[The diagnostic significance of the indirect hemagglutination test for the surveillance of toxoplasmosis during pregnancy (author's transl)].

In order to clarify the relevance of the indirect hemagglutination test (IHAT) for the surveillance of toxoplasmosis during pregnancy 2417 sera of pregnant women were tested for antibodies against Toxoplasma gondii in this test and in the fluorescent-antibody test (FAT). In addition 1319 of these sera were tested in the Sabin-Feldman test (SFT) adn 681 samples also in the complement fixation test (CFT). Significant correlations were found between the results obtained in the IHAT on one hand and in the FAT and SFT on the other hand: 95% of the sera which were negative in the FAT or SFT did not react in the IHAT as well, while most (but not all!) sera which were positive in the FAT or SFT gave positive results in the IHAT also. No correlations could, however, be found between titres obtained in the IHAT on one hand and in the CFT on the other hand. The suggestion recently published by several authors that it might be possible to decide from one single serum sample only whether or not a fresh infection had occurred by correlating FAT- (SFT-) and CFT-titres with IHAT-titres could not be confirmed. For a definite interpretation of serological results with respect to the risk of an infection of the fetus with Toxoplasma gondii it will still be necessary to test a second serum sample. As a screening method for detection of antibodies against Toxoplasma gondii -- without determination of the duration of infection -- the indirect hemagglutination test appears to be, however, a highly effective and economic method.