Norovirus: Causes, symptoms and what you can do

Close up 3d render of an norovirus like micro organism isolated on black.
Close up 3d render of an norovirus like micro organism isolated on black.

The norovirus (aka winter vomiting bug) is the most-common stomach bug in the UK, usually making itself apparent with very unpleasant vomiting and diarrhoea which often begin suddenly. As well as the fast onset, the illness can also clear up relatively quickly, with symptoms starting 24 to 48 hours after exposure and usually lasting for two or three days.

See also: Cases of norovirus vomiting bug at five-year high

Other symptoms can include painful stomach cramps, aching limbs, a slight fever and headaches. Most of us suffer at home, but around 3,000 are admitted to hospital with the condition each year – so it's important to understand what to do if you have it, or fear you could catch it...

How do you get norovirus?
It's not a pleasant thought, but the illness is spread when small particles of poo or vomit from an infected individual get into your mouth. This is commonly through breathing in particles that have been exhaled, touching infected surfaces or eating contaminated foodstuffs.

Sufferers are contagious from when their symptoms begin until 48 hours after symptoms have stopped. Because the precise nature of the virus is ever-changing, it's unfortunately not possible to develop a tolerance when you've had it once.

It's possible to catch it anywhere, but can be particularly prolific in closed environments such as schools, hospitals and care homes. The illness is known as the "winter vomiting bug" because it's most common from November to April, but it's actually possible to catch it all year round, if you're unlucky.

What should I do if I get it?
The NHS advises against going to see your GP if you suspect you have the illness, both because of its contagious nature and because your doctor is unlikely to prescribe anything for it. Antibiotics are ineffective because it is a virus.

What you are advised to do is...
Drink plenty of fluids to ensure that you stay hydrated. Fruit juice or soup are also recommended, though children should not be given juice or fizzy drinks.

Take paracetamol to treat any aches or pains and to reduce any fever.

Make sure you get plenty of rest

Eat if you feel up to it, but keep it plain with things like rice, pasta, bread and soup.

Use rehydration powders if you fear you may have become dehydrated. The telltale signs are dark urine and a dry mouth.

Babies and young children are at a particularly high risk of becoming dehydrated and should be kept to their usual milk feeds, seeking medical advice if symptoms last longer than two days.
Older people are also at a higher risk from norovirus – as are those with existing health conditions.

How can I prevent it?
While there is no vaccine against the illness, it is possible to lessen the likelihood of catching or spreading it by taking a few common-sense precautions.

Regularly wash your hands with soap and water, particularly after using the toilet and before preparing food. Alcohol hand gels do not kill the virus.

Use a bleach-based household cleaner to disinfect any surfaces that may be contaminated.
Wash any clothing or bedding that may have been infected on a hot programme.

Exercise caution with raw and unwashed produce. Only eat oysters from a trusted source as they are known to carry norovirus.

You might feel better, but make sure you stay away from work, school or other people for a full 48 hours after symptoms pass.