The Norwalk virus is highly contagious

Some 130 patients and staff at the Royal Cornwall in Treliske have succumbed to vomiting and diarrhoea caused by the bug. Ten wards are affected and six have been closed.

Some surgical sessions have been cancelled, and GPs are being asked to keep non-essential referrals to a minimum.

Relatives and friends of patients are being asked to keep visits to a minimum.

Emergency referrals

The virus has also led to new admissions being cancelled in one ward at the Royal Devon and Exeter Hospital in Exeter.

The hospital had only recently got back to normal after an outbreak which affected 30 patients and 50 staff.

The Norwalk bug is highly contagious and causes vomiting and stomach upsets, but is not life-threatening.

Managers at the Royal Cornwall Hospitals Trust are hoping to re-open the wards in the next few days.

Andrew Telfer Brunton, the director of the public health laboratory in Truro, said: "The illness comes at a time when we are also receiving high numbers of emergency referrals.

"And it is considerably more difficult to contain in one area when out breaks appear to originate from different sources.

"Over the past six months staff at the hospital have been successful in managing the virus, but it does pose difficulties for the hospital in terms of the ability to discharge patients to other care facilities and to free up beds for emergency and planned admissions."

Spreads rapidly

The number of reported cases of Norwalk around the UK has increased 10-fold in the past year.

Norwalk is an airborne virus and spreads rapidly in any setting where large numbers of people are in close proximity.

It can be brought into hospitals by newly admitted patients, visitors and staff.

In most people the symptoms are gone within a couple of days.