[Congenital toxoplasmosis: clinical and biological analysis of 11 cases in Tunisia]. / La toxoplasmose congénitale en Tunisie: analyse clinique et biologique de 11 cas.

ABSTRACT

Early diagnosis of congenital toxoplasmosis (CT) is necessary to prevent serious complications. The CT is diagnosed by the identification of the parasite in amniotic fluid during pregnancy or at birth by detection of antibodies synthesized by the fetus. The aim of this study was to determine the clinical and biological particularities of CT in a cohort of 11 cases observed in Tunisia and to evaluate the performance of the prenatal and neonatal diagnostic techniques that were used. In all patients, the presumed date of maternal contamination was determined based on the mother's serological data. Neonatal serological screening included assays for immunoglobulins (Ig) G and IgM by enzyme-linked-immuno-sorbent assay (ELISA), IgM by immuno-sorbent-agglutination-assay (ISAGA), and comparison of the mother-baby immunological profile by western blot IgG and IgM. Seven out of the 11 cases had been diagnosed prenatally; only 3 (43%) had a positive polymerase chain reaction (PCR) test. Ten newborns out of 11 had serological criteria of fetal infection; western blot results were positive in all of them, ISAGA was positive in 2 and ELISA in none. The newborn who had a negative serology had been treated in utero. The date of positivity of the western blot test varied 6 cases at birth, 2 at 12 days of life and 2 at 1 month of life. The 2 patients who had positive ISAGA results had been contaminated during the 3rd trimester of gestation.