The Norovirus bug, which has affected almost one million people in England and Wales, is highly contagious and can be transmitted through contact with an infected person or contaminated surfaces and objects.
It is known to spread rapidly in closed environments such as hospitals, schools and nursing homes.
Although people can suffer from norovirus at any time of the year, activity increases in the winter months, with most cases seen between January and March.
– John Harris, Heath Protection Agency Norovirus expert
The number of laboratory confirmed cases has risen once again as it appears that we have seen the rise in cases that usually begins in January start a little earlier than we normally expect.
Norovirus is very contagious, and very unpleasant. To help prevent spread of the disease, it's important that people who believe they are unwell with the virus maintain good hand hygiene and stay away from hospitals, schools and care homes, as these closed environments are particularly prone to outbreaks which can cause severe disruption.