Background: Chagas disease, a zoonosis transmitted mainly by hematophagous insects of the subfamily Triatominae, is caused by Trypanosoma cruzi, classified into six discrete typing units (DTUs: TcI-TcVI and Tcbat).
Methods: Insect vectors were collected from 84 human dwellings in the municipality of Santo Domingo Tehuantepec, Oaxaca, Mexico; 4.76% were infested. DTUs were determined using conventional and nested PCR.
Results: The infection rate was 43.6%. All insects were infected with TcI while one specimen showed mixed infection with TcII.
Conclusions: This is the first report of T. cruzi mixed infection in Triatoma phyllosoma, its main vector in the study region.