The parasites mature and can infect people for 2 to 5 days after they are passed in a cat's stool. No treatment can prevent cats from being infected or from passing the parasite. After the parasite infects an animal, it spreads throughout the animal's body. As a result, people can become infected by eating raw or undercooked meat. Women who become infected with Toxoplasma during pregnancy or within several months before pregnancy can pass the infection to their unborn infants.
Most infected people have no signs or symptoms.
Those who do might have flu-like symptoms, swollen lymph glands, or muscle aches and pains that last for a few days to several weeks. People with weakened immune systems can develop severe toxoplasmosis, which results in damage to the eye or the brain. Infants who are infected before birth can have serious mental or physical handicaps. Diagnosis is by blood test. In an otherwise healthy person who is not pregnant, no treatment is needed.