[Diagnosis and treatment of unilocular hydatid disease (Echinococcus granulosus infection)]

Unilocular hydatid disease occurs in humans after oral intake of eggs of the dog tapeworm, Echinococcus granulosus. Cysts develop mostly in the liver, but sometimes also in the lung. The diagnosis of Echinococcus infection is based on history-taking, physical examination, ultrasound and CT examination and serological testing; the diagnosis is confirmed by parasitological examination of cystic fluid. Treatment until some 15 years ago consisted in operation. Subsequently, treatment with initially mebendazole, later with albendazole or with percutaneous drainage (puncture, aspiration, injection of a scolicidal, respiration (PAIR)), or with combinations of the same, became accepted forms of management. The PAIR method is reported to give high proportions of success, low proportions of recurrence and few complications. However, adequate evaluation is not yet possible because of the short follow-up period. For the prevention of leakage it is recommended to perform the PAIR method with a transhepatic puncture under continuous ultrasonographic or CT guidance; for avoidance of recurrences, one week's pretreatment and 1-4 weeks' after-treatment with albendazole are recommended. The results of albendazole monotherapy are hard to predict and highly variable: success: 30-88% (median: 71%); failure: 22-32% (median: 25%); recurrences: 9.5-31% (median: 16%). Both albendazole therapy and the PAIR management should be followed by protracted follow-up to check regression of cysts and detect recurrences. It is not clear which treatment is the best one.