The epidemiology of Chagas' disease in a hyperendemic area of Cochabamba, Bolivia: a clinical study including electrocardiography, seroreactivity to Trypanosoma cruzi, xenodiagnosis, and domiciliary triatomine distribution.

A clinicoepidemiologic survey of Chagas' disease was conducted in the remote rural village of Tabacal in southcentral Cochabamba, Bolivia. In June and July 1988, we interviewed and examined 153 of 160 villagers > five years old for signs and symptoms of Chagas' disease. All participants had electrocardiograms (EKGs) and serologic analysis performed, and 20 villagers underwent xenodiagnosis. All 40 houses in the village were examined for triatomes, and house construction materials and defects were recorded. Seventy-four percent of all villagers had serologic evidence of Chagas' disease, and were defined as cases. Cases were three and one-half times more likely to have signs and symptoms of heart failure than non-cases (P = 0.2) and were nine times more likely to have EKG conduction abnormalities than non-cases (P = 0.02). Thirty-three percent of all EKG conduction defects occurred in individuals < 35 years of age. All dwellings had evidence of triatome infestation; 72% of the triatomes collected were positive for metacyclic trypanosomes. We conclude that Trypanosoma cruzi infection is highly prevalent in Tabacal and is a common cause of morbidity in that region.