Hospitals in England are now seeing very high rates of patients with flu, according to Public Health England figures.
A sharp rise in cases seen by GPs in the past week – up 78% on the week before – suggests it could be the worst flu season for seven years.
But PHE said the current levels of flu were “not unprecedented”.
Deaths from flu remained static with 27 in the past seven days.
Prof Paul Cosford, medical director from Public Health England, said: “The levels of flu being seen are high and of course that is contributing to the pressures in the NHS, but they are not unprecedented levels.”
He also suggested the coverage of the so-called Aussie flu outbreak was a little misleading, saying that while it was circulating at “significant” levels there were two other strains that were also causing problems.
The rate of hospital admissions in England rose by over 50% in the first week of January to 7.38 per 100,000.
In the same week, the GP consultation rate was 37.3 per 100,000 compared to 21 per 100,000 the week before.