TOXOPLASMOSIS AND PREGNANCY - FINDINGS FR OM CORD-BLOOD SCREENING IN 30000 NEWBORNS

Cord blood screening for congenital toxoplasmosis was performed prospe ctively on 30 000 samples collected between 1986 and 1994 in the regio n of Basel, Switzerland, covering up to 95% of all births. Congenital infection was suspected in cases of serum with specific antitoxoplasma IgM or IgA or with a level of specific IgG above 300 IU/ml as measure d by ELA from Sanofi-Pasteur. The percentage of cases to be screened d eclined from 2.5 to 1.2% and the cases of confirmed congenital toxopla smosis from 0.073 to 0.033% during the observation period. This observ ation may be due to several reasons, such as improved primary preventi on or more frequent diagnosis and treatment during pregnancy. In 178 c ases of cord blood serology suspicious for acute toxoplasmosis, an enq uiry with the gynecologist in charge of the pregnant woman was carried out. 126 mothers (71%) presented with a confirmed immunity against To xoplasma gondii early in pregnancy and screening of the child was not needed. From 37 pregnancies (21%) no information was available. 15 out of 24 confirmed cases of toxoplasmosis of the mother during pregnancy were detected by cord blood analysis. In 17 of 24 cases of maternal t oxoplasmosis treatment with spiramycin, pyrimethamine/sulfadoxine or b oth was performed. 10 of 17 newborns from mothers treated during pregn ancy had elevated toxoplasma IgG titres at birth, but only one child w as infected. 7 newborns had an inconspicuous toxoplasma serology at bi rth and were not infected. 7 cases of toxoplasmosis during pregnancy w ere detected by the check back and remained untreated; 4 out of 7 newb orns had congenital toxoplasmosis. Thus treatment reduced the risk of a congenital infection from 57% to 6% (P = 0.03). These data confirm t hat screening for acute toxoplasmosis during pregnancy on a voluntary basis, combined with primary prevention by hygienic measures and cord blood serology in all newborns from seronegative mothers, would marked ly reduce the number of congenital toxoplasmosis cases without introdu cing controversial national screening programs.