542 patients are left on A&E trolleys as flu strikes
Winter flu has arrived in Ireland, with 542 patients in need of a bed enduring delays on A&E trolleys yesterday.
The first case of the B strain of the virus has already been notified.
And the country's disease watchdog is to report other forms of the virus circulating this week.
Dr Cillian de Gascun, director of the National Virus Laboratory at UCD, said it was not possible to predict what kind of flu season was ahead.
Australia, which has its winter during Ireland's summer, had a "mild" season, he said.
The A(H1) strain - commonly known as swine flu - was the predominant virus circulating.
"In Ireland we have not seen an A(H1) predominant season since 2015 and 2016," said Dr de Gascun.
The strain has been detected this autumn in Ireland.
He said: "The number of hospitalisations is significantly lower in Australia this winter than last season.
"However, they are reporting the clinical severity as moderate. Although their season peaked in September, it is not over yet and we await their final analysis."
The vaccine produced before the flu season starts by predicting which strains are likely to be the most common during the upcoming season.
This year's shot provides some protection against three strains, including H1N1 and H3N2 and one influenza B strain.
Swine flu is now one of the seasonal viruses that circulate each winter.
Many people now have some level of immunity and it is much less of a concern than in 2009-10 when there was a flu pandemic.
People in at-risk groups are urged to get the flu vaccine.
Last winter, the impact was particularly severe for those aged 65 years and older, causing 65 deaths and putting 2,218 patients in hospital.
Meanwhile, A&E departments suffered one of the worst days in weeks yesterday as gridlock struck several hospitals.
There were 52 patients on trolleys waiting for a bed in University Hospital Limerick and 47 patients waiting on trolleys in both University Hospital Galway and Cork University Hospital.
It is expected to be early next year before the greater number of beds promised to ease the winter overcrowding crisis are in place.
The need for extra staff, as well as the delay in constructing modular buildings in a number of hospitals to accommodate the beds, is causing delays. The Budget allocated €10m to the winter initiative but many doctors fear there will be another record number of patients on trolleys in the coming months.