First Case of Congenital Toxoplasmosis After Maternal Reinfection in Colombia: Serotyping Evidence of Reinfection by Different Strains

Herein, we report the first case of confirmed maternal reinfection in an immunocompetent woman, resulting in congenital toxoplasmosis in Colombia. The child was referred to an infectious disease pediatrician at 17 months of age because of strabismus and typical bilateral chorioretinitis scars with elevated immunoglobulin (Ig)G anti-Toxoplasma. The mother tested positive for Toxoplasma antibodies (IgG-positive and IgM-negative) in 2020. Four months before becoming pregnant in 2023, both IgG and IgM were positive. Serotyping indicated that the mother had antibodies against GRA6 types I and III strains, but the child only had antibodies against type I, suggesting that the mother was reinfected with a different strain during the periconceptional period, which was transmitted to the child.