Doorknobs distributing viruses

A single doorknob can spread viruses to 40 to 60 percent of people in an office building in just a few hours.

Think about that for a minute. One doorknob can spread viruses – such as norovirus, an infection responsible for a lot of nasty symptoms – to more than half of the people in an entire workplace in just two to four hours.

A new study found the viruses from the doorknob are also spread to a majority of most commonly touched objects within office buildings, hotels and health care facilities.

Researchers placed a surrogate for norovirus on one or two commonly touched surfaces (a doorknob or table top at the beginning of the day in office buildings, a conference room and a health care facility.

After various periods of time (two to eight hours), they took samples from numerous surfaces within the buildings: light switches, bed rails, table tops, counter tops, push buttons, coffee pots handles, sink tap handles, doorknobs, phones and computer equipment.

“Within two to four hours between 40 to 60 percent of the fomites sampled were contaminated with the virus,” said Charles Gerba of the University of Arizona, Tucson, who presented the study at an annual infectious disease meeting.

“What we really learned was the hand is quicker than the sneeze in the spread of disease,” Gerba said during his presentation, according to a Washington Post article.

Viruses, such as norovirus and the flu, can cause illness when people have the viruses on their hands and then touch their faces – something people do once every three to four minutes, according to Gerba.

There is a solution, though. Hand washing, disinfecting wipes and hand sanitizer use significantly reduces the spread of viruses, Gerba said.

“Using disinfecting wipes containing quaternary ammonium compounds (QUATS) registered by EPA as effective against viruses like norovirus and flu, along with hand hygiene, reduced virus spread by 80 to 99 percent,” he said.

Anybody else need some hand sanitizer?

Marissa Harshman

Marissa Harshman

I'm the health reporter for The Columbian newspaper in Vancouver, Wash. I started at The Columbian -- my hometown newspaper -- in September 2009. Reach me at or 360-735-4546.

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