Profile of natural Trypanosoma cruzi infection among dogs from rural areas of southern Espírito Santo, Brazil

ABSTRACT Background: The emergence of Trypanosoma cruzi infection via oral transmission has a habitual character in its primitive endemic cycle. Recent findings revealed the first death by oral transmission of T. cruzi in the state of Espírito Santo, Brazil, in 2012, which was recorded in the rural area of Guarapari. This study evaluated the characteristics related to the occurrence of natural T. cruzi infection among dogs from the rural areas of Alegre and Iconha, municipalities of Espírito Santo. Methods: Logistic regression analysis of factors contributing to serological detection of T. cruzi in dogs was performed in environments where Espírito Santo’s Department of Health Surveillance had previously notified triatomines positive for Trypanosoma spp. from 2014 to 2017. Results: A total of 36 dogs were analyzed, of which 10 (27.77%) tested positive, one was borderline (2.79%), and 25 tested negative (69.44%) for T. cruzi infection. São Caetano, a district from the Iconha municipality, presented a 25 times greater chance for the detection of positive tests (OR:25; 95% CI; 2.37->100). Dogs with updated mandatory vaccination presented with a lower risk of positive serodiagnosis (OR:0.12; 95% CI: 0.02-0.63). Conclusions: Our results highlight for the first time the occurrence of natural T. cruzi canine infection, detected in the municipality of Iconha, mainly among dogs with un-updated mandatory vaccines in the district of São Caetano.