Toxoplasmosis

Definition: Toxoplasmosis is an infection that is caused by the protozoan parasite, Toxoplasma gondii. The parasite is carried by cats, birds, and other animals, and is found in soil contaminated by cat feces and in meat, particularly pork. The parasite can infect the lungs, retina of the eye, heart, pancreas, liver, colon, and testes. Once T. gondii invades the body, it remains there, but the immune system in a healthy person usually prevents the parasite from causing disease. If the immune system becomes severely damaged, as in HIV-infected persons, or is suppressed by drugs, T. gondii can begin to multiply and cause severe disease. In HIV-infected persons, the most common site of toxoplasmosis is the brain. When T. gondii invades the brain, causing inflammation, the condition is called toxoplasmic encephalitis. While the disease in HIV-infected persons can generally be treated with some success, lifelong therapy is required to prevent the infection from occurring.

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Parts of the Immune System