Toxoplasma is a common parasite that causes birth defects – but the US doesn’t screen for it during pregnancy

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Bill Sullivan, Indiana University

(THE CONVERSATION) Imagine the shock of your baby being born with a swollen brain, blindness and debilitating seizures. Now imagine learning that these devastating conditions could have been prevented if you took a simple test for the common parasite Toxoplasma gondii.

Toxoplasma can be picked up anywhere an infected cat has defecated, such as the litter box, sandbox, garden or yard. Other routes of infection include consumption of contaminated water, undercooked meat or shellfish. Most people experience mild illness and can get the infection under control.

However, if contracted for the first time while pregnant, Toxoplasma can cross the placenta and cause spontaneous abortion or serious birth abnormalities. Such mother-to-child transmission during pregnancy is called congenital toxoplasmosis. Up to 4,400 babies may be born with congenital toxoplasmosis in the U.S. each year.

As professor of microbiology at the Indiana University School of Medicine, I study the biology of Toxoplasma in my lab. Blood tests can monitor the amount of Toxoplasma antibodies in the parent. Increases indicate an acute infection is taking place, putting the fetus at risk of congenital toxoplasmosis....