Toxoplasmosis is a common infection in people, birds, and animals that often is not noticed or may cause mild flu-like symptoms. But the infection can cause problems for a fetus (when the mother becomes infected) and for people who have weakened immune systems.

Human infection usually happens when a person eats food that contains the toxoplasmosis parasite, such as undercooked meat from an infected animal. You also can get infected by touching an infected cat or its feces. Most people develop an immunity during the 2 months after the infection.

• Infection during pregnancy is rare. In most parts of North America, infected newborns are very rare. Toxoplasmosis can cause blindness or brain damage in an infected infant. Pregnant women and newborns who have toxoplasmosis are treated with antibiotics.
• People who have impaired immune systems are vulnerable to severe toxoplasmosis. People who have AIDS, are receiving cancer treatment, or are taking organ transplant medicine can develop life-threatening infections in the brain, lungs, or heart, as well as eye damage. Antibiotics are used to prevent toxoplasmosis as well as to aggressively treat the infection.