Ebola kills so fast it doesn't have time to mutate, and containing the spread of even a large scale outbreak would be fairly trivial due to the very limited transmission methodology and, again, the extremely rapid fatality rate. Most victims are only in a state where the're both infectious and mobile for a few days, maybe a week at the outside. Despite the nastiness of the disease, Ebola's one of the least dangerous bugs on a large scale. Naturally, if it turned up in a densely packed area where there was little central control to intitute a quarantine, or in a a relatively lightly populated area with little quarantine efforts and modern transport, it can spread further. Even then, absolute worst case is losing a city, and that would require so many things to go right it couldn't be done deliberately, only by an immense chain of unbelievable incompetence an absurd coincidences. Compared to smallpox, influenza, or resistant forms of bubonic plague, all of which have virtually wiped out continents over the centuries, Ebola's not even a factor.
Unrelated:
I may be losing my job tomorrow, because they made the unbelievably stupid decision to replace my position with (ostensibly, it's all but confirmed that they're actually just giving it to scabs in other facilities) an automated process that is wrong about 45% of the time. Due to asthma (made vastly worse by the filthy conditions there), most of the other jobs there are beyond my physical capability, and it is uncertain as yet how well they're going to accommodate such problems. Making things worse is that my condition isn't severe enough outside of those conditions to make it likely that I'll recieve benefits beyond unemployment while I try to find a (most likely lower paying and fewer hours) replacement job.