Diagnosis of congenital toxoplasmosis: prenatal and neonatal evaluation of methods used in Toulouse University Hospital and incidence of congenital toxoplasmosis

ABSTRACT

The aim of this study was to determine the incidence of congenital toxoplasmosis (CT) and to assess the performances of prenatal and neonatal diagnoses. From 1994-2005, in Toulouse University Hospital, France, amniocentesis was performed on 352 pregnant women who were infected during pregnancy. All women were treated with spiramycin and pyrimethamine-sulfadoxine when prenatal diagnosis was positive. Among the 275 foetuses with follow-up, 66 (24 percent) were infected. The transmission rates of Toxoplasma gondii were 7 percent, 24 percent and 59 percent in the first, second and third trimesters, respectively. The sensitivity and specificity of PCR on amniotic fluid (AF) were 91 percent and 99.5 percent, respectively. One case was diagnosed by mouse inoculation with AF and six cases were diagnosed by neonatal or postnatal screening. The sensitivity and specificity of PCR on placentas were 52 percent and 99 percent, respectively. The sensitivity of tests for the detection of specific IgA and IgM in cord blood was 53 percent and 64 percent, respectively, and specificity values were 91 percent and 92 percent. In conclusion, PCR performed on AF had the highest levels of sensitivity and specificity for the diagnosis of CT. This permits an early diagnosis of most cases and should be recommended.