Trypanosoma cruzi is a parasite (often abbreviated to T.cruzi), found in certain parts of Central and South America. It is transmitted to humans by biting insects or from mother to baby at the time of birth, or by blood transfusion. Over many years, the parasite can cause damage to the muscles in the heart and intestines, leading to an illness called Chagas disease. Not all infected people become ill. Our tests look for antibodies to the infection. A donor’s place of birth and travel history determine whether the test is required.