If we don't know the risk of something, especially if there is the possibility of serious illness, then we should stop doing it until we do know the risk. After

If we don't know the risk of something, especially if there is the possibility of serious illness, then we should stop doing it until we do know the risk. After all, it's not like convention centers are the only place where these things can be held. Imagine the headlines: "Disney tourists contract _______ because doctors did not know the risks of bringing dead bodies into convention center"