Characteristics of GII.4 Norovirus Versus Other Genotypes in Sporadic Pediatric Infections in Davidson County, Tennessee, USA

Abstract

Background Norovirus is a leading cause of epidemic acute gastroenteritis (AGE) in the U.S, with most outbreaks occurring during winter. The majority of outbreaks are caused by GII.4 noroviruses, but data supporting whether this is true for sporadic medically-attended AGE are limited. Therefore, we sought to compare the clinical characteristics and seasonality of GII.4 vs. non-GII.4 viruses in children presenting with vomiting and/or diarrhea. Methods Children from 15 days to 17 years with AGE symptoms were recruited from the outpatient, emergency department, and inpatient settings at Vanderbilt Children's Hospital, Davidson County, Nashville, TN from 12/2012-11/2015. Stool specimens were tested by RT-qPCR for GI and GII noroviruses and subsequently genotyped by sequencing a partial region of the capsid gene. Results A total of 3705 subjects were enrolled and stool specimens were collected and tested from 2885 (78%) of enrollees. Overall, 636 (22%) samples were norovirus-positive, of which 567 (89%) were GII. Of the 460 (81%) genotyped GII-positive samples, 233 (51%) were typed as GII.4 and 227 (49%) as non-GII.4. Compared to children with non-GII.4 infections, children with GII.4 infections were younger, more likely to have diarrhea and receive oral rehydration fluids. Norovirus was detected year-round but peaked during winter. Conclusion Approximately half of sporadic pediatric norovirus AGE cases were caused by GII.4 norovirus. Children infected with GII.4 had more severe symptoms requiring more medical care. Seasonal variations were noticed among different genotypes. These data highlight the importance of continuous norovirus surveillance and provide important information on which strains pediatric norovirus vaccines should protect against.

Development of a Recombinase-Aided Amplification Assay for Rapid Detection of Human Norovirus GII.4

“…Notably, the RT-RAA assay was so rapid that produced positive signal approximately 5 min, and the entire detection protocol could be completed within 30 min. In contrast, the RT-qPCR and RT-LAMP assays normally require 1.5 h for completion (Jeon and Seo et al, 2017;Zaid Haddadin, 2020). Finally, due to thermal cycler limitations, PCR-based detection assays were di cult to integrate in small-scale portable devices amenable for POCT.…”

Prevalence of GII.4 Sydney Norovirus Strains and Associated Factors of Acute Gastroenteritis in Children: Winter 2019-2020 in Guangzhou

“…Norovirus mutates and evolves rapidly, and it is classi ed into 7 genogroups and further divided into more than 40 genotypes based on the ORF2 gene [7]. These different norovirus genotypes are diverse in infectivity and virulence [14,15]. More than 90% of non-bacterial AGE cases are caused by GII, with GII.4…”

Serological Humoral Immunity Following Natural Infection of Children with High Burden Gastrointestinal Viruses

“…Infection may persist for longer in young children [110]. Secretor positive children with norovirus AGE present more severe symptoms than children with non-norovirus AGE [111][112][113][114]. Vomiting is a primary symptom in children seeking medical care for human norovirus AGE [115], sometimes with intensities indistinguishable from rotavirus infections.…”

“…Within GII, GII.4 variants are responsible for 40->95% of infections in children [107,137,138]. GII.4 infections are most frequently the first infecting strain and are more likely to have severe symptoms than non-GII.4 infections [107,112,113,139].…”