title: Norovirus genotypes implicated in two oyster-related illness outbreaks in Ireland.
abstract: We investigated norovirus (NoV) concentrations and genotypes in oyster and faecal samples associated with two separate oyster-related outbreaks of gastroenteritis in Ireland. Quantitative analysis was performed using real-time quantitative reverse transcription polymerase chain reaction and phylogenetic analysis was conducted to establish the NoV genotypes present. For both outbreaks, the NoV concentration in oysters was >1000 genome copies/g digestive tissue and multiple genotypes were identified. In faecal samples, GII.13 was the only genotype detected for outbreak 1, whereas multiple genotypes were detected in outbreak 2 following the application of cloning procedures. While various genotypes were identified in oyster samples, not all were successful in causing infection in consumers. In outbreak 2 NoV GII.1 was identified in all four faecal samples analysed and NoV GII concentrations in faecal samples were >108 copies/g. This study demonstrates that a range of NoV genotypes can be present in highly contaminated oysters responsible for gastroenteritis outbreaks.
authors.affiliation: Marine Institute,Rinville, Oranmore, Co. Galway,Ireland.
authors.forename: P
authors.initials: P
authors.lastname: Rajko-Nenow
authors.affiliation: Marine Institute,Rinville, Oranmore, Co. Galway,Ireland.
authors.forename: S
authors.initials: S
authors.lastname: Keaveney
authors.affiliation: Marine Institute,Rinville, Oranmore, Co. Galway,Ireland.
authors.forename: J
authors.initials: J
authors.lastname: Flannery
authors.affiliation: Marine Institute,Rinville, Oranmore, Co. Galway,Ireland.
authors.forename: A
authors.initials: A
authors.lastname: McINTYRE
authors.affiliation: Marine Institute,Rinville, Oranmore, Co. Galway,Ireland.
authors.forename: W
authors.initials: W
authors.lastname: Doré
mesh_terms: D000818:Animals; D017250:Caliciviridae Infections / Q000453:epidemiology* / Q000821:virology; D004196:Disease Outbreaks; D005243:Feces / Q000821:virology; D005759:Gastroenteritis / Q000453:epidemiology* / Q000821:virology; D005838:Genotype; D006801:Humans; D007494:Ireland / Q000453:epidemiology; D017720:Molecular Epidemiology; D029322:Norovirus / Q000235:genetics*; D010125:Ostreidae / Q000821:virology*; D012367:RNA, Viral / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019562:Viral Load
chemical_list: D012367:RNA, Viral