A new analysis of air traffic patterns by researchers shows that there's up to an 18 percent chance the Ebola virus will reach the U.S. by late September. Lead researcher Alessandro Vespignani of Northeastern University told NPR, "What is happening in West Africa is going to get here. We can't escape that at this point."

Before you panic, know that if Ebola does hit the states, it would likely only be in "very small clusters of cases, between one and three." That's still not zero. In other western countries, the risk is even higher; according to the study, published Tuesday in PLOS Currents: Outbreaks, there's a 25 to 28 percent chance Ebola will hit the U.K. by the end of the month.

These numbers are based on "the number of airline passengers coming from West Africa to various countries." Since it's impossible to block all airline traffic coming from the crisis region, eventually, infected passengers will make their way to other countries.

Three Americans have already contracted Ebola in West Africa, but they are all on the path to recovery.

[Photo via AP]