Incidence of Norovirus Infection among Hospitalized Patients in Bangladesh: A Case-Control Study.

Abstract

Norovirus is the most common cause of both outbreaks and sporadic non-bacterial gastroenteritis worldwide and one of the most common causes of acute gastroenteritis among children in developing countries. In this study, norovirus infections were investigated in diarrheal (Case) and non- diarrheal (Control) patients who have attended in nine hospitals during October, 2019 in Bangladesh. A total of 140 fecal specimens from both children and adults were tested for the presence of norovirus using real-time RT-PCR. Among them, ͠ 12% (n=16) of the specimens were found positive for norovirus RNA, among which only four were further genotyped by sequencing the partial capsid and polymerase gene. Norovirus GII was the most prevalent genogroup. Based on their clustering in the phylogenetic tree, two distinct genotypes were identified- GII.4 as the most prevalent genotype followed by one GII.3. A significant number of diarrhoeal patients hospitalized were found to be infected with norovirus; therefore, community surveillance is required to estimate the true burden of the virus in the country. Genomic analysis of the circulating norovirus strains would be very useful for understanding the pathogenesis and vaccine development. Moreover, the dynamic molecular epidemiology of norovirus requires routine strain surveillance to identify changes in prevailing strains.