And you shouldn't either, once you read the story, which refers to the ER staff, but doesn't actually go into any detail about how many left or where they went. It does say that a "case management" team went to handle matters. I suspect that most of the staff have a better idea of what the risks are than your average reporter. Quite probably some left in haste, but I'd guess that most didn't. I admit that panic can be contagious, but I'd still bet most people stayed around, though maybe not in the ER. ("We should sanitize the place." "Great idea! You go first.")
Back in the villages they have been hiding people with Ebola. There's a long tradition of kidnapping people to use body parts in magic. It didn't happen often--there was much more fear of it than actual instances--but it happened often enough to keep the fear alive. So if people in scary garments take your cousin away and you never see her again--what do you suspect, and what do you warn people about? It doesn't matter if the people telling you about the risks are important people--a Senator was caught trying to cement his power with some human sacrifice magic a few decades back.
So nobody really knows how many are sick.