A worsening flu outbreak could "spread like wildfire" in overcrowded hospital emergency departments, a leading consultant has warned.
There is growing concern about the spread of influenza and its potential to trigger more fatalities.
The number of reported deaths has risen sharply in the past week after a spike in people contracting the virus.
Five influenza-associated deaths have been reported which included an infant under four.
Beaumont Hospital in north Dublin is gripped in a flu outbreak and was forced to impose visitor restrictions at the weekend.
President of the Irish Association of Emergency Medicine Dr Fergal Hickey warned that overcrowded emergency departments were to blame for the exacerbated seasonal spread of flu.
Figures seen by the Irish Independent show the extent of the long wait facing many emergency patients in hospitals across the country.
The most overcrowded hospitals leave almost a third of patients enduring nine hours or longer waiting on trolleys.
Every hospital has failed to meet a target set by the HSE to have all patients admitted to a bed or discharged and sent home within nine hours, with Beaumont performing the worst.
During the first week of this month, the rate of people presenting to their GP with influenza-like illnesses around Ireland increased to 32.4 per 100,000 population, from a rate of 20.5 per 100,000 the week before.