Frequency of toxoplasmosis in the appearance of congenital hydrocephalus.

Thirty-eight children with signs of hydrocephalus have been tested for toxoplasmosis. On the basis of clinical data, including roentgenographical and ophthalmological findings, and serological data (Sabin-Feldman and IgM-IFA tests), congenital toxoplasmosis was confirmed in 15 (39%) infants. The diagnosis was established by demonstration of the persistence of Toxoplasma antibodies. In 13 (34%) infants aged 1 to 3 months there was not enough serological data and these were placed in a group of cases with "suspected congenital toxoplasmosis." Ten children with negative serology for toxoplasmosis and with hydrocephalus were considered not to be infected.