My sons’ library boasts a great set of books called “Who Would Win” where epic battles are theoretically fought: great white shark or giant squid? Polar bear or orca? They face off in different circumstances and environments, where they each unleash their own strengths; the finale results in a win for one beast over the rest.
As a doctor, I’m forever talking hand-washing with my patients. But is all hand wash created equal? In a battle between hand sanitizer and soap with water, who would win, pitted against big bad germs? Does the environment matter? Here’s what the science and the experts say about who’s bound to come out on top.
Water Alone: Loser
Handwashing is proven to reduce infection, and on a daily basis, helps prevent transmission of common illnesses such as stomach bugs (vomiting and diarrhea) and respiratory infections (coughs, colds, flu).
We’re always told to scrub with soap and water, rub with alcohol-based hand sanitizer, but what about plain water alone? It helps a bit, but still leaves your hands covered with plenty of creepy crawlies. In this battle, water is eliminated during round one.
Who Science Backs
Quite a few studies have compared different hand-washing techniques in a variety of settings both in vitro (in the lab) and in vivo (on us!). Most of the time, for infections that cause the common cold and gastroenteritis (the stomach flu), alcohol-based hand sanitizer comes out on top.
Researchers studied Rhinovirus (a culprit in the common cold) and the ability of different hand-wash formulations in eradicating it from the surface of our hands. Rhinovirus was placed on participants’ hands, then hands were washed with either alcohol-based hand sanitizer or soap and water. The results? Over 80% of hands were free of the virus following use of the hand-sanitizer, while only 30% of participants were clear of the virus following use of soap and water.
However, a few notable exceptions resist the power of alcohol-based sanitizers and respond better to soap and water: cryptosporidium, norovirus and C. difficile, to name a few. Cryptosporidium is a parasite that causes diarrhea; norovirus is a super-contagious bug that’s often responsible for diarrheal outbreaks such as those on cruise ships; C. difficile is a bacteria that capitalizes on guts stripped of their good bacteria through antibiotic use, often resulting in severe diarrhea, dehydration and hospitalization. Soap and water are required in these situations.
What about the flu (influenza)? Under the microscope, soap and water eradicates a bit more of the virus, but their effectiveness in everyday life is fairly equal.
So, round two is a bit of a toss-up. For common, everyday bugs, at least under research conditions (more on this to come), sanitizer wins. There are a few big, bad germs, however, which require the scrubbing power that comes with soap and water to be eliminated effectively.
The Experts Weigh In
When I think about bad germs, I think about the CDC (US Centers for Disease Control), which conjures up images of men and women in hooded, vented white suits. These people know their bugs! And they’ve weighed in on this debate. Here’s what they have to say about hand-washing in your daily life.
1. For visibly soiled hands (you can see the dirt), a good lather with soap and water is a must. These big particles need the friction that we create with our scrub to be eliminated.
2. When washing with soap and water, ensure you’re covering all fingers, thumbs, backs of the hands and in between. Scrub for at least 20 seconds (or singing “Happy Birthday” twice), rinse well with running water and dry with air or by a clean towel.
But why? If the studies often favour alcohol-based hand sanitizer in eliminating common germs, why this recommendation?
1. When people use soap and water, they tend to scrub more vigorously. Plus, they’re more likely to wash thoroughly. When using hand sanitizer under real-life conditions, people often use too little of the product, or wipe it off before it fully dries, limiting its effectiveness. If you want to harness its full power, use the recommended amount (read the label), and rub until hands are completely dry. Simply put, we aren’t giving hand sanitizer a chance to work its magic.
2. Our hands can be contaminated with more than just germs. Pesticides and heavy metals can also be found on our palms, and require the friction of soap and water washing to be removed effectively.
Doctors Are Given Different Advice
Why does your doctor use hand sanitizer before examining you at the hospital or office, if soap and water is clearly recommended by the experts? Interestingly, recommendations to healthcare workers vary from those given to the general public.
Healthcare workers are trained in proper handwashing technique (believe it!) to maximize the effectiveness of hand sanitizer and mimic results seen in studies. Also, strict compliance is required for hygiene and patient safety, and compliance is increased with using hand-washing methods that are quicker, more convenient, and less drying or irritating to hands that can be washed 100 times per day or more! Of course, certain situations require soap and water for doctors and nurses too, such as when treating patients known to be infected with specific bugs, such as C. difficile.
The Ultimate Champion
The CDC recommends that you wash your hands with soap and water using proper technique and if that’s not available, choose an alcohol-based hand sanitizer instead.
However, the research tells us that when used properly, alcohol-based hand sanitizer is more effective against those germs that many of us worry about encountering in our daily lives. Plus, let’s face it, for washing on-the-go, hand sanitizer in purse or pocket is just more convenient. If you choose to go this route, pick a sanitizer with at least 65% alcohol content and use it as directed (enough of it, and rub for long enough!). Plus, make sure you’re washing with soap and water occasionally in order to get rid of chemicals and other contaminants.
The most important part in all of this? Make sure you’re washing regularly.
What about “antibacterial” non-alcohol hand sanitizers? They can be more irritating, may not kill all types of germs, and there’s the potential for germs to become resistant to that type of sanitizer. For now, best to steer clear.
Are you winning at hand washing?