Toxoplasmosis is a parasitic disease caused by the protozoan Toxoplasma gondii.
During the first few weeks after exposure, the infection typically causes a mild, flu-like illness or no illness.
Those with weakened immune systems, such as AIDS patients or pregnant women, may become seriously ill, and it can occasionally be fatal. The parasite can cause encephalitis (inflammation of the brain) and neurologic diseases, and can affect the heart, liver, inner ears, and eyes (chorioretinitis). Recent research has also linked toxoplasmosis with attention deficit hyperactivity disorder, obsessive compulsive disorder, and schizophrenia. Numerous studies found a positive correlation between latent toxoplasmosis and suicidal behavior in humans.
During acute toxoplasmosis, symptoms are often influenza-like: swollen lymph nodes, or muscle aches and pains that last for a month or more. Rarely will a patient with a fully functioning immune system develop severe symptoms following infection. Young children and immunocompromised patients, may develop severe toxoplasmosis.
Cats are the primary source of infection to human hosts.