Genetic diversity and geographical distribution of Trypanosoma cruzi DTUs in Mexico: A Systematic Review.

Trypanosoma cruzi exhibits substantial genetic diversity, classified into discrete typing units (DTUs) that may differ in geographical distribution, host associations, and epidemiological relevance. Although several DTUs have been reported in Mexico, evidence on their national distribution across vectors, reservoirs, and humans remains fragmented. A systematic review was conducted following PRISMA guidelines to synthesize available information on the geographical distribution, host associations, and epidemiological cycles of Trypanosoma cruzi DTUs in Mexico. Seven scientific databases were searched for studies published between January 2006 and July 2025. Inclusion criteria focused on studies reporting molecular identification of T. cruzi DTUs in vectors, reservoirs, and humans within Mexican territory. Forty-seven studies were analyzed, providing a total of 1,337 individual records. The analysis confirmed the circulation of six DTUs (TcI-TcVI) in 22 states, with TcBat being absent from the records. TcI was identified as the most frequent and widely distributed lineage, present in 20 of the 22 states. Veracruz documented the highest genetic diversity, with all six DTUs reported. The genus Triatoma and domestic dogs exhibited the highest diversity of reported DTUs, acting as key epidemiological bridges between transmission cycles. TcI is the predominant lineage in Mexico, demonstrating high connectivity across all transmission cycles. This systematic review highlights significant information gaps in northern Mexico and underscores the need for strengthened surveillance to better understand the impact of T. cruzi genetic diversity on public health.