New paper

Genetic forecasting of male-driven invasions of vampire bat rabies

Pathogen invasions across landscapes are increasingly common. From Zika and Ebola viruses in humans to White nose syndrome and Chytrid fungus in wildlife, these invasions have profound importance, but are notoriously difficult to predict. We recently showed that rabies virus – long considered an endemic virus of vampire bats – is actually an emerging virus, spreading across landscapes in highly predictable wavefronts and causing major losses to livestock and human health as the virus hits large, historically rabies-free bat populations. In our current paper, now out in PNAS, we use genetic data from vampire bats and rabies viruses to show that these invasions are likely driven by the dispersal of highly mobile male bats, not by more sedentary females. Moreover, genetic inferences of bat population structure provided a roadmap of how rabies could spread across the landscape through patterns of bat movement. This viral invasion forecast was validated by an independent dataset on livestock rabies mortality. If invasions continue at the rates and trajectories that we predict, vampire bat rabies could invade the Pacific coast of South America for the first time in recorded history as soon as 2020, which would have serious implications for livestock management practices across several countries. Now work is needed to assess the value of rabies control strategies that target male bats and to figure out what triggers invasions to new populations in the first place. Stay tuned.

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Vampire bat rabies free areas on the Pacific coast of Peru might soon become infected as bat populations become more connected, allowing rabies to spread. Photo: Streicker

Some nice press on this paper from:

NPR, NSF, University of Georgia & University of Glasgow

Streicker, D.G., Winternitz, J., Satterfield, D., Condori-Condori, R.E., Broos, A., Tello, C., Recuenco, S., Velasco-Villa, A., Altizer, S., Valderrama, W. Host-pathogen evolutionary signatures reveal dynamics and future invasions of vampire bat rabies (2016) Proceedings of the National Academy of Sciences of the USA DOI: 10.1073/pnas.1606587113

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New paper

Predicting advancing wavefronts of vampire bat rabies

Our latest set of analyses of data from the Ministry of Agriculture of Peru, together with our own questionnaire data, show that rabies continues to spread to the fringes of the vampire bat distribution in surprisingly constant and predictable wave-like expansions. The ability to forecast when and where rabies will appear next provides a tantalizing opportunity to develop interventions like vaccination of humans and livestock (or perhaps even the bats themselves) before rabies arrives to new regions. Hopefully this puts us one step closer to preventative rather than reactive management of vampire bat rabies.

Forecasting traveling waves of vampire bat rabies using simple landscape-adjusted linear regression models. Pie charts show the percentages of farms reporting bat bites (green), indicating the presence of vampire bats ahead of wavefronts. Blue and red points are the locations of rabies outbreaks in livestock.

The paper is published free online at Proceedings of the Royal Society B.

Julio and I also wrote a short piece in The Conversation describing the results of this analysis against a broader context of vampire bat rabies in Latin America.

Benavides, J., Valderrama, W., & Streicker, D.G. Spatial expansions and travelling waves of rabies in vampire bats (2016) Proceedings of the Royal Society B. DOI: 10.1098/rspb.2016.0328