[Serologic diagnosis of congenital toxoplasmosis].

Objective: To investigate the serological diagnosis of congenital toxoplasmosis and the prevalence of antibodies against toxoplasma in pregnant women in our area.

Method: Toxoplasmosis seroprevalence was analyzed in 68 712 serum samples from 47 635 pregnant women living in the catchment area of Hospital Miguel Servet during the period of 1992 to 2008. Detection of toxoplasma-specific immunoglobulins (IgM, IgA, IgG) and IgG avidity studies were carried out in the microbiology laboratory.

Results: Toxoplasmosis seroprevalence was 31.9%. The incidence of primary infection was 0.01% in susceptible pregnant women. Fifteen women seroconverted during pregnancy, and 9 of them had infants with congenital toxoplasmosis.

Conclusions: The cases of congenital toxoplasmosis were detected by maternal seroconversion during pregnancy. IgA was the most sensitive marker for the detection of congenital infection in neonates.