How are people infected with Toxoplasma gondii?
Contact with oocyst-contaminated soil is probably the major means by which many different species-rodents, ground-feeding birds, sheep, goats, pigs, and cattle, as well as humans living in developing countries-are exposed to Toxoplasma gondii. In the industrialized nations, most transmission to humans is probably due to eating undercooked infected meat, particularly lamb and pork. People also become infected by eating unwashed fruits and vegetables. The organism can sometimes be present in some unpasteurized dairy products, such as goat’s milk. Toxoplasma gondii can also be transmitted directly from pregnant woman to unborn child when the mother becomes infected during pregnancy. There are two populations at high risk for infection with Toxoplasma gondii; pregnant women and immunodeficient individuals. Congenital infection is of greatest concern in humans. About one-third to one-half of human infants born to mothers who have acquired Toxoplasma during that pregnancy are infected. The v
