Influência da moradia, da guarda e da presença de cães soropositivos na ocorrência da Leishmaniose visceral em Unaí, Minas Gerais

Abstract

Visceral leishmaniasis (VL) is a vector transmission disease of great concern for public health, being the most severe form of diseases caused by protozoa of the genus Leishmania. It is a zoonosis that presents worldwide distribution, especially in developing countries, occurring mainly in the most vulnerable populations and with difficult access to health services, making it one of the main members of the group of neglected infectious diseases of higher priority in the world. Dogs are important reservoirs of Leishmania and participate in the chain of transmission of the disease, both in urban and rural environments. The aim of this study was to understand the impact of the environment and the canine reservoir on the epidemiology of human VL (HVL) and canine VL (CVL) in a small Brazilian municipality, in addition to discussing the importance of stratification of risk areas for disease control and prevention actions. Two databases were used in this study: the first contains all reported cases of HVL whose place of residence was the municipality of Unaí, covering the period between 2013 and 2016; the second, obtained with the performance of a Canine Serological Survey, provides the number of cases of CVL in the municipality between the years 2012 and 2016. The identification of the neighborhoods with the highest concentrations of VL cases in Unaí was performed, enabling the municipality to be stratified in areas at higher risk for the disease. The municipality of Unaí reported 115 suspected cases of HVL, with the confirmation of 21 of them in the period between January 2013 and December 2016. Of the confirmed cases of HVL in the municipality, about 76% (16/21) were concentrated in only five neighborhoods, mostly low-income, with an environment characterized by the large number of houses, in addition to the presence of numerous fruit trees, wastelands and stray dogs. Regarding the disease in dogs, these same five neighborhoods concentrated more than 47% (381/808) of CVL cases in Unaí. Living with seropositive dogs for CVL was a determining factor for the increased prevalence of the disease. In addition, dogs in a street situation presented a prevalence of VL 2.66 (95% CI: 1.22 - 5.77) times higher when compared to the prevalence of the disease in domiciled dogs, demonstrating the importance of stray dogs as determining factors in the occurrence of VL. Thus, the results of the present study demonstrate that dogs, especially those in street situations, play an important role in maintaining the disease within the territory, in addition to public policies of ethical population management are necessary and urgent.