They've traced the origin of the virus back to central Africa, back in the days the Polio vaccine was being researched on Chimps (illegally) in that area. Take from that what you will.
It could have just jumped species around 60 or more years ago from Chimp to human, since some of the tribes eat "bush meat" which is Chimpanzee and they don't always cook it thoroughly enough to kill a virus. They eat the brains, too, and that's an excellent way for a virus (SIV and HIV pass through the blood-brain barrier and dwell in the tissue) to be transmitted to humans.
But the point of this thread is that people are dying from a virus in the millions and one of the richest nations in the world is not sufficiently caring for some of its own citizens.
G.W. pledged to send billions to Africa to buy medicine (then the Republican congress hacked it to death) anyway, why the hell are people dying from lack of meds in South Carolina???