An investigation is underway and specialist cleaning has been carried out at a popular south Norfolk pub after a large party of diners came down with the virulent winter vomiting bug.

An investigation is underway and specialist cleaning has been carried out at a popular south Norfolk pub after a large party of diners came down with the virulent winter vomiting bug.

Eighteen people from a group of 21 suffered severe vomiting and upset stomachs as a result of the norovirus, which is very easily passed from person to person, and was recently responsible for a spate of ward closures and visiting bans at the Norfolk and Norwich University Hospital.

The Village Inn in Little Melton was recently rebranded as a Crown Carvery and has been successful at attracting customers with its �3.50 carvery offer.

The Norfolk, Suffolk and Cambs Health Protection Unit (HPU) and South Norfolk District Council environmental health officers are investigating the outbreak, which the pub's owners said was not related to food poisoning or hygiene standards at the pub.

After the winter vomiting bug struck on Saturday, February 21, the function room where the party was eating was closed but the rest of the pub remained open for business. The function room has since reopened after being sanitised.

A spokesman for Mitchells and Butlers - the pub's owners - said: 'As soon as the manager realised what the problem was, he did everything right. The environmental health officer was there and there was no need to close the whole pub.'

The group had visited the pub at around 7pm to celebrate a birthday.

A member of the party said they enjoyed the evening, but in the early hours of the following Monday, 13 of the party became violently ill, while another five also complained of feeling unwell.

A female member of the group said: 'Environmental health told us of the possibility of norovirus as it is such a virulent virus and can attack lots of people in 24 to 48 hours from the airborne particles which can travel everywhere and stick to everything.

'We were told 690 people went through those doors on the Saturday from the carvery ticket sales and I cannot believe there are not numerous more cases.'

The woman, who did not want to be named, said she was surprised and concerned the whole of the pub had not been closed, however environmental health experts and the pub's bosses said this was not necessary.

The Norfolk, Suffolk and Cambridgeshire Health Protection Unit (HPU) is working with environmental health officers from South Norfolk council to investigate the outbreak.

Dr Chris Williams, the Norfolk, Suffolk and Cambridgeshire Health Protection Unit's (HPU) consultant in Communicable Disease Control for Norfolk, said: 'Norovirus is a common cause of infectious gastroenteritis and can cause clusters of cases like this one.

'Health advice has been given to the people affected to prevent any secondary cases, and the restaurant has undertaken specialist cleaning of potentially affected areas.'

An investigation is underway to determine the exact cause of the sickness, and one possibility is that one of the party members was already carrying the virus.

Explaining further the reasons why the pub was not closed, a spokeswoman for Mitchells and Butlers said the only people affected by the virus were in a separate function room.

She added: 'No-one was affected in the main pub or other areas. It was all sanitised and given antiviral treatments. The environmental health officer was there and they were happy it was nothing to do with the pub and that it was a viral thing that is just passed from person to person.'

Norovirus is the most frequent cause of infectious gastroenteritis in England and Wales. It is also known as the 'winter vomiting disease' due to its seasonality and typical symptoms of vomiting and diarrhoea.