Toxoplasma life cycle

The cat is the main host, harboring the sexual forms or gametes in the intestine. The gametes form the oocytes that are shed in the environment where sporozoites are formed. These sporozoites may be ingested by humans, cats, or other animals. Organisms may then invade the brain and other organs of the animal and stay dormant with the risk of reactivation in immune deficient states, forming tachyzoites and bradyzoites. Meat-eating animals may, thus, be infected by ingestion of infected organs and muscles. (Contributed by Dr. Avindra Nath.)