title: Outbreaks of acute gastroenteritis on cruise ships and on land: identification of a predominant circulating strain of norovirus--United States, 2002.
abstract: In 2002, a sharp increase in outbreaks of norovirus-associated illness, both on cruise ships and on land, encouraged us to examine the molecular epidemiology of detected noroviruses, to identify a common strain or source. Of 14 laboratory-confirmed outbreaks on cruise ships, 12 (86%) were attributed to caliciviruses; among these 12, outbreak characteristics included continuation on successive cruises in 6 (50%), multiple modes of transmission in 7 (58%), and high (>10%) attack rates in 7 (58%). Eleven of the 12 calicivirus outbreaks were attributed to noroviruses, 7 (64%) of which were attributed to a previously unreported lineage, provisionally named "the Farmington Hills strain." From May 2002 to December 2002, 10 (45%) of 22 land-based outbreaks also were attributed to this strain. Nucleotide-sequence analysis provided insights into norovirus transmission, by documenting links among outbreaks, the introduction of strains onto ships, and viral persistence on board (despite cleaning). Control measures for outbreaks should address all routes of transmission. Better outbreak surveillance and collection of data on sequences will help to monitor norovirus strains and to identify common sources.
authors.affiliation: Atlanta Research and Education Foundation and National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA. zux5@cdc.gov
authors.forename: Marc-Alain
authors.initials: MA
authors.lastname: Widdowson
authors.forename: Elaine H
authors.initials: EH
authors.lastname: Cramer
authors.forename: Leslie
authors.initials: L
authors.lastname: Hadley
authors.forename: Joseph S
authors.initials: JS
authors.lastname: Bresee
authors.forename: R Suzanne
authors.initials: RS
authors.lastname: Beard
authors.forename: Sandra N
authors.initials: SN
authors.lastname: Bulens
authors.forename: Myrna
authors.initials: M
authors.lastname: Charles
authors.forename: Wairimu
authors.initials: W
authors.lastname: Chege
authors.forename: Elmira
authors.initials: E
authors.lastname: Isakbaeva
authors.forename: Jennifer G
authors.initials: JG
authors.lastname: Wright
authors.forename: Eric
authors.initials: E
authors.lastname: Mintz
authors.forename: David
authors.initials: D
authors.lastname: Forney
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Massey
authors.forename: Roger I
authors.initials: RI
authors.lastname: Glass
authors.forename: Stephan S
authors.initials: SS
authors.lastname: Monroe
mesh_terms: D000208:Acute Disease; D017250:Caliciviridae Infections / Q000453:epidemiology* / Q000635:transmission / Q000821:virology; D004196:Disease Outbreaks; D005759:Gastroenteritis / Q000453:epidemiology* / Q000821:virology; D006801:Humans; D029322:Norovirus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D011998:Recreation; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012767:Ships; D014195:Travel; D014481:United States / Q000453:epidemiology