Risk Presented by Copernicia prunifera Palm Trees in the Rhodnius nasutus Distribution in a Chagas Disease-endemic Area of the Brazilian Northeast

Abstract

With the aid of live-bait traps, we studied the risk that Copernicia prunifera palm trees, present in both periurban and rural localities of an endemic Brazilian northeast Chagas disease region, represent to domestic infestation by Rhodnius nasutus. In this area, this important vector has been encountered harboring and transmitting Trypanosoma cruzi, the etiologic agent of the American trypanosomiasis, to mammals, possibly including humans. Results indicate that this bug colonizes C. prunifera palm trees of both regions, mainly in dry seasons, and is infected with high levels of T. cruzi. Although more triatomines were captured in rural areas, proportionally the number of infected bugs from peri-urban regions was much higher. Herein we address the epidemiologic implications and challenge for the Brazilian health authorities to control the disease in this region, where the native palm trees have been largely destroyed causing a severe disturbance in the environmental equilibrium.

An entomoepidemiological investigation of Chagas disease in the state of Ceará, Northeast Region of Brazil

“…These results are corroborated by other studies that reported higher infection rates and colonization during the dry season 13,14,15 . This disparity highlights the need for further longitudinal studies to define optimum timing for vector control insecticide application.…”

“…These synanthropic animals often invade peridomicile areas using man-made structures, principally wood piles, as shelters, implying that triatomine T. cruzi infection may be taking place in the domestic environment. These small rodents have also been noted in the neighboring town of Jaguaruana 15 . Further studies on these insects' food sources and the distribution of synanthropic animals are needed to understand the disease infection cycle in the locality.…”

Feeding and Defecation Patterns of Rhodnius nasutus (Hemiptera; Reduviidae), A Triatomine Native to an Area Endemic for Chagas Disease in the State of Ceará, Brazil

“…Currently, sylvatic triatomines have drawn the attention of public health authorities because these insects have invaded domiciles and peridomiciles in rural and peri-urban zones of disease-endemic regions, which is probably a consequence of deforestation and alterations in their natural ecotopes. 10 This finding became more evident after the effective control of Triatoma infestans was achieved in countries where this triatomine was the main vector of Chagas disease. Such a change in the epidemiologic scenario has encouraged authorities to realize the importance of secondary vector species for the success of control of disease in disease-endemic areas.…”

“…Among these environments, the captured samples almost always harbored T. cruzi with an infection level more than 15%, therefore presenting a risk for humans. 9,10,[13][14][15][16] Recently, in addition to T. cruzi , T. rangeli was encountered for the first time in R. nasutus in the state of Ceará, with a natural infection rate of 7.7%. 9 In a recent survey conducted in Jaguaruana, Ceará, R. nasutus infected with T. cruzi were collected in intradomiciliar and peridomiciliar environments.…”

“…[4][5][6] Rhodnius nasutus (Stal 1859) is a wild species 7 that is widespread in the semi-arid environments (Caatinga) of northeastern Brazil, 2,8 where it inhabits the crowns of palm trees and bird nests. 5,[8][9][10] In the natural habitat, its feeding preference is for birds and opossums. 9 This species, when compared with other native Rhodnius species in northeastern Brazil, exhibits a greater capacity for spreading.…”