From a posting to the Southern Arizona Network User Group list server:
Techs can avoid cold/flu viruses by washing hands
Quick Tip: Protect yourself from colds and flu:
"Techs are constantly touching other user’s keyboards, mice, and phones.
While this contact may seem harmless, I have always theorized that this interaction is the cause of many a support tech’s misery during the cold and flu season. If I’m right, not only do support techs pick up cold and/or flu bugs from end users´ peripherals, they also pass them to other keyboards and, therefore, to other people. I decided to investigate this, and here’s what I found."
http://articles.techrepublic.com.com/5100-10878_11-1033381.html
Discussion here:
Wash your hands - dslreports.com
http://www.dslreports.com/forum/r20944881-Wash-your-hands

