Human skin — even in the most healthy of us — is teeming with bacteria. Most of those bacteria only cause disease under special circumstances. But everyone also carries potentially dangerous germs from time to time, such as staph, strep, and the intestinal bacteria that cause food poisoning and diarrhea. Sad to say, health care personnel — including your doctors and nurses — are particularly likely to carry the most troublesome bacteria, especially on their hands. And although viruses don't set up shop on the skin the way bacteria do, the viruses that cause diarrhea and respiratory infections — from the sniffles to the flu — can hang around on the hands long enough to spread from person to person.
If your skin is covered with so many bacteria, why don't they make you sick more often? Although the skin is a hospitable resting place for bacteria, it is also a tough barrier that prevents hostile bugs from reaching the body's vulnerable internal tissues. Ironically, perhaps, some of the traditional methods of removing bacteria from the skin can disrupt the skin's own defenses. Scrubbing can produce tiny abrasions that allow bacteria to sneak into your tissues. Detergents and even plain water can remove the skin's oils, which have important antibacterial properties.
Good handwashing, then, involves two potentially conflicting goals, removing microbes while still keeping your skin healthy.
Preached but not practiced
Handwashing is good advice — but do Americans follow it?
Often, we don't. When investigators surveyed public restrooms around the country, they found that only 83% of people washed up after using the toilet. Do posted reminders to "Please Wash Your Hands" help? When researchers tested this simple strategy, they found that handwashing improved in women but not in men.
The gender gap applies to hospitals, too. In one study, female physicians washed their hands after 88% of patient contacts, but male doctors washed after just 54%.
Does it work?
Yes. Just 30 seconds of simple handwashing with soap and water reduces the bacterial count on health care workers' hands by 58%. And there is an even better way: Alcohol-based handrubs reduce counts by 83%.
Soap and water is the time-honored technique, and it does work. In fact, it's still the best way to remove visible soilage and particulate material. But as the public has become concerned about the risk of infection, soaps with antibacterial additives have gradually taken over 45% of the market. It's understandable, but it's not helpful; antibacterial soap is no better than ordinary soap, and the additives actually increase the risk of allergic reactions and other side effects.
Plain soap will do the job — and so will plain water. Tap water is excellent, and cool or lukewarm temperatures serve as well as hot water. If soap and water are not available, antibacterial wipes can help. Although they are not as effective, they will reduce bacterial counts. Washing with soap and water is the best way to remove dirt, but waterless, alcohol-based handrubs are even better at killing germs. Handrubbing is faster and more convenient than handwashing, and it's also easier on the skin. Hospitals are switching to handrubs because they kill more bacteria and viruses and they are used more regularly.
When and how
How should you wash? Wet your hands with water, then apply the soap to your palms. Rub your hands together briskly for at least 15 seconds before rinsing.
Wash your hands before each trip to the dining room and after each trip to the bathroom. Wash after handling diapers and animals. Wash before and after you handle food. Wash after you take out the trash, work in the yard, clean the house, repair the car, or do other messy chores. Wash before and after sex. Wash after you come in contact with anyone who is sick. If you follow reasonable guidelines you'll be washing often, but you won't become obsessive or compulsive. Be careful, not fearful.
August 2006 Update