The infection is caused by a parasite called toxoplasma gondi and affects 10 to 20 out of every 100 people in North America by the time they are adults. In some cases the infection can also cause temporary blurred vision or loss of vision Most people who are infected do not show any signs of the disease. Persons who are pregnant or are experiencing a suppressed immune system due to AIDS, cancer or following organ transplants are at higher risk for illness. All animals and birds can be infected with the toxoplasmosis parasite. The parasite enters the muscles of a bird or animal when it eats raw meat or drinks the milk of another animal that is infected.
Cats can also spread the parasite in their feces.
Therefore humans can also become infected with toxoplasmosis when changing a cat litter box or working in an area contaminated with cat feces. Pregnancy and Toxoplasmosis A growing fetus can become infected with the toxoplasmosis parasite. This can happen if the mother is infected with the parasite while pregnant or before she becomes pregnant. Infection in the unborn child early in pregnancy can result in miscarriage, poor growth, early delivery or stillbirth. Treatment of an infected pregnant woman may prevent or lessen the disease in her unborn child.