There has been a confirmed case of the H1N1 flu virus - otherwise known as H1N1 - at Cork University Hospital.
The hospital has said that some other patients are displaying symptoms of the virus, these have not been confirmed.
CUH has closed off one ward as a precaution and imposed visitor restrictions.
Dr Bartley Cryan, consultant microbiologist at CUH confirmed that there is one case confirmed of swine flu, while other patients have lower and higher respiratory tract infections.
He said there were seven cases in one ward where the hospital is waiting on results from the virus reference laboratory.
"The number of influenza-like incidents has increased over the last few weeks," he told RTE's Morning Ireland.
"We've asked visitors to consider seriously if they actually need to visit."
But he said "this isn't one of the big pandemic years", predicting that the situation will "normalise" in the next few weeks.
CUH is appealing to people to adhere to its new visiting restrictions. Anyone with queries about these restrictions should call the hospital in advance on (021) 4922 000.