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Background & objectives: An outbreak of acute encephalitis syndrome was reported from Vidarbha region of Maharashtra state, India, during July 2012. Anti-IgM antibodies against Chandipura virus (CHPV) were detected in clinical samples. Sandfly collections were done to determine their role in CHPV transmission. Methods: Twenty nine pools of Sergentomyia spp. comprising 625 specimens were processed for virus isolation in Vero E6 cell line. Diagnostic RT-PCR targeting N-gene was carried out with the sample that showed cytopathic effects (CPE). The PCR product was sequenced, analysed and the sequences were deposited in Genbank database. Results: CPE in Vero E6 cell line infected with three pools was detected at 48 h post infection. However, virus could be isolated only from one pool. RT-PCR studies demonstrated 527 nucleotide product that confirmed the agent as CHPV. Sequence analysis of the new isolate showed difference in 10-12 nucleotides in comparison to earlier isolates. Interpretation & conclusions: This is perhaps the first isolation of CHPV from Sergentomyia spp. in India and virus isolation during transmission season suggests their probable role in CHPV transmission. Further studies need to be done to confirm the precise role of Sargentomyia spp. in CHPV transmission. [ABSTRACT FROM AUTHOR]

Background & Objectives: The genome of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), belonging to the family Coronaviridae, encodes for structural, non-structural, and accessory proteins, which are required for replication of the virus. These proteins are encoded by different genes present on the SARS-CoV-2 genome. The expression pattern of these genes in the host cells needs to be assessed. This study was undertaken to understand the transcription pattern of the SARS-CoV-2 genes in the Vero CCL-81 cells during the course of infection., Methods: Vero CCL-81 cells were infected with the SARS-CoV-2 virus inoculum having a 0.1 multiplicity of infection. The supernatants and cell pellets were harvested after centrifugation at different time points, post-infection. The 50% tissue culture infective dose (TCID 50 )and cycle threshold (C t ) values of the E and the RdRp-2 genes were calculated. Next-generation sequencing of the harvested sample was carried out to observe the expression pattern of the virus by mapping to the SARS-CoV-2 Wuhan HU-1 reference sequence. The expressions were in terms of the reads per kilobase million (RPKM) values., Results: In the inital six hours post-infection, the copy numbers of E and RdRp-2 genes were approximately constant, which raised 10 log-fold and continued to increase till the 12 h post-infection (hpi). The TCID 50 was observed in the supernatant after 7 hpi, indicating the release of the viral progeny. ORF8 and ORF7a, along with the nucleocapsid transcript, were found to express at higher levels., Interpretation & Conclusions: This study was a step towards understanding the growth kinetics of the SARS-CoV-2 replication cycle. The findings indicated that ORF8 and ORF7b gene transcripts were expressed in higher amounts indicating their essential role in viral replication. Future studies need to be conducted to explore their role in the SARS-CoV-2 replication., Competing Interests: None

Background & Objectives: Since the beginning of the year 2020, the pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) impacted humankind adversely in almost all spheres of life. The virus belongs to the genus Betacoronavirus of the family Coronaviridae. SARS-CoV-2 causes the disease known as coronavirus disease 2019 (COVID-19) with mild-to-severe respiratory illness. The currently available diagnostic tools for the diagnosis of COVID-19 are mainly based on molecular assays. Real-time reverse transcription-polymerase chain reaction is the only diagnostic method currently recommended by the World Health Organization for COVID-19. With the rapid spread of SARS-CoV-2, it is necessary to utilize other tests, which would determine the burden of the disease as well as the spread of the outbreak. Considering the need for the development of such a screening test, an attempt was made to develop and evaluate an IgG-based ELISA for COVID-19., Methods: A total of 513 blood samples (131 positive, 382 negative for SARS-CoV-2) were collected and tested by microneutralization test (MNT). Antigen stock of SARS-CoV-2 was prepared by propagating the virus in Vero CCL-81 cells. An IgG capture ELISA was developed for serological detection of anti-SARS-CoV-2 IgG in serum samples. The end point cut-off values were determined by using receiver operating characteristic (ROC) curve. Inter-assay variability was determined., Results: The developed ELISA was found to be 92.37 per cent sensitive, 97.9 per cent specific, robust and reproducible. The positive and negative predictive values were 94.44 and 98.14 per cent, respectively., Interpretation & Conclusions: This indigenously developed IgG ELISA was found to be sensitive and specific for the detection of anti-SARS-CoV-2 IgG in human serum samples. This assay may be used for determining seroprevalence of SARS-CoV-2 in a population exposed to the virus., Competing Interests: None

Background & Objectives: An outbreak of respiratory illness of unknown aetiology was reported from Hubei province of Wuhan, People's Republic of China, in December 2019. The outbreak was attributed to a novel coronavirus (CoV), named as severe acute respiratory syndrome (SARS)-CoV-2 and the disease as COVID-19. Within one month, cases were reported from 25 countries. In view of the novel viral strain with reported high morbidity, establishing early countrywide diagnosis to detect imported cases became critical. Here we describe the role of a countrywide network of VRDLs in early diagnosis of COVID-19., Methods: The Indian Council of Medical Research (ICMR)-National Institute of Virology (NIV), Pune, established screening as well as confirmatory assays for SARS-CoV-2. A total of 13 VRDLs were provided with the E gene screening real-time reverse transcription-polymerase chain reaction (rRT-PCR) assay. VRDLs were selected on the basis of their presence near an international airport/seaport and their past performance. The case definition for testing included all individuals with travel history to Wuhan and symptomatic individuals with travel history to other parts of China. This was later expanded to include symptomatic individuals returning from Singapore, Japan, Hong Kong, Thailand and South Korea., Results: Within a week of standardization of the test at NIV, all VRDLs could initiate testing for SARS-CoV-2. Till February 29, 2020, a total of 2,913 samples were tested. This included both 654 individuals quarantined in the two camps and others fitting within the case definition. The quarantined individuals were tested twice - at days 0 and 14. All tested negative on both occasions. Only three individuals belonging to different districts in Kerala were found to be positive., Interpretation & Conclusions: Sudden emergence of SARS-CoV-2 and its potential to cause a pandemic posed an unsurmountable challenge to the public health system of India. However, concerted efforts of various arms of the Government of India resulted in a well-coordinated action at each level. India has successfully demonstrated its ability to establish quick diagnosis of SARS-CoV-2 at NIV, Pune, and the testing VRDLs., Competing Interests: None

Novel coronavirus infection [coronavirus disease 2019 (COVID-19)] has spread to more than 203 countries of various regions including Africa, America, Europe, South East Asia and Western Pacific. The WHO had declared COVID-19 as the global public health emergency and subsequently as pandemic because of its worldwide spread. It is now one of the top-priority pathogens to be dealt with, because of high transmissibility, severe illness and associated mortality, wide geographical spread, lack of control measures with knowledge gaps in veterinary and human epidemiology, immunity and pathogenesis. The quick detection of cases and isolating them has become critical to contain it. To meet the increasing demand of the diagnostic services, it is necessary to enhance and expand laboratory capabilities since existing laboratories cannot meet the emerging demand. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a BSL-2 (Biosafety Level 2) agent and needs to be handled in biosafety cabinet using standard precautions. This review highlights minimum requirements for the diagnostic laboratories opting testing of material for the diagnosis of COVID-19 and associated biorisk to the individuals and to the community., Competing Interests: None

Background & Objectives: Several outbreaks of acute encephalitis syndrome (AES) have been reported in Alappuzha district, Kerala State, India, in the past. The aetiology of these outbreaks was either inconclusive or concluded as probable Japanese encephalitis virus (JEV) infection based on clinical presentation. The role of West Nile virus (WNV) in AES outbreaks was also determined. However, the extent of WNV infection has not been studied in this region previously. A population-based cross-sectional serosurvey study was undertaken to determine the seroprevalence of JEV and WNV in Alappuzha district., Methods: A total of 30 clusters were identified from 12 blocks and five municipalities as per the probability proportional to size sampling method. A total of 1125 samples were collected from all age groups. A microneutralization assay was performed to estimate the prevalence of JEV and WNV neutralizing antibodies in the sample population., Results: Of 1125 serum samples tested, 235 [21.5%, 95% confidence interval (CI): 15.2-27.8%] and 179 (15.9%, 95% CI: 9.6-22.3%) were positive for neutralizing antibodies against WNV and JEV, respectively. In addition, 411 (34.5%, 95% CI: 26.7-42.2%) were positive for cross-reactive antibodies against flaviviruses., Interpretation & Conclusions: The study showed the seroprevalence of WNV and JEV antibodies in the surveyed area and the WNV seroprevalence was greater than JEV. It is necessary to create awareness in public and adopt suitable policy to control these diseases.