Place des méthodes biologiques dans le diagnostic néonatal de la toxoplasmose congénitale en Tunisie

Abstract

INTRODUCTION: At birth, the biological diagnosis of congenital toxoplasmosis (CT) is essentially serological. AIM: To report the results of biological techniques used in the neonatal diagnosis of CT. METHODS: This was a descriptive study including newborns (NB) suspected of having CT who were referred to the Parasitology-Mycology laboratory of the Institut Pasteur of Tunis over a 17-year period. Newborns whose mothers had toxoplasmic infection during pregnancy, with either a negative or unperformed antenatal diagnosis, were included. The search for IgG and IgM antibodies was conducted using ELISA and western blot techniques. RESULTS: Among the 224 newborns included, the first sample was taken between days 1 and 3 of life in 58% of cases. In 181 newborns from our series, the disappearance of IgG was observed at an average age of 4.8 ± 1.6 months. IgM was positive after day 10 of life in 11 cases. A comparative mother-newborn western blot was performed for 216 newborns (96.4%). The diagnosis of CT was confirmed in 43 newborns (19.2%): either based on a positive western blot in 30 cases (69.8%), the presence of IgM by ELISA after day 10 of life in 11 cases (25.6%), or the persistence of IgG after 12 months of follow-up in two cases (4.6%). CONCLUSION: Our study confirms the undeniable contribution of the comparative western blot in the diagnosis of CT at birth.