It is called the winter vomiting bug, but norovirus prevails throughout the year and statistics show that outbreaks are increasing in the region's hospitals.

It is called the winter vomiting bug, but norovirus prevails throughout the year and statistics show that outbreaks are increasing in the region's hospitals.

The highly contagious stomach bug costs the NHS more than �100m each year and an expert has warned that a new strain - one to which no-one has immunity - could be on its way and introducing a vaccine would be “ideal”.

Statistics obtained via a Freedom of Information request show that at the Queen Elizabeth Hospital in King's Lynn 79 patients tested positive for norovirus in 2008 and 70 in 2009. So far this year, 135 patients tested positive.

At West Suffolk Hospital, in Bury St Edmunds, 13 patients tested positive in 2007, there is no test data for 2008 but 58 people had symptoms, and eight patients tested positive in 2009. So far this year, 98 patients tested positive.

For each hospital, there were additional patients who were affected with norovirus symptoms.

The Norfolk and Norwich University Hospital said they could not provide details of outbreaks for previous years, but between December 21, 2009 and May 28, 2010 there were 133 confirmed cases.

The James Paget University Hospital said they could not provide any information on norovirus.

Dr Jim Gray, of the virology laboratory at the N&N's microbiology department, said that busier hospitals have caused a spread of the virus since the 1990s.

“It's a very easy virus to pick up,” said Dr Gray. “Norovirus is very much like flu and behaves in exactly the same way. I think a vaccine would be ideal.”