Two wards at Roscommon County Hospital were closed to new admissions yesterday following an outbreak of the winter vomiting bug.
Some 17 patients were affected and the Health Service Executive (HSE) for the Western region (formerly the Western Health Board) said an outbreak control committee had been formed.
There were also 19 patients affected at Dublin's St James's Hospital and 11 patients were continuing to display symptoms of the bug at Tallaght Hospital, a spokeswoman confirmed. And at the Midlands Regional Hospital in Tullamore, some six patients were being treated for the condition. A small number of patients also have symptoms at Dublin's Beaumont and St Vincent's Hospitals.
The HSE in the west appealed to the public to help it prevent the bug spreading. People should not visit the Roscommon hospital unless it was essential to do so, it said.
"Visitors who themselves may be unwell or have vomiting or diarrhoea should not visit the hospital. Very young children, or those with some other serious illness, should avoid visiting the hospital as they may be particularly susceptible to the virus."
Meanwhile, there were again 277 patients on trolleys in A&E units across the State yesterday, according to the Irish Nurses Organisation.