Infection control experts are urging Australians to start practising a difficult but effective infection-control measure – not constantly touching their face.
Viruses like SARS-CoV-2, which is behind the latest coronavirus outbreak, generally need to get inside our noses, eyes or mouth to infect us. One of the ways this can happen is if you get the virus on your hand and then touch your face.
And we touch our faces constantly, about 23 times an hour.
Another thing we touch all the time: our mobile phones. Could they also help spread the virus?
“The public health message is this: try very hard to keep your hands away from your nose, mouth and eyes. If you need to touch them, carry some alcohol-based hand rub and decontaminate them,” says Professor Mary-Louise McLaws, an infection control researcher based at the University of NSW.
Viruses like SARS-CoV-2 are carried in tiny droplets released when an infected person coughs or sneezes.
If you’re standing close enough to a person when they cough, you can breathe in the droplets.
That’s the main way the virus spreads, and the reason the World Health Organisation recommends people stay at least one metre away from someone who is coughing.
But the droplets can also land on solid surfaces, like a train handrail.
Some viruses – possibly including COVID-19, although we don’t know for sure – can live for several hours in those droplets, just waiting for someone to touch one.
Our skin is a great barrier that blocks viruses getting inside our bodies.
But if you get virus on your hand, and then touch your mouth, nose or eyes, the germ can get inside your body and start infecting you.
Scientists long suspected this was an important source of virus transmission, but in recent years we have discovered it is a bigger one than expected.
In a 2015 study, Professor McLaws and her team filmed university students in a lecture for an hour. They touched their faces 23 times an hour on average. “That’s a lot of face-touching,” she says. Nearly half those touches were to the mouth, nose or eye.
Japanese researchers built a fake train carriage to see how people performed on public transport; their participants touched their faces almost 18 times an hour.
“Humans preen ourselves, that’s what we do. We do it nervously, we do it as a social gesture, we do it subconsciously. I’m just watching people do it now,” says Professor McLaws.
The WHO recommends against wearing masks to prevent the spread of COVID-19, but strongly recommends people wash their hands regularly and avoid touching their face.
There are few things we touch more during a day than our mobile phones.
If we touch something contaminated with virus droplets, and then touch our phones, they can become contaminated too, spreading the virus. We also drop our phones onto surfaces that could be contaminated.
However, experts consider this a very unlikely route of virus spread.
“It is such a small risk,” says Professor Anton Peleg, head of infectious diseases at The Alfred hospital.
“And your phone is usually used by you alone. If there was a clear event – someone sneezed or coughed on your phone – I think it would be reasonable to be wiping down your phone. But I don’t think this is going to be a huge mechanism of transmission.”
Professor Peleg led a 2018 study in a Melbourne hospital that found 7 per cent of mobile phones tested were contaminated with multi-drug resistant organisms.
But there was no sign those bugs were being transmitted to patients.
“There will 100 per cent be bacteria on your phone. But the clinical significance is likely to be minimal for most people,” he said.
After doing her research, Professor McLaws now carries around a small bottle of alcohol-based hand sanitiser she uses before touching her face.
“It’s hard” not touching your face, she admits. “And we can’t prevent everything. But when we have got this outbreak at our doorstep, it’s important to practise.”