Epidemiology of sylvatic trichinellosis in north-western Italy.

Muscle samples from 7,142 wild boars (Sus scrofa), 80 free-ranging hogs, 1,462 red foxes (Vulpes vulpes) 90 mustelids, 15 Alpine marmots (Marmota marmota), 873 rodents and 92 insectivores were examined for Trichinella Railliet, 1895. A wild boar, a badger (Meles meles) and 30 foxes (2.1%) were found to be infected. Eleven vulpine isolates and the wild boar isolate were identified as Trichinella britovi. These results show that the wild boar has little significance as a reservoir of T. britovi in the area under study. A vulpine isolate resulted in low infectivity in experimentally-infected swine. The prevalence of trichinellosis in the vulpine population is higher in the mountains than in lowland areas and indicates the key role played by this carnivore in the epidemiology of T. britovi. Preliminary results from four field trials seem to demonstrate that differences in attitudes towards cannibalism exist between mountain and lowland foxes.