1. WorldPop, Department of Geography and Environment, University of Southampton, Southampton, UK
2. Southampton Statistical Sciences Research Institute, University of Southampton, Southampton, UK
3. Flowminder Foundation, Stockholm, Sweden
4. Center for Infectious Disease Dynamics, The Pennsylvania State University, State College, PA, USA
5. Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, USA
6. Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA