Just 5% of people wash their hands long enough to destroy infectious germs after using the bathroom, researchers from Michigan State University reported in the Journal of Environmental Health.

Even more worrying, the authors added that 10% skipped washing their hands altogether, while 33% used no soap at all. It appears that men are less inclined to wash their hands after going to the toilet than women.

Lead researcher, Prof. Carl Borchgrevink, and team gathered and analyzed data on 3,749 people in public restrooms.

Borchgrevink said:

“These findings were surprising to us because past research suggested that proper hand washing is occurring at a much higher rate.”

The CDC (Centers for Disease Control and Prevention) says that the one thing people can do to lower the spread of infectious diseases is to maintain good hand hygiene. US public health authorities say that nearly 50% of foodborne illness outbreaks in the country are due to bad hand hygiene, which not only refers to people who do not wash their hands, but also to those who do not do it properly.

In order to kill off the germs, all it takes are 15 to 20 seconds of vigorous hand washing with soap and water, says the CDC. However, according to the study, most people spend around six seconds during each hand washing session.

Borchgrevink and team trained twelve college students on how to gather data, and sent them out to watch how many people wash their hands, and how well they wash them in the restrooms of restaurants, bars and other public places. They tried to be as unobtrusive as they could.

Borchgrevink says this is one of the few studies on hand hygiene that takes into account duration and soap usage.

The researchers found that:
  • 15% of men and 7% of women did not wash their hands
  • Only 50% of the men and 78% of the women who did wash their hands used soap
  • Dirty sinks were more likely to be avoided altogether – no handwashing was more commonly observed in bathrooms with dirty sinks
  • Good hand hygiene was more prevalent earlier in the day. The authors believe that during the evenings/nighttimes, when people are out eating and drinking, they are in a more relaxed mode and hand hygiene becomes less of a priority
  • Signs encouraging people to wash their hands seem to help. Hand washing was more prevalent in bathrooms with signs
Borchgrevink said their study has implications for both consumers and people who operate hotels and restaurants. Before becoming a researcher, Borchgrevink worked as a restaurant manager and also as a chef.

Borchgrevink said:

“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. You could lose your business.”

Good hand hygiene not only protects the general public from the spread of infections, it is also a vital part of keeping hospital acquired infections down to a minimum. The Clean Your Hands Campaign played a major role in reducing some healthcare associated infections in English and Welsh hospitals.

Written by Christian Nordqvist