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Foodborne gastroenteritis outbreaks owing to Salmonella enterica serovar Weltevreden ( Salmonella Weltevreden) represent a significant global public health problem. In the past two decades, Salmonella Weltevreden has emerged as a dominant foodborne pathogen, especially in South-East Asian countries. This report describes a community foodborne outbreak of gastroenteritis caused by Salmonella Weltevreden in August 2022 following consumption of panipuri from a street vendor in the Polba block in Hooghly district, West Bengal, India. This food item was consumed by 185 people, of whom 129 had acute watery diarrhea with other clinical symptoms and 65 of them were admitted to different District hospitals for treatment. Stool specimens collected from hospitalized cases were positive for S. enterica , and further serotyped as Salmonella Weltevreden. All the Salmonella Weltevreden strains possessed the Salmonella pathogenicity islands associated genes ( invA/E , orgA , ttrc , ssaQ , mgtC , misL , spi4D) , the enterotoxin ( stn ), and hyperinvasive locus gene ( hilA ). Except erythromycin, all the strains were susceptible for commonly used antimicrobials in the treatment of diarrhea. The Xba I-based pulsed-field gel electrophoresis analysis indicated that all the isolates responsible for the recent outbreak were similar, but diverged from other Salmonella Weltevreden that were previously reported in West Bengal. This report indicates that foodborne infection is a major public health concern in India and demands to strengthen capacity-building measures at the local health care levels for linking causative agents of outbreaks.

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., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

Human adenovirus-F (HAdV-F) (genotype 40/41) is the second-most leading cause of pediatric gastroenteritis after rotavirus, worldwide, accounting for 2.8%-11.8% of infantile diarrheal cases. Earlier studies across eastern India revealed a shift in the predominance of genotypes from HAdV41 in 2007-09 to HAdV40 in 2013-14. Thus, the surveillance for HAdV-F genotypes in this geographical setting was undertaken over 2017-2020 to analyze the viral evolutionary dynamics. A total of 3882 stool samples collected from children (≤5 years) were screened for HAdV-F positivity by conventional PCR. The hypervariable regions of the hexon and the partial shaft region of long fiber genes were amplified, sequenced, and phylogenetically analyzed with respect to the prototype strains. A marginal decrease in enteric HAdV prevalence was observed (9.04%, n = 351/3882) compared to the previous report (11.8%) in this endemic setting. Children <2 years were found most vulnerable to enteric HAdV infection. Reduction in adenovirus-rotavirus co-infection was evident compared to the sole adenovirus infection. HAdV-F genotypes 40 and 41 were found to co-circulate, but HAdV41 was predominant. HAdV40 strains were genetically conserved, whereas HAdV41 strains accumulated new mutations. On the basis of a different set of mutations in their genome, HAdV41 strains segregated into 2 genome type clusters (GTCs). Circulating HAdV41 strains clustered with GTC1 of the fiber gene, for the first time during this study period. This study will provide much-needed baseline data on the emergence and circulation of HAdV40/41 strains for future vaccine development., (© 2021 Wiley Periodicals LLC.)

Group A rotaviruses are the major cause of childhood gastroenteritis worldwide. Due to close proximity of human and cattle in rural areas of developing countries like India, interspecies transmission or zoonotic transmission is a major source of rapid generation of reassortants and genetic or antigenic variants. Previously, many human group A rotaviruses were found with porcine or bovine characteristics from eastern and north-eastern India. In this study, four unusual human G8P[4] strains were identified which had artiodactyl-like origins. During an ongoing community based surveillance for epidemiological profiling of diarrheal pathogens, these unusual human group A rotavirus G8P[4] strains were detected from the stool samples of 3-14 months old children with acute diarrhea in Sonarpur, eastern India. Analysis of eleven complete and/or partial gene segments of these unusual G8P[4] strains were done by reverse transcription-PCR (RT-PCR) followed by nucleotide sequencing and phylogenetic analysis. The VP7 nucleotide sequences revealed a close phylogenetic relationship to the G8P[7] porcine strain D-1 and bovine strain KJ59-2 from South Korea. Whereas the VP4 gene segments were also related closely to human rotavirus prototype strain DS-1. Other nine gene segments of these G8P[4] rotaviruses were related closely to either animal or animal-derived rotavirus members of the DS-1-like family. These results suggest that origin of these G8P[4] strains might have been resulted from multiple reassortment events between artiodactyls and ruminant-derived reassortant human rotaviruses. To date, this is the first report of G8P[4] rotavirus from India and the first genomic analysis of G8P[4] strains from Asian continent., (Copyright © 2012 Wiley Periodicals, Inc.)