Congenital toxoplasmosis: long-term follow-up.

The incidence in Europe is high, about 6 in 1000 births. Five percent of these babies either die or are severely damaged by the disease. In the others most infections are clinically asymptomatic in the neonatal period. In +/- 70% of all infants with congential infections relapses of chorioretinitis give rise to scars in their eyes after a follow-up of 16 years. The relapses were occurring later on both in treated and untreated infants. Most scars were in the periphery of the retina, but scars in the neighbourhood of the macula can threaten the vision. In 1--2% of these children later on uveitis impairing vision due to congenital toxoplasmosis will occur. As a control 117 children in the age 12--14 years without congenital toxoplasmosis were studied. No chorioretinitis-scars were found in the eyes although +/- 50--60% had antibodies against toxoplasmosis, resulting from an acquired infection. The problem of prevention is unsolved. There is no vaccine. Deliberately infecting girls before pregnancy is too dangerous. Screening of pregnant women is possible but no clear-cut safe therapy is available. Screening of the baby after birth is too late.