Outbreaks of lethal viruses in humans including Ebola, Nipah, and SARS have directed global attention towards bats as among the most important and least understood groups of viral reservoirs. As with other zoonotic wildlife pathogens, the economic and health impacts of bat viruses are traditionally mitigated by reactive vaccination and prophylaxis of humans and domestic animals. However, these strategies cannot alter transmission within bats and must be applied indefinitely, at escalating cost and ever-present risk. Controlling pathogens within the bat reservoir would represent a shift towards prevention, but policies implemented without scientific foundation risk unexpected and detrimental outcomes. Vampire bat rabies is a damaging zoonosis that governments across Latin America have sought to contain for over 30 years by culling bats. Our previous work identified potential pitfalls in this strategy, but no empirical studies have quantified whether culling actually reduces the burden of human or livestock rabies. We applied Bayesian state space models to data from an intensive, multi-year bat cull in southern Peru to test whether culling altered bat population dynamics or diminished rabies spillover to livestock. Next, we assessed the potential utility of an alternative ecological lever – self-spreading vaccines – to manage rabies in bats.
Results/Conclusions
Our analysis revealed that culls drastically reduced vampire bat populations over a vast geographic area, providing short-term relief to bat-livestock conflicts. However, culls had negligible effects on the burden of vampire bat rabies in livestock, with long-term disease dynamics instead driven by spatiotemporal processes unrelated to culling. The apparent failure of culls to control rabies implies a perpetually-incurred cost with limited benefits for rabies prevention. In contrast, field experiments and modelling efforts suggested that vaccines that spread autonomously among bats by could dramatically reduce the size, probability, and duration of rabies outbreaks, and we identify several promising recombinant viral vaccine platforms. Strategic vaccination of bats may significantly reduce the burden of rabies in Latin America where decades of culling and livestock immunization have been unable to do so.