Well, here are some facts gleaned from a few studies:
• In just 4 hours, one sick worker can contaminate 50% of surfaces in a typical office
• After 8 hours, one sick worker can contaminate 70%+ of surfaces
• Non-sick workers have a 40-90% chance of getting infected after spending one day with a sick worker
• A sneeze or cough can hurl virus 6 feet away from the mouth
• A sick person literally "emanates" virus up to 6 feet away... even if they are NOT sneezing or coughing.
• Some sick individuals are super-carriers spreading the virus around them 32 times more than others
The good news is that viruses can not survive on surfaces for long... They usually die off within a day (type of surface, temperature, and humidity affecting duration).
Flu Virus Can Travel Up to 6 Feet, Infect Up to 90 Percent of People Just from Contaminated Surfaces. Medical Daily News 2/1/13
Exposure to Influenza Virus Aerosols During Routine Patient Care. J Infect Dis. 2013 Jan 30. [Epub ahead of print]
InfluenzaVirus: Here, There, Especially Air? J Infect Dis. (2013) doi: 10.1093/infdis/jis774
Germs Spread Fast at Work, Study Finds. AHSC 1/30/13