Toxoplasmosis is usually spread by eating poorly cooked food that contains cysts, exposure to infected cat feces, and from a mother to a child during pregnancy if the mother becomes infected. Rarely, the disease may be spread by blood transfusion. It is not otherwise spread between people.The parasite is known to reproduce sexually only in the cat family. However, it can infect most types of warm-blooded animals, including humans. Diagnosis is typically by testing blood for antibodies or by testing amniotic fluid for the parasite's DNA.