
Swine flu in the UK: What are the symptoms of the new strain?
Peer reviewed by Dr Krishna Vakharia, MRCGPAuthored by Lydia SmithOriginally published 28 Nov 2023
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A case of a new strain of swine flu has been confirmed in the UK. The infection was detected in a routine flu screening test at a GP surgery in North Yorkshire. Here's everything you need to know about the virus.
What is swine flu?
Swine flu is a type of viral infection. It's called swine flu because it resembles a respiratory infection that pigs can get. This is the first detection of this particular strain of swine flu - called A(H1N2)v - in a human in the UK.
Swine flu is usually caused by three subtypes called H1N1, H1N2 and H3N2. These types occasionally infect humans, usually after direct or indirect exposure to pigs or contaminated environments.
In 2009, a swine flu pandemic caused by H1N1 infected millions of people worldwide. However, the current confirmed case is from a different strain.
The person infected, who has not been identified, had a mild illness but has now recovered.
How was this case of swine flu detected?
The case was discovered as part of routine national flu surveillance, undertaken by the UK Health Security Agency (UKHSA) and the Royal College of General Practitioners (RCGP).
The patient was tested by their GP in North Yorkshire on 9 November after experiencing respiratory symptoms. The infection was then identified via polymerase chain reaction (PCR) testing and genome sequencing - the process for analysing a sample of DNA.
Meera Chand, incident director at UKHSA, said experts are finding out more about how the person became infected1. They are not believed to have worked with pigs.
Officials are investigating where the infection came from and its risk to human health.
"It is thanks to routine flu surveillance and genome sequencing that we have been able to detect this virus," said Chand. "This is the first time we have detected this virus in humans in the UK, though it is very similar to viruses that have been detected in pigs.
"We are working rapidly to trace close contacts and reduce any potential spread. In accordance with established protocols, investigations are underway to learn how the person became infected and to assess whether there are any other related cases," she added.
What are the symptoms of swine flu?
For most people, swine flu is mild. The symptoms include tiredness, a high temperature, a cough, a sore throat, aching muscles, chills, a runny nose, loss of appetite and sometimes vomiting and diarrhoea. Usually, the symptoms last for around a week.
Some people can become seriously ill with flu, including those that are immunocompromised or are pregnant. This is why it's important to have the annual flu jab. However, the routine flu jab does not protect against swine flu.
How do you treat swine flu?
Swine flu is treated with rest, fluids and over-the-counter pain medication such as paracetamol.
The UKHSA advises avoiding contact with other people while you have symptoms, especially if they are elderly or have existing medical conditions.
How to protect yourself from the flu
Getting your annual flu vaccination will help to protect you from becoming seriously ill from other strains of flu.
Whilst there are vaccines for swine flu- these are only given under certain conditions.
To protect yourself from flu, it's important to wash your hands regularly with soap and water. You can also use hand sanitiser if you can't access soap and water - for example, if you're on public transport.
It also helps to keep your hands away from your face whenever possible, as germs are most likely to enter your body through your eyes, nose and mouth. If you’re ill with flu, being around others puts them at risk - so you should stay at home to avoid infecting others.
Further reading
1. Gov.uk: UKHSA detects human case of influenza A(H1N2)v.
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About the authorView full bio

Lydia Smith
Feature writer
BA, MA, MSc
Lydia Smith is an award-winning journalist and feature writer who has written extensively on women's health and mental health. She is currently studying for an MSc in psychology.
About the reviewerView full bio

Dr Krishna Vakharia, MRCGP
Chief Medical Officer for Health, Optum UK
MBChB, MRCGP(2013), BMedSci (hons), DFSRH, DRCOG, PGDipDerm (Distn)
Dr Krishna Vakharia is an NHS GP. She is also a regular examiner for the postgraduate Diploma in Practical Dermatology at Cardiff University as well as being the Chief Medical Officer for health at Optum UK.
Article history
The information on this page is peer reviewed by qualified clinicians.
Article also available in English, German, Spanish, French, Italian, Portuguese, Hindi, Hebrew, Arabic, and Swedish.
28 Nov 2023 | Originally published
Authored by:
Lydia SmithPeer reviewed by
Dr Krishna Vakharia, MRCGP

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