Outbreaks of acute gastroenteritis on cruise ships and on land: identification of a predominant circulating strain of norovirus--United States, 2002.
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.
Widdowson
Marc-Alain
MA
Atlanta Research and Education Foundation and National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA. zux5@cdc.gov
Cramer
Elaine H
EH
Hadley
Leslie
L
Bresee
Joseph S
JS
Beard
R Suzanne
RS
Bulens
Sandra N
SN
Charles
Myrna
M
Chege
Wairimu
W
Isakbaeva
Elmira
E
Wright
Jennifer G
JG
Mintz
Eric
E
Forney
David
D
Massey
Jeffrey
J
Glass
Roger I
RI
Monroe
Stephan S
SS
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