The type of Ebola causing the outbreak — called Zaire — is the deadliest strain. Until this year, it had been seen only in Central Africa, about 2,500 miles away. That's about the distance between Boston and San Francisco.
So how did it spread across this giant swath of land without anybody noticing?
To answer that, ecologist says we need to look at the history of Ebola Zaire.
Back in the summer of 1976, a young Zairian doctor named Ngoy Mushola traveled to a rural village in what is today the Democratic Republic of the Congo.
Nearly 300 people died in that first outbreak. Then about a year later, poof! Ebola Zaire vanished.
In 1994, the virus reappeared and started hopscotching around the rain forest of Central Africa. "It goes away for a while and comes back," Walsh says. "This year it's here, next year it's 30 kilometers down the road."
Over the past 38 years, Ebola Zaire has proved to be the deadliest of the five Ebola strains. It has the highest mortality rate and has caused the most outbreaks. But the virus always stayed in Central Africa. Continue Reading...