The outbreak of Ebola in West Africa has public health officials very alarmed. It is the world's largest and deadliest outbreak yet, and has infected about 3,600 people and killed at least 1,841 in three countries, according to the World Health Organization's tally. But there's a good chance the virus will spread outside of Guinea, Sierra Leone, and Liberia.
How good a chance? A study this week puts the odds that Ebola will arrive in the U.S. in late September as high as 18 percent. The study, published in PLOS Currents: Outbreaks, analyzed patterns of daily flights from the infected countries, keeping in mind how hard it will be to keep an infected person from boarding commercial airliners:
The 18 percent figure is the high end of the study's range for the U.S., but "what is happening in West Africa is going to get here," senior author Alessandro Vespignani tells NPR. "We can't escape that at this point." Vespignani isn't predicting a massive outbreak like in Africa, but "very small clusters of cases, between one and three." The odds of an Ebola panic are probably higher.
Still, the U.S. is fortunate in comparison. The chances of an Ebola carrier arriving elsewhere in Africa is much higher, and Britain's odds are as high as 25-28 percent by late September, the study found.