The handiwork of good health

That our hands are crawling with germs is old, old news. Adults have hectored children about the dangers of unwashed hands for generations. Over a century ago, a few pioneering doctors (Holmes, Semmelweis, Lister) figured out that physicians’ hands were infecting patients and making many people sick.

Today, those same hand-transmitted germs still make people sick; cold and flu viruses are a common example. New threats exist, such as Staphylococcus aureus, known as MRSA, and Clostridium difficile: both bacteria originated in hospitals but have made their way into the community. Yet hand washing is still one of the best ways to prevent these and other organisms from taking up residence on your skin and causing infection. It’s a standard item on flu-prevention lists, and health officials are putting special emphasis on it now because of the bird flu epidemic.

Americans say they wash their hands. Over 90% of those questioned in a telephone survey said they washed up after using a public bathroom. But when the American Society of Microbiology and a trade association group observed people in public restrooms (in stadiums, train stations, etc.), they found that only 75% of men washed their hands. Women weren’t perfect, but at 90%, did better than the men. This Mars-Venus disparity extends to those with medical degrees. In one study, female physicians washed their hands 88% of the time after seeing a patient; their male colleagues did so only 54% of the time.

Overkill overdoes it

There are those, both men and women, who overdo the hand washing. Our hands weren’t meant to be sterile objects. Having some bacteria on the skin is perfectly natural, and “resident flora,” as the experts call it, is probably healthful — unless you’re a surgeon about to put your hands inside someone’s body. Frequent hand washing, even with mild soap, can damage skin, worsening cuts and causing cracks that can harbor even more bacteria. Dry, damaged skin may also spread germs more easily because it flakes off, taking bacteria with it.

How often should you wash your hands? There’s no set frequency; it really depends on your activities. Must-wash occasions include after using the bathroom, before eating or preparing food, and after being with someone who’s ill, particularly if he or she has a respiratory or gastrointestinal infection.

Lathering up

New products clamor for our attention, but plain old soap and water is still a good way to clean your hands. In studies, washing hands with soap and water for 15 seconds (about the time it takes to sing one chorus of “Happy Birthday to You”) reduces bacterial counts by about 90%. When another 15 seconds is added, bacterial counts drop by close to 99.9% (bacterial counts are measured in logarithmic reductions). Few of us wash our hands that long — five seconds is more like it. One reason you’re supposed to use cool or lukewarm water is to increase the chances you’ll wash them a little longer. Hot water is also more damaging to skin.

Soap and water don’t kill germs; they work by mechanically removing them from your hands. Running water by itself does a pretty good job of germ removal, but soap increases the overall effectiveness by pulling unwanted material off the skin and into the water. In fact, if your hands are visibly dirty or have food on them, soap and water are more effective than the alcohol-based “hand sanitizers” because the proteins and fats in food tend to reduce alcohol’s germ-killing power. This is one of the main reasons soap and water is still favored in the food industry.

Even people who are conscientious about washing their hands make the mistake of not drying them properly. Wet hands are more likely to spread germs than dry ones. It takes about 20 seconds to dry your hands well if you’re using paper or cloth towels and 30 to 45 seconds under an air dryer.

Four dos and don'ts

• Don’t scrub. Scrubbing can damage skin, especially if you do it a lot. The resulting cracks and small cuts give pathogens a place to grow.
• Keep your fingernails short. Bacteria like the area under our fingernails. Long nails make it more difficult to keep those areas clean.
• Use hand lotions, especially during the winter. Keeping the skin of your hands intact is essential to good hand hygiene.
• Don’t be in such a hurry. It takes about a minute to properly wash and dry your hands.

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