Risk and protective factors of Leishmaniasis in the rural area of the western border region of Rio Grande do Sul, Brazil

Abstract

Background The Leishmaniases are on the top of the global list of tropical neglected diseases. The number of infected dogs in South America is estimated in millions and correlated to disease cases in humans, especially in Brazil. Equines may get infected too and can play a role in the epidemiological chain. Thus, the aim of the present study was to evaluate risk and protective factors of leishmaniasis in rural areas of the western border region of Rio Grande do Sul state, Brazil by Leishmania spp. protozoa molecular detection and serological evaluation (ELISA) in equine and canine blood samples. This work included nine farms around the city of Uruguaiana. Epidemiologic information regarding farm characteristics and biologic material collection of canine (22) and equine (91), totalizing 113 samples was collected. The polymerase chain reaction (PCR) technique was used to detect Leishmania spp. in biological samples. Variables related to the farm were collected and evaluated through descriptive analysis followed by chi-square test and a logistic regression analysis. Results Nineteen positive samples (19/113 – 16,81%) were detected, being 18 equines and 1 canine, in six of the nine farms included in the study. No animal showed clinical signs of the disease. According to the variables analyzed, when compared each characteristic separately, the presence of abundant vegetation and poor hygiene demonstrated to be risk factors to Leishmania infection in rural areas. The logistic regression showed that excellent general hygiene, proximity to the weir and trimmed grass were protective factors (p=0.038, p=0.001 and p=0.014, respectively). Having excellent hygiene represents a 70% lower chance of getting infected, keeping the grass cut protects the animal by more than 90% and the proximity of the weir represents a protective factor of 96%. Conclusions The presence of Leishmania infection in the western border region of Rio Grande do Sul was 16,81% and it was influenced by farm characteristics. The role of the excellent general hygiene as a protective factor is extremely relevant in the leishmaniases prevention.

PCR-RLFP characterization of Leishmania spp. in domestic animals from the south-western border of Brazil

“…The presence of L. infantum in the Brazil-Argentina-Uruguay transborder region was only discovered recently: until the past decade, this infection had never been diagnosed in southern Brazil. In addition, canine and human leishmaniasis cases have now been detected, as well as infections among horses (Escobar et al, 2019;Pradella et al, 2020Pradella et al, , 2021. This border region was not previously included as a focus of the federal healthcare system and it was believed that the disease would be cutaneous and not visceral, as studies had shown.…”

Hierarchical spatiotemporal modeling of human visceral leishmaniasis in Rio Grande do Norte, Brazil

“…Livestock was included to incorporate possible animal reservoirs which may influence the distribution and incidence of VL. Numerous mammals such as chickens [28,29], swine [30], horses [31,32] and cattle [10] have been documented as blood sources for sandflies in Brazil and thus serve as possible reservoirs. Livestock production for buffalo and quail were also PLOS NEGLECTED TROPICAL DISEASES available but were omitted from the analysis due to a lack of spatial heterogeneity.…”