[The epidemiology of Chagas' disease in a rural area of the city of Teresina, Piauí, Brazil].

In the rural areas of Teresina, 129 triatomines were captured distributed in (a) artificial ecotopes; a house with one Triatoma brasiliensis, one Panstrongylus geniculatus, Rhodnius pictipes, and one Rhodnius prolixus and in a uninhabited chicken house (7 Rhodnius nasutus). (b) Natural ecotopes; Pahus Orbignya martiana (41 Rhodnius neglectus, 33 Rhodnius prolixus and 41 Rhodnius nasutus) and Copernicia cerifera (3 Rhodnius neglectus). The 22.6% of captured triatomines were infected by flagellates similar to Trypanosoma cruzi. Twenty-eight sylvatic mammals were captured and examined. Seven Didelphia albiventris, 2 Rattus rattus and a Tamandua tetradactyla were infected with flagellates. The flagellates found in both triatomines and mammals were morphologically indistinguishable from Trypanosoma cruzi. Serology by the indirect immunofluorescence test for Chagas disease revealed two positive seroreactions of positivity among 123 inhabitants examined.