SUMMARY
Introduction: Trypanosoma cruzi (T. cruzi) has been classified into six lineages using molecular typing markers, which are easily amplified by the polymerase chain reaction (PCR) technique. The objective of this work was to identify and geographically locate the isolates of T. cruzi that circulate naturally in triatomines of the municipalities of the State of Hidalgo, Mexico, through the amplification from the conserved region of the mini-exon gene by end point PCR. Method: 170 specimens of hematophagous insects from 14 municipalities from the state of Hidalgo, Mexico, were collected. Optic microscopy and PCR from triatomine fecal and digestive tissue samples were used for laboratory diagnostic of T. cruzi infection and T. cruzi lineage classification. Results: Three triatomine taxas were found: Triatoma dimidiata (87/170), Triatoma mexicana (14/170) y Triatoma gerstaeckeri (7/170). For 36.47% (62/170) of the collected specimens, species could not be determined and were classified as T. spp. T. cruzi infection was determined in 1.76% of the collected specimens through optic microscopy and in 11.18% through PCR. All the classified parasites correspond to the TcI biotype of T. cruzi. Most abundant populations of triatomines (80.58%), as well as, the highest percentage (10.58%) of T. cruzi infected insects, were found in the peridomestic ecotope.Conclusion: The most important vector found in the región of study was Triatoma dimidiata, followed by T. mexicana and T. gerstaekeri and the only T. cruzi biotype found to be infecting triatomines was TcI. The vectors were mainly distributed in the peridomiciliary habitats of the studied municipalities. Results indicate a T. cruzi represents a risk of infection for the inhabitants of the studied regions of the state of Hidalgo, Mexico.