Mucus Experiment IDs Cold Culprits

Oct. 29, 2008 -- The next time you reach into the refrigerator to grab a bite to eat, consider that you might also be grabbing some microscopic moochers -- cold viruses.

New research details how several surfaces in a home with a family member who already has a cold are likely to become contaminated with a cold virus, including refrigerator doors, remote controls and bathroom faucets.

The report, conducted by researchers from the University of Virginia Health System, was presented today at a joint meeting of the American Society for Microbiology and the Infectious Diseases Society of America in Washington, D.C.

The researchers asked participants with a cold to identify 10 surfaces they had touched in the last 24 hours. The scientists then tested the surfaces for detectable levels of rhinoviruses -- the family of viruses that cause the common cold.

Forty-two percent of the surfaces examined tested positive, including eight out of 14 refrigerator door handles and six out of 18 doorknobs.

"The refrigerator door handle was a big boy, needless to say," said Dr. J. Owen Hendley, one of the study's authors and a professor of pediatric infectious disease at University of Virginia Children's Hospital.

Other objects that showed a higher percentage of positive test results included bathroom faucets (eight out of 10 tested) and television remote controls (five out of 10 devices tested).

"The sites that were contaminated were not particularly surprising, because it's what people touch a lot," said Hendley.

What was more interesting to Hendley, he says, was a second experiment the group did to see how easily the virus particles transferred to people's fingertips.

The experiment required participants to touch dried spots of virus-filled mucus on three pre-exposed objects -- a light switch, a phone handset and a phone keypad. The mucus came from the participants, themselves -- before they recovered from their illnesses.

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"At the times that they had a cold, we said, 'Bring us in a half a teaspoon of snot,'" said Hendley, who froze the mucus until the participants were cold-free.