Original: Toxoplasmosis , the disease of which T. gondii is the causative agent , is usually minor and self-limiting but can have serious or even fatal effects on a fetus whose mother first contracts the disease during pregnancy or on an immunocompromised human or cat .
Simplified: Toxoplasma gondii is a protozoan parasite that infects most species of warm blooded animals , including humans , causing the disease toxoplasmosis .