A solid phase immunoassay (DIG-ELISA) as a serodiagnostic tool in bovine and porcine Toxoplasma gondii infection.

The diffusion-in-gel enzyme-linked immunosorbent assay (DIG-ELISA) was compared with the indirect immunofluorescent antibody test (IFAT) and with conventional ELISA for the detection of antibodies to Toxoplasma gondii in three experimentally infected calves and in 100 naturally infected swine. Good agreement was observed between the results obtained with DIG-ELISA and those from IFAT or ELISA. It was noted that in early experimental infection of calves, the IFAT recorded higher antibody levels than did DIG-ELISA, thus reflecting the differences in antigens used for the two methods. The DIG-ELISA, being technically simple and inexpensive and having a large capacity, was found to be well suited for screening purposes with regard to Toxoplasma antibodies.