Prevention of congenital toxoplasmosis in Szeged, Hungary.

BACKGROUND: Toxoplasma gondii infection of the fetus can only be discovered or prevented by the appropriate serological screening and subsequent treatment of the mother and her offspring. In Hungary, there is no obligatory toxoplasma screening for pregnant women and both the reporting and follow-up of congenital toxoplasmosis cases is limited. In 1987 we started a systematic study in the Szeged region of Hungary, in which all pregnant women were screened and appropriate treatment given to all mothers and their offspring where congenital toxoplasmosis was suspected. METHODS: All pregnant women were routinely screened within the first 16 weeks of gestation for toxoplasma antibodies by complement fixation test (CFT). Seronegative cases were retested for possible seroconversion every second month. Patients with CFT titres > or = 1:256 were retested for anti-P30 immunoglobulin A (IgA), IgM and IgG antibodies by ELISA and/or SDS-PAGE-Western immunoblot in order to distinguish the acute and chronic phases of the infection. RESULTS: Up to the end of 1994, the sera of 17,735 gravidae were screened. Ten women were found to have seroconverted during pregnancy and 78 had high initial antibody levels accompanied by anti-P30 IgA antibodies at the very first screening. These two groups together were considered as definitely (10) or possibly (78) infected with Toxoplasma during pregnancy and were treated with Spiramycin. All of their offspring were also treated for one month and followed-up by systematic serological and clinical screening for 2 years. No congenital toxoplasmosis was found in any of the offspring. CONCLUSIONS: Antenatal, early diagnosis and treatment of toxoplasmosis in mothers, together with treatment and follow-up of their offspring, may considerably reduce the incidence of the disease in the offspring.

[Serodiagnosis of toxoplasmosis]. / A toxoplasmosis szerodiagnosztikája.

Generally, toxoplasmosis has mild symptoms, or is asymptomatic, in patients with intact immune system. The infection, however, may have serious consequences in immunodeficient or immunosuppressed patients, as well as in the off-springs of pregnant women. If the mother has acute toxoplasmosis during the pregnancy, the passage of parasites through the placenta may result in the death of the fetus, or, in the severe damage of the fetus or neonate. All these consequences can be prevented by the early detection of the disease followed by the immediate therapy of the mother. Contrary to the most infectious diseases, however, the high specific IgM level has not proved to be a reliable marker of the acute infection in the case of toxoplasmosis. Therefore, in the case of infections discovered in the "plateau" period [i.e. with persistent IgM ("residual" IgM) and/or persistent high level of IgG antibody), the "acute" and the "chronic" phases can be distinguished more reliably by the detection with ELISA of the IgA antibody response to the so called P30 protein of Toxoplasma gondii. The anti-P30 IgA antibody response appears very early and generally disappears in 3-9 months. Thus, it is possible to discriminate the acute phase of the disease from the harmless chronic phase. Between 1987 and 1996, practically all pregnant women in Szeged and its region (altogether 21,952 women), underwent serologic toxoplasma screening. Among them, 124 pregnant women were found highly suspicious for having acute toxoplasmosis. Appropriate counselling, followed by spiramycin therapy during pregnancy and regular ultrasound examination were their antenatal management. No clinically manifested fetal or neonatal infection was observed. The screening and treatment schedule seems to be promising in the prevention of fetal and neonatal toxoplasmosis.