Here's a continental view of Ebola outbreaks dated April 2014, needs updates for current conditions.
The thing that strikes one immediately is the vast distance between outbreaks. There appear to be local linear patterns but not continental ones, hightlighting the difficulty in identifying Ebola vectors and resevoirs. The leapfrogging is worrisome.
Things to consider, distances, topography and wildlife, migratory and avian territorial patterns and their parasites maybe.
link
http://www.zerohedge.com/sites/default/files/images/user5/imageroot/2014/03/ebola%20outbreaks.jpg