And the fact of the matter is Vinson wasn't just any traveler. She, like fellow Ebola sufferer and Dallas health care worker Nina Pham, had "extensive contact" with Duncan between September 28 and 30 when he had "extensive production of body fluids" such as vomit and diarrhea, Frieden said.

In other words, Vinson had special reason to be careful about her interactions with others.