Incidence of congenital toxoplasmosis in live Guatemalan newborns.

Five hundred and fifty samples of blood collected from the umbilical cords of an equivalent number of newborns were analyzed for serological evidence of congenital toxoplasmosis based on the detection of IgG and IgM. Six newborns presented serological evidence of congenital toxoplasmosis (IgM > 1:5, < 80 IU/ml), which represents an incidence of 10.9 per 1000 live births. During pregnancy four of the mothers of these six newborns were asymptomatic, whereas the other two mothers presented non-specific signs and symptoms. The six newborns did not present positive signs of acute toxoplasmosis at birth. Three false positive were identified, all secondary to the presence of a rheumatoid (RF) and/or antinuclear factor (ANF). And in one of them the diagnosis of congenital syphilis was confirmed. The percentage of women that tested serum positive for IgG antibodies increased with age, with 55.8% of the pregnant women testing serum-negative, therefore carrying the risk of acquired toxoplasmosis in future pregnancies.