Sylvatic trichinosis in British Columbia: potential threat to human health from an independent cycle.

The results of a 3-year study of trichinosis in British Columbia wild-life, based on the testing of more than 9,000 tissue specimens from a large variety of animal species, indicated that trichinosis is widespread among wild mammals in the southern and central parts of British Columbia. This continuing survey has established that the disease is carried by at least 15 species of terrestrial mammals including 3 species of rodents. The finding of Trichinella spiralis in ground squirrels and nonsynanthropic mice may be the first reported in North America. Although trichinosis appears to be eradicated in domestic pigs in British Columbia, a sylvatic cycle of the disease continues to exist independently and poses a potential threat to human health. It is possible for human beings to contract trichinosis by consuming inadequately cooked meat from certain wildlife species, especially bears, as well as meat products (such as pork or beef sausage) to which game meat has been added; several local outbreaks were caused by this source. Another hazard of unknown potential is the spread of trichinosis from the wild animal reservoir--from rodents in particular--to domestic pigs and thus to man.