Essessdeedee, I believe that you have just hit the nail on the head, we could have a destination based scale of sickness - LAGOS (sniffle and I'm on the phone) - NARITA (The Plague won't stop me!)
Caribbean Boy makes reference to "Social Sickness", I am led to believe that BA actually sends scouts to major social events looking for those crew who at certain times of the year find it "Socially" unacceptable to be at work.