Some computer simulations focus on the risk of Ebola spreading to other countries. Alessandro Vespignani, at Northeastern University, creates those models, using information about air travel and other kinds of transportation.
His work suggests that Ebola could find its way to African nations like Ghana, Gambia, and Senegal. “There is a tangible risk of spreading in the region to other countries,” says Vespignani, “probably in the ballpark of 20 to 30 percent in the next few weeks.”
He notes poor countries might have trouble keeping an imported case from spreading. And the larger this outbreak gets, the harder it will be to contain.