title: Spatial spread of the West Africa Ebola epidemic.
abstract: Controlling Ebola outbreaks and planning an effective response to future emerging diseases are enhanced by understanding the role of geography in transmission. Here we show how epidemic expansion may be predicted by evaluating the relative probability of alternativeepidemic paths.We compared multiple candidate models to characterize the spatial network over which the 2013-2015 West Africa epidemic of Ebola virus spread and estimate the effects of geographical covariates on transmission during peak spread. The best model was a generalized gravity model where the probability of transmission between locations depended on distance, population density and international border closures between Guinea, Liberia and Sierra Leone and neighbouring countries. This model out-performed alternative models based on diffusive spread, the force of infection, mobility estimated from cell phone records and other hypothesized patterns of spread. These findings highlight the importance of integrated geography to epidemic expansion and may contribute to identifying both the most vulnerable unaffected areas and locations of maximum intervention value.
authors.affiliation: Odum School of Ecology, College of Veterinary Medicine , University of Georgia , Athens, GA 30602 , USA.
authors.forename: Andrew M
authors.identifier: 0000-0002-9031-6580
authors.initials: AM
authors.lastname: Kramer
authors.affiliation: Odum School of Ecology, College of Veterinary Medicine , University of Georgia , Athens, GA 30602 , USA.
authors.forename: J Tomlin
authors.initials: JT
authors.lastname: Pulliam
authors.affiliation: Odum School of Ecology, College of Veterinary Medicine , University of Georgia , Athens, GA 30602 , USA.
authors.forename: Laura W
authors.initials: LW
authors.lastname: Alexander
authors.affiliation: Odum School of Ecology, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA; Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA.
authors.forename: Andrew W
authors.identifier: 0000-0003-4080-7274
authors.initials: AW
authors.lastname: Park
authors.affiliation: Odum School of Ecology, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA; Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA.
authors.forename: Pejman
authors.initials: P
authors.lastname: Rohani
authors.affiliation: Odum School of Ecology, College of Veterinary Medicine , University of Georgia , Athens, GA 30602 , USA.
authors.forename: John M
authors.initials: JM
authors.lastname: Drake
keywords: Ebola; disease ecology; epidemiology; gravity model; network model