Norovirus

Noroviruses are a group of viruses that can cause gastroenteritis. Gastroenteritis is an infection of the gut (intestines) which usually causes vomiting and diarrhoea. Norovirus is the most common virus causing gastroenteritis in adults in the UK. In most cases the infection clears within a few days, but sometimes takes longer and the main risk is dehydration. The treatment is to have plenty to drink. Also, once any dehydration is treated with fluids, you should eat as normally as possible. See a doctor if you suspect that you are becoming dehydrated.

How is norovirus spread?

A norovirus present in the gut of an infected person can pass out in their diarrhoea. It is easily spread from one infected person to another by close contact. This is usually because of the virus being present on the infected persons’ hands after they have been to the toilet. Surfaces or objects touched by the infected person can also allow transmission of the virus. The virus can be passed on if the infected person prepares food, or if water is contaminated with norovirus. Outbreaks of norovirus affecting large groups of people can occur in hospitals, on cruise ships and in schools. It usually takes 24-48 hours after first contact with norovirus before symptoms develop. This period is known as the incubation period for the virus.

Preventing spread of infection to others

If you or your family has a norovirus infection, the following points are recommended to prevent the spread of infection to others:

·        Wash your hands thoroughly after going to the toilet. Ideally, use liquid soap in warm running water, but any soap is better than none.

·        Dry properly after washing.

·        If your child wears nappies, be especially careful to wash your hands after changing nappies and before serving or eating food.

·        If a potty must be used, wear gloves when you handle it, dispose of the contents into a toilet, then wash the potty with hot water and detergent and leave it to dry.

·        Don't share towels and flannels.

·        Don't prepare or serve food for others.

·        If clothing or bedding is soiled, first remove any faeces into the toilet. Then wash in a separate wash at as high a temperature as possible.

·        Regularly clean your toilets with disinfectant (wipe the flush handle, toilet seat, tap surface and door handles with hot water and detergent at least once a day).

·        Keep a cloth just for cleaning the toilet (or use a disposable one each time).

·        Stay off work until at least 48 hours after the last episode of diarrhoea or vomiting. Avoid contact with other people as far as possible during this time.

Food handlers: if you work with food and develop diarrhoea or vomiting, you must immediately leave the food-handling area. For most, no other measures are needed other than staying away from work until at least 48 hours after the last episode of diarrhoea or vomiting.

Hand washing is the most important thing that you and your family can do. Always wash your hands and dry them thoroughly and teach children to wash and dry theirs:

·        After going to the toilet (and after changing nappies or helping an older child to go to the toilet).

·        Before preparing or touching food or drinks.

·        Before eating. 

·        If you smoke, you should also wash your hands before smoking.

The simple measure of washing hands regularly and properly is known to make a big difference to the chance of developing norovirus.

How common is norovirus infection and who gets it?

Norovirus is the most common virus causing gastroenteritis in adults in the UK. However, norovirus infection can occur in anyone of any age. You can get norovirus infection more than once because your body is not able to maintain immunity to norovirus infection.

What are the symptoms of norovirus infection?

Nausea (feeling sick) is usually the first symptom. This is followed by diarrhoea which tends to be watery. You may also start vomiting around the same time; sometimes there are other symptoms such as a fever, headache or aching muscles in your arms and legs. The symptoms tend to be relatively mild and short-lived, often only one to two days, however, in a few people symptoms can last longer. If symptoms are severe, dehydration can occur - this is when there is a lack of enough fluid in the body. You should consult a doctor quickly if you suspect that you or your family are becoming dehydrated. Mild dehydration is common and is usually easily reversed by drinking lots of fluids. Severe dehydration can be fatal unless quickly treated because the organs of your body need a certain amount of fluid to function properly.

When should I seek medical advice?

Most people who have gastroenteritis (including gastroenteritis caused by norovirus infection) have mild symptoms which will get better within a few days. The important thing is to ensure that you or your child has plenty to drink. In many cases, you do not need to seek medical advice; however, you should seek medical advice in the following cases (or if there are any other symptoms that you are concerned about):

·        If you suspect that you are, or your child is becoming dehydrated.

·        If you or your child are vomiting frequently and unable to keep fluids down.

·        If there is blood in the diarrhoea or vomit.

·        If there is blood in the diarrhoea or vomit

·        If you or your child have severe abdominal pain.

·        If you or your child have severe symptoms or if you feel that the condition is getting worse.

·        If you or your child have a persisting high fever.

·        If symptoms are not settling - for example, vomiting for more than 1-2 days, or diarrhoea that does not start to settle after 3-4 days. (for children vomiting for more than 24 hours, diarrhoea for more than 1 to 2 days)

·        Infections caught abroad.

·        If you are elderly or have an underlying health problem such as diabetes, epilepsy, inflammatory bowel disease or kidney disease.

·        If you have a weakened immune system because of chemotherapy treatment, long term steroid treatment, HIV infection etc.

·        If you are pregnant.

What is the treatment for norovirus in adults?

Symptoms often settle within a few days or so as your immune system usually clears the infection. Occasionally, admission to hospital is needed if symptoms are severe or if complications develop (see below). The following are commonly advised until symptoms ease.

Fluids - have lots to drink. The aim is to prevent dehydration, or to treat dehydration if it has developed. (Note: if you suspect that you are dehydrated, you should contact a doctor). As a rough guide, drink at least 200 mls after each bout of diarrhoea (after each watery stool). This extra fluid is in addition to what you would normally drink. For example, an adult will normally drink about two litres a day (more in hot countries).

If you vomit, wait 5-10 minutes and then start drinking again but more slowly i.e. a sip every 2-3 minutes, making sure that your total intake is as described above. You will need to drink even more if you are dehydrated.

A doctor will advise on how much to drink if you are dehydrated. For most adults, fluids should mainly be water, but ideally include some soup. It is best not to have drinks that contain a lot of sugar such as cola or pop, as they can sometimes make diarrhoea worse. Rehydration drinks are recommended in people who are frail, over the age of 60 or who have underlying health problems. These are sachets that you add to water and can be bought from pharmacies or are available on prescription. Whilst they do not stop or reduce diarrhoea, rehydration drinks provide a good balance of salts and sugar which helps the water to be absorbed from the gut into the body. Do not use home-made salt/sugar drinks as the quantity of salt and sugar must be exact.

Eat as normally as possible

It used to be advised not to eat for a while if you had gastroenteritis, however now it is advised to eat small, light meals if you can. Be guided by your appetite, you may not feel like food and most adults can do without food for a few days. Eat as soon as you are able but don't stop drinking. If you do feel like eating avoid fatty, spicy or heavy food. Plain foods such as wholemeal bread and rice are good foods to try eating.

Medication

Anti-diarrhoeal medicines are not usually necessary, but you may wish to reduce the number of trips that you need to make to the toilet. You can buy anti-diarrhoeal medicines from pharmacies.

 Reference Patient.co.uk

Children

Babies: Continue to give the baby their normal feeds but add extra fluid such as “Dioralyte”.

Your Health Visitor or GP surgery should be able to advise you on this.

If your baby has 3 or more episodes of vomiting in 24 hours and/or 6 or more episodes of diarrhoea in 24 hours, then they need to be seen by your GP or another doctor.

Children and Toddlers: To prevent dehydration, children and toddlers should be given clear fluids to drink, but you should avoid fizzy or sugary drinks especially in toddlers as this can make the diarrhoea worse. Soups and small meals are also advisable.

If your child has both vomiting and diarrhoea, diarrhoea for more than I to 2 days or evidence of blood in the diarrhoea, then advise should be sought from your GP or another doctor.

Reference: NHS Choices