We are in a world of trouble. The hospital had patient zero in the ER for hours in the ER waiting for treatment, next to other patients. The nurses who treated him went on to treat other patients.
All one needs to do is look at the situation and draw logical conclusions based on the evidence. We were screwed the moment that guy tested positive. Everyone he came into contact with has spread ebola since. And of them, extrapolate from there.
The thing is...you would have expected some of those ER patient and treatment teams to show symptoms long before now. I think we are still inside the 21 days but most people show signs and symptoms in less than 10 days.
It sounds to me, until we know more, that he most likely infected these people within the few days before his death or immediately post mortem. Which might mean that you just can’t be in the room with a crashing ebola patient unless you are in full spacesuit or in a Level 4 facility.