Dan GrimmerThe county's main hospital remains closed to visitors due to the spread of a winter vomiting bug.Dan Grimmer

The county's main hospital remains closed to visitors due to the spread of a winter vomiting bug.

People are being asked not to visit the Norfolk and Norwich University Hospital unless it is absolutely necessary and until the restrictions are reviewed later this week.

The norovirus stomach bug causes nausea and diarrhoea and is very easily spread from person to person. The spread of infection is easiest in places where group of people are in close proximity for reasonable amounts of time such as residential homes, schools, hospitals and workplaces.

The virus lasts about two days and no treatment is required, however even after the symptoms have cleared up people may still carry the virus and infect others up to three days after their own symptoms have stopped.