People with the flu or flu-symptoms are currently making up half of all patients in hospital emergency departments waiting to be admitted to beds, adding to the serious strain on the health service in recent weeks.
At least 18 people have died from the illness so far this season with up to 100 people expected to die before the flu season ends.
Anne O'Connor, Health Service Executive (HSE) chief operations officer, said the flu season was putting pressure on emergency departments with the national trolley count up by more than 11 per cent compared to this time last year.
“About 50 per cent of people in our emergency departments are there because of flu,” she said.
“We know that the flu has come early . . . The peak has come we think,” Ms O’Connor told media at a press briefing on Friday.
This flu season is more severe compared to last year and started four weeks earlier, with officials warning it is expected to last for a further five weeks.
Over 26,900 patients attended emergency departments in the week ending on 17th December, a 7.5 per cent increase on last year, according to HSE figures.
Minister for Health Simon Harris said the high numbers of flu patients presenting to emergency departments had put "significant pressure" on hospitals.
“We would hope over the coming weeks to see flu levels reduce in our country but there’s no doubt this is going to put significant pressure on our health service,” he said.
Dr Vida Hamilton, HSE national clinical advisor for acute hospitals, said around a quarter of those who attended emergency departments were admitted into hospital beds.
“That does not mean that the other 75 [per cent] did not require the expertise of the doctors, nurses in the emergency department,” she said.
“People don’t attend our emergency departments lightly, people do get complications of the flu, it can be a very severe illness,” she said.
“So if people are really sick, if they are confused, if they can’t complete a sentence without gasping for breath and if they are unable to pass water they do need to attend the emergency department,” Dr Hamilton said.
Dr Kevin Kelleher, HSE assistant national director for public health, said he expected the number of deaths directly related to the flu to reach 100 in the coming weeks.
However, he said many people who died after being admitted to hospital with the flu had other underlying conditions.
“So they will die from pneumonia, they will die from their heart disease or something else, and that figure longer term is normally around 300 or 400 in total,” he said.
The health service has issued more batches of the flu vaccine than any other year, with the number of healthcare workers receiving the vaccinations markedly up, Dr Kelleher said.
Health officials advised people with flu-like symptoms to isolate themselves and stay at home to treat the illness where possible.