[Chagas cardiopathy in the first region of Chile. Clinical, epidemiologic, and parasitologic study]

705 inhabitants of rural towns in northern Chile were surveyed to study chagasic infection and cardiac involvement. Clinical evaluation, electrocardiogram, indirect hemagglutination test and xenodiagnosis for reactors were employed. Culture of positive xenodiagnosis was done to identify different zymodemes and schizodemes of T cruzi, T spinolai was not found in this area implying the absence of a wild cycle. Triotomines were not found over 3000 m high. Four cases of Z2b T cruzi strains were found. Simultaneous infection by Z1 and Z2b strains was found in the same bug obtained from houses. Overall human infection rate was 10%, and 69% of them showed altered electrocardiograms. Therefore, a lower infection rate but greater evidence of cardiac involvement is found in northern Chile compared to other areas in the country.