Presence of triatominae (Hemiptera, Reduviidae) and risk of transmission of Chagas disease in Colima, Mexico

With the purpose of evaluating the risk of transmission of the Chagas disease in the State of Colima, Mexico, an entomological survey was performed to obtain triatominae and the rate of infection by Trypanosoma cruzi determined by examination of its dejections. Two hundred eighteen houses located in 16 villages were sampled. In each house the intradomestic and peridomestic habitats were examined by the man-hour-house method, sensor boxes and mouse-baited traps. Also, 12 silvatic places were explored around the same areas using the same techniques as the ones sampled. In total, 456 specimens were captured, of which 139 correspond to Triatoma phyllosoma pallidipennis; 80 to T. p. longipennis; one specimen of T. dimidiata and 236 nymphs of Triatoma sp. Two hundred ninety seven insects were captured in the intradomestic habitat, 132 in the peridomestic and 26 in the silvatic. The index of positive houses was 27%, located in the central area of the state. The rate of natural infection with T. cruzi showed 25.6%. This results confirmed the presence of two important vectors of the Chagas disease in Colima. Its preference for the domestic habitat and its high levels of natural infection with T. cruzi suggested the existence of a significant risk for its transmission in this area of the country.