Studies on Echinococcosis: Serology of Crude and Fractionated Antigens Prepared from Echinococcus Granulosus and Echinococcus Multilocularis

Abstract

Summary Hemagglutination (HA) and bentonite flocculation (BF) tests with 7 crude Echinococcus granulosus and Echinococcus multilocularis antigens were performed. Antisera prepared in rabbits against these antigens, antisera from patients with proven infections of E. granulosus and serum from patients believed to be infected with E. multilocularis were titrated. In both the HA and BF tests absolute specificity was not observed with hydatid fluid, scolices, cyst and membrane antigens of the two cestode species. E. granulosus hydatid fluid proved to be the antigen of choice in both the HA and BF tests of sera from humans with E. granulosus hydatid infections. Diagnostic tests with E. multilocularis antisera were not as satisfactory, suggesting that tests with crude antigens will not detect human chronic infections with this species of parasite. By precipitation with TCA, 7 fractions were obtained from E. granulosus hydatid fluid, and 11 from E. multilocularis cysts. A number of these fractions were non-reactive in both the HA and BF tests. Fractionated antigens were more sensitive than whole antigens when used with antisera prepared in rabbits. For diagnostic serology, the purified antigens were in some instances more active in the HA test but less reactive in the BF test. For the diagnosis of E. granulosus hydatid infection, the whole hydatid fluid of porcine origin was as reactive as the antigen fractions. For the diagnosis of E. multilocularis hydatid infections, the fractionated antigens prepared from whole cysts were superior.