Reports of flu are now at a record level, with the number of people being admitted to hospital with the condition higher than ever before.
There have been 2,889 people hospitalised with flu since the season began last December, with 134 admitted to critical care units.
The HSE said 102 patients have died from the illness over the past three months, compared to 95 during the same period last season.
Normally, between 80 and 120 people die every season from the illness.
The HSE's Assistant National Director for Health Protection, Dr Kevin Kelleher said the number of deaths this season is now expected to be at "the top end of the normal range".
Dr Kelleher said that flu activity has been at high levels for the past seven weeks.
He said that while the flu season would normally have been expected to be over at this stage, it is now difficult to tell when it might end.
Dr Kelleher said it is not clear what the reason for the prolonged activity is, but the combination of the two prevalent strains (B&A) may be a contributory factor.
Cases of flu are mainly in the over 35s and under 15s and Dr Kelleher said the HSE would be contacting the Department of Education to ask it to reiterate to schools how to prevent the spread of the condition.
He said the vaccine is still available for those in the at-risk groups and that anyone who experiences symptoms should stay at home to avoid infecting others.
Dr Kelleher said the outbreak is putting pressure on hospitals and GP services, but the level of activity is similar to what is being experienced all over Europe this season.