Epidemiology and Infection

A large-scale gastroenteritis outbreak associated with Norovirus in nursing homes

a1 Hadassah Braun School of Public Health, Hebrew University, Jerusalem, Israel
a2 Tel-Aviv District Authority, Israel Ministry of Health, Israel
a3 Center for Vaccine Development and Evaluation, Israel Defense Forces, Israel
a4 Department of Epidemiology and Biostatistics, Tel-Aviv University, Israel

Article author query
calderon-margalit r   [PubMed][Google Scholar] 
sheffer r   [PubMed][Google Scholar] 
halperin t   [PubMed][Google Scholar] 
orr n   [PubMed][Google Scholar] 
cohen d   [PubMed][Google Scholar] 
shohat t   [PubMed][Google Scholar] 


An increase in gastroenteritis outbreaks due to Norovirus has been reported worldwide. We investigated a large-scale outbreak affecting 246 residents and 33 staff members in six nursing homes in the Tel-Aviv district, Israel, during 3 weeks in 2002. Person-to-person spread was noticed in all nursing homes. The spread of disease could not be attributed to social interactions. Among the elderly residents, the hospitalization rate was 10·2% and the case-fatality rate was 2·0%. Bacteriological cultures were negative. Overall, 7 out of 15 stool specimens were positive for Norovirus by RT–PCR. All were sequenced and found to be 90% identical. The characteristics of this outbreak and the RT–PCR results suggest that illness was caused by Norovirus. Due to the high case-fatality rate of Norovirus gastroenteritis, there should be a high index of suspicion when encountering a gastroenteritis outbreak among the elderly. This will enable prompt action to stop the spread of illness.

(Accepted August 14 2004)

c1 Dr R. Calderon-Margalit, Hebrew University–Hadassah Braun School of Public Health, PO Box 12272, Jerusalem, 91120, Israel. (Email: ronitca@hadassah.org.il)