Can Tapeworms Survive in Idaho?

Tapeworms are parasites of humans and have a large animal reservoir that includes dogs, sheep, pigs, fish, cattle, deer and even wolves. There are many species of tapeworm and they are spread through fecal contact and undercooked meat.

Prevalence

• Tapeworm cysts of the species Echinococcus granulosus have been found widespread in wolves in Idaho and also occasionally in goats, deer and elk. Hunters can become infected by eggs from wolf feces and their dogs can become infected from eating uncooked game meat. According to Idaho Department of Agriculture's Fish and Game service, the presence of tapeworm cysts in slaughtered livestock is not regarded as a significant public health issue and cysts are simply trimmed from the meat before sale.

Life Cycle

• Tapeworms live in mammalian bodies and only spend time outside the body in the egg stage. The egg is excreted in feces and picked up by a new host, who becomes infected. Another stage is a hydatid cyst in which the tapeworm forms a larval ball in the muscle of the host. Eating raw meat with cysts can lead to infection.

Conditions

• Idaho has suitable environmental conditions for tapeworms, whose cysts are only killed by heating above 137 degrees Fahrenheit, or by freezing for a prolonged time. Therefore tapeworms will continue to be present in animals and will infect humans who come into contact with infected animal feces and who eat undercooked infected meat.