At least 1,649 people have been struck down with the potentially deadly strain in England and Wales over the Christmas period.
Data from Public Health England showed that cases shot up by 48 per cent in just seven days.
The lethal virus claimed its first victims in Ireland as medics fear it is about to sweep the UK.
The HSE has revealed a number of people have died from the flu as cases of the strong ‘Aussie’ strain doubled in just one week.
The ‘Aussie flu’ caused havoc in Australian hospitals during their winter months.
The H3N2 subtype, which is a strain of influenza A, triggered two and a half times the normal number of cases in Australia.
Government statistics showed 1,111 people were struck down with the disease as temperatures plummeted last week – a 156 per cent jump on the previous seven days.
And the HSE has revealed under ten people have died from influenza so far this winter.
A further 73 have been hospitalised – causing medics to urge people to get vaccinated as the flue “actively circulates” in Ireland.
Dr Kevin Kelleher, from the Health Protection department, told Independent.ie: “There have been a few deaths already… under 10 people have died so far this year.
Now Public Health England have revealed there has been a sharp rise in cases triggered by a surge in two aggressive sub-types of flu.
But two weeks ago, 522 cases of type A and 546 cases of type B were recorded across England and Wales – with 43 cases yet to be identified.
So far this winter, 23 people have died from the outbreak and nearly a third occurred two weeks ago.
Experts warned to expect the worst outbreak in 50 years back in September as the NHS urged all eligible Brits to get the free flu jab – but admitted it was too late to tweak the strains in their stockpile.