What if the next infected person decides to ride the subway for several days and go to a ball game, a movie, and so on. None of these people will have any protective gear that come into contact with this person. What if this infected person does vomit all over a bunch of people in a subway car or the movie theater. People will panic and run in every direction spreading this disease everywhere. We could easily have hundreds of people needing to be isolated regardless of how many actually contract the disease.