Leptospirosis in Rio Grande do Sul, Brazil: An Ecosystem Approach in the Animal-Human Interface

Abstract

BackgroundLeptospirosis is an epidemic-prone neglected disease that affects humans and animals, mostly in vulnerable populations. The One Health approach is a recommended strategy to identify drivers of the disease and plan for its prevention and control. In that context, the aim of this study was to analyze the distribution of human cases of leptospirosis in the State of Rio Grande do Sul, Brazil, and to explore possible drivers. Additionally, it sought to provide further evidence to support interventions and to identify hypotheses for new research at the human-animal-ecosystem interface.Methodology and findingsThe risk for human infection was described in relation to environmental, socioeconomic, and livestock variables. This ecological study used aggregated data by municipality (all 496). Data were extracted from secondary, publicly available sources. Thematic maps were constructed and univariate analysis performed for all variables. Negative binomial regression was used for multivariable statistical analysis of leptospirosis cases. An annual average of 428 human cases of leptospirosis was reported in the state from 2008 to 2012. The cumulative incidence in rural populations was eight times higher than in urban populations. Variables significantly associated with leptospirosis cases in the final model were: Parana/Paraiba ecoregion (RR: 2.25; CI95%: 2.03–2.49); Neossolo Litolítico soil (RR: 1.93; CI95%: 1.26–2.96); and, to a lesser extent, the production of tobacco (RR: 1.10; CI95%: 1.09–1.11) and rice (RR: 1.003; CI95%: 1.002–1.04).ConclusionUrban cases were concentrated in the capital and rural cases in a specific ecoregion. The major drivers identified in this study were related to environmental and production processes that are permanent features of the state. This study contributes to the basic knowledge on leptospirosis distribution and drivers in the state and encourages a comprehensive approach to address the disease in the animal-human-ecosystem interface.

Changes in leptospirosis etiology in animals and humans

“…The disease among the city residents was often associated with work in rural areas (suburban areas). The world literature also confirmed that the disease prevalence (2008)(2009)(2010)(2011)(2012) among the rural population of Brazil was 8 times higher than in urban areas [22]. At the same time, according to data from other countries, there is a trend to greater involvement of the urban population in the epidemic process [23], especially in adverse sanitary conditions -high water, contact with sewage, etc.…”

Leptospirose Humana: Uma Revisão Sobre a Doença E Os Fatores De Risco Associados À Zona Rural

“…De acordo com Schneider et al (2015) as populações rurais do Rio Grande do Sul, têm cerca de oito vezes maior risco de contrair leptospirose do que as populações urbanas, e os casos rurais estão principalmente em duas zonas, caracterizadas pela maior produção de tabaco (região central) e maior produção de arroz (região sul).…”

“…Um estudo realizado por Barcellos et al (2003) de casos notificados em Pelotas no Rio Grande do Sul, apresentou uma incidência de 16,3 casos por 100 mil habitantes, uma frequência superior à média nacional de 3,5 casos por 100 mil habitantes. Já Schneider et al (2015), também sobre casos notificados no Rio Grande do Sul, indicam uma incidência de 1,2 a 2,4 casos para cada 10 mil habitantes no município de Pelotas. A associação entre os trabalhadores da cultura do arroz e a leptospirose já foi descrita na literatura (CAMINITI et al, 2011;WHO, 2003).…”

“…De acordo com Costa et al (2015), a estimativa é que ocorra mais de 1 milhão de casos, que ocasionam mais de 58 mil mortes anualmente em todo o mundo. No estado do Rio Grande do Sul, mais de 400 casos são notificados anualmente, e estima-se que a real incidência da enfermidade seja mais elevada, especialmente em populações vulneráveis, onde a leptospirose é comumente diagnosticada e não declarada (SCHNEIDER et al, 2015).…”

PathogenicLeptospiraspecies are widely disseminated among small mammals in Atlantic Forest biome

“…Leptospirosis is an infectious disease that requires the study of human–animal–environment interface, based on the One health concept (Schneider et al., ). The pathogen is transmitted by exposure to contaminated water or urine from infected animals and may survive for days to months in freshwater, soil or mud (Rood, Goris, Pijnacker, Bakker, & Hartskeerl, ).…”