"Like the 10 Ebola crises he had handled before, in Uganda and Sudan and the Democratic Republic of Congo, this first substantial outbreak in West Africa seemed to be burning itself out after a few months and a few hundred infections.
“This is close to over,” Dr. Rollin told himself, a view common among the virus hunters. “That’s it for this outbreak.”
"Or so he thought. In fact, Dr. Rollin and other well-intentioned veterans of past Ebola campaigns had tragically underestimated this outbreak, overlooking clues that now seem apparent. Viewing the West Africa epidemic through the prism of nearly two dozen previous outbreaks across the continent, they failed to appreciate that the 2014 version would be unique in catastrophic ways..."
http://www.nytimes.com/2014/12/30/health/how-ebola-roared-back.html