Overview

Norovirus is an infection in your tummy (intestine or gut). It can live in people, and is passed on in their vomit (sick) or poo (stool). It’s very infectious and often has outbreaks in communities such as schools, care facilities, and families. It happens in the community and can be brought into hospitals and cause outbreaks on wards.

Symptoms of norovirus

Symptoms usually appear 1 to 2 days after exposure, and include:

• feeling sick (nausea)
• being sick (vomiting)
• diarrhoea
• stomach cramps

Infected people usually recover in 2 to 3 days without any serious long-term health effects.

How norovirus infections are spread

In a hospital or close-community setting, infection is very easily spread to others by contamination of bathroom and living areas when someone is sick or has diarrhoea. The virus can then be transmitted on other people’s hands, and then get into their mouths. 

You might also get the infection if you swallow food or water that has been contaminated with the virus by an infected person.

Anyone can get a norovirus infection, but it’s more common in adults and older children. The number of cases of norovirus changes all the time. Outbreaks are most common in winter.

Once you have the virus, it will start to be in your poo a few hours before you have any symptoms. This means you can be infectious before you feel ill. It will continue to be in your poo for up to 7 to 10 days.

You're most infectious between 24 and 72 hours (1 to 3 days) after you have been exposed to the virus. This might be before you show any symptoms.

How norovirus is diagnosed

Diagnosis can usually be made from your symptoms and the short time the illness lasts.  Sometimes samples of your poo or vomit need to be sent to a laboratory to confirm the diagnosis.

Treatment for norovirus infection

There’s no specific treatment, but you should drink lots of water to avoid dehydration. If you become severely dehydrated, you might need to be given liquids directly into a vein, through an IV (intravenous) drip.

How norovirus can be prevented and controlled

You can follow these steps to help prevent the spread of the virus.

At home and in the community

• Wash your hands with soap and water after toilet visits, and before preparing or eating food.
• Dispose of all sewage in a hygienic way.
• Cook all shellfish thoroughly before eating (most outbreaks caused by infected food have come from shellfish).
• Wash raw vegetables before eating them.
• Always wash your hands after handling bedding or clothing from someone who is unwell with any cause of diarrhoea.

In hospitals

• Wards with an outbreak of the infection might be closed to prevent the infection being passed to new arrivals. They might not be re-opened until 72 hours after the last new case.
• Visiting affected wards will be restricted to reduce the risk of cross-infection.
• Any visitors who have been unwell with the symptoms of the virus, or in contact with any known cases in the community, should not visit.
• If lots of cases happen, we might create isolation wards for patients that have the infection, or who have been in contact with other patients. This is because you can be infectious before you start feeling unwell (incubation period. If this happens, affected patients might be moved to the isolation wards. We only do this if we have to contain the outbreak and minimise the risk of the virus spreading.

Patients are expected to cooperate fully with the hospital to deal with this risk to the health of patients and staff.

We have information about the best way of washing your hands

Read the NHS information about norovirus