Congenital toxoplasmosis in the valley of Mexico. Results of a series of cases

BACKGROUND. In Mexico “virulent” strains of Toxoplasma gondii prevail, so the clinical picture may be different to that reported for regions where non-virulent strains are present, such as Europe, United States and Canada. METHODS. We report a series of children with congenital toxoplasmosis recruited since 2005 by prenatal or postnatal screening, or because they arrived as clinical cases at the INP. RESULTS. All the patients presented clinical manifestations, but the prenatal screening group presented a more localized and less severe infection, mainly with spasticity and mild psychomotor retardation. The postnatal screen group presented intermediate clinical characteristics, with mild, moderate or severe psychomotor retardation, low birth weight, micro or hydrocephalus, jaundice, hepatomegaly, splenomegaly, intracranial calcifications and spasticity. The most affected patients were those that presented as clinical cases, with a wide variety of clinical manifestations and the worst prognosis, including death. Six patients presented comorbidities. Twenty cases were positive for two or more laboratory tests; the rest only for one. CONCLUSIONS. Our results support that congenital toxoplasmosis in Mexico is more serious than in other countries, and that it is urgent to implement effective prenatal screening for prevention and prophylaxis.