RESUMO
The incidence of cardiomyopathies of obscure origin among patients admitted to hospital because of heart failure is of the order of 10 percent. About one half of these show the presence of complement-fixing antibodies against T. cruzi and are thought to be suffering from Chagas disease. The incidence of positive serology for Chagas disease in a sample of the general population obtained from venereal disease and antenatal clinics is 0.45 percent. Man does not form part of the transmission cycle, but acquires the infection from adult sylvatic triatomids in areas where men live close to the bush, particularly in hilly areas. The triatomid most likely to transmit infection to man is P. geniculatus. About one half of the members of this species harbour trypanosomes in the hind-gut, and many of the trypanosomes found have been shown to be T. cruzi. Adult P. geniculatus are most active, and thus most likely to transmit infection in the dry season on moonless nights. R. pictipes may also play a role in transmitting the disease to man. The sylvatic reservoir for infection transmitted to man is probably the nine-banded armadillo, though other mammals may also have subsidiary importance. Initial attempts at treating T. cruzi infection with "Flagyl" show some slight promise of success and may justify further investigation. Serological evidence suggests that Chagas disease may be a cause of cardiomyopathy in Jamaica and, possibly, also in other West Indian islands. (AU)
