[Outbreaks of norovirus gastroenteritis in nursing homes in Haifa, 2002-2003].
BACKGROUND
The incidence rate of Norovirus gastroenteritis is unknown since diagnostic tests are less readily available than for other agents. This pathogen is identified in less than 10% of acute gastrointestinal illness, despite the fact that recent reports from the United States attribute more than 50% of outbreaks to Noroviruses.


OBJECTIVE
This article describes three outbreaks of gastroenteritis caused by Noroviruses in three of Haifa's chronic care hospitals in order to raise awareness of its main role as a common agent in such outbreaks, and thereby include it in the differential diagnosis of outbreak investigations.


METHODS
Methods employed included epidemiological investigation of the outbreaks, sanitary inspection, personal interviews of hospital staff members, data collection from medical files and laboratory diagnosis by electron microscopy and RT-PCR of stool and vomitus for Noroviruses.


RESULTS
Noroviruses were identified in faeces and vomitus of patients in 2 outbreaks in chronic care hospitals in Haifa. Attack rates were high (20-41%). Proximity in time to these 2 outbreaks, and clinical and epidemiological findings lead us to attribute another outbreak in a third hospital to norovirus as well.


CONCLUSIONS
Physicians in institutions and the community should include Noroviruses in the differential diagnosis of outbreaks of gastroenteritis, particularly in cases where no other pathogens have been isolated. Timely requests for identification of Noroviruses are essential. The institution of good hygienic practices is important to prevent spread of this highly infectious agent.
Hefer
Elioz
E
Haifa District Health Office, Ministry of Health. lbhHefer@Matat.health.gov.il
Rishpon
Shmuel
S
Warman
Sigal
S
Rubin
Lisa
L
D017250:Caliciviridae Infections / Q000453:epidemiology*; D003937:Diagnosis, Differential; D004196:Disease Outbreaks; D005243:Feces / Q000821:virology; D005759:Gastroenteritis / Q000453:epidemiology* / Q000821:virology*; D006801:Humans; D007557:Israel / Q000453:epidemiology; D029322:Norovirus / Q000235:genetics / Q000302:isolation & purification; D009735:Nursing Homes; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014839:Vomiting / Q000821:virology