How to prevent gastroenteritis caused by norovirus

What is norovirus?

Norovirus is the most common viral cause of gastroenteritis (also known as winter vomiting disease) worldwide.

Outbreaks of norovirus usually occur in winter in Norway. People of all ages can become infected and sick

Symptoms and transmission route

The disease is usually mild and passes after 1–3 days in otherwise healthy people.

It takes 12–48 hours from infection to becoming unwell. Symptoms include acute nausea, vomiting, abdominal cramps, and diarrhoea. In addition, many develop influenza-like symptoms such as fever, muscle and joint pain and headache.

An infected person is most contagious while they have vomiting and diarrhoea but can still be contagious after these symptoms subside. After 48 hours, most people shed fewer virus particles.

How to relieve symptoms?

In the vast majority of cases, the infection will go away on its own within a couple of days. There is normally no need to see a doctor in case of norovirus infection.

There is no treatment for gastroenteritis, but you can relieve symptoms and prevent complications.

The most important thing is to prevent dehydration. It is therefore important to drink plenty of fluids to replace the fluid loss caused by diarrhoea and vomiting, preferably in small sips at a time. Avoid drinks with a high sugar content.

You can also buy various electrolyte solutions at pharmacies that can help replace salt, sugar and fluid loss.

Returning to work, school or childcare centre?

• You can usually return to work and school when you feel better. You may still be infectious even after the symptoms have subsided, so good hand hygiene is especially important in the first few days after recovery.
• People who handle food (for example in commercial kitchens or canteens) should not return to work until 48 hours after vomiting and diarrhoea have subsided.
• Children in nurseries/ childcare centres should stay at home if they have symptoms and should not return until 48 hours after their vomiting and/or diarrhoea has subsided.

Advice for preventing infection

The best preventive measures against norovirus infection are good hand and kitchen hygiene. Good hand hygiene means thoroughly washing hands with soap and running water.

Alcohol-based hand sanitisers are less effective against norovirus.

It is important to have handwashing facilities available in places where many people gather, for example in schools, childcare centres and public places. Use disposable paper towels for drying hands, not hand towels.

Wipe surfaces that are soiled with vomit or faeces immediately, preferably using household paper. The surface can then be cleaned in the usual way with a cleaning agent and water. Household bleach can be used in the concentration stated on the bottle (1.25 dl chlorine per 5 litres of water). Check to see if the surface tolerates chlorine. Wipe over all touch points (toilet, door handle, sink) with the same solution.