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PCR test (symbolic image): The influenza A(H1N2)v pathogen was discovered as part of routine surveillance

Photo: Ole Spata / dpa

In Great Britain, an infection with a special swine flu virus has been detected. Infection with this H1N2 variant has never been recorded in the country before, the UK Health Security Agency (UKHSA) said on Monday. The pathogen is therefore somewhat different from that of other recent cases in humans, but is similar to the viruses in British pigs.

The influenza A(H1N2)v pathogen was detected in a single case as part of routine surveillance by PCR test, the statement said. The person concerned had been tested for respiratory problems, had a mild course of the disease and had now fully recovered. The source of infection was not initially known.

Swine flu is a viral respiratory disease that is very common in pigs, with the subtypes H1N1, H1N2, H3N2 and H3N1 being particularly important. H and N refer to the two proteins of the viral envelope: hemagglutinin and neuraminidase. Sometimes infections occur in people, which are usually harmless. However, they carry the risk that the virus will turn into a more dangerous pathogen that can be transmitted from person to person.

Discovered during routine monitoring

The situation is being closely monitored. In parts of the county of North Yorkshire, surveillance measures have been tightened, the UKHSA said. "We are working urgently to identify the close contacts and reduce potential transmission," said Meera Chand, who is responsible for incidents at the UKHSA.

According to the UKHSA, there have been 2005 recorded cases of influenza A(H50N1)v in humans worldwide since 2. However, none of them was genetically related to the variant now found in Great Britain (1b.1.1).

"Although this is the first UK detection of this swine flu strain in humans, events occur regularly on a global scale in this context," Ian Brown of the Animal and Plant Health Agency told the Science Media Center (SMC). In general, these viruses are not able to spread from person to person. Rather, the infections are caused by direct or indirect contact with pigs, although the source of infection is unknown in the specific case. "This particular serogroup of influenza A virus has been present in British pigs for over 30 years and is often associated with herds suffering from respiratory diseases."

"The detection of a novel influenza virus is unusual, but not unique," John Edmunds of the London School of Hygiene & Tropical Medicine told SMC. This can occur when the flu skips different types or recombines two flu strains. Although these events usually cause viruses to have difficulty transmitting in their new hosts, there is always a risk that they will continue to adapt and thus become transmissible. The fact that the current case could have been discovered during routine surveillance is worrying. "This could indicate that the virus has already spread to some degree," Edmunds said.