DETECTION OF TOXOPLASMA-GONDII IN 94 PLACENTAE FROM INFECTED WOMEN BYPOLYMERASE-CHAIN-REACTION, IN-VIVO, AND IN-VITRO CULTURES

The biological diagnosis of congenital toxoplasmosis at birth is impor tant to determine the infant's treatment. The aim of this study was to evaluate the placenta results in the congenital toxoplasmosis diagnos is and to compare them with those obtained with other samples collecte d at birth (cord blood and newborn blood). A total of 94 placentas, of which 33 came from fetuses suspected of or with proven congenital tox oplasmosis (CT+) and 61 from definitely or probably non-infected fetus es (CT-), was analysed by in vitro culture, mouse inoculation and poly merase chain reaction (PCR). The PCR sensitivity was higher (60.9 per cent) than that of cell culture (29.6 per cent) and mouse inoculation (51.5 per cent) but the number of PCR positive results in CT- patients was also higher (9.5 per cent). The presence of Toxoplasma gondii in the placenta tissues was the only argument at birth (IgM and neosynthe sized Ig were negative) in three out of the 33 CT+ cases. The detectio n of IgM by ELISA and ISAGA and the detection of neosynthesized Ig by immunoblotting were more satisfactory to diagnose congenital toxoplasm osis but the placenta analysis was important to improve the sensitivit y of the diagnosis at birth, especially when the prenatal diagnosis wa s negative or not performed. Placenta (1998), 19, 545-549 (C) 1998 W. B. Saunders Company Ltd.