Hand-washing is fun when you’re two, judging by the shouts of glee each time my toddler heads to the bathroom for a spot of soap and water. Still, I know the day will come when my request to wash hands will not elicit a gleeful response. After all, only 40% of doctors can be bothered regularly washing their hands, according to a 2010 study, even though health professionals know hand-washing is the most effective way to stop the spread of infectious diseases.
Good hand hygiene is also critical for food safety; unwashed hands can transfer bacteria, viruses and parasites – some of them found in human faeces – onto food and into our mouths, leading to food-borne illnesses. Food safety is particularly important in summer, as the warmer weather makes it easier for bacteria to thrive and multiply in our environment.
Thorough hand-washing is the best way to stop the spread of food-borne illness, according to the Ministry for Primary Industries. This is great news if you’re a diligent hand-washer. Unfortunately, we live in a community where a significant number of people fail to follow basic hygiene guidelines, which places the rest of us, who share their environment, at increased risk of illness.
A 2008 survey assessing the hygiene habits of 1200 people in toilets at shopping malls in Auckland, Hamilton, Wellington and Christchurch found 13% of shoppers made no attempt to wash their hands after using the toilet. So perhaps a bottle of alcohol-based hand sanitiser is a good idea, particularly when visiting public places and dining out.
In 2000, researchers reported in the Journal of Food Protection that hand-washing with mild soap and water for 20 seconds was more effective at removing bacteria likely to cause food-borne illness than a 70% alcohol- based hand sanitiser. The study was funded by Procter & Gamble, which sells both hand sanitisers and soap.
In the fight against human noroviruses – the leading cause of non-bacterial gastroenteritis – the news is even less positive. A 2010 study, in Applied and Environmental Microbiology, found alcohol-based hand-rubs were relatively ineffective at destroying the virus on human hands. And unsurprisingly, a subsequent study in the American Journal of Infection Control found the use of alcohol-based hand sanitisers by staff in long-term care facilities was actually associated with an increased risk of a norovirus outbreak in the facility.
Likewise, soap and water were more effective than alcohol-based hand-rubs at removing Clostridium difficile from human hands. This bacterium can cause diarrhoea or inflammation of the bowel; infection typically occurs in hospitalised patients who have recently taken a course of antibiotics.
Soap and water were also more effective than alcohol-based hand-rubs at removing human influenza A virus (H1N1) from the hands of 20 brave volunteers, and at washing away human rhinovirus – the cause of many common colds – reports a 2012 study in the Journal of Medical Virology.
The best option, then, is to wash hands with soap and clean water if it’s available. Alternatively, use soap and any available water (whether fresh or not). If soap and water aren’t available, use an alcohol-based hand sanitiser, but choose one containing at least 60% alcohol. Hand-washing with soap and water may be a simple act, but it significantly reduces our risk of food-borne illnesses and much more.
In a 2012 issue of the New Zealand Medical Journal, the Auckland District Health Board reported a marked reduction in Staphylococcus aureus infections among patients after it implemented the Hand Hygiene New Zealand programme in 2009 and increased healthcare workers’ compliance with hand-hygiene regulations from 35% to 60%. Now that’s good news.
WHEN SHOULD YOU WASH YOUR HANDS?
- Before preparing food or eating.
- Before or after caring for someone who is sick.
- After preparing food.
- After blowing your nose, coughing, sneezing, touching an animal or handling animal waste.
- After using the toilet, changing nappies or cleaning a child who has used the toilet.
- After handling pet food or rubbish.
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