Evaluation of the indirect haemagglutination test (IHA) in diagnosis of Taenia saginata cysticercosis (Cysticercus bovis) infection in cattle.

Abstract

hree protein fractions, F1, F2 and F3, were obtained from antigens prepared from mature Taenia saginata. Using the IHA test, crude antigen and F1 consistently gave high titres with sera from calves experimentally infected with Cysticercus bovis whereas F2 and F3 either showed low antigenic reactivity or gave inconsistent results and were excluded from further experiments. The antibodies were detected during weeks 1 and 2 after infection up to 4 months after infection. The F1 fraction was purified further. Using F1a as antigen, low antibody titres were detected one week after infection and significant titres ( more than or equal to 1:64) were detected 2 to 4 weeks after infection. The titres tended to be lower than those obtained with crude antigen or F1. A higher level of cross-reactivity was found (using sera from 47 cattle infected with hydatid cysts) with T. saginata crude antigen (28 had titres of more than or equal to 1:64) than with F1 antigen (15 had titres of more than or equal to 1:64). F1 extract in the IHA test was found to have a sensitivity of 88.1% (52 of 59 naturally infected cattle were detected) and a specificity of 87.6% (198 of 226 cattle were shown not to be infected), compared to 71.2 and 80.5%, respectively, for crude antigen.