Why it’s vital to wash your hands

Over the last decade, one of the things that has impressed me most about my children’s education has been the opportunity for them to engage in the annual science fair.

I have found myself a very willing participant in many projects – the most memorable of which have included trying to change my taste buds by forcing myself to eat olives every day for two weeks, and taking our dog to school for a day to see if pets really can reduce stress and anxiety in children. All worthy stuff. But the one that sticks in my mind most is my daughter’s research into the benefits of handwashing.

I can’t recall which particular products she used, or which came out as the most effective, but what I can vividly remember is how revolted I was to realise how filthy hands can be. She swabbed the hands of all family members, and then cultured the swabs on agar gel for a few days. Every time I opened our linen cupboard, where all the petri dishes were lined up, I felt slightly queasy witnessing the huge amount of colourful bacterial growth that was occurring, almost in front of my eyes!

Hand washing (or ‘‘hand hygiene’’ as it is known in the medical world) is probably the single most important thing we can do to prevent the spread of disease, especially in countries where infections are rife and sanitation often lacking.

In fact, it is thought that effective hand hygiene can reduce the number of episodes of diarrhoeal illness by 50 per cent – no mean feat as diarrhoea is the second biggest killer of children under 5 around the world.

Plenty of infections can be spread by hand to hand contact, including influenza and common colds; hepatitis A; various bacteria and viruses that cause gastroenteritis; herpes virus that leads to cold sores; conjunctivitis; and skin infections such as impetigo or staphylococcus. These infections can lead to pretty unpleasant symptoms in anyone, but for very young, elderly, frail or immunocompromised individuals they can sometimes be fatal.

The bugs that cause these infections are often spread via droplets that land on the skin (for example when sneezing, coughing or going to the toilet) and are then passed on to someone else via hand contact.

Surprisingly to me, during my daughter’s project, I learned that some bugs, such as the influenza virus, have become so well adapted to this method of transmission that they can survive for several days on unwashed hands, or even on a hard surface, such as a bench top or magazine touched by infected fingers.

So how should we wash our hands, and how often, to reduce the risks?

Personally, I have never been a big believer in eradicating all ‘‘germs’’ from our lives – I fear, rightly or wrongly, that by doing so we do reduce our body’s ability to develop a robust immune response.

However, I think there is a happy medium between scrubbing our hands (or our children’s….not to mention their toys, books and playmates) every few minutes, and having such poor hygiene that you pick up an avoidable infection, or pass it onto someone else.

So the general advice would be to ensure that you thoroughly clean your hands at the following times: ❚ Before eating or preparing food. ❚ After using the bathroom. ❚ After doing housework. ❚ After contact with animals, including your pets. ❚ After visiting anyone sick or unwell. ❚ After blowing your nose, sneezing or coughing. ❚ After changing your baby’s nappy. ❚ After playing outside or being in a very muddy or rural environment. The best method to use appears to include the following steps: ❚ Wet your hands with clean, running water – the temperature isn’t too important, then turn off the tap and apply soap. ❚ Lather the soap by rubbing your hands together; pay extra attention to the backs of your hands, in between the fingers, and under finger nails. ❚ Scrub your hands for at least 20 seconds. ❚ Rinse well under clean running water. ❚ Dry using a clean towel or air. If you can’t access soap and water for whatever reason, a good alcohol-based sanitiser is a good second choice. ❚ Dr Cathy Stephenson is a GP and forensic medical examiner.