Everything you need to know about norovirus

Medically reviewed by words by Jenny Cook, Dr Louise Wiseman MBBS, BSc (Hons), DRCOG, MRCGP, Dr Roger Henderson
·6-min read
Photo credit: Getty Images
Photo credit: Getty Images

From Netdoctor

The Norovirus, also known as the winter vomiting bug, is one of the most common stomach bugs in the UK, affecting up to one million people each year. Typical symptoms include a sudden feeling of sickness followed by projectile vomiting and severe diarrhoea, often coupled with other flu-like symptoms including headache and aching limbs.

GP Dr Roger Henderson offers his expert advice on what to do if the bug strikes your family:

What is norovirus?

Norovirus is a viral infection which has some similarities to the flu. 'The difference is that it tends to be seasonal – occurring mainly in autumn and winter – because the number of other general viruses (coughs, colds etc) that increase at this time also help to spread the existing norovirus pool,' says Dr Henderson.

'Norovirus is highly contagious, so if you have one or two people with norovirus they will potentially expose that to 10 or 20 people and so very quickly it can go exponential, meaning that within a matter of weeks you can have a significant norovirus spread.'

⚠️ If you think you might have norovirus it is important that you stay off school or work for two days or until your symptoms have stopped, as this is is when you are most infectious.

Norovirus symptoms

The main symptoms of norovirus usually start within one to two days of being infected and include the following:

If you have the norovirus it's also common to have a high temperature of 38C or above, a headache and aching limbs.

Who is at risk of norovirus?

Norovirus is spread easily through close contact with an infected person, contaminated surfaces or objects, or eating contaminated food. While anyone can contract the virus, some people are more at risk than others.

'The most at-risk are the very young and very old because of the potential dehydration the virus can cause,' says Dr Henderson. 'The relatively small body size of babies and toddlers means that they can dehydrate far quicker than an adult and, while rarely fatal, it can sometimes mean hospital admission for young children for rehydration purposes.'

People with an impaired immune system – such as people undergoing chemotherapy treatment – are also at an increased risk from norovirus.

Norovirus and dehydration

Elderly people are at increased risk of contracting the norovirus due to the significant impact that dehydration can have on their physical and cognitive abilities. 'Elderly people are actually slightly more of a problem when it comes to norovirus, especially if they have pre-existing issues, such as kidney problems, diabetes, cardiac disease,' says Dr Henderson.

'Significant dehydration can have a really big impact – especially with kidney problems,' he adds. 'They can get very dehydrated very quickly, get confused, fall, develop UTIs… It can affect them really badly.'

Signs of dehydration to watch out for include the following:

  • Dry mouth

  • Peeing less frequently

  • Dark urine (your pee should be straw-coloured)

  • Feeling thirsty

  • Headache

  • Dizziness

Photo credit: Hero Images - Getty Images
Photo credit: Hero Images - Getty Images

Norovirus recovery

How long does norovirus typically last? According to the NHS, the virus usually goes away in a couple of days. 'The average amount of time that norovirus lasts in the UK is 1.2 days from exposure to presentation of symptoms,' says Dr Henderson. 'So that's 24-72 hours to clear, then 48 hours after symptoms have subsided before you can view yourself clear.'

However, some studies have found that you could be infectious for up to two weeks afterwards (with the virus remaining in your stool) so it is essential to be strict with hand hygiene and take care with food preparation at all times.

If you do contract norovirus, in order to prevent the spread of infection it's important that you let it run its course before returning to your usual routine. 'The mistake that people often make is going back to work or similar the day after symptoms have subsided, when they could still have the virus,' adds Dr Henderson.

Norovirus treatment

Where possible, the most effective norovirus treatment is simply to 'ride it out' at home. Here are some expert tips for managing the bug:

✔️ Keep hydrated

Drinking lots of fluids is the most important course of action for treating norovirus, as you need to replace the fluids your body loses through vomiting and diarrhoea.

✔️ Sip fluids to rehydrate

Sipping water little and often is the key to treating norovirus rather than drinking a lot all at once. This will help keep your stomach settled.

✔️ Take rehydration salts

Rehydration salts such as Dioralyte provides fast and effective treatment of fluid and electrolyte loss when you suffer from a bout of diarrhoea. Dioralyte doesn't stop the diarrhoea itself but it helps to stop you getting dehydrated.

✔️ Avoid caffeine and alcohol

Caffeine and alcohol can irritate the gut and exacerbate norovirus symptoms so try to avoid both until you feel better.

✔️ Avoid rich, spicy food

Eating little and often is key to norovirus recovery, but do not eat until you feel ready. Well cooked lean white meat is absolutely fine to eat if you can stomach it.

✔️ Take paracetamol

Paracetamol can help relieve headaches or other pains during a norovirus outbreak.

✔️ Wash your hands

Washing your hands frequently with soap and water is essential to prevent the spread of norovirus. Hand gels do not kill norovirus.

Should you visit your GP with norovirus?

To prevent the spread of infection, it's vitally important that you do not visit the hospital or your GP with norovirus unless you feel it is an emergency. Speak to your GP practice on the phone if you have any concerns.

However, the following high risk groups may need medical attention:

• Norovirus in the elderly

If you have an elderly relative with norovirus who has become very confused or you are worried about them, then do take them to a doctor. If you're not sure, call the GP practice in advance and ask for advice.

• Norovirus in children

With children, if they have vomiting or diarrhoea, a fever, get very quiet and drowsy, are irritable, stop weeing or develop a rash, then seek urgent medical help. Generally speaking, any child under the age of five who contracts a sickness bug should be seen by a GP. If you have any concerns about your child when they have a virus it is important that you speak to a doctor, as children can get dehydrated very quickly.

• Norovirus during pregnancy

If you contract norovirus during pregnancy try not to worry; it won't harm your baby and you can follow the same treatment guidelines as above. However, dehydration can be problematic when you're drinking for two, so take extra care to ensure you keep hydrated and speak to your doctor or midwife for advice.

Last updated: 18-11-20

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