Epidemiology and Infection

Outbreaks of gastroenteritis due to infections with Norovirus in Switzerland, 2001–2003

R. FRETZ a1a2, P. SVOBODA a1, T. M. LÜTHI a3, M. TANNER a2 and A. BAUMGARTNER a4c1
a1 Cantonal Laboratory Basel-Landschaft, 4410 Liestal, Switzerland
a2 Swiss Tropical Institute, 4002 Basel, Switzerland
a3 University of Applied Sciences Wädenswil, 8820 Wädenswil, Switzerland
a4 Swiss Federal Office of Public Health, 3003 Bern, Switzerland

Article author query
fretz r   [PubMed][Google Scholar] 
svoboda p   [PubMed][Google Scholar] 
luthi tm   [PubMed][Google Scholar] 
tanner m   [PubMed][Google Scholar] 
baumgartner a   [PubMed][Google Scholar] 


Viral infections, especially those with noroviruses are the most common cause of acute gastroenteritis in Europe. To obtain information about the epidemic situation of noroviruses in Switzerland, an initial study was launched in the German-speaking part of the country to systematically compile Norovirus outbreak information between 2001 and 2003. In total, 73 outbreaks were registered. Most affected were closed settings, e.g. nursing homes (34%) and hospitals (25%). Transmission pathways were identified in 74% of Norovirus outbreaks. In 81% of these cases person-to-person transmission was the primary route of infection and on seven occasions (13%), a foodborne transmission was the possible cause. Furthermore, Norovirus outbreak characteristics of epidemiological importance are highlighted with a discussion of four selected events.

(Accepted November 28 2004)

c1 Swiss Federal Office of Public Health, Food Safety Unit, 3003 Bern, Switzerland. (Email: [email protected])