Variability in Trypanosoma cruzi susceptibility among species of kissing bugs (Hemiptera: Reduviidae: Triatominae) in Mexico

Chagas disease, caused by the kinetoplastid Trypanosoma cruzi (Chagas, 1909), and transmitted by triatomine bugs, poses a significant public health challenge. Variability in the susceptibility of different triatomine species to T. cruzi infection can profoundly influence disease transmission dynamics and control measures. In this study, we assessed the susceptibility to T. cruzi infection in the first and third nymphal stages across eight triatomine species to T. cruzi infection using experimental inoculation with the NINOA strain and optical microscopy. The evaluated species were Dipetalogaster maximus (Uhler), Triatoma bassolsae (Alejandre-Aguilar, Nogueda-Torres, Cortéz-Jiménez, Jurberg, Galvão, Carcaballo), T. infestans (Klug), T. lecticularia (Stål), T. mexicana (Herrich-Schaeffer), T. pallidipennis (Stål), T. phyllosoma (Burmeister) and T. picturata (Usinger). The results indicated that T. bassolsae exhibited the highest susceptibility to infection, followed by T. pallidipennis and D. maximus. Our analysis also revealed that T. cruzi (NINOA) infection was significantly associated with triatomine species rather than nymphal stage (p < 0.0001), with substantial variability observed in susceptibility among species (p < 0.001). We ranked triatomine species susceptibility to T. cruzi infection as follows: T. bassolsae > D. maximus = T. pallidipennis = T. picturata = T. mexicana > T. phyllosoma = T. lecticularia = T. infestans. These findings enhance our understanding of T. cruzi transmission dynamics and offer valuable insights for the development of effective control strategies against this neglected tropical disease.