Echinococcosis is infection with larvae of Echinococcus
granulosus or E. multilocularis (alveolar hydatid disease).
Symptoms depend on the organ involved—eg, jaundice and abdominal
discomfort with liver cysts or cough, chest pain, and hemoptysis
with lung cysts. Cyst rupture can cause fever, urticaria, and
serious anaphylactic reactions. Diagnosis is with imaging,
examination of cyst fluid, or serologic tests. Treatment is with
albendazole, surgery, or both or with cyst aspiration and
instillation of a scolicidal agent. Echinococcus granulosus is
common in sheep-raising areas of the Mediterranean, Middle East,
Australia, New Zealand, South Africa, and South America. It
requires canines as definitive hosts and herbivores (eg, sheep,
horses, deer) or humans as intermediate hosts. Foci also exist
in regions of Canada, Alaska, and California. E. multilocularis
worms are present in foxes, and the hydatid larvae occur in
small wild rodents. Infected dogs and other canines are the main
link to occasional human infec