Investigations on a Swiss area highly endemic for Echinococcus multilocularis.

Anecdotal information suggested that a focus of hyperendemicity may be present in a small area of the Canton of Fribourg in Switzerland. Therefore, the prevalence of E. multilocularis was assessed both in the fox and the rodent population over a two-season-period. A high prevalence ranging between 47% and 56% was consistently determined in the fox population. An Arvicola terrestris population was infected at 39% in the first season of investigation and at 11% in the following season. A subsequent seroepidemiological survey in the population of inhabitants surrounding the area provided no indication of seroconversion and thus no indication of infection for humans. However, a longer-term survey will be needed to assess more precisely the risk of disease occurrence among these inhabitants.