I’d worry more about those who were exposed but haven’t displayed symptoms.
“The incubation period, that is, the time interval from infection with the virus to onset of symptoms, is 2 to 21 days.”
http://www.who.int/mediacentre/factsheets/fs103/en/
I have read multiple references in the past indicating that transmission through casual contact (i.e. just being in the area) is not possible until symptoms are manifest. Prior to that, contact with bodily fluids likely would be required. The average incubation period is 2-4 days.