Alasdair McGregorThe Norfolk and Norwich University Hospital has closed its doors to all visitors due to the spread of the stomach bug norovirus.Alasdair McGregor

The Norfolk and Norwich University Hospital yesterday closed its doors to all visitors due to the spread of the stomach bug norovirus.

A hospital spokesman said last night that the restrictions would be reviewed on Wednesday.

Dr Judith Richards, of the hospital, said: 'We want to protect our patients by restricting the chances of people spreading the infection.

'For this reason, regrettably, we are asking that people do not visit unless absolutely necessary.

'It is very important that people who have had the virus, or been in contact with someone who has had it, take precautions to avoid spreading it.

'That means not going back to work or school until two days after the symptoms have stopped.'

The norovirus bug causes sickness and diarrhoea and is very easily spread from person to person. The spread of the infection is easiest in places where groups of people are in close proximity for reasonable amounts of time.

The virus lasts for around 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.