Modeling Elk-to-livestock Transmission Risk to Predict Hotspots of Brucellosis Spillover

Résumé du livre

Wildlife reservoirs of infectious disease are a major source of human-wildlife conflict because of the risk of potential spillover associated with commingling of wildlife and livestock. In the Greater Yellowstone Ecosystem, the presence of brucellosis (Brucellaabortus) in free-ranging elk (Cervuscanadensis) populationsis of significant management concern because of the risk of disease transmission from elk to livestock. We identified how spillover risk changes through space and time by developing resource selection functions using telemetry data from 223 female elk to predict the relative probability of female elk occurrence daily duringthe transmission risk period.We combined these spatiotemporal predictions with elk seroprevalence, demography,and transmission timing data to identify when and where abortions (the primary transmission route of brucellosis)were most likely to occur. Additionally, we integrated our predictions of transmission risk with spatio temporal data on areas of potentia llivestock use to estimate the daily risk to livestock. We predicted that approximately half of the transmission risk occurred on areas where livestock may be present(i.e., private property or grazing allotments). Of the transmission risk that occurred in livestock areas,98% of it was on private ranchlands as opposed to state or federal grazing allotments. Disease prevalence, transmissiontiming, host abundance, and host distribution were all important factors in determining the potential for spillover risk. Our fine-resolution (250-m spatial,1-day temporal), large-scale (17,732km2) predictions of potential elk-to-livestock transmission risk provide wildlife and livestock managers with a useful tool to identify higher risk areas in space and time and proactively focus actions in the seare as to separate elk and livestock to reduce spillover risk.