The Australian medic pointed out that the bug causing Covid-19 can live in your fingernails – as well as bacteria, dirt and debris – meaning if you bite them then that is then transferred into your mouth.
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It comes as the number of cases of coronavirus in the UK last night rose to 9,704 – with the death toll standing at 468.
A woman posted on Facebook revealing she was given the warning by an Australian nurse that while many people have been prioritising washing their hands well, people are not focusing enough on the importance of having short nails.
“Among all the hand-washing instructions and the fun 20-second song suggestions, I haven’t seen anyone note that it is impossible to wash your hands properly if your fingernails are long,” the woman wrote.
The woman revealed that there is a simple test you can do at home to see whether your nails are too long and need to be cut during the coronavirus pandemic.
She added: “If you can’t put your fingernails straight down against your other palm without your nails adding too much distance to do it, you cannot wash under your fingernails properly unless you use a nail brush every time.”
The woman also warned people who have long nails that hand sanitiser “won’t do the trick”.
“If you can’t rub the very ends of your fingers against the other palm, then your hands aren’t truly clean after you wash them, no matter how long you soap up,” she wrote.
“Please, during this global emergency, keep your nails short.”
Many commented on the post and said they hadn’t heard about how important it was to keep your nails short before.
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Others added that germs can live in your nail polish too, meaning it’s a good idea to keep your nails both short and clean.
“Nurses can’t have painted or fake nails as they harbour an incredible amount of bacteria. This is true even when not in a pandemic,” one woman pointed out.
Nail biters were previously warned against the habit as it could increase the risk of catching coronavirus.
Purvi Parikh, from New York University’s Langone Medical Center, issued a severe warning to those with the bad habit.
She told The Cut: “Every time you touch your face — especially your mouth, nose, and eyes — you’re transferring all of those germs. And you can get sick.”
The infectious disease specialist added that germs going into the mouth is “the easiest way you can contract any infection”.
Purvi continued: “There are so many infections going around this time of year, from bacterial to viral to the flu.
“But then on top of that, given that we now have this coronavirus, there’s even more reason not to bite your nails.”
Sadly, there’s no magic solution for many people when it comes to stopping biting their nails, but there are a few steps you can take to try and kick the habit.
Dr Sarah Jarvis, GP and clinical director of Patient.info, told The Sun Online: “The first thing to do is to try and work out what your triggers are.
“Some people bite their nails when they’re bored, others when they’re stressed.
“If stress is the cause, consider finding another habit – some people use an elastic band around their wrist, which they ping when they’re stressed.
“Or relaxation exercises or mindfulness may be for you.
“If it’s boredom, find something to fiddle with – a stress ball or a Rubik cube – and try reaching for that.
“Chewing gum can also keep your mouth occupied.”
Using a nail clipper to keep them down, and even, will mean you’re less likely to bite them if there’s nothing there to sink your teeth into.
Dr Jarvis says: “Cutting your nails short may make chewing less satisfying, and liquids you can paint on, which make your fingers taste unpleasant, are also worth considering.”
Health bosses say the best way to protect yourself from catching the bug in this way is to wash your hands with soap and water for the time it takes to sing Happy Birthday twice.
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Happy Birthday takes about 20 seconds to sing twice and is said to be the perfect number to clean your hands to thoroughly.
You should also not touch your eyes, nose or mouth with unwashed hands and avoid close contact with people who are sick.
Cleaning and disinfecting objects and surfaces which you may have touched is also important.