EVALUATION OF THE ENZYME-LINKED IMMUNOSORBENT-ASSAY (ELISA) AND OTHER SEROLOGICAL TESTS FOR THE DIAGNOSIS OF TOXOPLASMOSIS

Abstract

The enzyme-linked immunosorbent assay (ELISA) was evaluated in human toxoplasmosis in 3 laboratories using their own procedures. The same batch of serum samples was investigated in the 3 laboratories. ELISA results were compared by statistical analysis with one another and with those of the dye test (DT), immunofluorescence (IF), complement fixation test (CFT) and indirect hemagglutination (IHA). Highly significant correlations were obtained between the 3 laboratories with ELISA using 2 different antigens and enzyme conjugates. The correlations between ELISA and the other serological tests showed the following sequence: CFT > IF > IHA > DT. Highly significant correlations were obtained between ELISA using anti-.gamma.-chain and anti-total immunoglobulin conjugates. The agreement in discrimination between sera with low and high antibody levels was good for all the different ELISA techniques but discrimination between positive and negative sera depended on the ELISA procedure used.