Birth prevalence and characteristics of congenital toxoplasmosis in Sergipe, North-east Brazil

Abstract

Objectives To estimate, by neonatal screening, the birth prevalence of congenital toxoplasmosis among live-born infants in Sergipe state, Brazil, and to investigate the clinical features of affected infants. Methods Dried blood spot specimens obtained from 15204 neonates were assayed for the presence of anti-T. gondii IgM antibodies. Duplicate retesting was done in infants with positive and borderline results. Confirmatory testing in peripheral blood samples consisted of testing for anti-T. gondii IgG and IgM in infants and mothers. Those with possible congenital toxoplasmosis were evaluated and followed up to a median age of 20months. Congenital infection was confirmed in the presence of persisting anti-T. gondii IgG antibodies beyond 12months of age. All infants with confirmed infection were treated with pyrimethamine, sulfadiazine and folinic acid for 1year. Results Fifty-three infants had detectable IgM in dried blood spot specimens. Confirmatory testing was reactive in 39/50, of which, 38 completed follow-up. Six of 15204 newborns were diagnosed with congenital toxoplasmosis, resulting in an estimated birth prevalence of four per 10000 [CI 95% 1.4-8.0]. Four infants (67%) showed signs of congenital toxoplasmosis in their first year of life; three (75%) had retinochoroidal scars, and one had cerebral calcifications. Two infants remained asymptomatic until 20months of age. Conclusions The birth prevalence of congenital toxoplasmosis is high in the Brazilian state of Sergipe, with most of the infants showing ocular lesions. Preventive measures are strongly warranted. © 2012 Blackwell Publishing Ltd.