"Nobody ever cleans a desktop until they start sticking to it, from what we've found". "A lot of people eat and slop on their desks all the time so it basically turns into a bacteria cafeteria during the day, and that's one of the reasons you get a lot on your desktops."
“The superhighways for bacteria are hands and the surfaces we touch”
People regularly touch their faces whilst working on their computers. A quick look around the office will usually confirm this. This habit facilitates the transfer of bacteria from surfaces to parts of the body.
"Viruses are transferred by our hands, especially cold viruses"
http://www.cnn.com/2004/HEALTH/12/13/cold.flu.desk/index.html
Some computer keyboards harbour more harmful bacteria than a toilet seat, research has suggested.
Consumer group Which? said tests at its London offices found equipment carrying bugs that could cause food poisoning.
Out of 33 keyboards swabbed, four were regarded as a potential health hazard and one harboured five times more germs than one of the office's toilet seats.
Microbiologist Dr Peter Wilson said a keyboard was often "a reflection of what is in your nose and in your gut".
During the Which? tests in January this year, a microbiologist deemed one of the office's keyboards to be so dirty he ordered it to be removed, quarantined and cleaned.
It had 150 times the recommended limit for bacteria - five times as filthy as a lavatory seat tested at the same time, the research found.
http://news.bbc.co.uk/go/pr/fr/-/1/hi/uk/7377002.stm
SWINE FLU PREVENTION ADVICE