Quantifying Spillover Risk with an Integrated Bat-Rabies Dynamic Modeling Framework

Abstract

Vampire bat-transmitted rabies has recently become the leading cause of rabies mortality in both humans and livestock in Latin America. Evaluating risk of transmission from bats to other animal species has thus become a priority in the region. An integrated bat-rabies dynamic modeling framework quantifying spillover risk to cattle farms was developed. The model is spatially explicit and is calibrated to the state of São Paulo, using real roost and farm locations. Roost and farm characteristics, as well as environmental data through an ecological niche model, are used to modulate rabies transmission. Interventions aimed at reducing risk in roosts (such as bat culling or vaccination) and in farms (cattle vaccination) were considered as control strategies. Both interventions significantly reduce the number of outbreaks in farms and disease spread (based on distance from source), with control in roosts being a significantly better intervention. High-risk areas were also identified, which can support ongoing programs, leading to more effective control interventions.

Incorporating environmental heterogeneity and observation effort to predict host distribution and viral spillover from a bat reservoir

“…It is conceivable that longer distance connectivity—occasionally reported—may be more common than previously recognized [ 28 , 45 ]. Regardless, both clustering and long-distance movement have important implications for rabies spatial spread which are not currently captured in existing epidemiological models [ 21 ]. More generally, our results illustrate the value of accessing the shape of the Matérn correlation range to understand and generate hypotheses about animal ecology and social behaviour.…”

“…Improving the implementation of culls or the spatial distribution of human and livestock vaccines requires knowledge of the spatial distribution of vampire bat populations and how this distribution determines spillover risk. However, with rare exceptions, neither the location nor the number of vampire bat roosts are known with certainty [ 21 ].…”