Toxoplasma and Its Impact on Infants

Toxoplasma is one of the prevalent infectious diseases, and its infection during pregnancy can cause chorioretinitis and delayed psychomotor development in infants.

Guidelines on the management of infants exposed to toxoplasmosis in utero recommend screening paired blood samples from the mother and baby and the target organs for disease at birth. Infants are considered not infected if Toxoplasma gondii immunoglobulin IgM titers are negative and IgG titers are equal to or lower than their mothers, with no evidence of congenital toxoplasmosis after complete clinical, radiologic, and laboratory evaluation.

In Brazil, which has the highest prevalence of Toxoplasmosis, researchers conducted a retrospective study at a tertiary care center to evaluate in utero toxoplasma-exposed infants.

Researchers included all infants up to 12 months of age with a history of in utero exposure to T. gondii between 2008 to 2017 and excluded those who were not followed up and who were diagnosed positive for congenital toxoplasmosis.

Infants were considered exposed to toxoplasma maternal acute infection during pregnancy, defined by the presence of serum IgM or reactive IgG for T. gondii in a woman with previously non-reactive IgG levels. In these exposed infants, monthly measurement of T. gondii IgG is recommended to exclude congenital infection, and levels of T. gondii IgG titers are expected to reduce by half every month until undetectable.

Key Findings of the Study

• Out of 341 reviewed cases, 240 cases were found exposed to in-utero Toxoplasma infection.
• The mean gestational age at the time of maternal diagnosis of T. gondii infection was 19.2 weeks (35.5% in the first and 42.7% in the second trimester of pregnancy). A total of 76.3% of mothers were started on treatment with spiramycin or sulphadiazine and pyrimethamine.
• The mean (range) time for toxoplasmosis IgG titers to become undetectable in the serum was 7.9 (0.8 to 25.0) months.
• Majority of infants were seronegative before 12 months except for 14 infants who took more than 12 months to become negative serology.

Authors conclude: "Infants with exposure may continue to be followed and be considered as only exposed in utero to toxoplasmosis but not infected when the serology is negative after 12 months of life."

Source: Indian Pediatrics Journal