A rare parasitic infection caused by the larva of a miniscule tapeworm called Echinococcus multilocularis. Transmission occurs through contact with foxes, coyotes, dogs and cats. The condition results in the development of parasitic tumors in the liver (sometimes other organs such as brain and lungs) but it generally causes no symptom for 5 to 15 years after infection. See also Alveolar echinococcosis