RESUMEN
The purpose of this study was to calculate the seroprevalence of Trypanosoma cruzi infection in a sample of inhabitants from a region considered to be at high risk of natural transmission of Chagas disease in Colombia. A cross-sectional study was conducted in subjects from 5 municipalities, recruited in urban and rural locations, distributed by gender according to the demographic information available. Socio-demographic information, history of potential exposure to insect vectors, blood donating, as well as symptoms suggesting cardiac disease were collected using a questionnaire. After giving written informed consent, blood specimens were obtained from 486 people to determine the serologic evidence of past exposure to T. cruzi. Infection was diagnosed when two different tests (ELISA and IHA) were positive. The seroprevalence of antibodies against T. cruzi was 16.91% considering an estimated population of 44,355 aged between 15 and 89 years (95%IC: 13.72 to 20.01). The factors significantly associated with the infection were: 1- Housing materials like vegetable material, adobe or unfinished brick walls; 2- The fact of having previous tests for Chagas disease (regardless of the result). Of note, the mean ages among infected and not infected participants were significantly different (49.19 vs. 41.66, p ≤ 0.0001). Among the studied municipalities, the one with the highest frequency of T. cruzi infection was Nunchia, with 31.15% of the surveyed subjects. Therefore it may be concluded that T. cruzi infection is highly prevalent in the north region of Casanare, in Colombia.