I think a lot of it has to do with employees taking sick days when they aren't really sick. My employer is one of the many who have changed from the separate sick time and vacation time allotment to strictly earned time off.

When I'm around sick folks I've started using "Zicam" spray. They have a mint flavor that is palatable. Stay FAR, FAR away from the cherry flavored tablets.

Whether it's a placebo effect or not, I don't know. But it does seem to work.