Domestic, peridomestic and wild hosts in the transmission of Trypanosoma cruzi in the Caatinga area colonised by Triatoma brasiliensis

Abstract

The role played by different mammal species in the maintenance of Trypanosoma cruzi is not constant and varies in time and place. This study aimed to characterise the importance of domestic, wild and peridomestic hosts in the transmission of T. cruzi in Tauá, state of Ceará, Caatinga area, Brazil, with an emphasis on those environments colonised by Triatoma brasiliensis. Direct parasitological examinations were performed on insects and mammals, serologic tests were performed on household and outdoor mammals and multiplex polymerase chain reaction was used on wild mammals. Cytochrome b was used as a food source for wild insects. The serum prevalence in dogs was 38% (20/53), while in pigs it was 6% (2/34). The percentages of the most abundantly infected wild animals were as follows: Thrichomys laurentius 74% (83/112) and Kerodon rupestris 10% (11/112). Of the 749 triatomines collected in the household research, 49.3% (369/749) were positive for T. brasiliensis, while 6.8% were infected with T. cruzi (25/369). In captured animals, T. brasiliensis shares a natural environment with T. laurentius, K. rupestris, Didelphis albiventris, Monodelphis domestica, Galea spixii, Wiedomys pyrrhorhinos, Conepatus semistriatus and Mus musculus. In animals identified via their food source, T. brasiliensis shares a natural environment with G. spixii, K. rupestris, Capra hircus, Gallus gallus, Tropidurus oreadicus and Tupinambis merianae. The high prevalence of T. cruzi in household and peridomiciliar animals reinforces the narrow relationship between the enzootic cycle and humans in environments with T. brasiliensis and characterises it as ubiquitous.

Reservoir host competence and the role of domestic and commensal hosts in the transmission of Trypanosoma cruzi

“…The probability of bug infection after feeding on an infected host is crucially related to bloodmeal size, which varies among bug stages, duration of exposure to the host and other factors (reviewed in Gürtler et al, 1996a). For example, the pioneering xenodiagnostic surveys of dogs conducted in Brazil (Freitas, 1950;Freitas et al, 1952;Martins et al, 1945) and recent ones using hemoculture (5-8 mL of host blood) and/or PCR (Bezerra et al, 2014;Eloy and Lucheis, 2012;Lucheis et al, 2005) documented the frequent occurrence of parasitologically-positive dogs or cats (Table 1). In contrast, dogs seropositive for T. cruzi across several areas were hemoculture-negative when smaller amounts (0.2-0.4 mL) of blood were tested (Roque et al, 2008;Xavier et al, 2012;Rocha et al, 2013).…”

“…Table 4). High seroprevalence rates (26.1%) for T. cruzi were also recorded in goats by an indirect immunofluorescence antibody test (IFAT) in Paraíba, northeast Brazil (Fuentes Castillo et al, 1988), whereas a more recent survey recorded <1% of IFAT-positive young goats and sheep in the same region (Bezerra et al, 2014). The interpretation of serological results is not straightforward because domestic ungulates are also infected by other trypanosomes (especially Trypanosoma evansi and Trypanosoma vivax) and Phytomonas sp.…”

Molecular Identification of Food Sources in Triatomines in the Brazilian Northeast: Roles of Goats and Rodents in Chagas Disease Epidemiology

“…Bezerra and others 17 detected the prevalence of Galea spixii and another native rodent, Kerodon rupestris, in wild ecotopes, along with goats, lizards, and chicken.…”

Influence of human population density on spatial distribution patterns of environmental suitability for triatomine vectors of Chagas disease

“…Most ecological studies on the vectors of Chagas disease focus on small-scale, environmental factors affecting species distribution and abundance locally (i.e., household, peridomestic and wild microenvironments) [11][12][13][14][15][16]. Only in recent years, research inquiring about the largescale spatial patterns of species distribution and species richness of triatominae vectors become available in the literature [10.17-23].…”