Materno-fetal Toxoplasma gondii infection: critical review of available diagnostic methods

Various critical issues still surround the management of toxoplasmosis in pregnant women and neonates. Although the study of specific antibodies remains an essential parameter for diagnosing materno-fetal infection and establishing time of infection, the method needs to be carefully and critically reviewed due to the distinctive immunological sensitivity of the neonate. We began a retrospective epidemiological study of the pre-natal management of Toxoplasma gondii (TG) infection to evaluate the incidence of congenital toxoplasmosis in children in a southern Italian area (Sicily). 230 children born between 1999 and 2005 to mothers with TG infection during pregnancy enrolled in the G. Di Cristina Children's Hospital of Palermo. Retrospective analysis of the maternal sample established that 150 (65%) of the 230 infants enrolled in the study were born to a mother with probable infection, while the remaining 80 (35%) were born to a mother with definite infection. To date, the results of the neonatal follow-up programme have confirmed the diagnosis of congenital infection in 16 infants (7%); for 43%, diagnosis was made early due to the presence, at birth or in the first month of life, of specific anti-TG IgM. Sequelae were observed in 8/16 infected infants. Sequelae in infected born to mothers with infection in the third trimester opens up the problematic issue of which therapeutic approach to adopt for these women: even without consensus support, a combined regimen of Pyrimethamine-Sulfadiazine could be advocated, even in the absence of prenatal diagnosis. Currently, the best diagnostic strategy involves the sequential or contemporaneous combination of more than one of the currently available methods, as no method on its own can ensure an appropriate level of accuracy.