Molecular characterization of Trypanosoma cruzi DTUs of the triatomine species in a Chagas disease endemic area

Trypanosoma cruzi is the etiological agent of Chagas disease, a neglected tropical infection with great public health importance. This protozoan has triatomine insects as vector but may also be transmitted through blood transfusion, organ transplants, ingestion of contaminated food, or congenitally. It has a heterogeneous population classified into Discrete Typing Units (DTUs), TcI–TcVI and TcBat. The aim of this study was to molecularly characterize the DTUs of T. cruzi in triatomines from a Chagas disease endemic area in Northeastern Brazil. Triatomines were collected and the gut content was microscopically analyzed to investigate the presence of trypanosomatid flagellates. In addition, digestive tracts of some specimens were dissected and molecularly analyzed through PCR for Trypanosoma spp. and sequencing. PCR positive samples were further submitted to a multiplex PCR for DTUs of T. cruzi. A total of 117 triatomines were collected, 93.16% being in intradomicile and 6.84% in peridomicile environments. Insects were identified as Panstrongylus lutzi (37.60%), Triatoma pseudomaculata (26.50%), Triatoma brasiliensis (23.08%) and Panstrongylus megistus (12.82%). The specimens herein analyzed presented infection rates by T. cruzi of 5.49% and 12.09% in parasitological and molecular examinations, respectively. Multiplex PCR screening revealed 70.59% of the TcI genotype, detected in all triatomine species identified in this study and 29.41% of the DTU TcIII/TcIV detected in P. megistus and P. lutzi. T. cruzi infect triatomines in intradomicile and peridomicile environments, which brings attention to the risk of human infections and to the importance of the implementation of surveillance and entomological control actions.