On 27th November (Monday), the UK Health Security Agency (UKHSA) informed that it had detected a single confirmed human case of influenza A(H1N2)v, the UK government’s official press release said. According to the official statement, Influenza A(H1N2)v is similar to flu viruses that are currently circulating in pigs in the United Kingdom.
According to the release, the individual concerned had experienced a mild illness and has fully recovered. Now, the health agencies are tracing the close contacts of the concerned individual.
This was the first detection of this strain of flu in a human in the UK. However, the source of this infection has not yet been ascertained and health experts are investigating the matter. The UK’s Health agency is working closely with partners to determine the characteristics of the pathogen and assess the risk to human health, the release added.
The first human case of this strain of influenza virus was detected as part of routine national flu surveillance. It was undertaken by the UKHSA and the Royal College of General Practitioners (RCGP). The infected individual was tested by their GP after experiencing respiratory symptoms.
As per the health release, Influenza A(H1N2)v virus was detected by UKHSA using polymerase chain reaction (PCR) testing and characterised using genome sequencing.
Incident Director at UKHSA, Meera Chand said, “It is thanks to routine flu surveillance and genome sequencing that we have been able to detect this virus. 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.”
Further, Chief Veterinary Officer, Christine Middlemiss highlighted that some viruses found in animals can transmit to humans which is why it is important to focus on animal healthcare. The official said, “We know that some diseases of animals can be transferred to humans – which is why high standards of animal health, welfare, and biosecurity are so important.”
Influenza Virus and notorious ‘Swine Flu’
Influenza A(H1) viruses are endemic in swine populations in most regions of the world. But when an influenza virus, normally circulating in swine, is detected in a person, it is referred to as a ‘variant influenza virus’. The major subtypes of swine influenza A viruses present in pigs but have infected humans are H1N1, H1N2, and H3N2.
These infected cases mostly take place after direct or indirect exposure to pigs or contaminated environments. Since 2005, around 50 human cases of influenza A(H1N2)v have been reported globally however none of them relates genetically to this strain, and this Influenza A(H1N2)v was not previously detected in humans in the UK.
As per initial information, the infection in a human detected in the UK is a distinct clade (1b.1.1). This strand is different from recent human cases of influenza A(H1N2) detected elsewhere in the world. However, the strain is similar to viruses present in UK swine.
In 2009, a human pandemic was triggered by an influenza virus, specifically the influenza A H1N1(pdm09), often called ‘swine flu.’ This virus carried genetic material from viruses present in pigs, birds, and humans during the 1990s and 2000s. Influenza A H1N1(pdm09) now circulates seasonally among humans and is no longer labeled as swine flu. It differs from the viruses currently active in pig populations.
