Scores of hospital beds have closed because of an outbreak of the highly contagious norovirus.

Health officials have urged those suffering from the virus, which causes diarrhoea and vomiting, to stay at home rather than visiting their doctor's surgery or A&E, as this can easily spread the illness to vulnerable patients and health workers.

Some 41 beds remain closed at the 500-bed Northwick Park in Harrow, after 14 patients were confirmed with the virus. Another previously closed ward reopened yesterday after deep cleaning.

Visitors were restricted at the Richard Wells Ward at Bedford Hospital, with one guest permitted per patient each day. And a number of wards at the Doncaster Royal Infirmary and Montagu Hospital in South Yorkshire were closed to new patients.

Figures from the Health Protection Agency show that in the fortnight from 28 November to 11 December, there were 15 reports of suspected norovirus outbreaks in hospitals. Eight were confirmed, and 12 resulted in ward closures. HPA spokeswoman Kate Swan said the spread of the virus was at a level expected for this time of year.

She said there was no specific treatment, other than to let the illness run its course.