Norovirus Gastroenteritis in a Birth Cohort in Southern India.

Vipin Kumar Menon,Gagandeep Kang,Anuradha Saravanabavan,Prasanna Samuel,Santosh George,James J Gray,Miren Iturriza-Gomara,Mary K Estes,David W Brown,Farzana Begum Liakath,Rosario Vivek,Rajiv Sarkar,Sidhartha Giri,Sasirekha Ramani,Andres G Lescano

doi:10.1371/journal.pone.0157007

Vipin Kumar Menon, Gagandeep Kang + Show 13 more

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https://doi.org/10.1371/journal.pone.0157007

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Abstract

BackgroundNoroviruses are an important cause of gastroenteritis but little is known about disease and re-infection rates in community settings in Asia.MethodsDisease, re-infection rates, strain prevalence and genetic susceptibility to noroviruses were investigated in a birth cohort of 373 Indian children followed up for three years. Stool samples from 1856 diarrheal episodes and 147 vomiting only episodes were screened for norovirus by RT-PCR. Norovirus positivity was correlated with clinical data, secretor status and ABO blood group.ResultsOf 1856 diarrheal episodes, 207 (11.2%) were associated with norovirus, of which 49(2.6%) were norovirus GI, 150(8.1%) norovirus GII, and 8 (0.4%) were mixed infections with both norovirus GI and GII. Of the 147 vomiting only episodes, 30 (20.4%) were positive for norovirus in stool, of which 7 (4.8%) were norovirus GI and 23 (15.6%) GII. At least a third of the children developed norovirus associated diarrhea, with the first episode at a median age of 5 and 8 months for norovirus GI and GII, respectively. Norovirus GI.3 and GII.4 were the predominant genotypes (40.3% and 53.0%) with strain diversity and change in the predominant sub-cluster over time observed among GII viruses. A second episode of norovirus gastroenteritis was documented in 44/174 (25.3%) ever-infected children. Children with the G428A homozygous mutation for inactivation of the FUT2 enzyme (se428se428) were at a significantly lower risk (48/190) of infection with norovirus (p = 0.01).ConclusionsThis is the first report of norovirus documenting disease, re-infection and genetic susceptibility in an Asian birth cohort. The high incidence and apparent lack of genogroupII specific immunity indicate the need for careful studies on further characterization of strains, asymptomatic infection and shedding and immune response to further our understanding of norovirus infection and disease.

Highlights

Noroviruses are a leading cause of non-bacterial acute gastroenteritis (AGE) outbreaks in all age groups worldwide and are increasingly recognized as the second most common cause of sporadic AGE in children after rotavirus [1,2,3]
Norovirus Gastroenteritis in Indian Children. This is the first report of norovirus documenting disease, re-infection and genetic susceptibility in an Asian birth cohort
The high incidence and apparent lack of genogroupII specific immunity indicate the need for careful studies on further characterization of strains, asymptomatic infection and shedding and immune response to further our understanding of norovirus infection and disease

Summary

Introduction

Noroviruses are a leading cause of non-bacterial acute gastroenteritis (AGE) outbreaks in all age groups worldwide and are increasingly recognized as the second most common cause of sporadic AGE in children after rotavirus [1,2,3]. Noroviruses are divided into 5 genogroups (GI-GV) of which GI, GII and GIV are known to cause gastroenteritis in humans [5, 6]. Among norovirus genogroups known to infect humans, GII noroviruses are the major genogroup causing outbreaks and sporadic infections worldwide and predominate in community studies [8, 9].

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