Molecular diagnosis and genotyping of cases of perinatal toxoplasmosis in Mexico.

Toxoplasma gondii congenital transmission depends partially on parasite load and genotype. Both factors were examined in 4 mother/newborn pairs with perinatal infection acquired in central Mexico. Type I and type I-related strains were identified. These results add information regarding T. gondii strains prevailing in humans, although neither the genotype nor the load were related to vertical transmission or damage.