Reports nationally indicate that Donegal and Dublin are the country's worst "flu hotspots" as doctors warn it is sweeping all areas of the country, claiming eight lives so far this winter.
The east and north-west are the worst hit by the flu while the west and midlands have so far reported fewer cases of the virus.
The majority of the deaths have occurred in people aged 65 years and over.
The A(H3) strain of flu which is circulating can cause serious illness among the elderly.
the flu can leave you exhausted and with aches and pains and a chronic dry cough for up to six weeks. “For some people,” a doctor added,"The level of flu circulating rose again last week and public health officials fear it will be a particularly bad winter for the illness.
The number of hospitalisations increased last week and the highest rates were seen in those aged less than five years old.
To date this season, 627 hospitalised confirmed flu cases have been reported.
Vaccination remains the most effective means of preventing infection by seasonal flu viruses and can reduce severe disease that can lead to hospitalisation and death.
The vaccine takes two weeks to take effect once received.
The HSE warned that flu "is now circulating in the community in Ireland".
Influenza-like illness rose to 57.9 per 100,000 population last week. This is a jump from 36.8 per 100,000 during the previous week.
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