Mapping antigenic diversity and strain specificity of mumps virus: a bioinformatics approach

Mumps is an acute infectious disease caused by mumps virus, a member of the family Paramyxoviridae. With the implementation of vaccination programs, mumps infection is under control. However, due to resurgence of mumps epidemics, there is a renewed interest in understanding the antigenic diversity of mumps virus. Hemagglutinin-neuraminidase (HN) is the major surface antigen and is known to elicit neutralizing antibodies. Mutational analysis of HN of wild-type and vaccine strains revealed that the hypervariable positions are distributed over the entire length with no detectable pattern. In the absence of experimentally derived 3D structure data, the structure of HN protein of mumps virus was predicted using homology modeling. Mutations mapped on the predicted structures were found to cluster on one of the surfaces. A predicted conformational epitope encompasses experimentally characterized epitopes suggesting that it is a major site for neutralization. These analyses provide rationale for strain specificity, antigenic diversity and varying efficacy of mumps vaccines.     

Phylogenetic Analysis of Spread of Hepatitis C Virus Identified during HIV Outbreak Investigation,Unnao, India

An HIV outbreak investigation during 2017–2018 in Unnao District, Uttar Pradesh, India, unearthed high prevalence of hepatitis C virus (HCV) antibodies among the study participants. We investigated these HCV infections by analyzing NS5B and core regions. We observed no correlation between HIV–HCV viral loads and clustering of HCV sequences, regardless of HIV serostatus. All HCV isolates belonged to genotype 3a. Monophyletic clustering of isolates in NS5B phylogeny indicates emergence of the outbreak from a single isolate or its closely related descendants. The nucleotide substitution rate for NS5B was 6 × 10⁻³ and for core was 2 × 10⁻³ substitutions/site/year. Estimated time to most recent common ancestor of these isolates was 2012, aligning with the timeline of this outbreak, which might be attributable to unsafe injection practices while seeking healthcare. HIV–HCV co-infection underlines the need for integrated testing, surveillance, strengthening of healthcare systems, community empowerment, and molecular analyses as pragmatic public health tools.     

A comparison of the tolerability of two dilution volumes (0.5 mL and 1.0 mL) of a purified chick embryo cell rabies vaccine administered intramuscularly to healthy adult volunteers: A randomized, intraindividual, assessor-blind study

Background: The current recommendation of the manufacturer for administering purified chick embryo cell rabies vaccine (PCECV) is to reconstitute the contents with 1.0 mL of water for injection (WFI). However, it has been debated whether a lower volume of WFI (0.5 mL) is likely to cause less pain.Objectives: The aims of this study were to compare the tolerability of PCECV administered IM at a volume of 0.5 mL versus 1.0 mL of diluent and to determine the immunogenicity of the vaccine when administered according to the World Health Organization-recommended preexposure prophylaxis regimen for rabies immunization.Methods: This comparative, intraindividual, assessor-blind study was conducted at the Department of Clinical Pharmacology, Topiwala National Medical College and Bai Yamunabai Laxman Nair Charitable Hospital Mumbai, India). Healthy volunteers aged 18 to 50 years received, by randomized sequence, 3 IM injections of PCECV, diluted in 0.5 mL or 1.0 mL of WFI, on study days 0, 7, and 28. Tolerability was assessed at 30 minutes and 24 hours after injection and included assessments for local and systemic reactions. For immunogenicity assessment, rabies virus-neutralizing antibody 0RVNA) titers were assayed at baseline and on day 49 (ie, 3 weeks after the third injection).Results: Twenty-six subjects (24 men, 2 women; mean [SD] age, 22.4 [2.4] years; mean [SD] body weight, 59.0 [11.3] kg) entered the study. Twenty-five subjects were included in the tolerability assessment; 24 in the immunogenicity assessment. No statistically significant differences were found between dilutions in the frequency of local and systemic reactions. Most reactions were mild. All subjects developed RVNA titers >0.5 IU/mL (indicative of protection) by day 49.Conclusions: In this population of healthy volunteers, a full antigenic dose of PCECV in a dilution of 0.5 mL WFI is as well tolerated locally and systemically as in a dilution of 1.0 mL. All subjects developed levels of RVNA far exceeding 0.5 IU/mL, which is indicative of protection against rabies.     

Awareness regarding COVID-19 and problems being faced by young adults with type 1 diabetes mellitus amid nationwide lockdown in India: A qualitative interview study

AimsTo assess the awareness about COVID-19 and the problems being faced by young adults with T1DM amid nationwide lockdown in India.MethodsA cross-sectional telephone-based qualitative interview study was conducted in young adults (aged 18–30 years) with T1DM amid lockdown. Following verbal consent, participants were asked 8 open-ended questions, 5 on awareness about COVID-19 and 3 catering to problems being faced concerning diet, physical activity and treatment amid lockdown. On average, 3 interviews were conducted per day with each lasting for 15?20 min. Interviews were recorded, transcribed and analyzed by qualitative content analysis.ResultsThirty-two participants were interviewed; after exclusion of two poorly recorded interviews, 30 were finally analyzed. Mean age of participants was 22.4 ± 4.0 years (M:F = 8:7). Only 30%, 40% and 53% of participants were aware of modes of transmission (respiratory droplets and fomites), cardinal symptoms (fever, cough and breathing difficulty) and means of prevention (staying indoors, social distancing and regular hand washing), respectively. Majority of participants were unaware of additional risks associated with COVID-19 in diabetes mellitus. Most participants could continue with their routine diet and prescribed treatment regime, however, 90% reported a reduction in physical activity and 72% experienced worsening of glycemic control amid lockdown.ConclusionsYoung adults with T1DM lack adequate awareness about COVID-19. Increasing awareness and imparting diabetes self-management education via digital/print media is needed.     

Biochemical characterization of deltamethrin resistance in a laboratory-selected strain of Aedes aegypti

A resistant strain (DR) of Aedes aegypti, generated by deltamethrin selection for 20 consecutive generations from a laboratory susceptible strain (DS) was studied for the possible resistant mechanisms. The pyrethroid resistance developed was characterized by biochemical assays and native polyacrylamide gel electrophoresis. Significant elevation in the activity of α- and β-esterases, glucose-6-phosphate dehydrogenase (G6PD), CYTP450 (CYTP450), and glutathione-s-transferase (GST) were noticed in DR. The gel profiles for esterases, G6PD, and CYTP450 were different in DR as compared to DS strain. The difference was either in the form of additional bands or increased intensity of the bands or both. Gel profile variations were also evident from densitometry. Our study suggests that these enzymes play an important role in deltamethrin resistance in the DR strain.