The post-natal serodiagnosis of congenital toxoplasmosis

Abstract

A total of 20 cases of suspected congenital toxoplasmosis, investigated in the post-natal period, were reviewed. Maternal and infant sera were examined by the dye test, latex agglutination test, immunoglobulin M immunosorbent agglutination assay (ISAGA) and double sandwich enzyme-liked immunosorbent assay (DS-ELISA). Ten children were found not to be infected. The diagnosis of congenital toxoplasmosis was confirmed in 10 infants by the persistence of specific antibody at the age of 12 months, with or without clinical signs of infection. Of these 10 cases of congenital infection, three had toxoplasma specific IgM detected by ISAGA and a further three showed positive reactions by ISAGA and DS-ELISA at the time of investigation. The ISAGA was found to be superior to DS-ELISA for the diagnosis of congenital toxoplasmosis in the post-natal period. However, four infants subsequently demonstrated to be congenitally infected did not have specific IgM detectable by ISAGA or DS-ELISA and there remains a need for improved diagnostic methods for this condition. © 1989.