Yersiniosis is a notifiable disease in the entire region. All the countries, expect Northwest Russia, report only laboratory confirmed cases. In Northwest Russia, cases epidemiologically linked to a laboratory confirmed case are also reported.
Figure 17. Number of cases of yersiniosis notified in 2003 per 100 000 population (1).
Yersinia enterocolitica is the dominating species occurring in Denmark, Norway, Sweden and Iceland; Yersinia pseudotuberculosis is much more common in Finland and Northwest Russia. The most important reservoir for Y. enterocolitica is pigs, and for Y. pseudotuberculosis rodents, hares, deers and birds. Several outbreaks of Y. pseudotuberculosis-infections have been reported in Northwest Russia and Finland. In 2003, Finland experienced a major outbreak of Y. pseudotuberculosis transmitted by grated carrots which were contaminated at the production farm (13). Risk factors for infections with Y. enterocolitica are consumption of pork and untreated drinking water. Outbreaks of yersiniosis occur rarely in the Nordic countries.
The incidence rates of yersiniosis are fairly stable in the region, and the majority of cases are acquired domestically. In Norway, a decreasing incidence was noted in the late 1990s. This decline coincided with the gradual introduction of improved slaughtering routines, which resulted in reduced contamination with Y. entero-colitica on the surface of pig carcasses.
Prevention of water and food-borne yersiniosis includes implementing public health measures at water supplies, farms, slaughter houses, commercial food processing and in private kitchens at home. An effective Food and Water Control Authority is important to prevent transmission of yersiniosis.
EpiNorth c/o Department of Infectious Disease Epidemiology, Norwegian Institute of Public Health, P.O.Box 4404 Nydalen, N-0403 Oslo, Norway. Tel: + 47 21 07 67 45, Fax: + 47 21 07 65 13, E-mail: