Circulation of genetically diverse non-polio enteroviruses in respiratory samples during COVID-19 pandemic period (2021-22)

ABSTRACT

Enteroviruses, beyond poliovirus, are important pathogens. Several non-polio enteroviruses (NPEVs) are causing epidemics all around the world. Limited data is available on the prevalence and diversity of these viruses from India. Objective(s) Detection and characterization of NPEVs in respiratory samples during the COVID-19 pandemic period. Material(s) and Method(s) COVID-19 negative samples from acute respiratory infections (ARI) [n = 105] and severe-acute respiratory infections (SARI) [n = 148] during the period 2021-22 were screened for NPEVs. Detection was carried out using the one step RT-PCR method targeting the 5'UTR region followed by molecular analysis. Results and Conclusion(s) Total positivity of NPEVs was noted in 35.23% and 31.08% of the ARI and SARI cases, respectively. Comparison within the two groups studied, showed significant difference in the age-wise distribution for cases>18 years of age. Year round seasonality for ARI cases while autumn seasonality for SARI cases was observed. Sequencing of representative samples of ARI cases showed prevalence of Rhinovirus A (RVA), Rhinovirus B (RVB), Rhinovirus C (RVC) and Echovirus, while predominance of RVC followed by RVA was observed for the SARI cases. Phylogenetic analysis of all the strains showed clustering of RVC strains in different clusters. Divergence was also noted in RVA and RVB strains studied. Circulation of a rare Echovirus-29 strain was noted in the ARI cases. The study highlighted significant divergence in the Rhinovirus strains studied. It warrants the need for surveillance of NPEVs, whole-genome sequencing of the circulating strains for better understanding of biodiversity among the NPEVs and the potential health burden.