To complicate things even more, Do you only get symptoms while your logged on? and does that in turn mean that the more you log the more your character experiences the negativve effects of being injured?
Third, maybe when you have severe coughing fits there should be a little pile of vomit that you emit, and players walking by it or touching it in any way get sick, maybe an easier to track who's left what nasties where. That could be overbearingly disgusting, but funny at the same time.
So ya just a few random thoughts brought up from recent happenings. sorry I have yet to have my coffee yet this morning so it's a bit random.