Genetic characterization and evolutionary analysis of norovirus genotypes circulating among children in eastern India during 2018-2019

Abstract

Noroviruses are significant etiological agents of acute gastroenteritis (AGE) across all age groups, especially in children under 5 years of age. Although the prevalence of norovirus infection is known to have increased in various countries, in India there are few reports pertaining to the norovirus disease burden. We investigated the epidemiology and molecular characteristics of noroviruses in children seeking health care at two hospitals in Kolkata, Eastern India. Faecal specimens were collected between January 2018 and December 2019 from 2812 children under 5 years of age with acute gastroenteritis. Noroviruses were detected in 6.04% (170/2812) of the samples, and 12.9% (22/170) of these were cases of coinfection with rotavirus. Among children (≤5 years), a higher infection rate (8.2%, n = 94/1152) was observed in the 6 to 12 month age group. GII.4 Sydney 2012 was the dominant norovirus capsid genotype (n = 75/90, 83.3%), followed by GII.3 (n = 10/90, 11.1%). Other capsid types GII.13 (n = 4/90, 4.4%) and GII.17 (n = 1/90; 1.1%) were also detected at low frequency. Phylogenetic analysis showed that the GII.P16 polymerase of strains in this region clustered with those of the phylogenetically distinct monophyletic clade of GII.P16 strains, whose members have been circulating worldwide since 2014. Inter-genotypic norovirus recombinants such as GII.P16-GII.3 (n = 10) and GII.P16-GII.13 (n = 4) were also observed among the circulating strains. In comparison to previous studies from eastern India, the present study shows a higher detection rate of norovirus infection in the paediatric population suffering from acute gastroenteritis. Continuous surveillance is required for predicting the emergence of novel genotypes and recombinant strains and for future vaccine development. Supplementary Information The online version contains supplementary material available at 10.1007/s00705-021-05197-6.

Hospital‐based norovirus surveillance in children <5 years of age from 2017 to 2019 in India

“…Globally, GII.4 Sydney is the most common genotype causing norovirus disease in hospitalized children with AGE 30 . In our 3‐year study, GII.4 Sydney was detected in 59.4% of the cases while in a recent study from eastern India, GII.4 Sydney was associated with 83.3% of the norovirus positive cases 19 . GII.4 Sydney[P16] was the most common strain in our study followed by GII.4 Sydney[P31].…”

“…To date, few studies from India have reported the prevalence of norovirus gastroenteritis in children ≤5 years hospitalized for AGE with positivity rates ranging from 1.2% to 15.1% 8–12,19,20 . Most of these studies were conducted before the introduction of oral rotavirus vaccine into the UIP in India 14 .…”

“…To date, few studies from India have reported the prevalence of norovirus gastroenteritis in children ≤5 years hospitalized for AGE with positivity rates ranging from 1.2% to 15.1%. [8][9][10][11][12]19,20 Most of these studies were conducted before the introduction of oral rotavirus vaccine into the UIP in India. 14 In contrast to our study, these studies used conventional RT-PCR to detect norovirus, which has been shown to be less sensitive than real-time RT-PCR.…”

“…30 In our 3-year study, GII.4 Sydney was detected in 59.4% of the cases while in a recent study from eastern India, GII.4 Sydney was associated with 83.3% of the norovirus positive cases. 19 viruses comprised more than 50% of the strains. 30 In our study, GI viruses were detected in 10.2% of the norovirus positive cases, which is higher than reported in other studies from India.…”

One-Year Surveillance of SARS-CoV-2 Virus in Natural and Drinking Water

“…Norovirus is an enteric virus that replicates in the gastrointestinal tract, and—like SARS-CoV-2—it is also excreted in the feces of infected individuals several weeks after infection [ 4 , 29 ]. They are non-enveloped viruses belonging to Caliciviridae and are classified into six genogroups (GI to GVI)—of which, only representatives of the genogroups I, II, and IV infect humans [ 32 ]. Norovirus RNA (considering together the genotypes I and II, evaluated in the present survey) was detected in just one sample of groundwater, 12 samples of surface water, and 11 samples of drinking water.…”