The first human case of swine flu strain H1N2 has been detected in the United Kingdom, according to the UK Health Security Agency (UKHSA).

This strain, which is very similar to what has been circulating between pigs, was detected after routine surveillance in GP surgeries.

The UKHSA says it is now carrying out contact tracing with those who have been close to the infected individual.

While it is not yet known how transmissible this strain is or how many cases there are in the UK, here is how swine flu is transmitted.

Dorset Echo: Swine flu variant H1N1 began spreading in 2009 (Getty)Swine flu variant H1N1 began spreading in 2009 (Getty) (Image: Getty)

What is swine flu?

Swine flu (H1N1 and H1N2 strains) is a combination of influenza viruses that infect, pigs, birds and humans. This previously spread across the UK in the flu season of 2009 and 2010.

Mayo Clinic states that this flu and its many complications can be deadly, especially for those at high risk.

What are the symptoms of swine flu?

There are a number of symptoms associated with swine flu such as: 

  • Fever (sometimes)
  • Aching muscles.
  • Chills and sweats.
  • Cough.
  • Sore throat.
  • Runny or stuffy nose.
  • Watery, red eyes.
  • Eye pain.
  • Body aches.
  • Headache.
  • Tiredness and weakness.
  • Diarrhea.
  • Feeling sick and vomiting (more common in children)

How is swine flu spread?

According to the Centres for Disease Control and Prevention, swine flu is thought to spread mainly when an infected pig coughs or sneezes near a human.

The droplets with flu virus in them then spread through the air. If and when these droplets land in the nose or mouth of a human, the person can be infected.

There is also some evidence to suggest that people can get infected by touching something that has the virus on it and then touching their own mouth or nose.

Scientists are still unsure which of these forms of spread are more common.