gms | German Medical Science

Antiparasitic drugs have been shown to be effective in the treatment of active Toxoplasma-infections in immunosuppressed individuals, whereas understanding and treatment of gestational and congenital toxoplasmosis is still “a work in progress”. Under the prevailing view that the available antibiotics provide an effective treatment, screening programs were later introduced in different European countries. Cost-benefit analysis and an ongoing discussion on the uncertainty about the effectiveness of the available treatment options (spiramycine, pyrimethamine, sulfonamides) gave way to large European multicenter and international studies [1], [2], which, after more than a decade, may be summarized as follows:

1.

there is weak evidence that early prenatal treatment may have an impact on brain lesions in live-born children,

2.

the effect of pyrimethamine-sulphonamide combinations over spiramycin is likely to be small,

3.

there is a lack of evidence regarding the effect of pre- and postnatal treatment to prevent late-onset retinochoroiditis,

4.

there is weak evidence that the risk of recurrence of retinochoroiditis is reduced after long-term treatment.

These results were in contrast to observational studies from Germany [3] and other countries why there was a call for large randomized, controlled clinical trials to prove the benefit of prenatal treatment and the effectiveness of the different treatment regiments.

Recently, the first randomized trial on prevention of congenital toxoplasmosis was completed [4]. When comparing pyrimethamine plus sulfadiazine vs. spiramycin the results indicate that parasite transmission from mother to child was lower (18.5% vs. 30%, odds ratio 0.53, 95% CI 0.23–1.22, not significant), and the incidence of cerebral ultrasound anomalies was significantly lower in 0% (0/73) vs. 8.6% (6/70) (p=0.01, NNT 12). These data suggest that early start of treatment with pyrimethamine-sulfadiazine is beneficial for fetuses with intrauterine Toxoplasma-infection. The impact of the results on the German recommendations for the prevention of prenatal toxoplasmosis will be discussed.