The Medical Minute: Hand-washing week 2007

The Medical Minute: Hand-washing week 2007

By John Messmer

It’s the season when colds spread like a rumor. Everywhere people go, coughing and sneezing abounds – spreading viruses into the air, surrounding them like a fog. It might be intimidating, but it’s really not a big threat. Except for the flu, respiratory infections do not come out of the air. People infect themselves; they literally “catch” a cold on their hands then put the virus into their respiratory tracts by touching their nose or eyes with contaminated hands.

As children, we were told to cover our mouths and noses when we cough and sneeze. This puts the viruses into our hands. Then we touch things: papers, doorknobs or other people’s hands. People transfer the viruses from these onto their hands. By touching noses or eyes they put the virus right where they can begin to cause infection. Our eyes are connected to our noses by a duct that drains tears so touching our eyes is a risk, too.

One way to avoid spreading infection to others is to cough or sneeze into the crux of the elbow, not the hand. That protects others, but to keep ourselves healthy, the best defense is to wash our hands.

To be effective, hands should be rubbed together vigorously with soap and warm water for at least 15 seconds. Brief rubbing or simply rinsing under running water is not enough. Contaminants are stuck in oils that adhere to the skin. Agitation by rubbing loosens the dead skin cells, and soap keeps the contaminants and germs suspended in the water so they rinse off. Soap does not kill the bacteria. In fact, germicidal soaps must remain in contact with the skin for several minutes to kill germs. Anti-bacterial soaps may give a false sense of security that could lead to less vigorous washing.

This technique also removes bacteria and viruses that can cause intestinal diseases. Cruise lines have made the news in recent times when large numbers of passengers have been sickened by infectious diarrhea and vomiting. Hepatitis A can be passed on by food handlers at home or in restaurants. Even bacteria from raw meat can be spread to others without proper hand washing.

Methicillin-resistant Staphylococcus aureus (MRSA) infections have made the news due to some deaths from the bacterium. While the existence of the bacteria is partly due to the widespread use of antibiotics, the organism is no more infectious than others people can have on their skin or in their noses. It’s just harder to eliminate once an infection is present. Preventing infection is the first line of defense against hard to treat infections. Medical personnel must be the leaders in this movement to reduce infections cleaning or sanitizing hands before and after each patient encounter.

If washing with soap is not an option, alcohol gel sanitizers are a good option. These alcohol-based sanitizers have been shown to kill pathologic bacteria in seconds. They can be kept close at hand to eliminate walking to a sink. With their introduction, non-medical people also may benefit. Research has shown significant reductions in illness in schools where hand sanitizers have been used because they can be kept in the classroom so sinks are not needed. Visible dirt should still be removed by washing, but hand sanitizers can eliminate germs that cause colds and other illnesses.

The germ elimination effort can be carried a bit too far, though. Some scientists believe that our immune systems learn to distinguish bad germs from good germs by being exposed to dirt and germs early in life. Studies are ongoing, but many doctors think that excessively clean environments may not be a good idea. It may not be necessary to maintain a completely antiseptic environment for children, but teaching children to wash their hands before eating and after using the bathroom is important.

There is more information on clean hands and hand washing at the Center for Disease Control and Prevention (CDC) Web site.

John Messmer is associate professor of family and community medicine at Penn State College of Medicine and a staff physician at Penn State Milton S. Hershey Medical Center.