There have been 46 outbreaks of suspected norovirus in hospitals over the past two weeks, with more than half of them leading to ward closures or restrictions to admissions, the Health Protection Agency (HPA) has said.
There were 26 (57%) ward closures or restrictions to admissions between December 12 and 25, according to the latest HPA figures.
Seventeen of these were then confirmed as cases of norovirus following laboratory tests.
Since the beginning of October, there have been 244 outbreaks reported, with 153 (63%) leading to ward closures, and 125 (51%) being confirmed as norovirus outbreaks following laboratory tests. The HPA said the levels were within seasonal norms.
Its data for England showed that the average number of beds closed per day more than doubled from 720 to 1,545 between the weeks ending December 11 and December 18.
Norovirus is highly contagious and symptoms include sudden vomiting, diarrhoea or both, a temperature, headache and stomach cramps. The bug usually goes away within a few days.
John Harris, an HPA epidemiologist specialising in norovirus, said: "It is not surprising that we are seeing hospital ward closures due to norovirus as norovirus infections increase during the winter. Because the virus is highly contagious once it is in a hospital, closing wards to reduce the spread is often necessary and we commonly see this measure introduced at this time of the year."
Dr Bob Adak, head of epidemiological services in the gastrointestinal diseases department at the HPA, added: "Every year millions of people will be affected by a bout of norovirus and for most people it will be an unpleasant but short-lived illness lasting around two days.
"Anyone who thinks they may have it should not to go to their doctor's surgery or A&E as this could spread the illness to vulnerable people and healthcare workers. Take advice from NHS Direct or your local GP practice on managing the symptoms - the most important is to remain hydrated and the symptoms will pass within a couple of days."