[Natural Trypanosoma Cruzi Infection of Triatominae Bugs Associated with Human Habitations in Mexico ]

Objective: To estimate the prevalence of infection with Trypanosoma cruzi in Triatominae species frequently found in and around Mexican dwellings, and to assess the frequency of Triatominae in towns by state.

Material And Methods: Between January 1993 and December 1999, 5,399 Triatominae bugs from 14 states of Mexico, were received in the Department of Entomology of the Institute for Epidemiologic Diagnosis and Referral (InDRE), for taxonomic determination and parasitoscopical search of Trypanosoma cruzi. Results obtained between 1993 and 1999 were analyzed globally.

Results: From 13 bug species associated with human dwellings, nine were naturally infected with T. cruzi. The highest percentage of infection occurred in Triatoma pallidipennis, T. picturata, Rhodnius prolixus and T. longipennis. Nayarit, Morelos, and Michoacán were the states with the highest percentage of infected bugs. The species T. dimidiata, T. gerstaeckeri, T. longipennis, T. mexicana and T. pallidipennis were first state records and Pastrongylus rufotuberculatus was a first local record.

Conclusions: These findings stress the importance of studying the biology of Triatominae and the need for permanent surveillance, to allow for up-to-date distribution records of Triatominae species in and around human dwellings, those adapting to human dwellings, and frequencies of those naturally infected by T. cruzi.