Cats are the only known reservoir for toxoplasma gondii, a parasite transmitted from cats to humans, which causes toxoplasmosis. Toxoplasmosis is assumed to be a self-limiting disease in patients older than five; and only warrants treatment in patients under five. Toxoplasmosis should not be assumed to be self-limiting or harmless. Parasites live off the energy of the host, can spread silently to preferred locations in the body over decades, and can survive and multiply as long as the host lives.

Some preferred locations for a toxoplasmosis infection include the intestine, the nervous system, and the brain; and toxoplasma gondii can cross the placenta to infect a fetus. The highest risk for transmission is from feral cats, recently infected cats, and kittens; and pregnant women are advised to avoid litter boxes, because of the risk to a fetus. Toxoplasmosis has been linked to virtually every mental illness, from depression to schizophrenia to bipolar disorder; and to intermittent explosive disorder with recurrent impulsive, problematic outbursts and violent and physical aggression, disproportionate to the situation.

Toxoplasmosis has been linked to regressive developmental disorders in infants and toddlers; to childhood epilepsy, with the severity of epilepsy linked to the site of attack in the brain and volume of cysts; and with adult epilepsy. Toxoplasmosis has also been linked to auto-immune disorders, lupus, neurologic disorders, and cancer; and now has been linked specifically to brain cancer.

People should be aware of the risk and informed of the potential relationship between toxoplasmosis and chronic illnesses. Healthcare providers should investigate toxoplasmosis in chronic disease, particularly in patients who own or have contact with cats, in mental illness, and in autoimmune diseases of unknown origin. https://onlinelibrary.wiley.com/doi/10.1002/ijc.33443

https://onlinelibrary.wiley.com/doi/10.1002/ijc.33443