Echinococcosis is caused by infection with the tapeworm echinococcus, which belongs to the family Taeniidae. Four species of echinococcus cause infection in humans. E. granulosus and E. multilocularis are the most common, causing cystic echinococcosis (CE) and alveolar echinococcosis (AE), respectively. The two other species, E. vogeli and E. oligarthus, cause polycystic echinococcosis, but have been rarely associated with human infection. Two new species have been identified: Echinococcus shiquicus in small mammals from the Tibetan plateau and Echinococcus felidis in African lions; their transmission potential to humans is not known [1,2].
The treatment of cystic and alveolar echinococcal infection will be reviewed here. The clinical manifestations, diagnosis, epidemiology, and control of echinococcal infection are discussed separately. (See "Clinical manifestations and diagnosis of echinococcosis" and "Epidemiology and control of echinococcosis".)
CYSTIC ECHINOCOCCOSIS (E. GRANULOSUS)
Overview — Management options for cystic echinococcosis (CE) include surgery, percutaneous management, drug therapy, and observation . Surgery has been the traditional approach for treatment of CE; subsequently, alternative approaches have been introduced and have replaced surgery as the treatment of choice in some cases .
In general, clinical approach depends on the World Health Organization (WHO) diagnostic classification (table 1 and image 1). Stage CE1 and CE3a cysts have a single compartment; such cysts that are <5 cm may be treated with albendazole alone . In settings where albendazole treatment with follow-up monitoring is not feasible, definitive management with percutaneous treatment via PAIR (puncture, aspiration, injection, and reaspiration) is an acceptable alternative approach. Stage CE1 and CE3a cysts that are >5 cm may be treated with albendazole in combination with PAIR. In situations where albendazole treatment is not feasible, percutaneous treatment with PAIR (in the absence of adjunctive drug therapy) is an acceptable alternative approach . Issues related to drug therapy are discussed below. (See 'Drug therapy' below.)
Stage CE2 and CE3b cysts have many compartments that require individual puncture; patients with such cysts commonly relapse after PAIR . Therefore management of these cysts requires either modified catheterization technique (eg, non-PAIR percutaneous therapy) or surgery (with adjunctive drug therapy) . The optimal choice between these approaches is uncertain and further study is needed.