The norovirus vomiting bug is making its nasty presence felt more this winter than in previous years.

Already there have been hospital ward closures due to outbreaks, 300 people reportedly fell ill following a suspected eruption of the virus at the Wahaca restaurant chain, and cases are said to be 55 per cent higher than this time last year according to Public Health England.

Chances are, it’s probably struck down a couple of people in your workplace – so, what can you do to avoid getting it and what should you do if you get norovirus?

You’re often best self-treating at home without clogging up your doctors’ surgery, as GP and media medic Dr Roger Henderson explains here with his expert advice.

IT CAN BE NASTY

Norovirus can knock you for six, often starting with an achy fever and nausea, usually one to two days after exposure to the virus.

Virus particles enter the body through the nose or mouth, travel to the stomach, but it's only when they hit the small intestine that they start multiplying and irritating the gut lining - then the vomiting and watery diarrhoea strikes.

"This is the body saying, 'Get it out, clear it, clear it, clear it!" said Dr Henderson.

You might have stomach cramps and a headache too. The good news is it passes quickly and you should be fine in a few days, though some people do suffer worse than others: "That's probably linked to the viral load you're exposed to. If you're exposed to a very heavy viral load, you might feel worse."

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THERE'S PROBABLY NO NEED TO SEE YOUR GP

Dr Henderson stressed: "There's no cure for norovirus, it's just a case of treating the symptoms."

This means a trip to your GP's probably going to be futile - and put other people at risk.

"It's a miserable thing to get, but the vast majority of people will bounce back quite quickly. What they should not do, if they can, is walk into a doctor's surgery - because we're going to say, nicely, 'Go away' and give them general advice. But in the meantime, they'll have sat there spreading their germs left, right and centre."

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Dr Roger Henderson

BUT DO SEEK ADVICE IF YOU'RE CONCERNED

Like flu, norovirus can be "more risky in the very young and very old".

While it's highly unlikely to be a threat to the majority of people, with a vomiting and diarrhoea bug, the biggest risk is often linked to dehydration, which can quickly become serious - particularly for, as well as babies, young children and older people, those with pre-existing conditions like diabetes or a heart or kidney condition.

"The dangers [of dehydration include] reduced levels of consciousness, impact on your kidney function, altered confused states, and more prone to falls in the elderly.

“In children, you will get lethargy and weakness.”

If anyone's showing worrying signs, or if symptoms don't clear after a few days and you're concerned, phone your GP surgery or local out-of-hours or NHS helpline (of course, if somebody's very unwell and losing consciousness, call 999).

SELF-CARE AND TLC

Dr Henderson said: “In terms of treatment, fluid replacement is the main thing.

"You can take paracetamol and ibuprofen for aches and pains if you want to, and avoid certain foods - spicy foods, oily foods - most people won't want them anyway.

“Little and often” is often the best approach with eating. "Some toast, dry biscuits - everything is fine, to keep your sugar levels up, but the most important thing is fluids.”

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If you're vomiting lots, "if fluid stays down for at least five minutes, at least half of it will have gone into your system.

"A lot of people worry if they take a drink and vomit 10, 20 minutes later, they're not getting any benefit from the drink, but they are. It's when you vomit it straight back out that it can be a problem.”

If somebody's reluctant, too poorly, or just not aware how important it is to take on fluids, “fluid replacement products and sachets like Dioralyte [£3.79 for pack of six, Boots; suitable infants, children and adults] can be really helpful, because they stop you from getting low in certain salts.”

Aside from that, it's a question of resting and waiting it out.

DON'T RUSH BACK TO WORK, EITHER

There's lots of pressure to 'battle through' and not take time off sick, but while you may feel fine once the sickness stops, Dr Henderson noted you may still be contagious for up to two days after symptoms have passed.

"It's variable, but I always say assume you remain infected for about 48 hours after your symptoms have cleared.”

STOP THE SPREAD

The other key factor - to avoid spreading and catching the bug - is "scrupulous hygiene".

The virus spreads via droplet transmission and infected droplets can remain 'live' for "at least an hour" on hard surfaces, which is how it spreads so widely through touch.

To minimise risk, there are practical steps to take such as “using hand gels, always washing your hands after the loo, obviously, keeping hard surface areas clean and using antibacterial wipes in those areas. And [don't forget] things like handles, and making sure your toilet is kept clean with disinfectant.”