Doorknob Germs Can Infect Half The Office In Hours

Washing your hands helps to keep you and your officemates healthy.

Karin Heineman, ISTV Executive Producer

(Inside Science TV) -- Viruses: they're too tiny for us to see, yet they're lurking everywhere. And guess what? They spread really fast through an office environment.

"Most people don't realize they easily spread by your hands," said University of Arizona microbiologist Charles Gerba. Most people think that viruses spread by inhaling sick people's coughs or sneezes, but "it's really when those droplets settle out and you touch that surface" that tiny viruses spread, he said. People unknowingly bring their virus-covered fingers to their noses, mouths, or eyes, kicking off infection.

It doesn't take much for a virus to start spreading like wildfire. In his research, Gerba has found that germs on just one doorknob can help spread a virus, like the noroviruses that cause stomach flu, throughout an office building in just a few hours!

"We found out that within four hours, over half the commonly touched surfaces had the virus on it, and half the people in the office building had the virus on their hands," said Gerba.

Researchers purposely put samples of a harmless virus on one or two office surfaces like doorknobs and tabletops, and then a few hours later, they tested different objects in the building, like cell phones, computers, and desks. They found that the virus had traveled -- and had been picked up by 40 to 60 percent of people in the building.

The ground zero for the viruses' spread? The break room. "The first object contaminated was the coffee pot handle," Gerba said, which makes sense, given the object's popularity. "What's the first thing you do in the morning? You go get a cup of coffee."

Surprisingly, the office restroom was the least contaminated place in the building, within the first two hours of the virus entering the office. Viruses didn’t show up in the restroom until later in the day.

Fortunately, there’s an easy solution to the infectious germ problem: washing your hands.

Researchers stress that hand washing along with disinfecting surfaces with wipes and gels can reduce spreading a virus by 80 to 90 percent.

"I think the number one thing is what your mother always told you: wash your hands, and use a hand sanitizer when you can," said Gerba.

Get Inside The Science:

How Quickly Viruses Can Contaminate Buildings -- From Just A Single Doorknob

Charles Gerba, University of Arizona - Tucson