The Midlands Health Board has asked members of the public who have experienced virus-like symptoms over the past four days to avoid visiting the regional hospital in Tullamore, Co Offaly.
In a statement issued this morning, the health board said a highly infectious virus had been detected in the region that, if contracted by the elderly or babies, could be dangerous.
The statement asks people who have experience nausea, vomiting and/or diarrhoea with the last 48 hours to avoid the hospital, and for those who have displayed the same symptoms over the past four days to report to staff if they visit the hospital.
Visitors are also being asked to obey all directives from staff and to avoid all isolated areas in the hospital.
The nature or origin of the virus is as yet unknown, as are its likely effects. Patients who were expecting to be admitted today, or in the near future have been asked to contact the hospital before turning up for admission.