Cork University Hospital is now the second busiest Covid hospital in the country.
Professor Conor Deasy, Emergency Medicine Lead at CUH, said the spread of the virus is the most serious since the start of the pandemic and that Cork has the second highest rate of Covid-19 in the country next to Dublin.
Healthcare workers at the hospital are seeing a lot of Covid positive patients who do not realise they have contracted the virus, Prof Deasy said.
100 nurses are currently off work at CUH due to being a close contact or because they have Covid.
Prof Deasy said CUH has had to adapt and reschedule out-patient appointments.
The hospital remains open but only for emergencies.
CUH continues to prioritise cancer care treatment and there have been no cancellations, he added.
Speaking on RTÉ's Morning Ireland, Porf Deasy said his strong advice is for the public to consider that everyone has CoviD-19.
"Stay at home and avoid taking a risk", he said.
Prof Deasy said CUH is coping at the moment but the neurosurgical ward has been closed to new admissions and the ICU is capacity.
"Things will get better, but we have a rough few weeks ahead", he added.
University Hospital Limerick is dealing with 47 Covid-19 positive cases and another 14 suspected cases. There were just four confirmed cases at the hospital on Christmas Eve.
There are six confirmed cases being treated at its ICU, up from zero on Christmas Eve.
Two critical care beds are available at the hospital, but they can increase that number and open further critical care beds as part of a surge plan as pressure on Covid numbers increases.
National figures show there were 652 cases of Covid infection in Limerick yesterday, the second highest in the country, so hospital admissions are expected to rise in the region.
They are fast approaching peak numbers of Covid patients - over 50 were being treated at the hospital during the peak Covid infection period last April.
No elective surgery takes place at UHL in the first two weeks of January as part of its normal winter plan.
Meanwhile, the HSE South/South West Hospital Group has confirmed that 2,500 frontline healthcare workers at three hospitals in Cork have been vaccinated against Covid-19 since last Friday.
500 doses of the Pfizer-BioNTech Covid-19 were first administered at Cork University Hospital on 29 December.
A further 2,000 doses of the vaccine were received on New Year's Day and staff at Cork University Hospital, the Mercy University Hospital and at the South Infirmary/Victoria University Hospital have since received their first dose of the vaccine.
More doses of the vaccine are due this week which will be distributed across the group, according to a spokesman today.
The group administers ten hospitals in counties Cork, Kerry and Tipperary with a total of 11,000 employees.