Isolation of two lipoprotein antigens from the metacestodes of Taenia hydatigena (Pallas, 1766) and Taenia multiceps (Leske, 1780) and their evaluation in sero-diagnosis.

Two identical host contaminant-free lipoprotein antigens were isolated from the metacestodes of T. hydatigena and T. multiceps, of which antigen 1 was more reactive than antigen 2. These antigens appear to be identical with antigens B and A, respectively, and antigen 2 with arc 5 of Echinococcus granulosus described by other workers. Attempts to use these antigens in serodiagnosis showed that only in the indirect haemagglutination (IHA) technique was there any increased sensitivity and specificity compared with the unpurified cyst fluid antigens. No correlation was found between the size of the infecting dose, the number of cysts found at necropsy, the IHA titres, or number of precipitation lines seen in immunodiffusion tests.