Molecular Epidemiology of “Norwalk‐like Viruses” in Outbreaks of Gastroenteritis in the United States

Abstract

Fecal specimens from 90 outbreaks of nonbacterial gastroenteritis reported to 33 state health departments from January 1996 to June 1997 were examined to determine the importance of and to characterize "Norwalk-like viruses" (NLVs) in these outbreaks. NLVs were detected by reverse transcription-polymerase chain reaction in specimens from 86 (96%) of 90 outbreaks. Outbreaks were most frequent in nursing homes and hospitals (43%), followed by restaurants or events with catered meals (26%); consumption of contaminated food was the most commonly identified mode of transmission (37%). Nucleotide sequence analysis showed great diversity between strains but also provided evidence indicating the emergence of a common, predominant strain. The application of improved molecular techniques to detect NLVs demonstrates that most outbreaks of nonbacterial gastroenteritis in the United States appear to be associated with these viruses and that sequence analysis is a robust tool to help link or differentiate these outbreaks.

Hospitalization due to norovirus and genotypes of rotavirus in pediatric patients, state of Espírito Santo

“…Most of the studies on seasonality describe winter peaks in NoV-associated outbreaks or sporadic cases (Fankhauser et al 1998, Fretz 2005 and some reports, in spring and summer, varying according to the NoV genogroups (Marshall et al 2003). Prevalence of NoV at the beginning of the dry season was previously observed in Vietnam (Hansman et al 2004).…”

Porcine enteric caliciviruses: Genetic and antigenic relatedness to human caliciviruses, diagnosis and epidemiology

“…In 2002, Norwalk and Norwalk-like viruses were assigned to the genus Norovirus [2]. Since the discovery of Norwalk virus, NoVs have emerged as the most common pathogen causing food-and water-borne viral gastroenteritis in humans including both outbreaks and sporadic cases worldwide [7][8][9][10]. The human NoVs have been listed as class B biological pathogens by the National Institutes of Health/Biodefense Program.…”

Genetic classification of "Sapporo-like viruses"

“…The members of the genera "Sapporo-like viruses" (SLVs) and "Norwalk-like viruses" (NLVs) in the family Caliciviridae [14,32] are an important cause of gastroenteritis in humans [4,8,10,12,21,28,30,39,40,43] and animals [7,15,26,38]. In humans, the illnesses caused by SLVs and NLVs differ in epidemiological features and clinical symptoms.…”