infections
Chagas Disease
Diagnosis of Chagas Disease
During the first stage, examination of a blood sample using a microscope or blood tests During the second stage, blood tests During the third stage, blood tests, electrocardiography, and imaging tests of the heart or digestive system Doctors can usually diagnose Chagas disease during the first stage by seeing the protozoa in a sample of blood examined with a microscope. A blood sample may also be tested for the protozoa's genetic material (DNA). During the second and third stages, the protozoa are seldom seen in a sample of blood examined with a microscope. So doctors do two or more different blood tests to check for antibodies to the protozoa. ( Antibodies are proteins produced by the immune system to help defend the body against a particular attack, including that by parasites.) Antibody tests for Chagas disease may be positive in people who are not infected (false positive). So if the initial test is positive, a different antibody test is then done to confirm the diagnosis. If the infection is diagnosed, doctors do other tests to check for damage to the heart or gastrointestinal tract. For example, Electrocardiography and If people have difficulty swallowing or constipation, a CT scan or x-rays of the gastrointestinal tract may be done. 