Echinococcus granulosus: in vitro maintenance of whole cysts and the assessment of the effects of albendazole sulphoxide and praziquantel on the germinal layer.

Small entire cysts of Echinococcus granulosus of human and animal origin were cultured in vitro in the presence or absence of albendazole sulphoxide (1000 micrograms/litre) or praziquantel (500 micrograms/litre) for 10 or 11 d, and subsequently passaged into the peritoneal cavity of gerbils to assess viability by continued cyst growth. Viability was reduced in the presence of albendazole sulphoxide, and disintegration of the germinal layer immediately after culture was demonstrated at the ultrastructural level. Praziquantel had no apparent effect on cyst growth.