Trypanosoma cruzi among wild and domestic mammals in different areas of the Abaetetuba municipality (Pará State, Brazil), an endemic Chagas disease transmission area

Abstract

The presence of acute Chagas disease (ACD) due to oral transmission is growing and expanding in several South American countries. Within the Amazon basin, the Abaetetuba municipality has been a site of recurrent cases spanning across distinct landscapes. Because Chagas disease is primarily a zoonotic infection, we compared the enzootic Trypanosoma cruzi transmission cycles in three different environmental areas of Abaetetuba to better understand this new epidemiological situation. Philander opossum was the most abundant mammalian species collected (38% of the collected mammals) with a T. cruzi prevalence of 57%, as determined by hemocultures. Didelphis marsupialis was abundant only in the area with the higher level of environmental disturbance (approximately 42%) and did not yield detectable parasitemia. Despite similarities observed in the composition of the small mammalian fauna and the prevalence of T. cruzi infection among the studied areas, the potential of these hosts to infect vectors differed significantly according to the degree of land use (with prevalences of 5%, 41%, and 64% in areas A3, A1 and A2, respectively). Domestic mammals were also found to be infected, and one canine T. cruzi isolate was obtained. Our data demonstrated that the transmission of T. cruzi in the Amazon basin is far more complex than had been previously taught and showed that the probability of humans and domestic mammals coming into contact with infected bugs can vary dramatically, even within the same municipality. The exposure of dogs to T. cruzi infection (indicated by positive serology) was the common feature among the studied localities, stressing the importance of selecting domestic mammals as sentinels in the identification of T. cruzi transmission hotspots.

2 nd Brazilian Consensus on Chagas Disease, 2015

“…It is recognized that the process of simplification of fauna is the result of unplanned occupation of the environment, having the following potential consequences: I) lower diversity of food supply for triatomines in different habitats; II) a greater tendency of displacement of triatomines in search of food (hematophagous activity) from their original habitat, to feed on more eclectic mammals species that remained and expanded numerically; III) the populations of the parasite will also expand from these species of mammals with this environmental eclecticism, in general large reservoirs of T. cruzi (21) (78) (79) (80) . As these animals (such as marsupials and rodents) have a high degree of synanthropy, the epidemiological risk becomes clear (79) (80) .…”

“…As these animals (such as marsupials and rodents) have a high degree of synanthropy, the epidemiological risk becomes clear (79) (80) .…”

“…cruzi is a multi-host flagellate parasite capable of infecting tens of species of wild and domestic mammals distributed in all phytogeographic regions in Brazil; it is found in the most diverse ecological niches, contributing, in each type of ecotope, to form singular modalities of natural transmission foci (21) (23) (27) (39) (78) (79) (80) . The integration of the reservoirs in the routine monitoring process should be taken into account given that domestic animals are not confined and can also act as a link between wild and domestic transmission routes (80) (81) . As with wild mammals, the importance of domestic animals (for example, dogs and cats) as reservoirs of T. cruzi varies in different places, and they can be used as sentinel populations of transmission of T. cruzi in a given area (21) (81) .…”

An overview on the ecology of Triatominae (Hemiptera:Reduviidae)

“…Finally, if one observes the approximation patterns of the vector populations with human habitats, such as peridomestic animal shelters and human dwelling it will be possible to notice that this proximity is a direct consequence of human behavior in such habitats (Betts et al, 2008;Roque et al, 2013). Therefore, those issues (e.g.…”

Hunting, Swimming, and Worshiping: Human Cultural Practices Illuminate the Blood Meal Sources of Cave Dwelling Chagas Vectors (Triatoma dimidiata) in Guatemala and Belize

“…Wild and human commensal animals were the next most preferred blood sources (29% and 21%, respectively). It is surprising that dog blood meals are rare (only 7%), since dogs usually accompany the hunters, but perhaps the dogs are eating bugs that come close [22]. Vectors from caves on this cattle farm had fed on the common vampire bat but interestingly had not fed on cattle, suggesting they do not leave the caves.…”