James M. Hassell 1,2,3($), Dishon M. Muloi 4,5,6, Kimberly L. VanderWaal 7, Melissa J Ward 4,8,9, Judy Bettridge 3,5, Nduhiu Gitahi 10, Tom Ouko 11, Titus Imboma 12, James Akoko 5, Maurice Karani 5, Patrick Muinde 5, Yukiko Nakamura 13, Lorren Alumasa 5, Erin Furmaga 14, Titus Kaitho 15, Fredrick Amanya 5, Allan Ogendo 5, Francesco Fava 5,16, Bryan A. Wee 4, Hang Phan 8, John Kiiru 11, Erastus Kang’ethe 10, Sam Kariuki 11, Timothy Robinson 17, Michael Begon 3, Mark E. J. Woolhouse 4,6(†), Eric M. Fèvre 3,5($,†) 1. Global Health Program, Smithsonian’s National Zoo and Conservation Biology Institute, Washington DC, US 2. Department of Epidemiology of Microbial Diseases, Yale School of Public Health, Connecticut, US 3. Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Neston, UK 4. Usher Institute, University of Edinburgh, Edinburgh, UK 5. International Livestock Research Institute, Nairobi, Kenya 6. Centre for Immunity, Infection and Evolution, University of Edinburgh, Edinburgh, UK 7. Department of Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota, St. Paul, US 8. Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK 9. Faculty of Medicine, University of Southampton, UK 10. University of Nairobi, Nairobi, Kenya 11. Kenya Medical Research Institute, Nairobi, Kenya 12. National Museums of Kenya, Nairobi, Kenya 13. Faculty of Veterinary Medicine, Hokkaido University, Japan 14. Department of Epidemiology, Columbia University, New York, US 15. Veterinary Services Department, Kenya Wildlife Service, Kenya 16. Department of Environmental Science and Policy, Università degli Studi di Milano, Milan, Italy 17. Food and Agriculture Organization of the United Nations, Rome, Italy (†) Contributed equally ($) Corresponding authors