New norovirus season – hygiene advice

Research shows that alcohol-based hand disinfection is not very effective against norovirus infection and that washing with soap and running water is important to remove the virus. In general, alcohol-based disinfection is an effective measure against other sources of infection.

Most common cause of gastrointestinal illness

Norovirus is responsible for at least 50 per cent of all outbreaks of gastrointestinal infection worldwide. In Norway, norovirus outbreaks usually occur in winter.

People of all ages can become infected but the disease is usually mild and otherwise healthy people feel better after 1-3 days.

It takes 12-48 hours from being infected to become sick. Symptoms include acute onset of nausea, vomiting, abdominal pain and watery diarrhoea. In addition, many experience influenza-like symptoms such as fever, muscle and joint aches and headache.

An infected person is most contagious while experiencing vomiting and diarrhoea, but can also be infectious when this has ceased. People can return to work or school when they feel better, but as they may still be infectious even after the symptoms have stopped, they should be extra vigilant about good hand hygiene in the first few days after recovery.

People who handle food should not return to work until 48 hours after vomiting and diarrhoea episodes have stopped. Children should be kept home from childcare until 48 hours after vomiting and diarrhoea have ceased.

Preventive hygiene

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

To clean surfaces, it is recommended to cover and wipe up vomit or faeces immediately, preferably with paper towels. Clean the surface with a bleach-based household cleaner, following the recommended concentration on the bottle (1 dl bleach to 5 litres of water). If the toilet, door handles, sink and other touch points are contaminated, wipe them over with a similar solution.