Hand-washing
Over 50%* of men do not wash their hands after using public restrooms. And of those that do, 80%* only rinse with water–no soap. This, surprisingly is no different for physicians, surgeons, and other healthcare professionals.
So, be careful who you shake hands with. And on a sidenote: does the same hold true for women?
* This data is by no means validated and is only a reflection of personal observation. No humans were harmed by the collection of this information.