Multi-epitope vaccine design using in silico analysis of glycoprotein and nucleocapsid of NIPAH virus

According to the 2018 WHO R&D Blueprint, Nipah virus (NiV) is a priority disease, and the development of a vaccine against NiV is strongly encouraged. According to criteria used to categorize zoonotic diseases, NiV is a stage III disease that can spread to people and cause unpredictable outbreaks. Since 2001, the NiV virus has caused annual outbreaks in Bangladesh, while in India it has caused occasional outbreaks. According to estimates, the mortality rate for infected individuals ranges from 70 to 91%. Using immunoinformatic approaches to anticipate the epitopes of the MHC-I, MHC-II, and B-cells, they were predicted using the NiV glycoprotein and nucleocapsid protein. The selected epitopes were used to develop a multi-epitope vaccine construct connected with linkers and adjuvants in order to improve immune responses to the vaccine construct. The 3D structure of the engineered vaccine was anticipated, optimized, and confirmed using a variety of computer simulation techniques so that its stability could be assessed. According to the immunological simulation tests, it was found that the vaccination elicits a targeted immune response against the NiV. Docking with TLR-3, 7, and 8 revealed that vaccine candidates had high binding affinities and low binding energies. Finally, molecular dynamic analysis confirms the stability of the new vaccine. Codon optimization and in silico cloning showed that the proposed vaccine was expressed to a high degree in Escherichia coli. The study will help in identifying a potential epitope for a vaccine candidate against NiV. The developed multi-epitope vaccine construct has a lot of potential, but they still need to be verified by in vitro & in vivo studies.

Surveillance of Nipah virus in Pteropus medius of Kerala state, India, 2023

Introduction

Since 2018, the Indian state of Kerala has reported four Nipah virus (NiV) disease outbreaks, raising concerns about NiV spillover from bats to the human population. Considering this, a cross-sectional study was undertaken in the Pteropus medius bat population around the Nipah virus-affected regions of Kozhikode, Kerala, India, during February, July, and September 2023.

Methods

Throat swabs, rectal swabs, and organ samples were collected from bats to test for NiV using the real-time reverse transcriptase polymerase chain reaction (RT-PCR), while serum samples were screened for anti-Nipah IgG antibodies through ELISA.

Results

An overall seroprevalence of 20.9% was observed in 272 P. medius bats tested. The throat and rectal swab samples of 321 bats were negative for NiV RNA. However, 4 of 44 P. medius bats tested positive for NiV in their liver/spleen samples. The partial N gene retrieved showed more than 99% similarity with the earlier reported NiV genome from Kerala state, India.

Discussion

The findings of the study caution that there is a spillover risk in the region and necessary precautions should be taken.

Clinico-epidemiological presentations and management of Nipah virus infection during the outbreak in Kozhikode district, Kerala state, India 2023

India experienced its sixth Nipah virus (NiV) outbreak in September 2023 in the Kozhikode district of Kerala state. The NiV is primarily transmitted by spillover events from infected bats followed by human-to-human transmission. The clinical specimens were screened using real-time RT-PCR, and positive specimens were further characterized using next-generation sequencing. We describe here an in-depth clinical presentation and management of NiV-confirmed cases and outbreak containment activities. The current outbreak reported a total of six cases with two deaths, with a case fatality ratio of 33.33%. The cases had a mixed presentation of acute respiratory distress syndrome and encephalitis syndrome. Fever was a persistent presentation in all the cases. The Nipah viral RNA was detected in clinical specimens until the post-onset day of illness (POD) 14, with viral load in the range of 1.7-3.3 × 104 viral RNA copies/mL. The genomic analysis showed that the sequences from the current outbreak clustered into the Indian clade similar to the 2018 and 2019 outbreaks. This study highlights the vigilance of the health system to detect and effectively manage the clustering of cases with clinical presentations similar to NiV, which led to early detection and containment activities.

Clinical, epidemiological, and molecular investigation of Kyasanur forest disease from Karnataka state, India during 2018-2019

BACKGROUND

In this study, we carried out an investigation of Kyasanur Forest Disease (KFD) suspected human cases reported in Karnataka state, India from December 2018 to June 2019.

METHODS

The clinical samples of KFD suspected cases (n = 1955) from 14 districts of Karnataka were tested for KFD using real-time RT-PCR and IgM ELISA. Further, the KFD-negative samples were tested for IgM antibodies against dengue and chikungunya viruses. Monkey samples (n = 276) and tick pools (n = 11582) were also screened using real-time RT-PCR. KFD-positive samples were further analysed using next-generation sequencing along with clinico-epidemiological analysis.

RESULTS

Of all, 173 (8.8%) cases tested positive for KFD either by real-time RT-PCR (n = 124), IgM ELISA (n = 53) or both tests (n = 4) from seven districts. Among KFD-negative cases, IgM antibody positivity was observed for dengue (2.6%), chikungunya (5.8%), dengue and chikungunya coinfection (3.7%). KFD cases peaked in January 2019 with fever, conjunctivitis, and myalgia as the predominant symptoms and a mortality of 4.6%. Among confirmed cases, 41% received a single dose and 20% received two doses of the KFD vaccine. Of the seven districts with KFDV positivity, Shivamogga and Hassan districts reported KFD viral RNA positivity in humans, monkeys, and ticks. Sequencing analysis of 2019 cases demonstrated a difference of less than 1.5% amino acid compared to prototype KFDV.

CONCLUSION

Although the KFD has been endemic in many districts of Karnataka state, our study confirms the presence of KFDV for the first time in two new districts, i.e. Hassan and Mysore. A comparative analysis of KFDV infection among the KFD-vaccinated and non-vaccinated populations demonstrated an insignificant difference.

Comparative pathogenicity of BA.2.12, BA.5.2 and XBB.1 with the Delta variant in Syrian hamsters

Omicron variant is evolving into numerous sub variants with time and the information on the characteristics of these newly evolving variants are scant. Here we performed a pathogenicity evaluation of Omicron sub variants BA.2.12, BA.5.2 and XBB.1 against the Delta variant in 6-8-week-old Syrian hamster model. Body weight change, viral load in respiratory organs by real time RT-PCR/titration, cytokine mRNA quantification and histopathological evaluation of the lungs were performed. The intranasal infection of the BA.2.12, BA.5.2 and XBB.1 variants in hamster model resulted in body weight loss/reduced weight gain, inflammatory cytokine response and interstitial pneumonia with lesser severity compared to the Delta variant infection. Among the variants studied, BA.2.12 and XBB.1 showed lesser viral shedding through the upper respiratory tract, whereas the BA.5.2 showed comparable viral RNA shedding as that of the Delta variant. The study shows that the Omicron BA.2 sub variants may show difference in disease severity and transmissibility amongst each other whereas the overall disease severity of the Omicron sub variants studied were less compared to the Delta variant. The evolving Omicron sub variants and recombinants should be monitored for their properties.

Genomic characterization, transcriptome analysis and pathogenicity of the Nipah virus (Indian isolate)

Nipah virus (NiV) is a high-risk pathogen which can cause fatal infection in humans. The Indian isolate from the 2018 outbreak in the Kerala state of India showed ~ 4% nucleotide and amino acid difference in comparison to the Bangladesh strains of NiV and the substitutions observed were mostly not present in the region of any functional significance except for the phosphoprotein gene. The differential expression of viral genes was observed following infection in Vero (ATCC® CCL-81™) and BHK-21 cells. Intraperitoneal infection in the 10-12-week-old, Syrian hamster model induced dose dependant multisystemic disease characterized by prominent vascular lesions in lungs, brain, kidney and extra vascular lesions in brain and lungs. Congestion, haemorrhages, inflammatory cell infiltration, thrombosis and rarely endothelial syncitial cell formation were seen in the blood vessels. Intranasal infection resulted in respiratory tract infection characterised by pneumonia. The model showed disease characteristics resembling the human NiV infection except that of myocarditis similar to that reported by NiV-Malaysia and NiV-Bangladesh isolates in hamster model. The variation observed in the genome of the Indian isolate at the amino acid levels should be explored further for any functional significance.

Molecular characterization & recombination analysis of complete enterovirus-88 isolated from acute flaccid paralysis cases in India

Background & objectives

Focus on non-polio enteroviruses (NPEVs) causing acute flaccid paralysis (AFP) due to myelitis has increased with the containment of the poliovirus. Enterovirus-B88 (EV-B88) has been associated with the AFP cases in Bangladesh, Ghana, South Africa, Thailand and India. In India, EV-B88 infection was linked to AFP a decade ago; however, to date, no complete genome has been made available. In this study, the complete genome sequence of EV-B88 was identified and reported from two different States (Bihar and Uttar Pradesh) in India using the next-generation sequencing technique.

Methods

Virus isolation was performed on the three AFP suspected cases as per the WHO-recommended protocol. Samples showing cytopathic effects in the human Rhabdocarcinoma were labelled as NPEVs. Next-generation sequencing was performed on these NPEVs to identify the aetiological agent. The contiguous sequences (contigs) generated were identified, and reference-based mapping was performed.

Results

EV-B88 sequences retrieved in our study were found to be 83 per cent similar to the EV-B88 isolate from Bangladesh in 2001 (strain: BAN01-10398; Accession number: AY843306.1). Recombination analyses of these samples demonstrate recombination events with sequences from echovirus-18 and echovirus-30.

Interpretation & conclusions

Recombination events in the EV-B serotypes are known, and this work reconfirms the same for EV-B88 isolates also. This study is a step in increasing the awareness about EV-B88 in India and emphasizes future studies to be conducted in the identification of other types of EV present in India.

Needle-free injection system delivery of ZyCoV-D DNA vaccine demonstrated improved immunogenicity and protective efficacy in rhesus macaques against SARS-CoV-2

The apprehension of needles related to injection site pain, risk of transmitting bloodborne pathogens, and effective mass immunization have led to the development of a needle-free injection system (NFIS). Here, we evaluated the efficacy of the NFIS and needle injection system (NIS) for the delivery and immunogenicity of DNA vaccine candidate ZyCoV-D in rhesus macaques against SARS-CoV-2 infection. Briefly, 20 rhesus macaques were divided into 5 groups (4 animals each), that is, I (1 mg dose by NIS), II (2 mg dose by NIS), III (1 mg dose by NFIS), IV (2 mg dose by NFIS) and V (phosphate-buffer saline [PBS]). The macaques were immunized with the vaccine candidates/PBS intradermally on Days 0, 28, and 56. Subsequently, the animals were challenged with live SARS-CoV-2 after 15 weeks of the first immunization. Blood, nasal swab, throat swab, and bronchoalveolar lavage fluid specimens were collected on 0, 1, 3, 5, and 7 days post infection from each animal to determine immune response and viral clearance. Among all the five groups, 2 mg dose by NFIS elicited significant titers of IgG and neutralizing antibody after immunization with enhancement in their titers postvirus challenge. Besides this, it also induced increased lymphocyte proliferation and cytokine response. The minimal viral load post-SARS-CoV-2 challenge and significant immune response in the immunized animals demonstrated the efficiency of NFIS in delivering 2 mg ZyCoV-D vaccine candidate.

Host immune responses in aged rhesus macaques against BBV152, an inactivated SARS-CoV-2 vaccine, and cross-neutralization with beta and delta variants

The magnitude and duration of immune response to COVID-19 vaccination in older adults are known to be adversely affected due to immunosenescence and inflammaging. The threat of emerging variants warrants studies on immune response in older adults to primary vaccination and booster doses so as to understand the effectiveness of vaccines in countering the threat of emerging variants. Non-human primates (NHPs) are ideal translational models, as the immunological responses in NHPs are similar to those in humans, so it enables us to understand host immune responses to the vaccine. We initially studied humoral immune responses in aged rhesus macaques employing a three-dose regimen of BBV152, an inactivated SARS-CoV-2 vaccine. Initially, the study investigated whether the third dose enhances the neutralizing antibody (Nab) titer against the homologous virus strain (B.1) and variants of concern (Beta and Delta variants) in aged rhesus macaques immunized with BBV152, adjuvanted with Algel/Algel-IMDG (imidazoquinoline). Later, we also attempted to understand cellular immunity in terms of lymphoproliferation against γ-inactivated SARS-CoV-2 B.1 and delta in naïve and vaccinated rhesus macaques after a year of the third dose. Following the three-dose regimen with 6 µg of BBV152 with Algel-IMDG, animals had increased Nab responses across all SARS-CoV-2 variants studied, which suggested the importance of booster dose for the enhanced immune response against SARS-CoV-2-circulating variants. The study also revealed the pronounced cellular immunity against B.1 and delta variants of SARS-CoV-2 in the aged rhesus macaques even after a year of vaccination.

Clinical presentation, viral kinetics, and management of human monkeypox cases from New Delhi, India 2022

We describe the clinical and demographic characteristics, virological follow-up, and management of five confirmed monkeypox cases from New Delhi, India without any international travel history. The viral load kinetics and viral clearance were estimated in oropharyngeal swabs (OPS), nasopharyngeal swabs (NPS), EDTA blood, serum, urine, and various lesion specimens on every fourth day of follow-up ranging from 5 to 24 post onset day (POD) of illness. All five cases presented with mild to moderate-grade intermittent fever, myalgia, and lesions on the genitals, groins, lower limb, trunk, and upper limb. Four cases had non-tender firm lymphadenopathy. No secondary complications or sexually transmitted infections were recorded in these cases except for the presence of viral hepatitis B infection marker hepatitis B virus surface antigen (HBsAg) in one case. All the cases were mild and had a good recovery. A higher viral load was detected in lesion fluid (POD 9), followed by lesion roof (POD 9), urine (POD 5), lesion base (POD 5), and OPS/NPS (POD 5). The monkeypox virus (MPXV) DNA was detected in clinical samples from 5th to 24th POD. These monkeypox cases without international travel history suggest the underdiagnosed monkeypox infection in the community. This emphasizes the need for active surveillance of MPXV in the high-risk population such as men having sex with men and female sex workers.

Lack of evidence of viability and infectivity of SARS-CoV-2 in the fecal specimens of COVID-19 patients

SARS-CoV-2 can be shed in feces and can enter sewage systems. In order to implement effective control measures and identify new channels of transmission, it is essential to identify the presence of infectious virus particles in feces and sewage. In this study, we attempt to utilize Molecular techniques, cell cultures and animal models to find out the infectivity of SARS-CoV-2 in the feces of COVID-19 patients. Our findings exclude the presence of infectious virus particles, suggesting that fecal-oral transmission may not be the main mode of transmission. Larger-scale initiatives are nevertheless required, particularly considering the emergence of new viral strains.

Protective efficacy of COVAXIN® against Delta and Omicron variants in hamster model

The immunity acquired after natural infection or vaccinations against SARS-CoV-2 tend to wane with time. Here, we compared the protective efficacy of COVAXIN® following two- and three-dose immunizations against the Delta variant and also studied the efficacy of COVAXIN® against Omicron variants in a Syrian hamster model. Despite the comparable neutralizing antibody response against the homologous vaccine strain in both the two-dose and three-dose immunized groups, considerable reduction in the lung disease severity was observed in the 3 dose immunized group after Delta variant challenge. In the challenge study using the Omicron variants, i.e., BA.1.1 and BA.2, lesser virus shedding, lung viral load and lung disease severity were observed in the immunized groups. The present study shows that administration of COVAXIN® booster dose will enhance the vaccine effectiveness against the Delta variant infection and give protection against the BA.1.1 and BA.2 variants.

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COVAXIN immunization protected hamsters against Delta variant infection

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Pneumonia severity was considerably reduced in three-dose immunized hamsters

Development of Nipah virus-specific IgM & IgG ELISA for screening human serum samples

Background & objectives

Nipah virus (NiV) is a zoonotic paramyxovirus that causes fatal encephalitis in humans. Enzyme Linked Immunosorbent Assay (ELISA) is a safe, sensitive, specific, and affordable diagnostic tool that can be used during screening of large-scale epidemiological investigations. Development and evaluation of IgM and IgG ELISA for screening serum samples of NiV suspected cases would also help in planning public health interventions.

Methods

An IgM capture (MAC) ELISA and an indirect IgG ELISA were developed using NiV antigen to detect IgM and IgG antibodies against NiV in human sera. The sensitivity, specificity, and cross-reactivity of the assays were evaluated using NiV IgM, IgG positive, negative human sera and measles, mumps, rubella, Crimean-Congo haemorrhagic fever, Kyasanur forest disease IgM, IgG positive sera, respectively.

Results

The developed anti-NiV IgM and IgG ELISAs have shown specificity of 99.28 per cent and sensitivity of 100 per cent compared to reference test from Centers for Disease Control and Prevention, USA. Assays demonstrated negative predictive value of 100 per cent and positive predictive value as 90 and 93.94 per cent for anti-Nipah IgM ELISA and IgG ELISA respectively with test accuracy of 99.33 per cent.

Interpretation & conclusions

Timely diagnosis of NiV is crucial for the management of cases, which could prevent further spread of infection in the community. IgM ELISA can be used as primary diagnostic tool followed by polymerase chain reaction. These assays have advantages of its applicability during outbreak investigations and surveillance activities at hospital or onsite laboratories with basic biosafety practices.

Zika a Vector Borne Disease Detected in Newer States of India Amidst the COVID-19 Pandemic

Background

During the second wave of the COVID-19 pandemic, outbreaks of Zika were reported from Kerala, Uttar Pradesh, and Maharashtra, India in 2021. The Dengue and Chikungunya negative samples were retrospectively screened to determine the presence of the Zika virus from different geographical regions of India.

Methods

During May to October 2021, the clinical samples of 1475 patients, across 13 states and a union territory of India were screened and re-tested for Dengue, Chikungunya and Zika by CDC Trioplex Real time RT-PCR. The Zika rRTPCR positive samples were further screened with anti-Zika IgM and Plaque Reduction Neutralization Test. Next generation sequencing was used for further molecular characterization.

Results

The positivity was observed for Zika (67), Dengue (121), and Chikungunya (10) amongst screened cases. The co-infections of Dengue/Chikungunya, Dengue/Zika, and Dengue/Chikungunya/Zika were also observed. All Zika cases were symptomatic with fever (84%) and rash (78%) as major presenting symptoms. Of them, four patients had respiratory distress, one presented with seizures, and one with suspected microcephaly at birth. The Asian Lineage of Zika and all four serotypes of Dengue were found in circulation.

Conclusion

Our study indicates the spread of the Zika virus to several states of India and an urgent need to strengthen its surveillance.

SARS-CoV-2 Kappa Variant Shows Pathogenicity in a Syrian Hamster Model

Objectives: The emergence of SARS-CoV-2 lineage B.1.617 variants in India has been associated with a surge in the number of daily infections. We investigated the pathogenic potential of Kappa (B.1.617.1) variant in Syrian golden hamsters. Methods: Two groups of Syrian golden hamsters (18 each) were inoculated intranasally with SARS-CoV-2 isolates, B.1 (D614G) and Kappa variant, respectively. The animals were monitored daily for the clinical signs and body weight. Throat swab, nasal wash, and organ samples (lungs, nasal turbinate, trachea) were collected and screened using SARS-CoV-2-specific RT-qPCR. Histopathologic evaluation of the lung samples was performed. Results: The hamsters infected with the Kappa variant demonstrated increased body weight loss compared to the B.1 lineage isolate. The highest viral RNA load was observed in the nasal turbinate and lung specimens of animals infected with both variants. A significantly higher sgRNA load was observed in the nasal swabs (7 DPI), trachea (3 DPI), and lungs (3 DPI) of hamsters infected with the Kappa variant. Neutralizing antibody response generated in the B.1 lineage-infected hamster sera were comparable against both B.1 and Kappa variant in contrast to Kappa variant-infected hamsters, which showed lower titers against B.1 lineage isolate. Gross and microscopic evaluation of the lung specimens showed severe lung lesions in hamsters infected with Kappa variant compared to B.1. Conclusions: The study demonstrates pathogenicity of Kappa variant in hamsters evident with reduced body weight, high viral RNA load in lungs, and pronounced lung lesions. Both Kappa variant- and B.1-infected hamsters produced neutralizing antibodies against both variants studied.

Pathogenicity of SARS-CoV-2 Omicron (R346K) variant in Syrian hamsters and its cross-neutralization with different variants of concern

Background

SARS-CoV-2 Omicron variant is rampantly spreading across the globe. We assessed the pathogenicity and immune response generated by BA.1.1 sub-lineage of SARS-CoV-2 [Omicron (R346K) variant] in 5 to 6-week old Syrian hamsters and compared the observations with that of Delta variant infection.

Methods

Virus shedding, organ viral load, lung disease and immune response generated in hamsters were sequentially assessed.

Findings

The disease characteristics of the Omicron (R346K) variant were found to be similar to that of the Delta variant infection in hamsters like viral replication in the respiratory tract and interstitial pneumonia. The Omicron (R346K) infected hamsters demonstrated lesser body weight reduction and viral RNA load in the throat swab and nasal wash samples in comparison to the Delta variant infection. The viral load in the lungs and nasal turbinate samples and the lung disease severity of the Omicron (R346K) infected hamsters were found comparable with that of the Delta variant infected hamsters. Neutralizing antibody response against Omicron (R346K) variant was detected from day 5 and the cross-neutralization titre of the sera against other variants showed severe reduction ie., 7 fold reduction against Alpha and no titers against B.1, Beta and Delta.

Interpretation

This preliminary data shows that Omicron (R346K) variant infection can produce moderate to severe lung disease similar to that of the Delta variant and the neutralizing antibodies produced in response to Omicron (R346K) variant infection shows poor neutralizing ability against other co-circulating SARS-CoV-2 variants like Delta which necessitates caution as it may lead to increased cases of reinfection.

Funding

This study was supported by 10.13039/501100001411Indian Council of Medical Research as an intramural grant (COVID-19) to ICMR-National Institute of Virology, Pune.

Prolonged Shedding of SARS-CoV-2 in Feces of COVID-19 Positive Patients: Trends in Genomic Variation in First and Second Wave

The main route of the transmission of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are through respiratory pathways and close contact of human-to-human. While information about other modes of transmission is comparatively less, some published literature supporting the likelihood of a fecal-oral mode of transmission has been accumulating. The diagnosis of SARS-COV-2 infected cases is based on the real-time reverse transcription-PCR (RT-PCR). The fecal excretion of SARS-COV-2 has been reported frequently, however, the role of fecal viral load with the severity of disease is not yet clear. Our study focused on the investigation of SARS-CoV-2 shedding in the fecal samples of patients with coronavirus disease 2019 (COVID-19). A total of 280 RT-PCR-positive patients were enrolled, among them 15.4% had gastrointestinal (GI) symptoms. It was shown that 62% of the patients were positive for SARS-CoV-2 RNA in fecal specimens. This positivity was not related to the presence of GI symptoms and the severity of disease. The next generation sequencing [NGS] of SARS-CoV-2 from fecal samples of patients was performed to analyze mutational variations. Findings from this study not only emphasized the potential presence of SARS-CoV-2 in feces, but also its continuing mutational changes and its possible role in fecal-oral transmission.

Nipah Virus Outbreak in Kerala State, India Amidst of COVID-19 Pandemic

We report here a Nipah virus (NiV) outbreak in Kozhikode district of Kerala state, India, which had caused fatal encephalitis in a 12-year-old boy and the outbreak response, which led to the successful containment of the disease and the related investigations. Quantitative real-time reverse transcription (RT)-PCR, ELISA-based antibody detection, and whole genome sequencing (WGS) were performed to confirm the NiV infection. Contacts of the index case were traced and isolated based on risk categorization. Bats from the areas near the epicenter of the outbreak were sampled for throat swabs, rectal swabs, and blood samples for NiV screening by real-time RT-PCR and anti-NiV bat immunoglobulin G (IgG) ELISA. A plaque reduction neutralization test was performed for the detection of neutralizing antibodies. Nipah viral RNA could be detected from blood, bronchial wash, endotracheal (ET) secretion, and cerebrospinal fluid (CSF) and anti-NiV immunoglobulin M (IgM) antibodies from the serum sample of the index case. Rapid establishment of an onsite NiV diagnostic facility and contact tracing helped in quick containment of the outbreak. NiV sequences retrieved from the clinical specimen of the index case formed a sub-cluster with the earlier reported Nipah I genotype sequences from India with more than 95% similarity. Anti-NiV IgG positivity could be detected in 21% of Pteropus medius (P. medius) and 37.73% of Rousettus leschenaultia (R. leschenaultia). Neutralizing antibodies against NiV could be detected in P. medius. Stringent surveillance and awareness campaigns need to be implemented in the area to reduce human-bat interactions and minimize spillover events, which can lead to sporadic outbreaks of NiV.

Isolation of SARS-CoV-2 B.1.1.28.2 (P2) variant and pathogenicity comparison with D614G variant in hamster model

Background

Considering the potential threat from emerging Severe Acute Respiratory Syndrome-Corona Virus-2 (SARS-CoV-2) variants and the rising COVID-19 cases, SARS-CoV-2 genomic surveillance is ongoing in India. We report herewith the isolation of the P.2 variant (B.1.1.28.2) from international travelers and further its pathogenicity evaluation and comparison with D614G variant (B.1) in hamster model.

Methods

Virus isolation was performed in Vero CCL81 cells and genomic characterization by next generation sequencing. The pathogenicity and host immune response of the isolate was assessed in Syrian hamster model and compared with B.1 variant.

Results

B.1.1.28.2 variant was isolated from nasal/throat swabs of international travelers returned to India from United Kingdom and Brazil. The B.1.1.28.2 variant induced body weight loss, viral replication in the respiratory tract and caused severe lung pathology in infected Syrian hamster model in comparison, with B.1 variant infected hamsters. The sera from B.1.1.28.2 infected hamsters efficiently neutralized the D614G variant virus whereas 6-fold reduction in the neutralization was seen in case of D614G variant infected hamsters’ sera with the B.1.1.28.2 variant.

Conclusions

B.1.1.28.2 lineage variant could be successfully isolated and characterization could be performed. Pathogenicity of the isolate was demonstrated in Syrian hamster model and the findings of neutralization reduction is of great concern and point towards the need for screening the vaccines for efficacy.

Urinary immunoglobulins in viral diagnosis: An overview

Antibody detection by serological methods gained a lot of interest in recent years and has become the backbone of virological diagnosis. Despite the detection of all five classes of immunoglobulins in urine, not much attention has been paid to the use of urine as a diagnostic sample to detect viral antibodies. Unlike venipuncture, this non-invasive mode of sample collection can help cover all age groups, especially paediatric and old age patients, where blood collection is difficult. Using urine as a sample is also economical and involves lesser risk in sample collection. The antibodies are found to be stable in urine at room temperature for a prolonged period, which makes the sample transport management easier as well. A few recent studies, have also shown that the detection limit of antibodies in urine is at par with serum or other clinical material. So, the ease in sample collection, availability of samples in large quantity and stability of immunoglobulins in urine for prolonged periods can make urine an ideal sample for viral diagnosis.

ZRC3308 Monoclonal Antibody Cocktail Shows Protective Efficacy in Syrian Hamsters against SARS-CoV-2 Infection

We have developed a monoclonal antibody (mAb) cocktail (ZRC-3308) comprising of ZRC3308-A7 and ZRC3308-B10 in the ratio 1:1 for COVID-19 treatment. The mAbs were designed to have reduced immune effector functions and increased circulation half-life. mAbs showed good binding affinities to non-competing epitopes on RBD of SARS-CoV-2 spike protein and were found neutralizing SARS-CoV-2 variants B.1, B.1.1.7, B.1.351, B.1.617.2, and B.1.617.2 AY.1 in vitro. The mAb cocktail demonstrated effective prophylactic and therapeutic activity against SARS-CoV-2 infection in Syrian hamsters. The antibody cocktail appears to be a promising candidate for prophylactic use and for therapy in early COVID-19 cases that have not progressed to severe disease.

Tobacco use and exposure to second-hand smoke among high school students in Ernakulum district, Kerala: A cross-sectional study

Objectives

Tobacco use and exposure to second-hand smoke (SHS) in the home setting are major health hazards for adolescents. The objectives of this study were to estimate tobacco use and exposure to SHS among high school students in Ernakulam district of Kerala, India, and to investigate associated factors.

Study design

Cross-sectional study.

Methods

A school-based cross-sectional study was carried out in 25 randomly selected high schools from 210 schools in the Ernakulam educational district of Kerala, India. The minimum calculated sample size for ever-use of tobacco and SHS exposure was determined to be 2500, with 95% confidence interval (CI) and 10% relative precision. Data were collected using a semi-structured, pre-tested questionnaire from 2585 high school students. Data analyses were performed using SPSS version 20.

Results

The ever-use of tobacco was reported to be 3.9% (95% CI 3.16 to 4.54) and the mean age of the participants was 13.97 ± 0.77 years. One-fifth of participants had tried a tobacco product before the age of 10 years. SHS exposure at home was reported by one in every 5 respondents (20.3%). Male gender (adjusted odds ratio [aOR] 8.79; 95% CI 3.16, 24.53), presence of a family member who smokes within the home (aOR 4.28; 95% CI 2.58, 7.12), lack of awareness about the harmful effects of SHS exposure (aOR 2.47; 95% CI 1.41, 5.18) and having seen an advertisement or promotion at point of sale (aOR 2.16; 95% CI 1.29, 3.60) were found to be independent predictors for tobacco use.

Participants with respiratory infections were three times more likely to have experienced SHS exposure at home (aOR 2.87; 95% CI 2.21, 3.74), there was an 86% protective effect of SHS exposure for participants with a father in a professional occupation compared with unskilled profession (aOR 0.14; 95% CI 0.02, 0.67; p < 0.15) and participants with ever-use of tobacco were two times more likely to have experienced SHS exposure at home (aOR 1.63; 95% CI 3.13, 8.98).

Conclusions

SHS exposure in the home environment continues to be high. Urgent innovative measures are necessary for the implementation of tobacco smoke-free homes and to reduce tobacco use in this vulnerable population. Further studies are necessary to determine ways to reduce smoking within homes and to increase population awareness.

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This study estimates the ever use of tobacco among adolescents to be low at 3.5%.

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However, alarmingly one fifth of the students continue to be exposed to secondhand smoke at home this is associated with increasing respiratory infections.

Identification of Phasi Charoen-Like Phasivirus in Field Collected Aedes aegypti from Karnataka State, India

Background: A wide range of insect-specific viruses (ISVs) have been reported worldwide. There are no studies from India that have reported ISVs. The current study describes the identification of Phasi Charoen-like virus (PCLV) from Aedes aegypti mosquito-pools from six districts of Karnataka state, India. Materials and Methods: During the Chikungunya virus (CHIKV) outbreak in the Bangalore Urban district in 2019, using conventional PCR, it was found that both human and mosquito samples were positive for CHIKV. For retrieve the complete genome sequence, mosquito samples were subjected to next generation sequencing (NGS) analysis and PCLV was also found. During 2019, as part of a vector-borne disease surveillance, we received 50 mosquito pool samples from 6 districts of the state, all of them were subjected to NGS to identify PCLV. Results: The A. aegypti mosquito-pools samples were subjected to the NGS platform that led to identification of an ISV, PCLV. PCLV was identified in 26 A. aegypti mosquito-pools collected from 6 districts. We also found mixed infection of PCLV with the Dengue virus (DENV; genotypes 1 and 3) and CHIKV from five pools. The nucleotide identity for the L gene of Indian PCLV sequences ranged between 97.1% and 98.3% in comparison with the Thailand sequences. Conclusions: To the best of our knowledge, this is the first report of PCLV dual infection with DENV and CHIKV in India. The present study confirms the presence of PCLV in A. aegypti mosquitoes from Karnataka state. The study adds India in the global geographical distribution of PCLV.

SARS-CoV-2 Delta Variant Pathogenesis and Host Response in Syrian Hamsters

B.1.617 is becoming a dominant Severe Acute Respiratory Syndrome-Coronavirus-2 (SARS-CoV-2) lineage worldwide with many sublineages, of which B.1.617.2 is designated as a variant of concern. The pathogenicity of B.1.617.2 (Delta) and B.1.617.3 lineage of SARS-CoV-2 was evaluated and compared with that of B.1, an early virus isolate with D614G mutation in a Syrian hamster model. Viral load, antibody response, and lung disease were studied. There was no significant difference in the virus shedding pattern among these variants. High levels of SARS-CoV-2 sub genomic RNA were detected in the respiratory tract of hamsters infected with the Delta variant for 14 days, which warrants further transmission studies. The Delta variant induced lung disease of moderate severity in about 40% of infected animals, which supports the attributed disease severity of the variant. Cross neutralizing antibodies were detected in animals infected with B.1, Delta, and B.1.617.3 variant, but neutralizing capacity was significantly lower with B.1.351 (Beta variant).

Comparison of SARS-CoV-2 Variants of Concern 202012/01 (U.K. Variant) and D614G Variant Transmission by Different Routes in Syrian Hamsters

Introduction: Many SARS-CoV-2 variants of concern (VOC) have been reported recently that were linked to increased transmission. In our earlier study using VOC 202012/01 (U.K. variant) and D614G variant in the hamster model, we observed higher viral RNA shedding through nasal wash in the case of U.K. variant with lower pathogenicity in lung. In this study, we have studied transmission of these two variants by direct contact, aerosol, and fomite routes in Syrian hamsters and compared the viral load and body weight changes in hamsters exposed by both variants to understand the transmission efficiency. Methods: Nasal, throat, and rectal swabs were collected sequentially to assess viral load till 14 days. Results: Transmission could be established by direct, aerosol, and fomite contact in Syrian hamsters. Body weight loss or viral load in the contact animals exposed did not show any statistical significance. Conclusion: The study demonstrated comparable transmission of both U.K. and D614G variants of SARS-CoV-2 in Syrian hamsters in the given conditions. Provided these data, it seems that all the routes of exposure are effective leading to higher transmission.

A qualitative IgG ELISA for detection of SARS-CoV-2-specific antibodies in Syrian hamster serum samples

This protocol describes an indirect enzyme-linked immunosorbent assay for qualitative detection of IgG antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in Syrian hamster serum samples. We describe the preparation of inactivated virus antigens and the negative control antigen and the use of antigen-coated microtiter plates to detect SARS-CoV-2-specific antibodies from SARS-CoV-2-infected hamsters, including the criteria for differentiating positive versus negative reaction. The limited batch-to-batch variability of this assay has been verified with two batches of independently prepared antigens.

For complete details on the use and execution of this protocol, please refer to Mohandas et al. (2021).

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Inactivated SARS-CoV-2 whole-virion-based IgG ELISA

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Qualitative detection of anti-SARS-CoV-2 IgG antibody in infected hamster serum samples

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Criteria for determination of cutoff values for the assay

Th1 skewed immune response of whole virion inactivated SARS CoV 2 vaccine and its safety evaluation

We report the development and evaluation of safety and immunogenicity of a whole virion inactivated (WVI) SARS-CoV-2 vaccine (BBV152), adjuvanted with aluminum hydroxide gel (Algel), or TLR7/8 agonist chemisorbed Algel. We used a well-characterized SARS-CoV-2 strain and an established Vero cell platform to produce large-scale GMP-grade highly purified inactivated antigen. Product development and manufacturing process were carried out in a BSL-3 facility. Immunogenicity and safety were determined at two antigen concentrations (3μg and 6μg), with two different adjuvants, in mice, rats, and rabbits. Our results show that BBV152 vaccine formulations generated significantly high antigen-binding and neutralizing antibody titers (NAb), at both concentrations, in all three species with excellent safety profiles. The inactivated vaccine formulation contains TLR7/8 agonist adjuvant-induced Th1-biased antibody responses with elevated IgG2a/IgG1 ratio and increased levels of SARS-CoV-2-specific IFN-γ+ CD4+ T lymphocyte response. Our results support further development for phase I/II clinical trials in humans.

Comparison of the immunogenicity & protective efficacy of various SARS-CoV-2 vaccine candidates in non-human primates

BACKGROUND & OBJECTIVES

The COVID-19 pandemic has emerged as a global public health crisis and research groups worldwide are engaged in developing vaccine candidates to curb its transmission, with a few vaccines having progressed to advanced stages of clinical trials. The aim of this systematic review was to compare immunogenicity and protective efficacy of various SARS-CoV-2 vaccine candidates tested in non-human primate (NHP) models.

METHODS

Literature on effect of SARS-CoV-2 vaccines in NHP models reported on PubMed and preprint platforms (medRxiv and bioRxiv) till October 22, 2020, was searched with the following terms: coronavirus vaccine, COVID-19 vaccine, SARS-CoV-2 vaccine, nonhuman primate, and rhesus macaque.

RESULTS

Our search yielded 19 studies, which reported immune response elicited by 18 vaccine candidates in NHP. All the vaccines induced detectable neutralizing antibody (NAb) titres in the serum of vaccinated animals, with some showing effective viral clearance from various organs. The vaccinated animals also showed nil to mild histopathological changes in their lungs compared to placebo groups in the trials that performed necropsy.

INTERPRETATION & CONCLUSIONS

Our findings highlighted onset of quick immunogenicity and protective efficacy of mRNA-1273, followed by Ad26.CoV2.S, NVX-CoV2373, BNT162b2, RBD and BBV152 vaccine candidates in preclinical trials as compared to the others. NHP data also showed correlation with clinical trial data available for a few vaccines. Preclinical trials of COVID-19 vaccine candidates in NHPs yielded promising results, with some candidates faring better than others.

Characterization of anthocyanin from red sorghum (Sorghum bicolor) bran by liquid chromatography-electron spray ionization mass spectrometry analysis

In the present study, anthocyanin pigments from red sorghum (Sorghum bicolor) bran were identified and characterized by Liquid Chromatography-Electron Spray Ionization Mass Spectrometry. The individual anthocyanins were identified by comparing their mass spectrometric data and retention times, published data. 3-deoxyanthocyanidins and methyl 3-deoxyanthocyanidins were identified in red sorghum bran. This paper presents complete LCMS profile and MS spectrometric data of red sorghum bran.

Immunogenicity and protective efficacy of inactivated SARS-CoV-2 vaccine candidate, BBV152 in rhesus macaques

The COVID-19 pandemic is a global health crisis that poses a great challenge to the public health system of affected countries. Safe and effective vaccines are needed to overcome this crisis. Here, we develop and assess the protective efficacy and immunogenicity of an inactivated SARS-CoV-2 vaccine in rhesus macaques. Twenty macaques were divided into four groups of five animals each. One group was administered a placebo, while three groups were immunized with three different vaccine candidates of BBV152 at 0 and 14 days. All the macaques were challenged with SARS-CoV-2 fourteen days after the second dose. The protective response was observed with increasing SARS-CoV-2 specific IgG and neutralizing antibody titers from 3^rd-week post-immunization. Viral clearance was observed from bronchoalveolar lavage fluid, nasal swab, throat swab and lung tissues at 7 days post-infection in the vaccinated groups. No evidence of pneumonia was observed by histopathological examination in vaccinated groups, unlike the placebo group which exhibited interstitial pneumonia and localization of viral antigen in the alveolar epithelium and macrophages by immunohistochemistry. This vaccine candidate BBV152 has completed Phase I/II (NCT04471519) clinical trials in India and is presently in phase III, data of this study substantiates the immunogenicity and protective efficacy of the vaccine candidates.

Immunogenicity and protective efficacy of BBV152, whole virion inactivated SARS- CoV-2 vaccine candidates in the Syrian hamster model

The availability of a safe and effective vaccine would be the eventual measure to deal with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) threat. Here, we have assessed the immunogenicity and protective efficacy of inactivated SARS-CoV-2 vaccine candidates BBV152A, BBV152B, and BBV152C in Syrian hamsters. Three dose vaccination regimes with vaccine candidates induced significant titers of SARS-CoV-2-specific IgG and neutralizing antibodies. BBV152A and BBV152B vaccine candidates remarkably generated a quick and robust immune response. Post-SARS-CoV-2 infection, vaccinated hamsters did not show any histopathological changes in the lungs. The protection of the hamster was evident by the rapid clearance of the virus from lower respiratory tract, reduced virus load in upper respiratory tract, absence of lung pathology, and robust humoral immune response. These findings confirm the immunogenic potential of the vaccine candidates and further protection of hamsters challenged with SARS-CoV-2. Of the three candidates, BBV152A showed the better response.

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Vaccine candidates, BBV152 induced potent humoral immune response in Syrian hamsters

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Early viral clearance from lower respiratory tract in vaccinated hamsters

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BBV152 vaccine candidates protected Syrian hamsters from pneumonia

Study of Kyasanur forest disease viremia, antibody kinetics, and virus infection in target organs of Macaca radiata

The present manuscript deals with experimental infections of bonnet macaques (Macaca radiata) to study disease progression for better insights into the Kyasanur Forest Disease (KFD) pathogenesis and transmission. Experimentally, 10 monkeys were inoculated with KFD virus (KFDV) (high or low dose) and were regularly monitored and sampled for various body fluids and tissues at preset time points. We found that only 2 out of the 10 animals showed marked clinical signs becoming moribund, both in the low dose group, even though viremia, virus shedding in the secretions and excretions were evident in all inoculated monkeys. Anti-KFDV immunoglobulin (Ig)M antibody response was observed around a week after inoculation and anti-KFDV IgG antibody response after two weeks. Anaemia, leucopenia, thrombocytopenia, monocytosis, increase in average clotting time, and reduction in the serum protein levels were evident. The virus could be re-isolated from the skin during the viremic period. The persistence of viral RNA in the gastrointestinal tract and lymph nodes was seen up to 53 and 81 days respectively. Neuro-invasion was observed only in moribund macaques. Re-challenge with the virus after 21 days of initial inoculation in a monkey did not result in virus shedding or immune response boosting.

Vector competence of Aedes vittatus (Bigot) mosquitoes from India for Japanese encephalitis, West Nile, Chandipura and Chittoor viruses

BACKGROUND & OBJECTIVES

Aedes vittatus (Bigot), an anthropophilic mosquito, plays an important role in the maintenance and transmission of yellow fever (YF), dengue (DEN), chikungunya (CHIKV) and Zika (ZIK) viruses in Africa. In India, though natural isolation of none of these viruses was reported from the mosquito, experimental studies have shown vector competence to DEN and CHIK viruses. Despite wide prevalence in India, their potential in transmitting viruses of public health importance viz., Japanese encephalitis (JEV), West Nile (WNV), Chandipura (CHPV), Chittoor (CHITV) etc., has never been investigated. The objective of the present study is to determine the vector potential of the mosquito to these viruses.

METHODS

Mosquitoes were infected by intra-thoracic inoculation as well as by oral feeding, and growth kinetics was determined. Virus dissemination to organs was investigated by determining virus in the harvested organs on specified days' post infection (PI). Vector competence was determined by detecting the virus in saliva.

RESULTS

Intra thoracic inoculation has shown vector competence of the mosquito to JEV, WNV, CHIV and CHPV. However, using the oral route of infection, replication was observed with only WNV, JEV and CHITV. High degree of WNV replication (6.7log TCID₅₀/ml) with rapid dissemination to wings, legs and salivary glands was seen from 5^th day PI onwards. WNV was detected in saliva with a titer of 0.7log₁₀ TCID₅₀/ml on 5^th day PI. JEV and CHITV replicated in the mosquito yielding 3log and 4log₁₀ TCID₅₀/ml on 5^th and 10^th day PI respectively, but virus was not detected in saliva till 15^th day PI.

INTERPRETATION & CONCLUSION

From the results it is difficult to indict the mosquito as a vector of the viruses studied. However, presence of WNV in saliva of the mosquito shows its potential as a bridge vector and poses a concern especially when virulent WNV strains are circulating in the country.

Detection of coronaviruses in Pteropus & Rousettus species of bats from different States of India

Background & objectives:

Bats are considered to be the natural reservoir for many viruses, of which some are potential human pathogens. In India, an association of Pteropus medius bats with the Nipah virus was reported in the past. It is suspected that the recently emerged severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) also has its association with bats. To assess the presence of CoVs in bats, we performed identification and characterization of bat CoV (BtCoV) in P. medius and Rousettus species from representative States in India, collected during 2018 and 2019.

Methods:

Representative rectal swab (RS) and throat swab specimens of Pteropus and Rousettus spp. bats were screened for CoVs using a pan-CoV reverse transcription-polymerase chain reaction (RT-PCR) targeting the RNA-dependent RNA polymerase (RdRp) gene. A single-step RT-PCR was performed on the RNA extracted from the bat specimens. Next-generation sequencing (NGS) was performed on a few representative bat specimens that were tested positive. Phylogenetic analysis was carried out on the partial sequences of RdRp gene sequences retrieved from both the bat species and complete viral genomes recovered from Rousettus spp.

Results:

Bat samples from the seven States were screened, and the RS specimens of eight Rousettus spp. and 21 Pteropus spp. were found positive for CoV RdRp gene. Among these, by Sanger sequencing, partial RdRp sequences could be retrieved from three Rousettus and eight Pteropus bat specimens. Phylogenetic analysis of the partial RdRp region demonstrated distinct subclustering of the BtCoV sequences retrieved from these Rousettus and Pteropus spp. bats. NGS led to the recovery of four sequences covering approximately 94.3 per cent of the whole genome of the BtCoVs from Rousettus bats. Three BtCoV sequences had 93.69 per cent identity to CoV BtRt-BetaCoV/GX2018. The fourth BtCoV sequence was 96.8 per cent identical to BtCoV HKU9-1.

Interpretation & conclusions:

This study was a step towards understanding the CoV circulation in Indian bats. Detection of potentially pathogenic CoVs in Indian bats stresses the need for enhanced screening for novel viruses in them. One Health approach with collaborative activities by the animal health and human health sectors in these surveillance activities shall be of use to public health. This would help in the development of diagnostic assays for novel viruses with outbreak potential and be useful in disease interventions. Proactive surveillance remains crucial for identifying the emerging novel viruses with epidemic potential and measures for risk mitigation.

Development of indigenous IgG ELISA for the detection of anti-SARS-CoV-2 IgG

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.

Canine Distemper Virus in Asiatic Lions of Gujarat State, India

In September 2018, an epizootic infection caused by canine distemper virus emerged in an Asiatic lion population in India. We detected the virus in samples from 68 lions and 6 leopards by reverse transcription PCR. Whole-genome sequencing analysis demonstrated the virus strain is similar to the proposed India-1/Asia-5 strain.

Involvement of dual serotypes during a severe dengue outbreak in Wadi area, Nagpur district, Maharashtra 2017

BACKGROUND & OBJECTIVES

An outbreak of dengue-like illness was reported from Wadi area within the Nagpur Municipal Corporation during September-October 2017 with five deaths. Major symptoms reported were high fever (103-106 ^oF), acute joint pains, myalgia, drowsiness, breathlessness, etc. An investigation was conducted to confirm the etiological agent, its characterization and the vectors involved in the outbreak.

METHODS

Serological analysis was conducted to detect dengue (DEN)/chikungunya IgM antibodies in 158 sera samples. Nested-PCR was carried out to serotype eight ELISA positive samples. Adult and larval mosquito collections were conducted in the affected areas to determine species composition and mosquito density.

RESULTS

Dengue IgM antibodies were detected in 44 sera samples. Molecular typing revealed involvement of DEN-2 and DEN-3 serotypes. Dengue hemorrhagic fever symptoms were observed in two patients. Aedes aegypti breeding was found rampant with Breteu index and house index ranging from 23 to 70 and 17 to 56, respectively. Major breeding habitats encountered were, used tyres, cement tanks and refrigerator trays.

INTERPRETATION & CONCLUSION

Clinical symptoms, detection of anti-DEN IgM antibodies in high number of samples and heavy breeding of Ae. aegypti confirmed it was a dengue outbreak.

Identification and phylogenetic analysis of herpes simplex virus-1 from clinical isolates in India

Human herpes simplex virus (HSV)-1 infection is acquired in childhood and persists throughout a person’s lifetime. Here, we present two cases from India; one showing symptoms of postpartum haemorrhage with disseminated intravascular coagulation, and the second one showing signs of acute encephalitis syndrome. The aetiological agent in both cases was identified as HSV-1 using the PCR method. The next-generation sequencing method retrieved ~97 % of the viral genome from the isolates of the clinical samples. The phylogenetic analysis of the retrieved genomes revealed that they belong to clade II of HSV-1. This study identifies a few sequence variations in the glycoprotein region of HSV-1 during two different clinical manifestations. There are a couple of papers that analyse variations in the glycoprotein region of clinical samples. Further, this study also highlights the importance of considering HSV-1 during differential diagnosis when analysing the nosocomial infection.

Growth Kinetics of Kyasanur Forest Disease Virus in Mammalian Cell Lines and Development of Plaque Reduction Neutralization Test

Kyasanur forest disease virus (KFDV) is a tick-borne flavivirus identified in 1957 in the Karnataka state of India causing fatalities in monkeys and humans. Even after the introduction of a vaccine in the endemic areas, hundreds of cases are reported every year. Being a high-risk category pathogen, the studies on this virus in India were limited till the past decade. The growth characteristics of this virus in various mammalian cell lines have not yet been studied. In this study, we have demonstrated the growth pattern of virus in BHK-21, Vero E6, Vero CCL81, rhabdomyosarcoma, porcine stable kidney, and Pipistrellus ceylonicus bat embryo cell lines, and found BHK-21 to be the best. We have developed KFDV plaque reduction neutralization test for the first time.

Postcholecystectomy syndrome (PCS)

The term postcholecystectomy syndrome (PCS) comprises a heterogeneous group of symptoms and findings in patients who have previously undergone cholecystectomy. Although rare, these patients may present with abdominal pain, jaundice or dyspeptic symptoms. Many of these complaints can be attributed to complications including bile duct injury, biliary leak, biliary fistula and retained bile duct stones. Late sequelae include recurrent bile duct stones and bile duct strictures. With the number of cholecystectomies being performed increasing in the laparoscopic era the number of patients presenting with PCS is also likely to increase. We briefly explore the syndrome and its main aetiological theories.