TUESDAY, June 11, 2013 (HealthDay News) -- The next time you reach out to shake someone's hand, consider this finding: A recent study of hand-washing habits found only 5 percent of people who used the restroom scrubbed long enough to kill germs that can cause infections.
Thirty-three percent didn't use soap, and 10 percent didn't wash their hands at all, according to the study, based on Michigan State University researchers' observations of more than 3,700 people in a college town's public restrooms.
"These findings were surprising to us because past research suggested that proper hand washing is occurring at a much higher rate," lead investigator Carl Borchgrevink, an associate professor of hospitality business, said in a university news release.
Among the other findings:
- Men were less likely than women to clean their hands. Fifteen percent of men and 7 percent of women didn't wash their hands at all. When they did wash their hands, only 50 percent of men used soap, compared with 78 percent of women.
- People were less likely to wash their hands if the sink was dirty.
- People were more likely to wash their hands earlier in the day. This may be because when people are out at night for a meal or drinks, they are relaxed and hand washing becomes less important, the researchers suggested.
- People were more likely to wash their hands if they saw a sign encouraging them to do so.
Hand washing is the single most effective thing a person can do to reduce the spread of infectious diseases, according to the U.S. Centers for Disease Control and Prevention. Failure to sufficiently wash hands contributes to nearly 50 percent of all foodborne illness outbreaks, the agency says.
It takes 15 to 20 seconds of vigorous hand washing with soap and water to effectively kill germs, the CDC says, but people only wash their hands for an average of about 6 seconds, according to the study, published recently in the Journal of Environmental Health.
The findings have implications for consumers and restaurant and hotel owners, says Borchgrevink.
"Imagine you're a business owner and people come to your establishment and get foodborne illness through the fecal-oral route -- because people didn't wash their hands -- and then your reputation is on the line," he said. "You could lose your business."
The U.S. Centers for Disease Control and Prevention has more about hand washing.