Canine leishmaniasis in the Atlantic Rainforest Biome region of Bahia, Brazil, affected by deforestation: a one health perspective

Canine visceral leishmaniasis (CVL) is a zoonotic disease whose etiological agent is transmitted by phlebotomine sand flies, with dogs as the primary reservoir. Urbanization and deforestation have created conditions favorable to pathogen transmission. In Eunápolis, Bahia, the epidemiological situation of CVL remains entirely unknown. In this study, the prevalence of CVL and its associated socio-environmental factors were investigated. A cross-sectional study was conducted involving 243 dogs residing in both urban and rural areas. Blood samples were analyzed using the rKDDR-plus immunochromatographic test, conventional polymerase chain reaction (cPCR), and quantitative real time polymerase chain reaction (qPCR). In addition, household questionnaires were administered to assess socio-environmental conditions. Based on the rKDDR-plus serology, four samples tested positive (1.6%), and qPCR confirmed the presence of Leishmania infantum DNA in three samples (1.2%). Among the environmental factors analyzed, improper waste management (38.3%) and proximity of households to vegetation (54.7%) were notable. The detection of seropositive samples and L. infantum DNA suggests the existence of a transmission cycle of canine visceral leishmaniasis (CVL) in the studied area. In this context, public health measures, including vector control, health education initiatives, and responsible pet ownership, are essential to mitigate risks and prevent the spread of the disease.