Raiva dos herbívoros na Região da Floresta dos Guarás, Maranhão: interações entre fatores ambientais, socioculturais e a dinâmica de Desmodus rotundus

Abstract

Rabies in herbivores represents a significant sanitary and economic problem for Brazilian livestock production, with the vampire bat Desmodus rotundus acting as the main vector of the rabies virus in rural areas. This thesis analyzed the spatial dynamics of animal rabies in the state of Maranhão and the patterns of livestock attacks caused by vampire bats in the Floresta dos Guarás region, integrating ecological, environmental, and sociocultural factors across different spatial scales. Official data on rabies outbreaks in cattle and equines from 2005 to 2024, records from 475 nocturnal capture expeditions of D. rotundus (of which 384 were successful, corresponding to an 80.84% success rate), and 170 structured interviews with rural producers were analyzed. The analyses included exploratory spatial statistics, Kernel density estimation, the Bivariate Local Moran’s Index (BiLISA), Poisson regression, and Random Forest (RF) predictive modeling, complemented by nonparametric statistical tests. At the state level, rabies showed a heterogeneous spatial distribution, with higher incidence in the northern microregions of Maranhão, positively associated with the loss of surface water (p < 0.05), whereas forest fire frequency and deforestation were negatively associated with rabies incidence (p < 0.05). In the Guarás region, the RF model for predicting vampire bat attacks showed high predictive performance (AUC > 0.80), with livestock density emerging as the most important variable (MDA = 39.86; MDG = 35.99), followed by distance to water bodies. Livestock attacks were predominantly concentrated in areas with lower slope, higher herd density, and less fragmented forest landscapes. A total of 1,174 vampire bats were captured and treated, with a predominance of females (61.0%); however, these interventions were not associated with a proportional reduction in livestock attacks. Interviews revealed that 67.1% of producers reported a history of livestock attacks, with cattle being the most frequently affected species (64.6%), in addition to a low level of knowledge regarding bat ecology and a greater predisposition to roost destruction among producers with lower educational levels and prior attack experience. Overall, the results indicate that rabies occurrence and vampire bat attacks respond differently to anthropogenic landscape changes, although they share common environmental determinants, highlighting the need for integrated strategies that combine epidemiological surveillance, sanitary education, environmental management, and wildlife conservation. As outcomes of this research, a scientific article addressing the effects of deforestation, wildfires, and drought on animal rabies incidence in Maranhão and a technical manual for the ethical management and control of vampire bats, aligned with the guidelines of the National Program for the Control of Herbivore Rabies, were produced