The report on the Danish newborn screening programme for congenital toxoplasmosis in this month’s issue adds to evidence from similar programmes across the globe that newborn screening is feasible.^1–5 Screening for toxoplasma specific IgM antibodies in newborn dried blood spots was first offered in 1988 by the New England Neonatal Screening Program. Since then, newborn screening programmes for congenital toxoplasmosis have been established in Denmark (in 1992),¹ Poznan, Poland (in 1994),⁴ Porto Alegre, Brazil (in 1995),⁶ and Campos dos Goytazaces, Brazil (in 1999).⁷ In addition, screening studies have been conducted for a limited period in southern Sweden (1997–98)⁸ and Ireland (2005–07).⁹ The estimated birth prevalence of congenital toxoplasmosis per 10 000 live births reported by these programmes ranges from 0.7 in Sweden⁸ and 0.8 in Massachusetts,³ to 7.1 in Poland,^4,10 and in Brazil, 5.4 in the private sector² and 20 in the public sector.⁷ In European cohorts, approximately 10% of infected children have retinochoroiditis during infancy, rising to 16–18% by 4 years old.^11,12 Bilateral visual impairment is rare, affecting up to 4% of children with retinochoroiditis.¹³ Screening detects between 43% and 85% of infected neonates.^4,8,14–17 The very low false positive rate means that the probability of congenital toxoplasmosis in screen positive infants is usually over 25%.^1,2,4,8

Newborn screening offers an apparently attractive option for preventing sequelae from congenital toxoplasmosis. It costs about one tenth as much as antenatal screening and avoids the inconvenience of repeated testing during pregnancy, the risk associated with amniocentesis for prenatal diagnosis, prolonged antibiotic administration during pregnancy, and termination of fetuses at very low risk of disability.^18–20 …