title: The epidemiology of published norovirus outbreaks: a review of risk factors associated with attack rate and genogroup.
abstract: The purpose of this study was to examine global epidemiological trends in human norovirus (NoV) outbreaks by transmission route and setting, and describe relationships between these characteristics, viral attack rates, and the occurrence of genogroup I (GI) or genogroup II (GII) strains in outbreaks. We analysed data from 902 reverse transcriptase-polymerase chain reaction-confirmed, human NoV outbreaks abstracted from a systematic review of articles published from 1993 to 2011 and indexed under the terms 'norovirus' and 'outbreak'. Multivariate regression analyses demonstrated that foodservice and winter outbreaks were significantly associated with higher attack rates. Foodborne and waterborne outbreaks were associated with multiple strains (GI+GII). Waterborne outbreaks were significantly associated with GI strains, while healthcare-related and winter outbreaks were associated with GII strains. These results identify important trends for epidemic NoV detection, prevention, and control.
authors.affiliation: Hubert Department of Global Health, Emory University Rollins School of Public Health, Atlanta, GA 30322, USA.
authors.forename: J E
authors.initials: JE
authors.lastname: Matthews
authors.forename: B W
authors.initials: BW
authors.lastname: Dickey
authors.forename: R D
authors.initials: RD
authors.lastname: Miller
authors.forename: J R
authors.initials: JR
authors.lastname: Felzer
authors.forename: B P
authors.initials: BP
authors.lastname: Dawson
authors.forename: A S
authors.initials: AS
authors.lastname: Lee
authors.forename: J J
authors.initials: JJ
authors.lastname: Rocks
authors.forename: J
authors.initials: J
authors.lastname: Kiel
authors.forename: J S
authors.initials: JS
authors.lastname: Montes
authors.forename: C L
authors.initials: CL
authors.lastname: Moe
authors.forename: J N S
authors.initials: JN
authors.lastname: Eisenberg
authors.forename: J S
authors.initials: JS
authors.lastname: Leon
mesh_terms: D050936:Basic Reproduction Number; D017250:Caliciviridae Infections / Q000453:epidemiology* / Q000821:virology; D003428:Cross Infection / Q000453:epidemiology* / Q000821:virology; D004196:Disease Outbreaks; D005502:Food / Q000821:virology; D005759:Gastroenteritis / Q000453:epidemiology / Q000821:virology; D005838:Genotype; D014943:Global Health; D006801:Humans; D029322:Norovirus / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D012307:Risk Factors; D012621:Seasons; D014871:Water Microbiology