Epidemiology of leptospirosis in humans and unowned dogs: a One Health approach

Abstract

The focus of the present dissertation was to contribute to the knowledge about epidemiology of leptospirosis in humans and dogs. For this, a time series analysis of leptospirosis human cases from 2007 to 2019, a systematic review and a longitudinal study on the prevalence and seroprevalence of leptospirosis in unowned dogs were conducted. The time series analysis showed that human leptospirosis is endemic in Brazil, with a heterogeneous distribution among the Brazilian regions and most cases occurring at the raining season. Moreover, a robust forecast model for leptospirosis human cases in Brazil was built, exhibiting seasonality and successfully predicting the cases for the last six months of 2019. For the systematic review, the results pointed for a lack of well-developed cross-sectional studies among the recovered articles, preventing a meta-analysis to estimate the prevalence or seroprevalence of leptospirosis in street and sheltered dogs. On the other hand, the presence of Leptospira spp. or antibodies anti-Leptospira spp. in stray and sheltered dogs worldwide was fully observed. Finally, the preliminary results of the study on the prevalence of leptospirosis in dogs from a shelter revealed the absence of infection and a low seroprevalence of the disease (2.12%, 95%CI: 0.86 to 4.33) among the sampled dogs. In general, our results showed that leptospirosis as an important public and animal health issue in Brazil and worldwide, and a lack of robust epidemiological information on the disease among unowned dogs; but they also pointed to a controlled disease situation in a dog shelter in the municipality of Lavras, Minas Gerais state, Brazil.