Sero-prevalence of Nipah antibodies among close contacts of the index case during 2019 Ernakulam outbreak

Introduction: Nipah virus (NiV) infection is a fatal emerging zoonotic disease. Infection with NiV has a wide range of clinical spectrum which can range from asymptomatic cases to acute respiratory distress syndrome (ARDS). The index case of NiV infection of 2019 outbreak in Ernakulam district was a 23-year-old male who presented with features of encephalitis. This study was undertaken to address the subclinical or asymptomatic NiV infection amongst the close contacts of this index case by using NiV-specific Immunoglobulin IgM and IgG antibodies. The index case was first treated in a primary care center. He survived the infection and was discharged after a period of 108 days from the tertiary care facility where he was treated eventually. Methods: Serum samples from 49 close contacts of the index case were collected and tested for anti-NiVIgM and anti-NiVIgG antibodies. The contacts included health care workers including those from the primary care facility, family members, and his friends. Results: Most common type of exposure included physical contact (59.2%), followed by exposure to body fluids (22.4%). Conclusion: None of the 49 contacts tested positive for anti-NiV human IgM and anti-NiVIgG antibodies. There were no subclinical cases amongst the close contacts of Nipah index case during the 2019 Kerala outbreak

Clinical & epidemiological significance of Kyasanur forest disease

Kyasanur forest disease (KFD) is a known viral haemorrhagic fever in India, for the last 60 years. However, in recent years, the change in epidemiological profile of the disease has suggested that it is now time to consider KFD as an emerging tropical disease in India. The preference should be to educate not only the villagers where it is being reported or detected but also to public health experts, veterinarians, forest officials and medical professionals to pay attention while seeing a patient overlapping with endemic diseases such as Japanese encephalitis, West Nile, dengue, chikungunya, malaria and tuberculosis. Although the existence of KFD is known for a long time, updated understanding of its clinical profile in humans is still limited. This article describes in detail the clinical presentation of KFD reported till date. It also highlights geographical distribution of the disease, risk factors for virus transmission, biochemical/haematological findings and control measures. There is an urgent need for research on KFD, particularly for understanding biphasic nature of illness, development of cost-effective diagnostic tools, utility of non-invasive samples for diagnosis and development of new vaccines

Guidance for building a dedicated health facility to contain the spread of the 2019 novel coronavirus outbreak

Preparedness for the ongoing coronavirus disease 2019 (COVID-19) and its spread in India calls for setting up of adequately equipped and dedicated health facilities to manage sick patients while protecting healthcare workers and the environment. In the wake of other emerging dangerous pathogens in recent times, such as Ebola, Nipah and Zika, it is important that such facilities are kept ready during the inter-epidemic period for training of health professionals and for managing cases of multi-drug resistant and difficult-to-treat pathogens. While endemic potential of such critically ill patients is not yet known, the health system should have surge capacity for such critical care units and preferably each tertiary government hospital should have at least one such facility. This article describes elements of design of such unit (e.g., space, infection control, waste disposal, safety of healthcare workers, partners to be involved in design and plan) which can be adapted to the context of either a new construction or makeshift construction on top of an existing structure. In view of a potential epidemic of COVID-19, specific requirements to handle it are also given

Waning natural and vaccine-induced immunity leading to reinfection with SARS-CoV-2 Omicron variant

We have investigated six COVID-19 recovered cases with two doses of Covishield vaccination followed by reinfection. The primary SARS-CoV-2 infection found to occur with B.1 and reinfection with Omicron BA.1 and BA.2 variants. The genomic characterization and duration between two infections confirms these cases as SARS-CoV-2 reinfection. The immune response determined at different time intervals demonstrated boost post two dose vaccination, decline in pre-reinfection sera post 7 months and rise post reinfection. In conclusion, it was observed that these cases got SARS-CoV-2 reinfection with declined hybrid immunity acquired from primary infection and two dose covishield vaccination. This findings suggests the need to protect the community through booster dose of vaccination and prevent further infections following personal hygiene and non-pharmaceutical interventions

Acute Encephalitis with Atypical Presentation of Rubella in Family Cluster, India

We report 3 atypical rubella cases in a family cluster in India. The index case-patient showed only mild febrile illness, whereas the other 2 patients showed acute encephalitis and died of the disease. We confirmed rubella in the index and third cases using next-generation sequencing and IgM

Differential Cell Line Susceptibility to the SARS-CoV-2 Omicron BA.1.1 Variant of Concern

The unique mutations of the SARS-CoV-2 Omicron variant are associated with increased transmissibility, immune escape, increased binding affinity to ACE-2, and increased viral load. Omicron exhibited a shift in tropism infecting the upper respiratory tract compared to other variants of concern which have tropism for the lower respiratory tract. The tropism of omicron variants in cell lines of different hosts and tissue origins still remains unclear. Considering this, we assessed the susceptibility of different cell lines to the SARS-CoV-2 omicron BA.1.1 variant and permissiveness among different cell lines for omicron replication. Susceptibility and permissiveness of a total of eleven cell lines, including six animal cell lines and five human cell lines for omicron BA.1.1 infection, were evaluated by infecting individual cell lines with omicron BA.1.1 isolate at a 0.1 multiplicity of infection. Virus replication was assessed by observation of cytopathic effects followed by viral load determination by real-time PCR assay and virus infectivity determination by TCID50 assay. The characteristic cytopathic effect, increased viral load, and productive omicron replication was detected in Vero CCL-81, Vero E6, Vero/hSLAM, MA-104, and Calu-3 cells. Although LLC MK-2 cells showed an increased TCID50 titer at the second infection, the viral load did not show much difference in both infections. Caco-2 cells did not show evident CPE, but they supported omicron replication at a low level. A549, RD, MRC-5, and BHK-21 cells supported omicron BA.1.1 replication without the CPE. This is the first study on the comparison of susceptibility of different cell lines to Omicron variant BA.1.1, which might be useful for future studies on emerging SARS-CoV-2 variants

Nipah Virus Sequences from Humans and Bats during Nipah Outbreak, Kerala, India, 2018

We retrieved Nipah virus (NiV) sequences from 4 human and 3 fruit bat (Pteropus medius) samples from a 2018 outbreak in Kerala, India. Phylogenetic analysis demonstrated that NiV from humans was 96.15% similar to a Bangladesh strain but 99.7%–100% similar to virus from Pteropus spp. bats, indicating bats were the source of the outbreak

Table_1_Surveillance of Nipah virus in Pteropus medius of Kerala state, India, 2023.DOCX

IntroductionSince 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.MethodsThroat 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.ResultsAn 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.DiscussionThe findings of the study caution that there is a spillover risk in the region and necessary precautions should be taken.</p

Isolation and Genomic Characterization of SARS-CoV-2 Omicron Variant Obtained from Human Clinical Specimens

Due to the failure of virus isolation of the Omicron variant in Vero CCL-81 from the clinical specimens of COVID-19 cases, an initial in vivo and subsequent in vitro approach was utilized for the isolation of the virus. A total of 74 oropharyngeal/nasopharyngeal specimens were collected from SARS-CoV-2 positive international travellers and a contact case at Delhi and Mumbai, India. All the specimens were sequenced using next-generation sequencing and simultaneously inoculated onto Vero CCL-81 cells for virus isolation. Subsequently, two omicron positive specimens were inoculated into Syrian hamsters for two passages. The initial passage of the positive hamster specimens was inoculated onto Vero CCL-81 cells. The clinical specimens, hamster specimens, and Vero CCL-81 passages were sequenced to assess the mutational changes in different host species. The replication of the Omicron variant in hamsters was confirmed with the presence of a high viral load in nasal turbinate and lung specimens of both passages. The successful isolation of the virus from hamster specimens with Vero CCL-81 was observed with cytopathic effect in infected cells and high viral load in the cell suspension. The genome analysis revealed the presence of L212C mutation, Tyrosine 69 deletion, and C25000T nucleotide change in spike gene of hamster passage sequences and an absence of V17I mutation in E gene in hamster passage sequences, unlike human clinical specimen and Vero CCL-81 passages. No change was observed in the furin cleavage site in any of the specimen sequences, suggesting intact pathogenicity of the virus isolate. Our data demonstrated successful isolation of the Omicron variant with the in vivo method first followed by in vitro method. The virus isolate could be used in the future to explore different aspects of the Omicron variant

Evaluation of immunogenicity post two doses of inactivated SARS-CoV-2 vaccine, Covaxin after six months

We have evaluated the immunogenicity of two dose of Covaxin given at a one-month interval to two adult populations, i.e. COVID-19 naïve-vaccinated individuals (n = 118) and COVID-19 recovered individuals (n = 128) with the vaccination. The immune response in the study population were assessed at three follow-ups, namely at one month post first dose, one and six months after the second dose. The persistence of S1RBD IgG and neutralizing antibodies for six months post vaccination was observed at different time intervals. The enhanced immune response was observed in both the participant groups. The study emphasizes the need for a booster dose post six months of vaccination