspicious for COVID-19. The fever-CT technologist, with the highest probability\nof exposure, remains PCR negative.\nDiscussion\nIt has been 17 years since the severe acute respiratory syndrome (SARS) epidemic, the last", "national spread of severe infectious disease, broke out. Currently, the Chinese people are\npanicking again. The speed and extent by which COVID-19 has spread in 2 months are\n12\nunprecedented, beyond those of SARS, and this has been aided by its contagious nature and\nrapid spread via droplets and contact. The droplet mode of transmission means that a person can\nbe infected easily by means of casual contact or even fomites on contaminated environmental\nsurfaces. Another theory has yet to be proved: aerosol propagation.\nHow radiology departments respond to any infectious disease outbreak is determined\nprimarily by the estimated risk of cross-infection to the staff and other patients. Appropriate\nprecautions taken only by staff in direct contact with patients may be adequate when the risk is\nlow. The strongest measures need to be implemented to limit the spread of the disease when the\nrisk is high. With severe infectious diseases such as COVID-19, the highest level of infection", "control measures must be implemented; these include providing adequate standard protective\nequipment, training staff, and instituting proper emergency plans.\nOnce a contagious infectious disease has been identified, the EMICT must consider four\nmain areas of response: data gathering, collaboration, needs assessment, and expert advice [10].\nData gathering includes dissemination of up-to-date case definitions and information about\nconfirmatory tests to all staff with direct patient contact to allow appropriate barrier precautions\nto be taken. All typical and atypical imaging features of the disease should be made known to\nall radiologists to assist in recognition of the disease on images and to allow accurate reporting\nof these findings. We have stored images of all probable cases of COVID-19 in the PACS so\nthat these images were readily available for any radiologist to review, and images from\nprevious imaging studies are also available for comparison.", "Collaboration with the radiology departments of other hospitals is very important because\npatients may initially present to different centers, depending on geographic location and travel\n13\ndistance. These patients may be few in number at a single hospital, but if data from patients at\nseveral hospitals are available, a more accurate overall understanding of both imaging features\nand epidemiology can be achieved. Dissemination of this information to all healthcare facilities\nwill also lead to early recognition of the disease, and appropriate isolation measures may be\ninstituted.\nThe Internet and social media apps, especially WeChat, have been used for distribution of\nmedical information, and because the exchange of information regarding infectious disease\noutbreaks is almost instantaneous, it is an indispensable tool for radiologists. In fact, within a\nmonth of the outbreak, the hospital that received the most infected patients from the source of", "the outbreak made a PowerPoint presentation of the CT manifestations of COVID-19, which\nwas shared via WeChat and disseminated across the country in a very short time. Subsequently,\nCOVID-19-teaching PowerPoint presentations from various hospitals appeared and were\nquickly shared via WeChat.\nOur diagnostic process is limited as chest CT along is not diagnostic of COVID-19\nbecause of lack of imaging specificity. But when combined with other epidemiological,\nclinical, laboratory and virus nucleic acid information, typical chest CT imaging findings are\nhelpful for making the diagnosis. In our opinion, the major role of chest CT is to understand the\nextent and dynamic evolution of lung lesions induced by COVID-19. The reasons why we\nadopted the low-dose chest CT scan protocol are as follows: low-dose chest CT has been\nwidely used in the screening of early lung cancer. It is well known that many early lung cancers", "are ground-glass opacities (GGO), so we believe that low-dose screening is also applicable for\nCOVID-19. In addition, considering the rapid development of COVID-19, many CT\n14\nexaminations may be conducted in the same individual to monitor disease progress. Low-dose\nscanning can reduce the radiation damage to patients.\nAlthough the processes we established minimized the exposure of hospital staff, ancillary\npersonnel and other patients, it remains limited as follows. Sichuan province is not the center of\nthe epidemic. The number of patients with COVID-19 whom we have treated has not been\nhigh, and most cases are from other provinces of China. However, we believe that our\nexperience in management, the reconfiguration of our radiology department, and the workflow\nchanges implemented in the current COVID-19 situation are useful for other radiology\ndepartments that must prepare for dealing with patients with COVID-19. While no radiology", "personnel developed symptoms suspicious for or were confirmed as having COVID-19, there\nmay be asymptomatic personnel.\nREFERENCES\n1. National Health Commission of the People’s Republic of China.(2020). March 12: Daily briefing\non novel coronavirus cases in China. Retrieved from\nhttp://en.nhc.gov.cn/2020-03/12/c_77618.htm. Accessed March 11, 2020.\n2. World Health Organization. (2020). Coronavirus disease 2019 (COVID-19) Situation Report-52.\nRetrieved from\nhttps://www.who.int/docs/default-source/coronaviruse/20200312-sitrep-52-covid-19.pdf?sfvrsn=e\n2bfc9c0_2 9. Accessed March 11, 2020.\n3. National Health Commission of the People’s Republic of China.(2020). Latest developments in\nepidemic control on Feb 15. Retrieved from http://en.nhc.gov.cn/2020-02/16/c_76622. Accessed\nMarch 11, 2020.\n15\n4. Health Commission of the People’s Republic of China.(2020). The notification of the trial\noperation based on the guideline version 6 in the coronavirus disease diagnosis and treatment.", "Retrieved from\nhttp://www.nhc.gov.cn/xcs/zhengcwj/202002/8334a8326dd94d329df351d7da8aefc2.shtml.\nAccessed March 11, 2020\n5. Health Commission of the People’s Republic of China.(2020). The notification of the trial\noperation based on the guideline version 6 in the coronavirus disease diagnosis and treatment.\nRetrieved from\nhttp://www.nhc.gov.cn/xcs/zhengcwj/202002/8334a8326dd94d329df351d7da8aefc2.shtml.\nAccessed March 11, 2020.\n6. Health Commission of the People’s Republic of China.(2009). The guideline for pathogens\nisolated operations in hospital. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/200904/40116.shtml. Accessed March 11, 2020.\n7. Health Commission of the People’s Republic of China.(2017). The guideline for prevention and\ncontrol of hospital acquired infections of airborne pathogens. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201701/7e0e8fc6725843aabba8f841f2f585d2.shtml. Accessed\nMarch 11, 2020.", "8. Health Commission of the People’s Republic of China.(2017). The guideline for prevention and\ncontrol of hospital acquired infections of airborne pathogens. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201701/7e0e8fc6725843aabba8f841f2f585d2.shtml. Accessed\nMarch 11, 2020.\n9. Health Commission of the People’s Republic of China.(2012). The standardization for\nsterilization techniques in hospital. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201204/54510.shtml. Accessed March 11, 2020.\n10. Health Commission of the People’s Republic of China.(2012). The standardization for\nsterilization techniques in hospital. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201204/54510.shtml. Accessed March 11, 2020.\n11. Katona P. Bioterrorism Preparedness: Generic Blueprint for Health Departments, Hospitals, and\nPhysicians. Infectious Diseases in Clinical Practice. 2002;11(3):115-122. Accessed March 11,\n2020.\n16\nFigure Legends", "Figure 1. Diagram of the layout of our radiology department was divided into four areas: contaminated\n(shaded in black), semicontaminated (shaded in dark gray), buffer (shaded in light gray), and clean areas\n(shaded in white). The contaminated area was separated from other areas by barriers.\nFigure 2. Diagram shows CT protocol for suspected and confirmed patients with COVID-19.\nFigure 3. Diagram shows CT protocol for regular patients.\nAbbreviations:\nCOVID-19: coronavirus disease 2019\nCT: computed tomography\nDR: digital radiography\nEMICT: emergency management and infection control team\nNHC: National Health Commission\nPACS: picture archiving and communication system\nSARS: severe acute respiratory syndrome", "Sentence Summary\nWith severe infectious diseases such as COVID-19, the highest level of infection control\nmeasures must be implemented, collaboration with the radiology departments of other\nhospitals be needed, and social media be employed.\nTake-home points\n1. To response to a community infection emergency, a special emergency management team\nneeds to be setup at the departmental level to implement infection containment and\ncontrol procedures that continues to allow the imaging examination and imaging\ndiagnosis of those with suspected infection, and to prevent intra-departmental spreading\nof infection (EMICT).\n2. Infection control measures, such as reconfiguration of department areas, personal\nprotection and anti-infection training of all staff, standardized procedures including\ncontact minimization for chest CT and DR examinations, and timely disinfection of CT\nand DR examination rooms, should be implemented properly.", "3. If there are more than one scanner in a hospital, only one of them should be assigned to\nsuspected cases." ]	[ 4 ]	3,975	6,764
188	What were the number of cases in mainland china as of March 11th?	2,463	[ "80,793" ]	[ "The Battle Against Coronavirus Disease 2019 (COVID-19): Emergency Management\nand Infection Control in a Radiology Department\nhttps://www.jacr.org/article/S1546-1440(20)30285-4/pdf\nJournal Pre-proof\nZixing Huang, Shuang Zhao, Zhenlin Li, Weixia Chen, Lihong Zhao, Lipeng Deng, Bin\nSong\nPII: S1546-1440(20)30285-4\nDOI: https://doi.org/10.1016/j.jacr.2020.03.011\nReference: JACR 5139\nTo appear in: Journal of the American College of Radiology\nReceived Date: 24 February 2020\nRevised Date: 13 March 2020\nAccepted Date: 15 March 2020\nPlease cite this article as: Huang Z, Zhao S, Li Z, Chen W, Zhao L, Deng L, Song B, The Battle Against\nCoronavirus Disease 2019 (COVID-19): Emergency Management and Infection Control in a Radiology\nDepartment, Journal of the American College of Radiology (2020), doi: https://doi.org/10.1016/\nj.jacr.2020.03.011.\nThis is a PDF file of an article that has undergone enhancements after acceptance, such as the addition", "of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of\nrecord. This version will undergo additional copyediting, typesetting and review before it is published\nin its final form, but we are providing this version to give early visibility of the article. Please note that,\nduring the production process, errors may be discovered which could affect the content, and all legal\ndisclaimers that apply to the journal pertain.\n© 2020 Published by Elsevier Inc. on behalf of American College of Radiology\nThe Battle Against Coronavirus Disease 2019 (COVID-19): Emergency Management\nand Infection Control in a Radiology Department\nZixing Huang, Shuang Zhao, Zhenlin Li, Weixia Chen, Lihong Zhao, Lipeng Deng,\nBin Song\nDepartment of Radiology, West China Hospital, Sichuan University, Chengdu, China\n*Zixing Huang and Shuang Zhao contributed equally to this work as co-first author.\nCorresponding Author: Bin Song, MD", "Address: Department of Radiology, West China Hospital, Sichuan University.\nNo. 37, GUOXUE Alley, Chengdu, 610041, China\nTel.: (+86)28 85423680, Fax: (+86)28 85582944\nEmail: [email protected].\nAuthors’ contributions\nZXH: conceived the study and drafted the manuscript.\nZS: conceived the study and drafted the manuscript.\nZLL: The member of the emergency management and infection control team (EMICT)\nand was involved in the formulation of the measures.\nWXC: The member of the EMICT and was involved in the formulation of the\nmeasures.\nLHZ: The member of the EMICT and was involved in the formulation of the\nmeasures.\nLPD: The member of the EMICT and was involved in the formulation of the\nmeasures.\nBS: Leader of the EMICT, conceived the study and reviewed the manuscript.\nAll authors read and approved the final manuscript.\nThe authors declare no conflict of interest.\nThe authors declare that they had full access to all of the data in this study and the", "authors take complete responsibility for the integrity of the data and the accuracy of\nthe data analysis\n1\nThe Battle Against Novel Coronavirus Pneumonia (COVID-19): Emergency\nManagement and Infection Control in a Radiology Department\nAbstract\nObjective: To describe the strategy and the emergency management and infection control\nprocedure of our radiology department during the COVID-19 outbreak.\nMethods: We set up emergency management and sensing control teams. The team formulated\nvarious measures: reconfiguration of the radiology department, personal protection and training\nof staff, examination procedures for patients suspected of or confirmed with COVID-19 as well\nas patients without an exposure history or symptoms. Those with suspected or confirmed\nCOVID-19 infection were scanned in the designated fever-CT unit.\nResults: From January 21, 2020 to March 9, 2020, 3,083 people suspected of or confirmed with\nCOVID-19 underwent fever-CT examinations. Including initial examinations and", "reexaminations, the total number of fever-CT examinations numbered 3,340. As a result of our\nprecautions, none of the staff of the radiology department were infected with COVID-19.\nConclusion: Strategic planning and adequate protections can help protect patients and staff\nagainst a highly infectious disease while maintaining function at a high volume capacity.\nKeywords: Coronavirus, COVID-19, novel coronavirus pneumonia, infection control", "2\nIntroduction\nThe whole world has been closely focusing on an outbreak of respiratory disease caused by a\nnovel coronavirus that was first reported in Wuhan, China, on December 31, 2019, and that\ncontinues to spread. On February 11, 2020, the World Health Organization (WHO) named the\ndisease “coronavirus disease 2019” (COVID-19).\nAs of 24:00 on March 11, 2020, the National Health Commission (NHC) had received reports\nof 80,793 confirmed cases and 3,169 deaths on the Chinese mainland. There remain 14,831\nconfirmed cases (including 4,257 in serious condition) and 253 suspected cases still\nhospitalized. To date, 677,243 people have been identified as having had close contact with\ninfected patients of whom13,701 are under medical observation [1]. Outside China, 44,067\nlaboratory-confirmed cases and 1,440 deaths have occurred in 117 countries /territories/areas\naccording to the WHO [2]. COVID-19 poses significant threats to international health. Like the", "flu, COVID-19 is thought to spread mainly from person-to-person between people who are in\nclose contact with one another through respiratory droplets produced when an infected person\ncoughs or sneezes. In light of the infectious nature of this disease, healthcare workers are at\nhigh risk of infection of COVID-19. In China, healthcare workers account for 1,716 confirmed\ncases of COVID-19, including six deaths [3].\n Computed tomography (CT) can play a role in both diagnosing and categorizing\nCOVID-19 on the basis of case definitions issued by the WHO and the treatment guidelines\nfrom the NHC [4]. Suspected patients having the virus may undergo chest CT. Isolation and\nbarrier procedures are necessary to protect both the department staff and other patients in the\nhospital. Note should be made that due to overlap of imaging findings with other respiratory\n3\ndiseases, CT is not helpful as a screening tool. But it can help identify the degree of pulmonary\ninvolvement and disease course.", "Our hospital is a national regional medical center with 4,300 beds and a tertiary referral\ncenter in Sichuan province. The initial response started on January 21, 2020, after transmission\nof COVID-19 was confirmed to be human-to-human on January 20, 2020. The first suspected\ncase of COVID-19 in Sichuan province was reported on January 21, 2020. The Sichuan\nprovincial government immediately launched the first-level response to major public health\nemergencies. On the same day, our hospital was designated to care for Sichuan province\npatients with COVID-19.\nThis article describes the emergency management procedure of our radiology department\nfor situations involving severe infectious diseases, such as COVID-19, and the\ninfection-protection experience of the department staff.\nMethods\nThe hospital provided personal protective equipment (medical protective clothing,\nsurgical cap, N95 mask, gloves, face shields, and goggles) to all its healthcare staff, erected", "three medical tents (fever tents) for screening of fever cases in the parking lot of the emergency\ndepartment, planned an examination route and examination area for patients suspected of\nharboring the virus, and placed confirmed patients in an isolation ward. “Fever” was the\ncolloquial term used to designate suspected COVID-19 based on symptoms such as a fever or\nwith an epidemiological history of a potential exposure as well as those with confirmed\nCOVID-19 referred for treatment. Further, during outbreak, emergency and outpatient patients\n4\nwithout fever were asked for information such as epidemiological history and sent to fever tents\nas long as they met suspected criteria.\nThe radiology department has 65 diagnostic radiologists and 161 other staff members\n(trained technologists, nurses, engineers, and support staff). The equipment of the radiology\ndepartment includes 12 magnetic resonance (MR) scanners, 14 CT scanners, 15 digital", "subtraction angiography (DSA) systems, 32 sets of digital radiography (DR) systems\n(including nine mobile bedside DR sets), and 130 imaging diagnostic workstations for picture\narchiving and communication systems (PACS). Most of the equipment is distributed among\nfour buildings at the hospital main campus. 4 CT scanners, 4 MR scanners, 1 DR are located on\nthe first floor of the first inpatient building, and 9 DR and 8 DSA are located on the second\nfloor. 1 CT and 1 MR scanner are located in the third inpatient building. 1 CT and 1 MR scanner\nare located in the sixth inpatient building. 2 CT scanners, 2 MR scanners and 7 DSA are located\nin the technical building. The rest of the equipment is located in the seventh inpatient building\nin the branch campus.\nThe first inpatient building, located next to the emergency department, was reconfigured to\nhandle cases of COVID-19. Fever tents were set up by the emergency department in the", "emergency department parking lot to separate normal emergency patients from patients with\nsymptoms or exposure history suspicious of COVID-19. We established separate means of\naccess between fever tents and between the fever examination area of the radiology department\nto avoid cross-contamination.\nThe emergency management and infection control measures, as described below and\nimplemented in the radiology department during the outbreak, have been approved by the\n5\ninfection control committee of hospital. These measures are in accordance with relevant laws\nand regulations, in order to protect patients as well as the staff.\nRadiology Emergency Management and Infection Control Team (EMICT)\nThe radiology department director chaired the EMICT. Its members include the deputy\ndirector, chief technologist, head nurse, equipment engineer supervisor, and infection control\nnurse of the radiology department. Team responsibilities included (1) coordination between the", "hospital’s management and planning of infection control and radiology departments; (2)\ncollection of the most up-to-date protection-related information to educate and train staff in the\ndepartment; (3) reallocation of staff according to the actual situation; (4) establishment of the\nCT procedures for patients with COVID-19; and (5) establishment of an emergency\nmanagement plan for the radiology department to ensure that the department would run\nnormally.\nSuspected patients\nThe suspected patients were identified according to the Diagnosis and Treatment Program of\nthe Novel Coronavirus Pneumonia of the NHC [5], mainly based on epidemiological history.\nReconfiguration of the radiology department\nThe radiology department was divided into four areas [6]: contaminated, semicontaminated,\nbuffer, and clean areas (Figure 1). The contaminated area is connected to the fever clinic and\nincludes the fever accessway, the CT examination room, and the DR examination room for\n6", "confirmed and suspected cases. One CT scanner and one DR system closest to the emergency\ndepartment are designated the fever-CT and fever-DR to examine patients with suspected and\nconfirmed COVID-19. There is a separate dedicated access between the contaminated area and\nthe fever screening tents. The semicontaminated area includes the fever-CT control room,\nfever-DR control room, and other patient examination access areas. The buffer zone includes\naccess areas for medical personnel and a dressing area for technologists. The clean area\nincludes the administrative office and the diagnostic room.\nThe contaminated area was isolated from other areas using physical barricades.\nDirectional signs were newly installed to guide patients and staff.\nPersonal protection and training of staff\nFor providing care for patients with confirmed and suspected COVID-19, all hospital staff\nare required to wear complete personal protective equipment [7]: medical protective clothing,", "surgical cap, N95 mask, gloves, face shields, and goggles. Wearing and removing of the\nequipment must be performed in accordance with the procedures and under the supervision of\nthe infection control nurse.\nBecause staff members working in the contaminated area are under much situational\npressure, periodically taking time off could lower their physical and mental stress levels. The\ntechnologists on fever-CT duty shifts are provided a break once a week for four hours. In\naddition, the health of staff in the contaminated area must be monitored closely for the\nsymptoms of COVID-19. Pregnant staff must be assigned to the clean area.\n7\nThe EMICT formulates and continually updates guidelines and educates all staff for West\nChina Hospital of Sichuan University. The EMICT training for staff is mainly involves\ndocuments regarding infection control and CT findings of COVID-19 and maintains an EMICT\nWeChat group for West China Hospital of Sichuan University. WeChat is the most widely used", "social media app in China. The EMICT releases the latest national and hospital-based\ninformation regarding COVID-19, guidance documents, and other notices from the hospital\nand radiology department in the WeChat group on a daily basis. Staff can also report to the\nEMICT in the WeChat group any time. Protocols for each modality and infection control\ninstructions are posted on the walls in all examination rooms. The EMICT periodically reminds\nstaff to undertake personal measures to reduce infection, such as wearing masks at all instances\nin the radiology department and N95 masks if working in the contaminated area; not touching\nthe mask and the eyes; practicing hand hygiene; facing away from colleagues when eating,\ndrinking, and talking; and not using personal cell phones while on duty.\n In addition, the chief thoracic radiologist provided lectures on all radiologists and\ntechnologists on typical CT findings of COVID-19 infection using materials developed in", "Wuhan, the epicenter of the outbreak in China.\nCT examination procedures\nThere are two sets of procedures for CT examination: the fever-CT procedure and routine CT\nprocedure for those not suspected of COVID-19.\nThe fever-CT procedure for suspected or confirmed COVID-19 (Figure 2)\n8\nBefore the fever-CT technologist operates the equipment, he or she should wear personal\nprotective equipment according to three-level protection standard [8]. Before the CT\nexamination of patients with suspected and confirmed COVID-19 begins, the fever tent or\nisolation ward notifies the radiologist in advance. The fever-CT technologist checks the\nequipment and prepares to disinfect the imaging equipment immediately after the examination.\nThe patient enters the fever-CT waiting area through the fever access area. If the patient\ncan get onto and off the examination table by themselves, the patient is allowed to do so. If the", "patient cannot get onto or off the examination table independently, the person accompanying\nthe patient assists the patient, rather than the technologist. The technologist checks the patient\ninformation and, using an intercom system in the examination room, asks the patient to remove\nany metal ornaments on the neck and chest. Also, by intercom, the technologist trains the\npatient to hold his or her breath during the examination.\nThe technologist uses a low-dose chest CT protocol to scan the patient. After scanning, the\noriginal images are reconstructed as 1 mm-thick layers. The technologist browses the images to\nensure that their quality meets the diagnostic requirements and then guides the patient to leave\nthrough the fever access area. The disposable sheets for patient examination are changed after\neach patient. The equipment is disinfected according to the procedure below.\nTo protect themselves, the technologists assigned to the fever-CT wear N95 mask and", "other personal protection as established by the EMICT.\nThe CT procedure for regular patients (figure.3)\n9\nSome patients with COVID-19 have no symptoms, and they may call at the general clinic for\nother reasons. The following CT procedure is applicable under these circumstances:\nWhen the patient makes an appointment for examination, the staff asks the patient about\ntheir epidemiological history, symptoms, and signs. If suspected criteria are met, the patient\nwill be sent to the fever tent for further screening. When a patient presents to the radiology\ndepartment entrance, his/her temperature is measured. If the temperature is higher than 37.2 , ℃\nthe patient is sent to the fever tent for further investigation.\nThose with no exposure history, suspicious symptoms or fever are screened in one of the\nnon-contaminated CT scanners. The technologists assigned to these scanners wear surgical\nmasks. All patients and the person accompanying them are required to wear surgical masks.", "After the CT examination, the technologist browses the images quickly. If the CT appearance is\ntypical of lung infection, the technologist immediately reports it to the chest radiologist on duty\nand asks the patient to wait in the CT examination room. If the chest radiologist does not\nsuspect COVID-19 infection, the patient can leave the CT examination room. If the chest\nradiologist does suspect COVID-19 infection, the technologist immediately reports it to the\nEMICT and sends the patient to the fever tent. The floor and equipment in the CT examination\nroom are disinfected according to regulations, and air disinfection is conducted for 30 min\nbefore examining other patients. These CT scanners are considered noncontaminated (not\nfever-CTs) after these sterilization procedures.\nFever-DR examination procedure\n10\nThe COVID-19 guideline of the NHC does not recommend chest DR because its ability in\ndiagnosing COVID-19 is limited. At our hospital, we only use mobile DR units to provide", "bedside examination for critically ill patients. The technologist operating the mobile DR\nwears personal protective equipment according to the three-level protection standard and\nsterilizes the mobile DR according to the ward management requirements as described below.\nEquipment and environment disinfection procedures\nRoutine disinfection procedure [9]\n1) Object surface disinfection: Object surface is wiped with 1000mg/L chlorine-containing\ndisinfectant, wipe twice with 75% ethanol for non-corrosion resistance, once /4 hours.\n2) Equipment disinfection: The equipment in the contaminated area are wiped with\n2000mg/L chlorine-containing disinfectant. The DR and CT gantry in the contaminated\narea are wiped with 75% ethanol. The equipment in the buffer area is wiped with\n500-1000mg/L chlorine-containing disinfectant or alcohol-containing disposable\ndisinfectant wipes twice a day.\n3) Air disinfection: Turning off all central air conditioners to prevent air contamination with", "each other. Polluted area: open the door for ventilation, each time more than 30 minutes,\nonce /4 hours; The air sterilizer is continuously sterilized or the ultraviolet ray is\ncontinuously used in the unmanned state for 60 minutes, four times a day, remembered to\nclose the inner shielding door when air disinfection. Other ambient air is sprayed with\n1000mg/L chlorine-containing disinfectant and ventilated twice a day\n4) Ground disinfection: The ground is wiped with 1000mg/L chlorine-containing\ndisinfectant, once /4 hours.\n5) When contaminated, disinfect at any time. In case of visible contamination, disposable\nabsorbent materials should be used first to completely remove the pollutants, and then a\ncloth soaked with 2000mg/L chlorine-containing disinfectant should be used for 30\nminutes before wiping.\n11\nFever-CT disinfection procedures after examination\nIn addition to the above, disinfect the examination bed and ground with chlorinated disinfectant\ncontaining 2000mg/L [10].", "Noncontaminated CT disinfection procedures after suspected COVID-19 case examination\nIn addition to the above routine disinfection procedure, air disinfection is conducted for 30 min\nbefore examining other patients.\nResults\nFrom January 21, 2020 when screening for epidemiological history or symptoms\nsuspicious for COVID-19, to March 9, 2020, our hospital screened a total of 7,203 individuals\nand confirmed 24 cases of COVID-19. Of these, 3,083 people underwent fever-CT\nexaminations. Including the initial examination and reexamination, the total number of fever\nCT examination numbered 3,340. The fever-CT scanned a patient approximately every 21.5\nminutes. As a result of our precautions, none of the staff of the radiology department developed\nsymptoms suspicious for COVID-19. The fever-CT technologist, with the highest probability\nof exposure, remains PCR negative.\nDiscussion\nIt has been 17 years since the severe acute respiratory syndrome (SARS) epidemic, the last", "national spread of severe infectious disease, broke out. Currently, the Chinese people are\npanicking again. The speed and extent by which COVID-19 has spread in 2 months are\n12\nunprecedented, beyond those of SARS, and this has been aided by its contagious nature and\nrapid spread via droplets and contact. The droplet mode of transmission means that a person can\nbe infected easily by means of casual contact or even fomites on contaminated environmental\nsurfaces. Another theory has yet to be proved: aerosol propagation.\nHow radiology departments respond to any infectious disease outbreak is determined\nprimarily by the estimated risk of cross-infection to the staff and other patients. Appropriate\nprecautions taken only by staff in direct contact with patients may be adequate when the risk is\nlow. The strongest measures need to be implemented to limit the spread of the disease when the\nrisk is high. With severe infectious diseases such as COVID-19, the highest level of infection", "control measures must be implemented; these include providing adequate standard protective\nequipment, training staff, and instituting proper emergency plans.\nOnce a contagious infectious disease has been identified, the EMICT must consider four\nmain areas of response: data gathering, collaboration, needs assessment, and expert advice [10].\nData gathering includes dissemination of up-to-date case definitions and information about\nconfirmatory tests to all staff with direct patient contact to allow appropriate barrier precautions\nto be taken. All typical and atypical imaging features of the disease should be made known to\nall radiologists to assist in recognition of the disease on images and to allow accurate reporting\nof these findings. We have stored images of all probable cases of COVID-19 in the PACS so\nthat these images were readily available for any radiologist to review, and images from\nprevious imaging studies are also available for comparison.", "Collaboration with the radiology departments of other hospitals is very important because\npatients may initially present to different centers, depending on geographic location and travel\n13\ndistance. These patients may be few in number at a single hospital, but if data from patients at\nseveral hospitals are available, a more accurate overall understanding of both imaging features\nand epidemiology can be achieved. Dissemination of this information to all healthcare facilities\nwill also lead to early recognition of the disease, and appropriate isolation measures may be\ninstituted.\nThe Internet and social media apps, especially WeChat, have been used for distribution of\nmedical information, and because the exchange of information regarding infectious disease\noutbreaks is almost instantaneous, it is an indispensable tool for radiologists. In fact, within a\nmonth of the outbreak, the hospital that received the most infected patients from the source of", "the outbreak made a PowerPoint presentation of the CT manifestations of COVID-19, which\nwas shared via WeChat and disseminated across the country in a very short time. Subsequently,\nCOVID-19-teaching PowerPoint presentations from various hospitals appeared and were\nquickly shared via WeChat.\nOur diagnostic process is limited as chest CT along is not diagnostic of COVID-19\nbecause of lack of imaging specificity. But when combined with other epidemiological,\nclinical, laboratory and virus nucleic acid information, typical chest CT imaging findings are\nhelpful for making the diagnosis. In our opinion, the major role of chest CT is to understand the\nextent and dynamic evolution of lung lesions induced by COVID-19. The reasons why we\nadopted the low-dose chest CT scan protocol are as follows: low-dose chest CT has been\nwidely used in the screening of early lung cancer. It is well known that many early lung cancers", "are ground-glass opacities (GGO), so we believe that low-dose screening is also applicable for\nCOVID-19. In addition, considering the rapid development of COVID-19, many CT\n14\nexaminations may be conducted in the same individual to monitor disease progress. Low-dose\nscanning can reduce the radiation damage to patients.\nAlthough the processes we established minimized the exposure of hospital staff, ancillary\npersonnel and other patients, it remains limited as follows. Sichuan province is not the center of\nthe epidemic. The number of patients with COVID-19 whom we have treated has not been\nhigh, and most cases are from other provinces of China. However, we believe that our\nexperience in management, the reconfiguration of our radiology department, and the workflow\nchanges implemented in the current COVID-19 situation are useful for other radiology\ndepartments that must prepare for dealing with patients with COVID-19. While no radiology", "personnel developed symptoms suspicious for or were confirmed as having COVID-19, there\nmay be asymptomatic personnel.\nREFERENCES\n1. National Health Commission of the People’s Republic of China.(2020). March 12: Daily briefing\non novel coronavirus cases in China. Retrieved from\nhttp://en.nhc.gov.cn/2020-03/12/c_77618.htm. Accessed March 11, 2020.\n2. World Health Organization. (2020). Coronavirus disease 2019 (COVID-19) Situation Report-52.\nRetrieved from\nhttps://www.who.int/docs/default-source/coronaviruse/20200312-sitrep-52-covid-19.pdf?sfvrsn=e\n2bfc9c0_2 9. Accessed March 11, 2020.\n3. National Health Commission of the People’s Republic of China.(2020). Latest developments in\nepidemic control on Feb 15. Retrieved from http://en.nhc.gov.cn/2020-02/16/c_76622. Accessed\nMarch 11, 2020.\n15\n4. Health Commission of the People’s Republic of China.(2020). The notification of the trial\noperation based on the guideline version 6 in the coronavirus disease diagnosis and treatment.", "Retrieved from\nhttp://www.nhc.gov.cn/xcs/zhengcwj/202002/8334a8326dd94d329df351d7da8aefc2.shtml.\nAccessed March 11, 2020\n5. Health Commission of the People’s Republic of China.(2020). The notification of the trial\noperation based on the guideline version 6 in the coronavirus disease diagnosis and treatment.\nRetrieved from\nhttp://www.nhc.gov.cn/xcs/zhengcwj/202002/8334a8326dd94d329df351d7da8aefc2.shtml.\nAccessed March 11, 2020.\n6. Health Commission of the People’s Republic of China.(2009). The guideline for pathogens\nisolated operations in hospital. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/200904/40116.shtml. Accessed March 11, 2020.\n7. Health Commission of the People’s Republic of China.(2017). The guideline for prevention and\ncontrol of hospital acquired infections of airborne pathogens. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201701/7e0e8fc6725843aabba8f841f2f585d2.shtml. Accessed\nMarch 11, 2020.", "8. Health Commission of the People’s Republic of China.(2017). The guideline for prevention and\ncontrol of hospital acquired infections of airborne pathogens. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201701/7e0e8fc6725843aabba8f841f2f585d2.shtml. Accessed\nMarch 11, 2020.\n9. Health Commission of the People’s Republic of China.(2012). The standardization for\nsterilization techniques in hospital. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201204/54510.shtml. Accessed March 11, 2020.\n10. Health Commission of the People’s Republic of China.(2012). The standardization for\nsterilization techniques in hospital. Retrieved from\nhttp://www.nhc.gov.cn/wjw/s9496/201204/54510.shtml. Accessed March 11, 2020.\n11. Katona P. Bioterrorism Preparedness: Generic Blueprint for Health Departments, Hospitals, and\nPhysicians. Infectious Diseases in Clinical Practice. 2002;11(3):115-122. Accessed March 11,\n2020.\n16\nFigure Legends", "Figure 1. Diagram of the layout of our radiology department was divided into four areas: contaminated\n(shaded in black), semicontaminated (shaded in dark gray), buffer (shaded in light gray), and clean areas\n(shaded in white). The contaminated area was separated from other areas by barriers.\nFigure 2. Diagram shows CT protocol for suspected and confirmed patients with COVID-19.\nFigure 3. Diagram shows CT protocol for regular patients.\nAbbreviations:\nCOVID-19: coronavirus disease 2019\nCT: computed tomography\nDR: digital radiography\nEMICT: emergency management and infection control team\nNHC: National Health Commission\nPACS: picture archiving and communication system\nSARS: severe acute respiratory syndrome", "Sentence Summary\nWith severe infectious diseases such as COVID-19, the highest level of infection control\nmeasures must be implemented, collaboration with the radiology departments of other\nhospitals be needed, and social media be employed.\nTake-home points\n1. To response to a community infection emergency, a special emergency management team\nneeds to be setup at the departmental level to implement infection containment and\ncontrol procedures that continues to allow the imaging examination and imaging\ndiagnosis of those with suspected infection, and to prevent intra-departmental spreading\nof infection (EMICT).\n2. Infection control measures, such as reconfiguration of department areas, personal\nprotection and anti-infection training of all staff, standardized procedures including\ncontact minimization for chest CT and DR examinations, and timely disinfection of CT\nand DR examination rooms, should be implemented properly.", "3. If there are more than one scanner in a hospital, only one of them should be assigned to\nsuspected cases." ]	[ 5 ]	3,975	6,764

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