Maintenance of Trypanosoma cruzi, T. evansi and Leishmania spp. by domestic dogs and wild mammals in a rural settlement in Brazil-Bolivian border

Abstract

Domestic dogs are considered reservoirs hosts for several vector-borne parasites. This study aimed to evaluate the role of domestic dogs as hosts for Trypanosoma cruzi, Trypanosoma evansi and Leishmania spp. in single and co-infections in the Urucum settlement, near the Brazil-Bolivian border. Additionally, we evaluated the involvement of wild mammals’ in the maintenance of these parasites in the study area. Blood samples of dogs (n = 62) and six species of wild mammals (n = 36) were collected in July and August of 2015. The infections were assessed using parasitological, serological and molecular tests. Clinical examination of dogs was performed and their feeding habits were noted. Overall, 87% (54/62) of sampled dogs were positive for at least one trypanosomatid species, in single (n = 9) and co-infections (n = 45). We found that 76% of dogs were positive for T. cruzi, four of them displayed high parasitemias demonstrated by hemoculture, including one strain types TcI, two TcIII and one TcIII/TcV. Around 73% (45/62) of dogs were positive to T. evansi, three with high parasitemias as seen by positive microhematocrit centrifuge technique. Of dogs sampled, 50% (31/62) were positive for Leishmania spp. by PCR or serology. We found a positive influence of (i) T. evansi on mucous pallor, (ii) co-infection by T. cruzi and Leishmania with onychogryphosis, and (iii) all parasites to skin lesions of sampled dogs. Finally, feeding on wild mammals had a positive influence in the Leishmania spp. infection in dogs. We found that 28% (5/18) coati Nasua nasua was co-infected for all three trypanosamatids, demonstrating that it might play a key role in maintenance of these parasites. Our results showed the importance of Urucum region as a hotspot for T. cruzi, T. evansi and Leishmania spp. and demonstrated that dogs can be considered as incidental hosts.

Epidemiological aspects of Leishmaniasis in the Pantanal region of Mato Grosso

“…Roque & Jansen (2014), cite different orders of mammals (Didelmorphia, Pilosa, Cingulata, Rodentia, Carnivora and Primata) infected by several species of Leishmania responsible for the integument form; however, they conclude that the reservoirs of these species are still unknown, probably because the researches have concentrated on the search for a specific host as observed for dogs and Leishmania infantum and that, however, these species of Leishmania can be kept in the wild through a reservoir system. In this region of the Pantanal Norte, data with these species are scarce; however, in Corumbá, in the state of Mato Grosso do Sul, the serological and molecular tests (PCR) with different wild mammals demonstrated the occurrence of Leishmania in 50% of the quatis (Nasua nasua), 9/18, 56% of the monkeys (Sapajus cay), 5/9 and 40% of the foxes (Cerdocyon thous), 2/5, but the study did not identify the species of Leishmania involved (PORFIRIO et al, 2018).…”

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

“…Another relevant aspect is the occurrence of mixed infection with T. cruzi and Leishmania spp. in dogs in Latin America because there is an overlap of endemic areas for Chagas disease and cutaneous and visceral leishmaniasis [ 5 , 30 , 58 – 61 ]. Fluralaner (Bravecto ® ) treatment of dogs also has an insecticidal effect on sand flies [ 37 ], suggesting that it this treatment could possibly assist in reducing the canine infection rate by T. cruzi and Leishmania spp.…”

Triatomine Feeding Profiles and Trypanosoma cruzi Infection, Implications in Domestic and Sylvatic Transmission Cycles in Ecuador

“…In Colombia, dogs have been found as an important source of blood for T. maculata [ 35 ]. In other areas, such as the USA (Texas and Louisiana) and Brazil, the T. cruzi seroprevalence of dogs ranged from 7 to 76% [ 50 , 51 , 52 , 53 ]. In Northern Argentina, infected dogs constitute a risk factor and have been used as sentinels for T. cruzi domestic transmission [ 54 , 55 ].…”