Dynamics of food sources, ecotypic distribution and Trypanosoma cruzi infection in Triatoma brasiliensis from the northeast of Brazil

Abstract

Innovative approaches used to combat Chagas disease transmission tend to combine a set of comprehensive efforts to understand the ecology of local vectors. In this work we identified molecularly the blood meal of 181 Triatoma brasiliensis, distributed in 18 populations (8 sylvatic and 10 peridomestic), which were collected across a range of 240 km (East-West) and 95 km (North-South) in the semi-arid region of northeastern, Brazil. We used the vertebrate mitochondrial gene (cytochrome B) sequencing applied to DNA isolated from bug midgut to identify the insect blood meal sources via the BLAST procedure. The peridomestic populations were classified according to two main hypotheses of site-occupancy for T. brasiliensis: the first says that the infestation is mainly driven by structures that resemble its natural habitat (stony-like ecotopes) and the second assumes that it is associated with key-hosts (rodents and goats). Rodents of the Caviidae family (Galea spixii and Kerodon rupestris) were identified as the key-host of T. brasiliensis, but also the potential Trypanosoma cruzi reservoir-able to connect the sylvatic and domestic T. cruzi cycle. Cats also deserve to be studied better, as potential T. cruzi reservoirs. By modeling the food sources + site-occupancy + T. cruzi natural infection, we identified man-made ecotopes suitable for forming dense triatomine infestations with high rates of T. cruzi natural infection, which may be taken into account for vector control measures.

Wild mammals involved in the transmission of Trypanosoma cruzi and food sources of Triatoma sherlocki in an endemic region of northeastern Brazil

“…The triatomines of the T. sherlocki species analysed fed on mammals, birds and reptiles, totaling nine different vertebrate species, highlighting the feeding eclecticism of this triatomine. This dietary diversity, as well as that found in the species T. brasiliensis , which is considered as domiciled in northeastern Brazil (Lilioso et al, 2020; Lima‐Neiva et al, 2021), may lead to a future domiciliation of T. sherlocki , since these two species belong to the same complex. Other studies point to a wide diversity of food sources of domestic and wild triatomines, such as the species of: (i) triatomine Rhodnius ecuadoriensis , which in Ecuador is considered as domiciled, but is often captured in the wild.…”

Revisiting the hybridization processes in the Triatoma brasiliensis complex (Hemiptera, Triatominae): Interspecific genomic compatibility point to a possible recent diversification of the species grouped in this monophyletic complex

“…Recently, was observed that reptile blood is the main food source for T. petrocchiae [78]. On the other hand, T. b. brasiliensis is mainly associated with rodents [49]. Taking into account that these two taxa live in sympathy [50], it is likely that the ecological (or habitat) isolation is the main pre-zygotic barrier that makes unfeasible the formation of natural hybrids between T. petrocchiae and T. b. brasiliensis.…”

Insecticidal efficacy of fluralaner (Bravecto®) against Triatoma brasiliensis, a major vector of Trypanosoma cruzi in Brazil

“…Other transmission routes, such as oral and congenital routes, are also important in some endemic countries [ 1 , 5 ]. It is important to highlight that oral transmission is also vector dependent as infected insects are responsible for food or drink contamination [ 6 ].…”