I hope they can figure out when it becomes contagious. I was around a man who had just started to feel sick that day, in October 2009 (he came onto our property with a portable mill to mill some logs, DH worked with him that day). He was coughing just a tad as I walked him down to the back of the property.
Within 24 hours I felt the onslaught of the flu like a freight train.
Self Quarantine. Post a Notice on the door-pretend you are sick? Might keep the unknown and uninvited away?