Trends of respiratory syncytial virus sub-types in children hospitalised at a tertiary care centre in Jaipur during 2012-2014

Characterizing human respiratory syncytial virus among children admitted with acute respiratory tract infections from 2019 to 2022

Respiratory syncytial virus is a major causative agent of lower respiratory tract infection in children, especially infants with substantial morbidity and mortality implications. The virus undergoes continuous evolution documented by accumulation of mutations in the glycoprotein gene necessitating vigilant surveillance to provide essential data to epidemiologists and researchers involved in development of vaccines. This study was aimed to perform molecular characterization of respiratory syncytial virus (RSV) among children ≤ 5 years admitted in hospital. In the current study we observed RSV-A (2019 (n = 95) and 2021 (n = 61) seasons) and RSV-B (2022 season (n = 68)). Phylogenetic analysis revealed all RSV-A strains (n = 47) to be GA.2.3.5 and RSV-B (n = 22) were classified as GB.5.0.5a. Selection pressure analysis identified one positive (P274L/V) and one negative site (P230T) in RSV-A, while in RSV-B there was only one negatively selected site (S295). This study spanning over three seasons contributes to RSV evolutionary dynamics in India emphasizing the importance of on-going surveillance to inform effective public health strategies and vaccine development efforts.

Reclassification of respiratory syncytial virus genotypes in India

Respiratory syncytial virus (RSV) is known to be the major cause of lower respiratory tract infections in infants and in the elderly. RSV was recently reclassified and simplified into three genotypes of the RSV-A subgroup (GA1-GA3) and into seven genotypes of the RSV-B subgroup (GB1-GB7). This classification strategy was not implemented globally. This study intended to reclassify the sequences that were submitted in GenBank till September 2021 from India. The gene sequences of the ectodomain region, second hypervariable region (SHR), and the partial second hypervariable region (PSHR) of the G gene were selected for the analysis. 25 ectodomain, 36 s hypervariable, and 19 partial second hypervariable regions of the RSV-A subgroup and 42-ectodomain, 49-s hypervariable region and 11-partial second hypervariable region of RSV-B subgroup were used for phylogenetic analysis. P-distance was calculated to support the genotype determination done by phylogenetic analysis. Phylogenetic analysis revealed that GA2.3.1, GA2.3.3, GA2.3.4, GA2.3.5, and GA2.3.6b lineages of GA2 genotype for RSV-A; and GB5.0.1, GB5.0.2, GB5.0.3, GB5.0.4a, GB5.0.4c, GB5.0.5a, GB5.0.5c lineages of GB5 genotype and GB7 genotype for RSV-B were that circulated in India. This work has implication for RSV vaccine research, and also for strategies for the prevention and control of RSV infection in humans.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13337-022-00802-x.

Respiratory syncytial virus among children hospitalized with severe acute respiratory infection in Kashmir, a temperate region in northern India

Background

Severe acute respiratory infections (SARI) are a leading cause of hospitalizations in children, especially due to viral pathogens. We studied the prevalence of respiratory viruses among children aged <5 years hospitalized with severe acute respiratory infections (SARI) in Kashmir, India.

Methods

We conducted a prospective observational study in two tertiary care hospitals from October 2013 to September 2014, systematically enrolling two children aged <5 years with SARI per day. We defined SARI as history of fever or measured fever (≥38°C) and cough with onset in the last 7 days requiring hospitalization for children aged 3-59 months and as physician-diagnosed acute lower respiratory infection for children aged <3 months. Trained study staff screened children within 24 hours of hospitalization for SARI and collected clinical data and nasopharyngeal swabs from enrolled participants. We tested for respiratory syncytial virus (RSV) A and B, influenza viruses, rhinoviruses (HRV)/enteroviruses, adenovirus (AdV), bocavirus (BoV), human metapneumovirus (hMPV) A and B, coronaviruses (OC43, NL65, C229E), and parainfluenza viruses (PIV) 1, 2, 3 and 4 using standardized duplex real-time polymerase chain reaction.

Results

Among 4548 respiratory illness admissions screened from October 2013 to September 2014, 1026 met the SARI case definition, and 412 were enrolled (ages = 5 days to 58 months; median = 12 months). Among enrolees, 256 (62%) were positive for any virus; RSV was the most commonly detected (n = 118, 29%) followed by HRV/enteroviruses (n = 88, 21%), PIVs (n = 31, 8%), influenza viruses (n = 18, 4%), BoV (n = 15, 4%), coronaviruses (n = 16, 4%), AdV (n = 14, 3%), and hMPV (n = 9, 2%). Fifty-four children had evidence of virus co-detection. Influenza-associated SARI was more common among children aged 1-5 years (14/18, 78%) while most RSV detections occurred in children <12 months (83/118, 70%). Of the RSV viruses typed (n = 116), the majority were type B (94, 80%). Phylogenetic analysis of G gene of RSV showed circulation of the BA9 genotype with 60bp nucleotide duplication.

Conclusions

Respiratory viruses, especially RSV, contributed to a substantial proportion of SARI hospitalizations among children <5 years in north India. These data can help guide clinicians on appropriate treatment and prevention strategies.

Disease Burden Due to Respiratory Syncytial Virus in Indian Pediatric Population: A Literature Review

Respiratory syncytial virus (RSV) is one of the leading causes of lower respiratory tract infections in young children. Globally, there is huge disease burden, high treatment cost, and health impact beyond acute episodes due to RSV which necessitate development and implementation of preventive strategies for the control of RSV infection. The disease burden due to RSV in pediatric population across India is still not clearly understood so this literature review was therefore conducted to gather data on disease burden due to RSV in Indian pediatric population. Systematic literature search was performed using PubMed and Google search with different medical subject headings from 2007 to 2020. Studies performed in Indian pediatric population were selected for review. Literature review revealed that in India, epidemiology of RSV infection is well documented in young children (0-5 years) as compared to children from other age groups. The rates of RSV detection in various studies conducted in younger children (0-5 years) vary from 2.1% to 62.4% in India which is higher as compared to children from other age groups. In India, RSV mainly peaks around rainy to early winter season, that is, during months of June through October while smaller peak was noted during December, January, and February. In 2020, higher RSV-associated disease burden was reported among children (<5 years) in low-income and lower-middle-income countries. Considering significant disease burden due to RSV in young Indian children, availability of RSV vaccine would be crucial to prevent RSV infections in children and its spread in the community.

Respiratory syncytial virus infections in India: Epidemiology and need for vaccine

Respiratory syncytial virus (RSV) has been identified as a leading cause of lower respiratory tract infections in young children and elderly. It is an enveloped negative-sense RNA virus belonging to Genus Orthopneumovirus. The clinical features of RSV infection range from mild upper-respiratory-tract illnesses or otitis media to severe lower-respiratory-tract illnesses. Current estimates show that about 33.1 million episodes of RSV-acute lower respiratory infection (ALRI) occurred in young children in 2015, of these majority that is, about 30 million RSV-ALRI episodes occurred in low-middle-income countries. In India, the rates of RSV detection in various hospital- and community-based studies mostly done in children vary from 5% to 54% and from 8% to 15%, respectively. Globally, RSV epidemics start in the South moving to the North. In India, RSV mainly peaks in winter in North India and some correlation with low temperature has been observed. Different genotypes of Group A (GA2, GA5, NA1 and ON1) and Group B (GB2, SAB4 and BA) have been described from India. The burden of RSV globally has kept it a high priority for vaccine development. After nearly 50 years of attempts, there is still no licensed vaccine and challenges to obtain a safe and effective vaccine is still facing the scientific community. The data in this review have been extracted from PubMed using the keywords RSV and Epidemiology and India. The data have been synthesised by the authors.

Genetic diversity of human respiratory syncytial virus in children with acute respiratory infections in Chennai, South India

Introduction

Human respiratory syncytial virus (HRSV) an RNA virus belonging to Pneumoviridae family, is an important cause of acute respiratory infections (ARIs) in young children. HRSV circulates as two subgroups A and B, which are further categorised into several genotypes. New genotypes may replace existing ones over successive epidemic seasons and multiple genotypes may cocirculate in the same community rendering it important to monitor them at the molecular level. The present study assessed the circulating genotypes of HRSV in Chennai.

Materials and Methods

Two hundred and sixty-seven children with ARI were recruited during the study from April 2016 to March 2018 for detecting HRSV A and B by real-time reverse transcription-polymerase chain reaction. Phylogeny and selection pressure analysis were done.

Results

Fifty-seven of the 267 samples (21.3%) were positive for HRSV, of which 7.1% and 14.2% were HRSV A and B, respectively, indicating that HRSV B was the major subgroup circulating in Chennai. Peak activity of HRSV was observed during the monsoon and winter months. Phylogenetic analysis of 2nd hypervariable region (HVR) of attachment glycoprotein gene (G gene) revealed that the HRSV A strains belonged to ON1 and HRSV B strains belonged to BA9 genotypes. Several unique amino acid substitutions were observed among the study strains. The Shannon entropy plot revealed that the HRSV A strains from our study have a high potential for amino acid substitutions in the 2nd HVR of G gene.

Conclusion

This study underlines the genetic diversity of HRSV and emphasises the need for continued molecular surveillance for infection management and prevention strategies.