Hand Sanitizer Vs. Soap And Water - Which Wins?

Germ-phobic Americans have become the world's number one consumers of buying hand sanitizers. Why? Disturbed by some reports of flu epidemics, simply sick and tired of getting sick and tired from colds, and alarmed by reports of especially virulent strain of Australian norovirus that causes the stomach flu, some Americans use hand sanitizers as much as 5, 10, and even 20 times a day. This leaves a big question. Do hand sanitizers actually work well at getting rid of germs or is soap and water just as effective or more?

To figure this out, let's take a look at the lineup of hand sanitizers versus soap and water for getting rid of the Norwalk virus, an especially nasty cause of a condition known as viral gastroenteritis, or more commonly referred to as the winter stomach flu.

Viral Infection Spread By the Fecal-Oral Route

The Norwalk virus was, as the name suggests, named after the town of Norwalk, Ohio, where it was first detected after a massive epidemic of winter vomiting occurred among the school children at Bronson Elementary School in the year 1968.

If you get any kind of the "stomach flu" in the United States, there is a 90 percent chance that you came down with the illness after you were exposed to the Norwalk virus.

Technically speaking, instead of "Norwalk virus" the term "norovirus" should be used to refer to a broader group or genus of viruses. However, Norwalk virus is actually the only species of virus identified in the genus, so the terms "Norwalk virus" and "norovirus" can be used interchangeably while meaning the same thing in either case.

So, how does the Norwalk virus spread?

Well, Norwalk virus is transmitted by the fecal-oral route. If you get feces, or vomit, from a person who is infected with the virus into your mouth, then you almost certainly will get the disease. This thing spreads quite fast. In fact, it only takes about 20 copies of the virus to cause an infection. (Scientists say that the strain of the virus that was going around during the winter of 2012-2013 in Australia and the United States require even less copies, taking a mere 12 copies of the virus to cause an infection.) That is an almost unimaginably small amount of the virus, so how in the world could anyone avoid the Norwalk virus? There's actually a pretty simple way to avoid it. It turns out that keeping hands clean works for preventing the infection.

Hand Sanitizers versus Soap and Water for Norwalk Virus

Researchers at the schools of public health at Emory University in Atlanta and North Carolina State University in Raleigh tested the hand sanitizers against plain old soap and water for getting Norwalk virus off the hands of students who volunteered for the study. They started by diluting feces they collected for a student who had had the disease, and then they asked the study volunteers to get their hands contaminated by the diluted feces solution, cleansing them with antibacterial soap, regular soap and water, or water alone.

The results of the study were more than a little surprising:

• Cleansing hands with alcohol-based hand sanitizer got rid of no more than 50% of the virus, leaving a high likelihood of infection.
• Cleansing hands with liquid soap and water got rid of more than 90% of the virus, still not enough to prevent infection.
• Cleansing hands under running water for 15 seconds (long enough to sing "Happy Birthday to You" or "Row, Row, Row Your Boat") got rid of up to 99% of the virus, enough to prevent infection.

Dipping your hands in sodium hypochlorite (Clorox) would have been even more effective for getting rid of the virus, but really hard on your skin. Don't try it. But the most effective way to get rid of the world's most common stomach flu virus turned out to be purely mechanical, rinsing it down the drain, not trying to kill it with chemicals. What about bacteria that are transmitted by the fecal-oral route.

Hand Sanitizers Versus Soap And Water For Preventing E. Coli Transmission

The single most common bacterial "stomach bug" is the familiar E. coli. We all have E. coli in our digestive tracts and even in our bloodstreams most of the time, but certain strains of E. coli can cause serious inflammation and irritation in the colon along with watery diarrhea, bloating, and gas.

Relatively rare strains of E. coli also cause most urinary tract infections, many cases of gallbladder inflammation, pneumonia, and even meningitis.

The most common way of getting an E. coli infection is transferring the microbe from feces to the mouth, but it usually isn't human feces that is the source of the infection. Most E. coli infections are acquired from animal feces present in invisible traces in uncooked meat or eggs.

Obviously, if you want to avoid an E. coli infection, you need to wash you hands. But what should you wash them with?

Surprisingly Effective (and Ineffective) Hand Cleansers for Preventing E. coli

The Center for Public Health at the University of Georgia tested a variety of methods for preventing the spread of E. coli in commercial kitchens. They tested washing hands with plain tap water, regular liquid soap, antibacterial soap, and alcohol-based hand sanitizer gel. They also tested washing hands with regular liquid soap followed by the application of an alcohol-based hand sanitizer, and washing the hands with regular liquid soap followed by use of a nailbrush.

The smallest amount of E. coli was removed by use of the alcohol-based hand sanitizer gel. Even washing hands under the faucet was better than using sanitizer gel, even if they were washed with liquid soap first.

Other studies have found that the only kind of alcohol-based sanitizer that removes bacteria and viruses from the hands is a foaming sanitizer called Sani-Twice. It is almost as effective as washing the hands with soap and water. It is only recommended when soap and water are not available.

But if you really want to get bacteria off your hands, you have to scrub under your nails.

And For Preventing Transmission of Colds and Flu?

As you might guess by now, the only proven methods of preventing the transmission of colds and flu from person to person involve washing hands with soap and water.

How often should you wash your hands? A good rule of thumb is to wash your hands with soap and water every time you can, but especially after you have handled vomit or feces, or when you come in from a public place. Try to avoid putting your hands on your face, and always wash your hands before you eat, even if it is inconvenient. Be sure to wash your fingertips, where you pick up the most germs.