Norovirus, also known as winter vomiting disease, causes gastroenteritis and is highly infectious. The virus is easily transmitted through contact with infected individuals from one person to another.
Outbreaks are common in semi-enclosed environments such as hospitals, nursing homes, schools and cruise ships and can also occur in restaurants and hotels.
The virus is usually mild and lasts for 1 to 2 days. Symptoms include vomiting, projectile vomiting, diarrhoea and fever. Most people make a full recovery within a couple of days but it can be dangerous for the very young and elderly people.