Human movement and transmission dynamics early in Ebola outbreaks.

, EBOV) to the road and river networks surrounding each spillover location at the time of each spillover event. We measured the road and river networks by digitizing a series of paper maps that were printed during or near the year of each spillover. We show that the connectivity of spillover locations is consistently correlated to the severity of the outbreak over time and across all locations of EBOV spillover events.