A newborn screening programme for congenital toxoplasmosis in the setting of a country with less income

A well‐established newborn screening programme for congenital toxoplasmosis has been reported in a European country with low prevalence¹; however, this programme has also been implemented in countries with lower income but with a higher percentage of newborn infected children. We conducted a study in 11 public health community hospitals in the Department of Quindio, excluding the capital (Armenia), in Columbia; about 4560 children are delivered in these hospitals annually. Infants born from August 2003 to December 2003 were enrolled in the study. Informed consent was obtained from mothers during sampling and results were reported in accordance with the resolution 008430 of 1993 of the Ministry of Public Health concerning medical research in Colombia. All serum samples were tested with the Platelia Toxo IgM Neonatal assay (Bio‐Rad, Hercules, California, USA) as recommended by the manufacturer. In all, 322 samples were collected, including 106 dry paper samples from the heel, which about 25% of which were insufficient. Thus, 216 samples were taken in 5‐ml tubes at the arm at the first medical check of the newborn (10–30 days after birth). All the poor‐quality dry paper samples were taken again at the arm. Five samples showed positive Platelia IgM assay (one from a filter card and four from the tubes). All positive samples were then confirmed on the same sample by testing immunoglobulin (Ig)M and IgA using the ISAGA assay (ISAGA Plus, BioMérieux, Marcy L'Etoile, France) and a commercial western blot assay (ID Blot Toxoplasma DPC Diagnostics, Los Angeles, CA, USA) was performed according to the manufacturer's protocol. Diagnosis of congenital toxoplasmosis was conclusive for two children (a dry paper sample in one case and a tube sample in the other). Both children showed the simultaneous presence of toxoplasma‐specific IgM and IgA in ISAGA and western blot assays. Three children with negative ISAGA and ID Blot assays were considered not to be infected. Thus, the prevalence of congenital toxoplasmosis during this newborn screening programme in community hospitals in Quindio was 0.62% (95% confidence interval 2.2 to 0.19). The two infected children were asymptomatic and were treated with weekly doses of pyrimethamine–sulfadoxine for 1 year. Both children remained asymptomatic and without ocular signs or gross neurological problems at the end of the first year of life. Our results show that it is possible to carry out neonatal screening for toxoplasmosis and to identify congenitally infected but asymptomatic children.

We think that in countries such as ours, detection programmes for congenital toxoplasmosis should be established urgently. Newborn screening programmes would be an attractive strategy in countries with less income for two reasons. Firstly, the toxoplasmosis prenatal screening programmes are very costly. Thus, in Colombia, despite their proved effect on the health of Colombian children,²,³,⁴ the public and private health assurance companies are reluctant to implement these programmes. Secondly, a large number of mothers (10–20%) did not have prenatal care, and congenital infections can be detected only in newborns.

Acknowledgements

We thank Dr Alvaro Velez and his staff at Velezlab Ltd, Bogota, Colombia, for their support and his donation of the ID Blot kits. We also thank the gynaecologists, paediatricians and nurses who helped with this study.