Norovirus is extremely infectious and spreads very easily in public places such as nursing homes and schools. It's usually brought into hospital by visitors once it becomes prevalent in the community.
WATCH: Norovirus: The 'winter' vomiting bug
Beverley Geary, chief nurse at York Teaching Hospital NHS Foundation Trust, explains how norovirus outbreaks can disrupt services in hospitals and other healthcare facilities.
Become a norovirus-know-it-all
You might take chocolates, magazines or grapes when visiting a friend or relative in hospital but, whatever you bring, make sure it’s not norovirus. If you’ve been vomiting or had diarrhoea in the last 48 hours, do not visit hospitals or other healthcare centres such as GP surgeries. Read more
Norovirus explained: Q&A with a local GP
Every year, seemingly, wards in hospitals across the UK are temporarily closed in an attempt to prevent the spread of norovirus. But what is it? How is it spread? Is it treatable? Read more