How does washing your hands help prevent the spread of germs and disease?

It may be some time before Mr. Lynn’s clean-hands identification mechanism is in widespread use, but in the meantime, you might want to wash your hands more often anyway, whether you can be caught at it or not.

There is indisputable evidence that washing hands, we’re talking about the general public here, not surgical personnel, is very effective in preventing the spread of disease, especially of pathogens that are transiently on your hands (like cold germs) and those that are spread by the fecal-oral route.

Plain soap and water is just as effective as any other agent for this purpose, if only people would wash frequently enough and long enough when they do wash. Unfortunately, they don’t. To wash your hands well enough to prevent disease transmission you have to use soap and warm water, and you have to rub your hands together vigorously for 10 to 15 seconds, working up a good lather and covering all the surfaces of your hands and fingers.

Then you have to dry your hands with a paper towel (preferred) or a clean towel or air dryer. Then you’re supposed to use a paper towel to turn off the faucet. And you’re supposed to do this before preparing food; before eating; after sneezing, coughing, or blowing your nose; after using the toilet or touching a pet; whenever your hands are obviously dirty; and after cleaning activities.

And that’s just for your average person, for some people the hand washing has to be more elaborate and more frequent. Food service employees, for example, in addition to the washing we’re all supposed to do, are supposed to wash their hands before beginning or returning to work, immediately after preparing food, after touching any bare human body parts other than clean hands and arms, after handling money, and every time they switch between working with raw food and working with ready-to-eat food.

Let’s face it: very few people are going to run in and wash their hands every time they cough or sneeze, and even if they do they aren’t very likely to follow such an elaborate hand-washing regimen. Using the toilet is another matter, though, and it seems reasonable to expect that people will wash their hands after moving their bowels.

People overwhelmingly say they wash after they use the toilet, but observation proves they often don’t. The American Society for Microbiology, in the survey mentioned above, found that while 95 percent of people say they wash their hands after using a public toilet, when you actually watch them in action, only 67 percent do. Men are worse than women, 92 percent of them claimed to wash their hands, but only 58 percent did.

With women, the gap was smaller, but still surprising: 97 percent said they did, 75 percent actually did. For some reason, people who make less money wash more often than people who make more, or at least they say they do. In every category, before eating, after petting a dog or cat, after coughing or sneezing, after handling money, people who make less than $35,000 a year report more hand washing than people who make more, and people with only a high school diploma report more hand washing than those who went to college.

It is even possible to infect yourself with your own stool. Pinworms are often recirculated in this way by children. If stool gets into your urinary tract, this can cause infection as well. And stool can also infect sores or abscesses around the rectum. People who are immunocompromised can be infected with their own intestinal flora through breaks in the intestinal mucosa.

In any case, germs don’t care how much money you make, and they don’t care whether you went to college. Everyone has them, and anyone can spread them. The stratum corneum, as the topmost layer of your skin is called, is a mixture of flattened dead cells and lipids that forms a tough protective outer layer.

Healthy people shed particles of this layer every day, 10 million of them, and about 10 percent of them contain viable bacteria. Men give off more than women, and while there is considerable variation from person to person, bathing routines don’t have much effect: a person using exactly the same hygiene measures as another can nevertheless disperse more than five times as much bacteria. You are a walking bacteria factory, spreading germs wherever you go, and there isn’t much you can do to prevent it. Nor do you have to for the sake of your health or anyone else’s.

If you’ve been reading, you know that the fecal-oral route is a common one for the transmission of disease, and that if you touch food after using the toilet without washing your hands, you are asking for trouble. Human feces, even the feces of perfectly healthy people, are filled with dozens of different species of disease-causing microorganisms.
The natural disgust at putting feces anywhere near your mouth finds justification in scientific fact: you can get really sick by doing so.

Approximately a third of the weight of human feces is bacterial debris, 100 billion bacteria of 75 different kinds are excreted by every healthy person every day. Among these normally excreted bacteria are many pathogens. And if you’re not healthy, your feces can be even more dangerous. Improvements in plumbing and waste water disposal in the first 40 years of the twentieth century were a major contributing factor to the sharp reduction in infectious disease simply by keeping feces polluted water away from people’s lips.

Okay, so we know it’s important to wash your hands when you leave the bathroom. But is there such a thing as being too clean? Washing your hands too much? Alas, yes.

Every time you wash your hands, you change their bacterial flora. Most of these changes are temporary, after a few hours, your skin has returned to its normally bacteria-laden state. But if you wash your hands repeatedly (health care workers, for example, may wash their hands as often as 10 or 15 times a day), and especially if you use strong detergents, you can cause contact dermatitis, irritated, damaged skin. Damaged skin harbors and disperses more disease-causing bacteria than undamaged skin, which is clearly not the desired result in hand washing. Skin condition under these circumstances takes on great importance.

Antiseptic soaps reduce bacteria on the hands, but not beyond a certain level. And using them instead of soap for washing may actually make things worse. In one study, the number of organisms spread from the hands of nurses who used antibacterial soap actually increased, probably because of skin irritation.

In another, nurses with damaged skin did not have higher microbial counts, but did have a greater number of colonizing species and were more likely to be contaminated with drug-resistant staphylococcus than nurses with undamaged skin. So it’s probably best to find some moderate position: enough hand washing to encourage infection control, but not so much as to damage the skin.

Antibacterial soaps are not necessary for the general public for routine bathing, although they might be useful in special situations, such as when skin infections are present or when preparing to perform surgery. Even for food handlers, the use of antibacterial preparations has to be weighed against the possibility of encouraging the proliferation of resistant strains of bacteria.

As a substitute, for health care workers and others, alcohol can be used as a disinfectant. Alcohol kills a large variety of germs and doesn’t lead to the formation of resistant strains. Alcohol-based hand washing products are widely available over the counter and have their own problems.

If you wash your hands often, whether with antibacterial preparations or not, the use of hand moisturizers can be beneficial for skin health.

About Karen Hill

Karen Hill is a freelance writer, editor, and columnist. Born in New York, her work has appeared in the Examiner, Yahoo News, Buzzfeed, among others.

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