“I realize you’re joking. But there are noted behavioral abnormalities in ebola patients. I wonder if the urge to be social is one way it spreads itself. Hmmm”
I got that from the thread on the nurse that jumped on the airliner. Others also said similar comments to yours, that maybe it triggers an instinct to want to be in crowds. I think the word is gregarious, like herd animals when they feel threatened.
Maybe the victims are worried that they are going to die within a week and want one final fling on the town/see family, etc.