Cork University Hospital has moved to its highest level of visitor restrictions due to a major outbreak of the winter vomiting bug.
It says several wards are now affected by Norovirus and multiple strains are circulating.
The CUH says al entrances to the hospital have now been secured and access is being tightly managed.
The public is asked not to visit friends or relatives unless a visit has been approved in advance on compassionate grounds.
Norovirus causes sudden vomiting and diarrhoea and spreads very easily, particularly in healthcare settings.
Anyone with symptoms should avoid attending the hospital unless urgent medical care is needed.
Patients who need urgent treatment and cannot access a GP or urgent care clinic are still advised to attend the Emergency Department.
