The Mater Hospital in Dublin has asked people not to come and visit the hospital unless absolutely necessary.
It says this is because of the high levels of patients admitted with influenza.
Children under the age of 12 are not permitted to visit the hospital under any circumstances.
The Mater Hospital is currently experiencing high levels of patients admitted with Influenza and advises that members of public visit only when absolutely necessary.
Children under the age of 12 are not permitted to visit the hospital.
We thank the public for their cooperation
— Mater Hospital Trauma (@MaterTrauma) January 3, 2020
Recent statistics from the Health Protection Surveillance Centre (HPSC) indicated that influenza activity increased in Ireland in December.
It said influenza-like illness (ILI) rates rose to 57.9/100,000 population during week 50 of 2019.
Influenza A (known as H3N2) was the predominant influenza virus, with influenza activity expected to increase over the coming weeks.
During week 50 of 2019, it increased in all age groups - except in persons aged 65 years and older.
The number of influenza hospitalisations also increased, with the highest hospitalisation rates seen in those aged under five.
To date, 627 hospitalised confirmed influenza cases have been reported to HPSC - the majority due to influenza A.
Twenty-five confirmed flu cases have been admitted to critical care units.
While 17 influenza outbreaks and eight influenza-associated deaths have been reported to HPSC to date this season.
The majority of the deaths are in those aged 65 years and older.
Anyone who gets flu is advised to stay at home, rest, drink plenty of fluids and use over-the-counter remedies like paracetamol to ease symptoms.
Those in an at-risk group with flu symptoms should contact their GP.