Definition:

Toxoplasmosis is a worldwide infection caused by the intracellular parasite Toxoplasma gondii. The majority of horizontal transmissions to humans is caused either by the ingestion of tissue cysts in infected meat or by the ingestion of soil, water, or food contaminated with sporulated oocysts derived from the environment or, less frequently, directly from feline feces. The parasite usually causes asymptomatic infection but in immunocompromised individuals, it can result in fatal disease with encephalitis. Transmission can also occur vertically. Congenital infection causes spontaneous abortion or serious defects such as hydrocephalus, chorioretinitis, and intracranial calcification in infants.