Detection of circulating antigen in sera of Fasciola gigantica-infected cattle with antibodies reactive with a Fasciola-specific 88-kDa antigen.

Antibodies against a specific 88-kDa antigen of Fasciola gigantica were used for the detection of circulating antigen in the sera of cattle with experimental and natural infections of F. gigantica by a double antibody ELISA. Circulating antigen was detectable as early as the second and third weeks after infection and positive absorbance values were obtained for the entire duration of infection. Absorbance values decreased below the cutoff point 3 weeks after chemotherapy with oxyclozanide. This immunoassay also greatly enhanced the specificity of immunodiagnosis of fasciolosis in naturally infected cattle. The test system has excellent potential for the accurate diagnosis of ruminant fasciolosis.