The Department of Health and Children has reported a doubling of human swine flu cases in the past week.
GPs have diagnosed around 5,400 new cases this week - double the number of cases found in the previous week.
26 patients are being treated in intensive care units for the virus.
The latest figures represent a rate of over 120 new cases for every 100,000 people.
Doctors expect the rates to increase further over the next few weeks with the reopening of workplaces and schools, but believe they should then start to decline.
The Department's Chief Medical Officer Dr Tony Holohan said the number of human swine flu cases could exceed the peak seen during the pandemic in 2009.
He said there is likely to be a continued rise in cases over the next two to four weeks.
During the peak of the pandemic in 2009, Ireland was seeing over 200 new cases for every 100,000 people.
No further deaths have been reported.
Latest figures from the Public Health Agency show the number of people being treated for swine flu continues to rise in Northern Ireland.
A total of 185 people had the H1N1 virus in the last week of December. This indicates an increase of 49 cases on the previous week.
The rates are highest in the 15-44 age group.
The PHA has said it is confident there will be no shortage of swine flu vaccines in Northern Ireland.