ABSTRACT
To determine the extent of <i>Trypanosoma cruzi</i> infection and/or transmission in the southern Amazon region of Ecuador, three indigenous communities in the provinces of Pastaza and Morona Santiago were serosurveyed. Chagatest<sup>TM</sup>, Immunocomb<sup>®</sup>II and immunofluorescent (IF) assays were used. Among the 385 inhabitants examined, nine (2.34%) were seropositive for <i>T. cruzi</i> infection. Of the nine positive sera, four (44.4%) fall in the 10–19, one each in the 20–29, 30–39 and 40–49, and two in the 50–59 age groups. These results suggested the possible existence of an autochthonous active <i>T. cruzi</i> transmission in the region and provide the first serological evidence for <i>T. cruzi</i> infection in the southern province of Morona Santiago bordering Peru. Further studies are needed in these Amazonian provinces to ascertain the spread of <i>T. cruzi</i> infection in the area.