Fertility of the cysts of Echinococcus granulosus in domestic herbivores from Benghazi, Libya, and the reactivity of antigens produced from them.

Unilocular cysts produced by Echinococcus granulosus were recovered from 110 domestic herbivores (60 sheep, 25 cattle, 20 goats and five camels) slaughtered in Benghazi. The proportion of the cysts from the sheep found to be fertile (75%) was higher than that of the cysts from the goats (55%), camels (40%), or cattle (0%). When tested in indirect haemagglutination assays (IHA) with eight sera from human cases of cystic echinococcosis, the fluid from the cattle cysts never gave a positive reaction. Antigens in the fluids collected from sheep or goat cysts did react with the sera, with antigens from each of the two sources giving similar titres with each serum. However, crude somatic antigens (prepared from protoscolices and brood capsules collected from sheep cysts) appeared to be more sensitive for the immunodiagnosis of human cystic echinococcosis than the cyst-fluid antigens.