Triatominae (Hemiptera, Reduviidae) in the Pantanal region: association with Trypanosoma cruzi, different habitats and vertebrate hosts

Abstract

Introduction:The transmission cycle of Trypanosoma cruzi in the Brazilian Pantanal region has been studied during the last decade. Although considerable knowledge is available regarding the mammalian hosts infected by T. cruzi in this wetland, no studies have investigated its vectors in this region. This study aimed to investigate the presence of sylvatic triatomine species in different habitats of the Brazilian Pantanal region and to correlate their presence with the occurrences of vertebrate hosts and T. cruzi infection. Methods: The fi eldwork involved passive search by using light traps and Noireau traps and active search by visual inspection. The light traps were placed at fi ve selected points along forested areas for seven nights during each of the nine excursions. At each point where a light trap was set, eight Noireau traps were placed in palm trees and bromeliads. Results: In all, 88 triatomine bugs were collected: two and one individuals from light traps and Noireau traps, respectively; three from peridomestic areas; 23 in coati nests; and 59 in thornbird nests. In this study, active search in microhabitats showed higher effi ciency than passive search, since 95% of the triatomine bugs were caught in nests. Further, triatomine bugs were only found to be infected by T. cruzi in coati nests. Conclusions: Coati nests might act as a point of convergence and dispersion for triatomine bugs and mammal hosts infected by T. cruzi, thereby playing an important role in the sylvatic cycle of T. cruzi in the Pantanal region.

Trypanosoma cruzi transmission in the wild and its most important reservoir hosts in Brazil

“…During a study of coati ecology, Santos et al [ 55 ] collected Triatoma sordida ( n = 13) and Rhodnius stali ( n = 2) from seven coati resting nests. Additionally, 21 nymphs of all stages were collected from these nests, confirming these as suitable habitats for triatomines.…”

Complexity and multi-factoriality of Trypanosoma cruzi sylvatic cycle in coatis, Nasua nasua (Procyonidae), and triatomine bugs in the Brazilian Pantanal

“…Triatomine bugs living in close association with free-ranging coatis have been observed in the Nhecolândia region [ 20 , 21 ]. Herein, we observed that the majority of these nests sheltered triatomine bugs infected with T. cruzi , suggesting that coatis might be infected early in these nests through two mechanisms, the oral route and the contaminative route.…”

“…Precipitin tests revealed that these bugs fed on coati, bird, rodent and marsupial species [ 20 ]. Additionally, this habitat might act as a point of convergence and dispersion for triatomine bugs and mammal hosts infected with T. cruzi in the Pantanal region [ 21 ].…”

First report of Triatoma sordida Stål, 1859 (Hemiptera, Reduviidae, Triatominae) in the State of Acre and Brazilian Western Amazon

“…The occurrence of this species in nests is already known, as it has recently been found in bird and mammal nests in the Brazilian Pantanal region 2,9 . However, the discovery in poultry nests, such as those of G. gallus, generates a concern due both to the proximity of these animals to humans, especially species that have a high frequency of infection by T. cruzi 10 , and the findings of the present study, because the two specimens collected tested positive for trypanosomatids, although no molecular analysis was performed to confirm the species.…”

“…Triatominae (Hemiptera, Reduviidae, Triatominae) are insects of medical importance, since they can transmit Trypanosoma cruzi, the etiologic agent of American trypanosomiasis, also known as Chagas disease 1 , which affects approximately 12 million people, with a further 60 million people living in areas of risk around the world 2 .…”