Gastrointestinal aspects of Chagas' disease.

Chagas' disease is an endemic infectious disease caused by a trypanosome prevalent in South America. An acute illness occurs in childhood (1) and, if the patient survives, an enlarged heart , dilated colon and megaesophagus (2) may develop 30 to 40 years later as manifestations of chronic Chagas' disease. The majority of those infected will always have a positive complement fixation test for trypanosomiasis; only the minority progress to this chronic phase with clinical signs and symptoms. It is established from autopsy incidence that 4 million people in Brazil have trypanosomiasis (3). In Sao Paulo 10% of blood donors have a positive complement fixation text (4). The disease is most prevalent in the Minas Gerais area of Brazil, where about 25% of the population have a positive complement fixation test (5), but it occurs elsewhere in Brazil and to a lesser extent in most South American countries. The trypanosome itself is found in the North American continent (6, 7) but does not usually cause Chagas' disease; the strain of trypanosome is different and the vectors do not have such a close relationship to man as in South America. There is no evidence that it exists in Europe (8) or Asia (9), and the trypanosome of Africa causes sleeping sickness rather than Chagas' disease.