Swine flu could be spreading silently in Britain, experts fear as officials scramble to curb a potential crisis.
It comes after a Briton fell ill with a strain never before seen in this country. The patient, who lives in North Yorkshire, was only picked up because they had been tested by their GP.
They had ‘mild’ flu-like symptoms, but recovered completely at home.
Bosses at the UK Health Security Agency (UKHSA) do not know how the person contracted the virus but the investigation is ‘ongoing’.
MailOnline understands that the infected Briton has not worked with pigs.
The unidentified person, believed to be from North Yorkshire, tested positive after visiting his GP with ‘respiratory symptoms’. UK Health Security (UKHSA) bosses are yet to identify how they contracted the virus. Officials are now rushing to trace all contacts of the Briton, who suffered from a ‘mild’ illness
Dr. Isabel Oliver, chief scientific officer at the UKHSA, revealed that ‘all possible routes of transmission’ are being investigated. Previous cases of H1N2, the variant that the infected Briton carried, have been traced to national fairs in the US.
She said: ‘It is possible that there has been limited transmission between people.
“We are increasing surveillance efforts to understand exactly whether any transmission has occurred and, if so, to what extent the virus has been transmitted.”
Professor John Edmunds, an influential infectious disease expert who is a member of SAGE and advised No10 during the Covid pandemic, said: ‘It appears the case was picked up during routine surveillance.
‘This is worrying because it could indicate that the virus has already spread to some extent.’
Epidemiologist Professor Francois Balloux, from University College London, also said the single case “may indicate circulation in humans” and requires “further monitoring”.
GP Dr Helen Wall said the detection was a ‘pure fluke’.
She told BBC Breakfast: ‘There will be a lot of studies now to find out whether it is more transmissible or more serious.”
Only a fraction of patients who go to the doctor with respiratory complaints, such as runny nose and cough, are tested.
The Briton, who was not identified, was given a PCR test, which can take days for the results to come back. UKHSA bosses have not confirmed whether the infected Briton had to self-isolate at any point.
The swine flu itself can lurk in the body for days before it also causes tell-tale symptoms.
Dr. Azeem Majeed, a public health expert from Imperial College London, told MailOnline: ‘It is possible that there are other undetected cases.’
Professor James Wood, an infectious disease epidemiologist from the University of Cambridgewarned that it is “very likely that a number of other people were also infected.”
Health chiefs are still looking for all contacts of the person who was ill.
Britons suffering from ‘respiratory complaints’, such as a runny nose, coughing and sore throat, are now being urged to avoid contact with other people. Similar advice is being used for Covid.
The symptoms of swine flu – which caused a pandemic that swept around the world in 2009 – mirror those of the regular flu and Covid.
But it does not spread easily between people.
Most cases occur in people exposed to infected pigs, such as fairground visitors and farmers. The number of cases of swine flu increases in pigs in the autumn and winter.
Deaths are rare and the disease usually clears up within a few weeks. In addition to the usual flu symptoms, some may experience diarrhea and vomiting.
The symptoms of swine flu – which caused a pandemic that swept around the world in 2009 – mirror those of the regular flu and Covid. But it does not spread easily between people. Most cases occur in people exposed to infected pigs, such as fairground visitors and farmers. The number of cases of swine flu increases in pigs in the autumn and winter
Since 2005, only 50 human cases of H1N2 have been reported worldwide.
But none of them have been to Britain. Nor is there one genetically related to this particular species.
However, virologists fear that swine flu could eventually pick up mutations that could cause the flu to quickly rip through populations.
Professor Edmunds said spillover events are ‘not unheard of’, but they usually just result in viruses that ‘struggle to be transmitted’.
Meanwhile, Professor Wood said the lone case was ‘not in itself a major concern’, adding: ‘Occasional skip and limited transmission of viruses such as swine flu from person to person are likely to be much more common than is detected.’
Dr. Majeed added: ‘The enhanced testing that the UKHSA will introduce should detect any increase in cases of H1N2.
‘I consider the risk of a major outbreak of swine flu in Britain to be low, although sporadic cases may continue to occur. People need to be vigilant, but not overly concerned about the risks of H1N2.”
In 2009, a swine flu pandemic emerged after a mutated version of H1N1 spread to humans.
That variant, scientifically known as H1N1(pdm09), contained genetic material from viruses circulating in pigs, birds and humans.
A independent assessment of the British response The 2009 pandemic revealed that 457 deaths were caused by swine flu in the country.
But the strain – which has killed tens of thousands of people across the planet – has barely spread in Britain since 2019. The disease now circulates seasonally among humans.
The mortality rate – the percentage of patients who died from the disease – was estimated at about 0.02 percent. By comparison, when Covid first hit, it had a mortality rate of up to three percent.