Norovirus – a nasty winter bug

What is it, how can you avoid catching it and what should you do if you think you have the norovirus?

PHE estimates noroviruses cause nearly three million cases of acute gastroenteritis annually, making it the leading cause of gastroenteritis in adults and children in the UK. It is usually around this time of the year where we start to see an increase in number of cases.

Each year there are a number of outbreaks of norovirus in cruise ships, hospitals and care homes due to close contact amongst people in these settings.  Norovirus is highly contagious and can spread anywhere people gather together, making people sick with vomiting and diarrhoea.

Norovirus outbreaks are difficult to prevent. Transmission occurs either person-to-person or through contamination of water or food. 

Symptoms usually develop 24 to 48 hours after ingestion of virus particles. Symptoms can include nausea, vomiting, diarrhoea and abdominal pain. Headache and a slight fever can also accompany this illness.   People infected will usually recover in one or two days without serious or long-term health effects. Many infections show similar symptoms to norovirus, so confirmed diagnosis is through testing of diarrhoea samples of those affected.

Young children, elderly people and immuno-compromised people can become more seriously ill, this is usually through severe dehydration. There is no treatment for norovirus and it is particularly important that more vulnerable patients remain hydrated.

The good news about norovirus is that thoroughly cooking foods destroys the virus because it does not multiply in foods as many bacteria do.    While traveling in areas that have polluted water sources, raw vegetables should be washed thoroughly before being served, and travellers should drink only boiled drinks or carbonated bottled beverages without ice.

One of the simplest and most effective methods to avoid the spread of norovirus outbreaks is to maintain good hand hygiene – washing hands thoroughly with soap and water when you have used the toilet, and before preparing food.

Avoid preparing food if you have symptoms of norovirus and avoid close contact with other people.

PHE has published information on the prevention of norovirus outbreaks on the website.