Just the thing to do with a contagious disease, get on an international flight.
Especially hot epidemics burn themselves out quickly so they don't spread, so goes the theory. However, if the carriers are travelling anyway, such as during WW I or during the Crusades, flu or Black Death can spread all over. Will the public cry out if anyone with symptoms is booted from an international or even a commuter flight? Who knows what the famous epidemiologists on the Ninth Circuit Court will decide.