Serodiagnosis of human G and M immunoglobulins to Toxoplasma gondii by ELISA using whole tachyzoites as antigens: a comparative study with the indirect haemagglutination (IHA) and immunofluorescence (IFA) tests.

An indirect ELISA using whole tachyzoites of Toxoplasma gondii fixed onto the bottom of microtiter plate wells is described for detection of specific G and M anti-toxoplasma antibodies. ELISA results were compared with those of IFA and IHA tests. Similarity of antigens (cell surface) involved in ELISA and IFA permits high correlation between the two tests (r = 0.84-0.93, P less than 0.001) and results in good accordance for negative sera. As ELISA offers several advantages over the classical IFA test, it may be considered an alternative method for screening of G and M anti-toxoplasma antibodies.