March 11, 2005 -- When it comes to hand washinghand washing, using soap and water is still one of the best bets for good hygiene.
That's not to dismiss other methods, such as waterless hand rubs or hand wipes, which may also help. Whatever hand cleanser you choose, use it for at least 10 seconds and consider washing your hands a couple of times a day, just to be on the safe side, researchers suggest.
"Our study showed that the antimicrobial hand washing agents were significantly more effective in reducing bacteria than the alcohol-based hand rubs and waterless hand wipes," writes William Rutala, PhD, MPH, a professor of medicine at the University of North Carolina at Chapel Hill.
The finding is especially important for health care professionals -- and their patients. "Health-care associated infections rank in the top five causes of death, with an estimated 90,000 deaths each year in the United States," the study shows.
Studies have repeatedly shown that good hand hygiene by health care workers can help avoid those infections. Likewise, people who keep their hands clean may have fewer colds or other illnesses.people who keep their hands clean may have fewer colds or other illnesses.
But with so many hand cleaners on the market, which are best at removing bacteria and viruses? And how long does it take to scrub, rub, or wipe your hands clean?
Testing the Cleansers
To find out, 62 volunteers rolled up their sleeves and got their hands dirty in the name of science.
First, they washed their hands with plain old soap without any microbe-fighting agents. Next, their hands were covered with liquid laden with a harmless bacterium and virus. Those bugs were chosen because they mimic more threatening germs.
Then, the clock started ticking. Volunteers had 10 seconds to use the hand-cleaning product assigned to them.
That's how long health care workers typically take to wash their hands, according to the study. Previous research has tested 30-second hand washing sessions, but that's not always done in real life, say the researchers.
Cleansers included waterless hand rubs, waterless hand wipes, and antimicrobial soaps. For comparison, the volunteers also tried using plain soap and water, as well as tap water alone.
Each person tried their assigned products 10 times. That let the researchers see if the cleansers' effectiveness changed with repeated use. The bacterium and virus levels were measured after the first, third, fifth, seventh, and 10th trials of each product.
Results Come Clean
Most of the cleansers drastically cut the bacteria. However, some were better than others.
"Our study showed that, at a short exposure time of 10 seconds, all agents with the exception of hand wipes demonstrated a 90% reduction of bacteria on the hands," says Rutala, in a news release.
After one round of hand washing, the best bacterium removers were:
- Hand washes with chlorhexidine gluconate (CHG) sold under name brands such as PrimaKare or Bactoshield, and triclosan, sold as Prevacare
- Plain soap and water (without antimicrobial agents)
- Tap water alone
Next came alcohol-based hand rubs, followed by hand hygiene wipes.
After 10 rounds, the antimicrobial hand-washing agents were all more effective at removing the bacterium than the alcohol-based hand rubs and waterless hand wipes.
Of the antimicrobial hand washing agents, those containing CHG were the most effective at removing bacterium, the study shows.
Which Cleansers Are Best at Removing Viruses?
In terms of removing the virus, the antimicrobial hand-washing agents and controls (plain soap and water, or tap water alone) fared best.
By the 10th round, the best virus removers were:
- Hand-washing agent containing benzethonium chloride
- Plain soap and water (without microbe-fighting chemicals)
- Tap water alone
After 10 sessions, hand-washing agents with CHG were less effective at removing the virus than those with benzethonium chloride or plain soap and tap water.
"Although viruses are a less common cause of health care-associated infections than are bacteria, in situations in which infection with viruses are likely (e.g., gastroenteritis because of norovirus or hepatitis A infections), the use of soap and water washes should be considered," says the researchers.
Hand Wipes, Rubs Still Useful
"Hand-washing agents were superior to both alcohol-based hand rubs and hand hygiene wipes" in removing the virus, the study cites.
One alcohol-based hand rub -- which contained ethyl alcohol and silver iodide -- made a lesser but still significant reduction in the virus. "All other agents except PCMX, which included alcohol-based hand rubs and wipes failed to demonstrate a statistically significant reduction in [the virus]," the study reads.
But those products may still come in handy. It's not always possible for health care workers (or anyone else) to get to a sink to use soap and water.
"The use of alcohol-based hand rubs will continue to be an important addition to our existing infection control [options] to improve hand hygiene compliance and at those locations at which sinks are not available," the researchers write.
It would be prudent for health care workers to also use "traditional hand hygiene with an antiseptic agent or a nonantimicrobial soap throughout the day," they say.
The report appears in the American Journal of Infection Control's March edition.