Symptoms often start with the sudden onset of nausea followed by vomiting and watery diarrhoea.
Some people may have a raised temperature, headaches and aching limbs.
The illness is self-limiting and the symptoms will last for 12 to 60 hours. Most people make a full recovery within 1-2 days. However some people (usually the very young or elderly) may become very dehydrated and require hospital treatment.
Those who have been infected should be excluded for up to 48 hours after their symptoms have ceased.
There is no specific treatment for norovirus apart from letting the illness run its
course. It is important to drink plenty of fluids to prevent dehydration. Norovirus does not respond to treatment with antibiotics.
Usually 24 to 48 hours.
The infective dose is extremely low, a person can become infected as a result of contact with a very small number of virus particles e.g. from touching a contaminated toilet or touching the area surrounding a vomiting incident.
A person remains infectious for 48 hours after symptoms have ceased.
Noroviruses are found in the vomit and faeces of infected people.
People can become infected with the virus in several ways including by:
- Eating food or drinking liquids that are contaminated with norovirus
- Touching surfaces or objects contaminated with norovirus (e.g. toilets, handles and taps and then placing their hand in their mouth).
- Having direct contact with another person who is infected and showing symptoms (for example, when caring for someone with illness, or sharing foods or eating utensils with someone who is ill).
Prevention of cases of norovirus
Good hygiene is especially important in preventing yourself and others from becoming infected.
Norovirus is easily spread from one person to another and the virus is able to survive in the environment for many days.
Norovirus is prevented from spreading by excluding those with symptoms, regular hand washing and robust environmental cleaning.
After every visit to the toilet and before handling or eating food pupils and staff should wash their hands thoroughly with soap and hot water, and should dry them on single use paper towels.
Young children may need supervision to ensure that adequate hand washing takes place.
An adequate supply of toilet paper, soap and paper towels should be available in school toilets at all times.
Regular cleaning is important.
Vomiting and diarrhoea can cause widespread contamination of the surrounding area (clothing, furniture, flooring, doors and handles). Any surfaces potentially contaminated should be thoroughly cleaned with hot soapy water and a diluted bleach solution at the correct dilution-see manufacturers’ guidance on bottle.
Toilet bowls, seats and flush handles along with any other surfaces that may
have been touched by contaminated hands (i.e. door handles, tap handles etc.) should be washed and disinfected daily with and a diluted bleach solution at the correct dilution-see manufacturers guidance on bottle.
Pupils and staff who have been infected should be advised to remain off school for 48 hours after their symptoms have ceased.
They should not visit friends or relatives in hospitals, nursing or residential care homes for 48 hours after their symptoms have ceased.
Care of affected cases
If possible anyone with symptoms should use a designated toilet not in general use by others.
Disposable gloves and aprons should be worn by staff cleaning up after an episode of illness.
Soiled clothes and bed linen should be washed on a hot wash.