[Congenital toxoplasmosis].

Congenital toxoplasmosis is characterized by the classical triads: hydrocephaly, chorioretinitis and intracerebral calcifications. In fact it is an uncommon manifestation of congenital infection with the parasite Toxoplasma gondii, that is generally subclinical in the neonatal period. But there is a substantial risk of delayed clinical manifestation due to exacerbation of infection: chorioretinitis with loss of vision. With some case histories the interpretation of serodiagnostic techniques is explained and the necessity of repeated tests up to the age of one year in order to exclude a congenital infection definitely, is emphasized.