Echinococcus
Abstract
Echinococcosis is a zoonosis caused by the adult or larval stages of tapeworms (cestodes) belonging to the genus Echinococcus (family Taeniidae). Larval infection (hydatid disease; hydatidosis) is characterized by long-term growth of metacestode (hydatid) cysts in the intermediate host. Four forms of echinococcosis are recognized clinically: cystic echinococcosis (CE) caused by E. granulosus, alveolar echinococcosis (AE) caused by E. multilocularis, unicystic echinococcosis caused by E. oligarthrus, and polycystic echinococcosis caused by E. vogeli. Until 2005, only these four Echinococcus species were considered to be valid taxonomically, but E. shiquicus, present in small mammals from the Tibetan Plateau, and E. felidis from the African lion are now recognized as well.