If you're like most Americans, you put in long hours at work--and you have less time off than anyone in the developed world (U.S. workers average 13 vacation days a year, while the Japanese have 25, the Canadians take 26, and the French enjoy 37). Is all that time at the office making you sick? It could be, according to a study conducted by the University of Arizona.

The study, funded by Clorox, found that the average office desk contains 20,961 germs per square inch—400 times more bacteria than the average toilet seat. The worst desktop offenders? Phones, computer keyboards, and mice, all of which can serve as a petri dish for bacteria and the viruses that cause colds and flu.

6 Ways to Win the War Against Germs

So how can workers stay healthy this season? According to the Centers for Disease Control (CDC), there are several preventative steps you can take to reduce your workplace risk.

  • Wipe down work areas. Workers should clean shared spaces, such as telephones, computer keyboards, steering wheels, and office equipment, every day during flu season. Use disinfectant wipes, and to prevent the accumulation of bacteria, avoid eating at your desk.

  • Make handwashing a habit. This may be the most important thing you can do to stay well. Experts recommend that you wash your hands with soap and warm water for at least 20 seconds; if you can't get to a sink, use an alcohol-based hand sanitizer.

  • Be hands-off. If you come into contact with a contaminated surface and then touch your face, bacteria can spread quickly. So avoid touching your face, especially your eyes, nose, and mouth.

  • Eat, drink, and be healthy. Try to eat a balanced diet with plenty of fruits and vegetables, and don't forget to drink eight glasses of water a day. Instead of getting snacks from the office vending machine, keep a stash of fruit, yogurt, juice, or other nutritious snacks.

  • Cover your mouth. Always use a tissue or handkerchief when coughing or sneezing to keep germs from spreading around the workplace. To prevent getting sick yourself, encourage your coworkers to do the same.

  • Stay home sweet home. If your cold symptoms indicate that you're contagious a fever of more than 100.5, a productive cough, pain when coughing or speaking, or the inability to breathe through your nose it's best to take a sick day. If you have the flu, which can be highly contagious, it's best for everyone if you call in sick.