[Toxoplasmosis screening of pregnant patients in Austria].

The frequency of congenital Toxoplasma infection is strictly correlated with the frequency of Toxoplasma primary infection in child bearing age. The latter corresponds directly to the increase of contamination rate in the normal population between 20 and 40 years of age, if determined with a sensitive method detecting also low antibody concentrations with certainty (Sabin-Feldman-dye test). In four representative studies the relation was 0.52 conversions id est 0.26 congenital infection per 1 000 per 1% contamination increase. Most congenitally infected children seem normal in newborn age. Follow up studies for long enough periods--many years!--have shown that practically all these children develop sequelea, chorioretinitis and/or cerebral defects. Postnatal treatment does not influence this evolution but preventive treatment in pregnant women selected by serological screening uncovering primary infections does prevent fetal infections with their consequences.