[ghshephard]

" Health care workers are aware that they must wash their hands after having contact with a sick patient"

Take that a step up - Health Care workers must wash their hands after having contact with any patient and before touching any patient (and themselves for that matter).

http://www.cdc.gov/features/handwashing/

It takes 20 seconds, and is probably one of the most effective ways of preventing the spread of various infections/diseases.