We're getting good at keeping our hands clean. Here's why we should make the habit stick
Never before have so many of us been so attentive to the cleanliness of our hands.
With the quest to avoid COVID-19, we can't so much as enter a supermarket without magic fluid being squirted into our upturned palms, and most of us are lathering up at the basin multiple times a day too.
But will this newfound love of soap and sanitiser last? And if so, how will it change things?
Will we all enjoy extended stints free of the common bugs that hands can help spread, like nasty colds and gastro illnesses?
Or could there be a downside? Could all this cleanliness perhaps weaken our immune systems, increasing our risk of developing allergies and autoimmune diseases?
Clean hands have benefits beyond controlling coronavirus
Infectious diseases specialist Peter Collignon can't see anything bad about the current spike in attention to our hands. And he's talking about more than controlling COVID-19.
Research has shown that hand washing can prevent about 30 per cent of diarrhoea-related sickness and about 20 per cent of respiratory infections.
Some scientists go as far as arguing 80 per cent of diseases could be prevented if we all kept our hands clean.
But the impact of grubby hands in spreading disease has long been under-appreciated by the public.
Studies before the pandemic said as many as 30 per cent of people did not wash their hands at all after using a bathroom and that correct hand washing was practised at such low rates that only 20 per cent of people in airports had clean hands.
But the fact that hand sanitiser was impossible to buy for many weeks and social media sites buzzed with questions about making your own (perhaps using vodka or gin from your drinks cupboard to meet the required alcohol content), suggested COVID-19 had turned our attitudes to our hands around.
It seems our efforts are paying off.
Not only have we had success in "flattening the curve", there is now "good evidence" from GP reports and laboratory assessments that there's been a 70 per cent drop in colds and flu-like illnesses since the pandemic began, Professor Collignon says.
While it's hard to separate the effects of physical distancing, cleaner hands would certainly have contributed to this.
"You see a lot more hand rub everywhere you go. Overall I think people's behaviour.. has improved quite markedly."
In the past it was easy to dismiss the idea grubby hands spread germs, he says.
People thought "oh well maybe [hand washing] works, but I'm not convinced" or "the common cold and even the flu is trivial for me, so it doesn't matter".
But it's since become clear that not only can COVID-19 kill, it can also cause profound and often lasting damage from one end of the body to the other.
Self-interest can be a powerful motivator and "here is a disease you don't want to get", Professor Collignon says.
"If you [practise] hand hygiene, you decrease remarkably the chance of inoculating yourself."
That's because one of the key ways COVID-19 spreads is as droplets, which you can easily pick up on your hands from surfaces contaminated when an infected person coughs or sneezes.
If you then touch your eyes, nose or mouth, virus can easily latch onto cells and multiply. It can then be inhaled into your airways or possibly even make its way around the body by passing from the inside of one infected cell to another.
Washing your hands with soap and water not only breaks up the virus, it also washes it away.
So long as you don't have clumps of dirt or other material that could harbour hidden virus particles, a sanitiser that contains at least 60 per cent alcohol, will also destroy the virus.
There's a good chance our changed behaviour around hand washing will become entrenched, because living with the threat of COVID-19 has become the new normal, Professor Collignon says.
"The reality is this virus isn't going to go away soon," he says.
"We've got this problem for at least a year-and-a-half or two years and that's on the proviso a vaccine comes that is safe and effective.
"But no vaccine is 100 per cent perfect, so even vaccination doesn't make the risk go away completely.
"I think we might see a sustained drop in lots of respiratory transmissions."
Isn't a bit of dirt good for your immune system?
But plenty of us have heard the notion being too clean can cause your immune system to stop working properly.
It's thought this might result in conditions like autoimmune diseases and allergies.
So as we diligently wash and dissolve away the new coronavirus from our hands, could we also be wiping out a host of other microbes that we actually need to keep us healthy?
The notion that exposure to certain bacteria, fungi and other micro-organisms in our environment may be important in 'training' our immune systems is known as "the hygiene hypothesis".
But evidence to support this idea is limited.
In any case, the bugs that seem to matter are mostly those from the gut of our mothers passed to us as babies, along with organisms from the natural environment, not the germs that cause serious infections.
Early research suggested infections in childhood were important, but later work showed this wasn't the case.
The short story is we have much more to gain than to lose by paying good attention to hand hygiene, Professor Collignon says.
"I don't think there's good evidence if you're more hygienic with your hands, you're going to have more autoimmune diseases. Even if you are, that [drawback] would be more than offset by having less of the diseases that can kill you in a hurry," he says.
"The hygiene hypothesis is just that — a hypothesis. Whereas there is no doubt COVID and typhoid and cholera can kill you and you want to avoid them.
"Washing your hands is a great way to help do that."
There is even evidence that bacteria that are "good" for us are better than other types of bacteria at sticking to the skin of your hands when you wash them with soap and water.
"So basically the bugs that are better for you are less likely to wash down the drain."
We're good at hand-washing... for a while
Marylouise McLaws, who has been involved in many studies of hand hygiene, agrees the current pandemic has been a turning point in attitudes, but says it's common in outbreaks for there to be an initial surge in interest in hand washing. This often subsides when the threat passes.
Her studies of compliance with hand hygiene among health care workers suggest they do the right thing only on average around half the time, with nurses more diligent than doctors.
But both have been shown to perform better when being watched by human auditors compared to remote monitoring based on use of a hand washing station.
Lack of knowledge isn't the problem, it's more that doctors and nurses "get busy thinking about other things," says Professor McLaws, from the University of NSW.
If healthcare workers can manage to do the right thing only about half the time, she's not so confident the general public will do better.
"The general public don't see a lot of disease in our community. Only 44 per cent of people get a flu vaccine," she says.
While Professor Collignon concedes changing any behaviour long term is difficult, he says we need only look at the success of quit smoking and drink driving campaigns to see what is possible.
"There are behaviours you wouldn't think you'd be able to change, that with time, you can."
So do your best to make hand washing a lasting habit.
To reduce the risk of drying out your skin, wet your hands before applying the soap, Professor McLaws says.
Soap that is too concentrated or is not washed away properly can be a problem, she says.
And if you use alcohol-based rub, don't use soap and water straight afterwards because the alcohol makes your skin more 'penetrable' by the soap, and therefore more prone to drying out.
"Once you've sanitised, you don't need to wash your hands until your next hand hygiene."
Article from ABC Health & Wellbeing