A surge in flu cases will present the NHS with a challenge “unlike any it has seen since the pandemic”, Health Secretary Wes Streeting has said.

Writing in the Times, Streeting said the NHS was in a “precarious situation”, and warned that next week’s planned strikes by resident doctors could be the “Jenga piece that collapses the tower”.

The number of patients in hospital with influenza has risen more than 50% in the past week, with officials warning there is still no sign of it peaking yet.

In the week up to Sunday there were 2,660 flu cases a day on average in hospital, which NHS England said was the equivalent of having three hospitals full of flu patients.

But the Medical Director for the NHS in London, Chris Streather, said the flu situation was “well within the boundaries” of what the NHS could cope with and that hospitals were better prepared for large disease outbreaks since the Covid pandemic.

Speculation is probably not helpful and can cause people to worry, he added.

Flu has come early this winter, and it looks to be a particularly nasty season because of a new mutated version of the virus which is circulating, say experts.

People have not encountered much of it in recent years, which means there is less built up immunity against it in the community. For these reasons, many are now calling it “super flu”, but it is not more severe or harder to treat.

Streeting told LBC in an interview that the “double whammy” of flu and strikes was extremely worrying.

A five-day strike by resident doctors, the new name for junior doctors, is set to begin on 17 December. There are hopes it could be called off after a fresh offer from the health secretary to the British Medical Association (BMA) earlier this week.

The BMA has agreed to poll their members to see if they were willing to call off the walkout, with the results of the vote to be released on Monday.

The number of patients in hospital with flu is at its highest level at this time of year since records began – although they only date back to 2021 and so do not capture the two worst flu seasons of the past 15 years which were seen in 2014-15 and 2017-18.

Officials said cases had continued rising throughout the week, with fears they could top 5,000 by the weekend.

In Scotland, the number of confirmed cases rose by nearly a quarter in the last week, while the number of people admitted to hospital for flu went up 15%.

The picture was similar in Wales and Northern Ireland, with children and young people particularly affected, according to health officials there.

Some schools have had to bring back Covid-like measures to prevent the spread of the virus. One site in Caerphilly had to close temporarily while some schools in Aberdeenshire reduced their hours.

Children and young people aged five to 14 also had the highest positivity rates for flu in England.

But in terms of who is most affected or sickest, hospital admission rates for flu in England are highest among people over 75 and children under five.

Despite the sudden surge in cases, medical director for NHS London Chris Streather said the scale of the problem was “nothing like the 2020 pandemic”.

He warned that professionals needed to choose their language carefully to ensure they do not cause alarm.

“The NHS is coping at the moment but flu rates are still going up and in some ways we can’t tell until its peaked when that peak will be”, he said.

Meanwhile, NHS England medical director Prof Meghana Pandit said: “This unprecedented wave of super flu is leaving the NHS facing a worst-case scenario for this time of year – with staff being pushed to the limit to keep providing the best possible care for patients.”

In his article for the Times, Streeting said that the number of people admitted to hospital with flu “could triple by the peak of the pressures – and the NHS doesn’t know when the peak will hit”.

He also urged people to get a flu jab, noting that 17 million people have already been vaccinated against the virus.

Flu rates began rising a month earlier than normal this year driven by a mutated strain of the virus. The dominant strain is H3N2, but it has some genetic changes this year.

It means the general public has not encountered this exact version of flu before, which means there is maybe less immunity.

NHS England said the number of patients in hospital with the vomiting bug norovirus was also on the rise, with more than 350 beds occupied by people with that virus.

The “incredibly difficult” period is why Streeting said he was “appealing directly to resident doctors to accept the government’s offer” and avert their planned strike.

Prime Minister Sir Keir Starmer has accused the BMA of being “irresponsible” and said it should accept it, adding the offer can only go forward if they stop strike action “particularly in the run-up to Christmas, particularly when we’ve got a problem with flu.”

Daniel Elkeles, of NHS Providers, which represents hospitals, said: “The NHS is in the thick of a storm come early. Flu is hitting hard and other winter bugs are surging.

“Now more than ever, the NHS needs all hands on deck.

“We have to hope that BMA resident doctors will step back from next week’s strike, take up the government’s sensible offer and end their damaging dispute.”

Earlier this week, BMA resident doctors committee chairman, Dr Jack Fletcher, said the offer from the government was “the result of thousands of resident doctors showing that they are prepared to stand up for their profession and its future”.

He said they had “forced the government to recognise the scale of the problems”, but said the offer did nothing to restore pay for doctors.

Data from the UK Health Security Agency (UKHSA), which takes into account levels of infection in the community as well as hospitals, shows infection rates are continuing to rise, but not as sharply as they were in the previous week.

But officials stressed it was too early to take that as a sign that flu could be peaking, adding that the virus was unpredictable and a lull could be followed by another surge.

Dr Conall Watson, an infectious diseases expert at the UKHSA, urged people who are eligible for a free flu vaccine on the NHS – which includes the over 65s, those with certain health conditions and pregnant women – to still come forward ahead of the Christmas period.

It can take up to two weeks following vaccination to develop the fullest protection from the jab, Dr Watson added.

Dr Vicky Price, president of the Society for Acute Medicine, accused NHS England and the government of using winter viruses as a “convenient scapegoat” for the “predictable breakdown” in NHS capacity caused by workforce shortages.

“The situation in emergency departments has become so dire that what was once considered a critical incident is now seen as normal and routine. What is happening is not an isolated emergency, but the culmination of systemic failure.”

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