New Approaches to the Ecology of Triatoma sordida in Peridomestic Environments of an Endemic Area of Minas Gerais, Brazil

Abstract

Triatoma sordida is a native South American species and the most frequently captured triatomine in artificial environments in Brazil. Although considered a secondary vector of Trypanosoma cruzi, it is typically associated with low infection rates. To investigate its role in an endemic area for Chagas disease in northern Minas Gerais, Brazil, we employed a multidimensional approach that combined triatomine capture data with quantitative and qualitative analyses of T. cruzi. A total of 1861 T. sordida specimens were captured, of which 1455 were examined and 210 (14.4%) were found to be infected with T. cruzi. The most prevalent discrete typing unit (DTU) was TcI (80%), followed by TcII (8%), TcV (5%), and TcIII (3%). Molecular techniques provided new insights into the ecology of T. sordida, revealing a higher infection rate than previously reported and a parasitic load lower than that observed in other quantified species. Chickens were confirmed as the primary food source, playing an epidemiological role in maintaining infected insects with four T. cruzi DTUs. The observed diversity of T. cruzi DTUs suggests a lack of environmental segregation, likely due to the extensive movement of various host species between wild and domestic habitats, resulting in overlapping transmission cycles.