Skip to content
My WebMD Sign In, Sign Up

Cold, Flu, & Cough Health Center

Font Size

Germ Warfare: Common Cold & Flu Culprits

It's cold and flu season again, and the most innocent of objects could be your greatest health threat.

Shake Down

With between 20% and 50% of Americans coming down with the flu every year, shaking hands is one of the main culprits. It's simple: You cover your mouth, sneeze, forget to wash your flu-virus-laden hands, and then politely press palms with your real estate agent. "Flu spreads one of two ways, primarily by air or by contact," Gerba says. "Shaking hands is at the top of the list."

Lip Service

Kissing can help prevent cavities; it stimulates the flow of saliva, which naturally cleanses away cavity-causing food particles. But it can also make you sick. When you lock lips, you exchange saliva, and if you have the flu, your saliva is teeming with the influenza virus -- something for which mistletoe is no match.

Travel Bug

Forget stale air and reusable blankets: It's the person in 27B you should be worried about. While filtration systems on airplanes are supposed to prevent a cold or flu virus from circulating in the air, there's nothing to stop it from passenger-hopping. And with travelers topping more than 4.6 million during last year's holiday season, that's a lot of to-and-fro for the flu. "If someone is sick on a plane, the people sitting next to him, behind him, and in front of him are at risk for getting sick," says Zachary Rubin, MD, an assistant professor of epidemiology at Santa Monica-UCLA Medical Center. "The rule of thumb is everyone within three feet is at risk."

Nasty Neckties

An ugly tie just took on a whole new meaning. Researchers at the New York Hospital Medical Center of Queens found that almost half of the neckties worn by doctors were swarming with disease-causing germs. In fact, doctors' ties were found to be eight times as likely to harbor germs as those of security personnel, who apparently have an undeserved reputation for being slovenly. Why the germ factory on neckties? It probably stems from the inordinate amount of sneezing a doctor's professional attire must face on a daily basis. And since we know that sneezes are laden with flu and cold viruses, maybe we're all better off seeing doctors who adhere to "casual Fridays."

Close Encounters

Almost 2 billion people ride New York City's 4,000 subway cars every year. So, short of buying a hermetically sealed hazmat suit, fuggedaboudit: If you're a straphanger, you're on track for a close encounter with germs that cause cold and flu. And that risk goes beyond the Big Apple: Whether it's a trolley in San Francisco or a steamboat on the Mississippi, flu and cold viruses find a way to stow away -- no matter where the road trip.

Touch & Go

Germs can live on surfaces like doorknobs for more than two hours. And with working adults touching as many as 30 objects an hour, that means washing your hands frequently -- after using the bathroom, eating, working or playing outdoors, playing with pets, or coughing, sneezing, or blowing your nose -- to keep them clean. It takes warm water, soap, and 15 to 20 seconds of scrubbing to rid them of cold and flu germs. P.S.: While 95% of people say they wash their hands after using a public restroom, only 67% actually do -- yikes! Of that group, just 33% use soap, and only 16% wash their hands long enough to make it count.


Published January 2007.

Reviewed on December 18, 2006

Today on WebMD

hot toddy
15 tips to help you feel better.
man sneezing into elbow
Do echinacea and vitamin C really help a cold?
teen girl coughing
Get a good night’s rest with these remedies.
elder berry
Eat these to fight colds, flu, and more.
Natural Cold Flu Remedies Slideshow
blowing nose
Allergy And Sinus Symptom Evaluator
Health Check
Boy holding ear
woman receiving vaccine shot
Bacterial or Viral Infection
How To Calm Your Cough
Sore Throat

WebMD Special Sections