Aims Congenital toxoplasmosis can cause neurological impairment and ocular disease. To describe clinical profile of infants with suspected congenital toxoplasmosis.

Methods Observational study of infants born to mothers with a suspected infection with Toxoplasma gondii during pregnancy between 2002 and 2011.

Serological tests were performed at birth: Toxoplasma specific antibodies IgA, IgM, IgG by Enzyme Immune Assay (EIA), Enzyme Linked Fluorescent Assay (ELFA), Western Blot (WB) tests and WB-IgG compared analysis for mother-infant pairs. Infants underwent cranial Ultrasound Scanning, fundoscopy examination, Auditory Brainstem Response, and periodic clinical evaluations.

Results One hundred thirty-one infants Toxoplasma IgG-positive at birth were evaluated; 118/131 (90%) become IgG-negative at 12 months of life.

Congenital toxoplasmosis was confirmed in 13/131 infants (9.9%). Transmitters pregnant women seroconverted in the third trimester (mean 28±8weeks).

IgM-ELFA test was positive in 9/13 infants; in 4/13 infants IgM positivity was detected by WB test (negative IgM-EIA/ELFA). Three of 6 infants had a different IgG-WB reactivity compared to their mothers.

Six of 13 infected infants (46%) were symptomatic at birth: 2/13 infants developed chorioretinitis; 4/13 had a pathological neuroimaging (4/4 cerebral calcifications, 1/4 ventriculomegaly). None had hearing loss. Infected infants received one-year therapy (pyrimethamine/sulfadiazine); 1/13 infant developed neutropenia as adverse therapy effect.

At a median age of 2 years all infected infants had a normal psychomotor development (range 1–10 years).

Conclusions It is advisable to perform IgM/IgG-WB on infant serum and the compared analysis for mother-infant pairs within the first month of life when high risk factors for Toxoplasmosis transmission are present.