Researchers said the new virus - found in pigs - has become more infectious to humans and needs to be watched closely.
A new form of swine flu that has become more infectious to humans must be watched closely in case it becomes the next pandemic, researchers have warned.
The virus, found in pigs, has the potential to become a ‘pandemic virus’, a study in China found. Experts have said there is no ‘imminent threat’.
A team of researchers looked at influenza viruses found in pigs from 2011 to 2018 and found a ‘G4’ strain of H1N1 that has ‘all the essential hallmarks of a candidate pandemic virus’, according to a paper published by the US journal Proceedings of the National Academy of Sciences (PNAS).
Pig farm workers also showed elevated levels of the virus in their blood, the authors said, adding that ‘close monitoring in human populations, especially the workers in the swine industry, should be urgently implemented’.
The study warned there is a risk of viruses crossing from animals to humans – especially in densely populated areas in China where millions live close to farms, slaughterhouses and wet markets.
It is widely believed by experts that the virus behind the Covid
-19 pandemic originated in horseshoe bats in southwest China and spread to humans via a seafood market in the city of Wuhan, where coronavirus was first identified.
The PNAS study said pigs are considered important ‘mixing vessels’ for the generation of pandemic influenza viruses and called for ‘systematic surveillance’ of the problem.
China took action against an outbreak of avian H1N1 in 2009, restricting incoming flights from affected countries and putting tens of thousands of people into quarantine. The new virus identified in the study is a recombination of the 2009 H1N1 variant and a once prevalent strain found in pigs.
University of Washington biologist Carl Bergstrom said that while the virus is capable of infecting humans, there is no imminent risk of a new pandemic.
He said on Twitter following the study’s publication: ‘There’s no evidence that G4 is circulating in humans, despite five years of extensive exposure. ‘
That’s the key context to keep in mind.’