CASES of the illness which has hit York District Hospital have gone up dramatically overnight.

A total of 47 patients and 19 staff were said to be suffering from the virus, compared with 29 patients and 12 staff yesterday.

But George Wood, deputy chief executive of the York Health Trust, said changes in the numbers of people showing symptoms of the illness were to be expected, and the crucial factor was containing the virus to the seven wards which are already affected. "What critically matters is that no new areas are affected since yesterday - and they aren't," he said.

Hospital chiefs are waiting for symptoms to clear on the seven wards, which are closed to new admissions.

The outbreak of the illness, called a Norwalk-type virus which causes stomach upsets and diarrhoea, has led to the cancellation of all non-emergency operations at the hospital until after Easter.

A decision will be taken later today on whether these routine operations can resume on Tuesday.

Emergency operations have not been affected, and outpatient and day patient cases are being seen as normal.

Mr Wood said: "Staff are coping magnificently under very difficult circumstances, and overall the position continues to be very closely monitored."