Researchers have discovered a strain of swine flu virus in China with all the characteristics capable of causing a future pandemic, according to a study published on Monday in the American scientific journal PNAS.
The virus, named G4, is genetically descendant from the H1N1 strain that caused a swine flu pandemic in 2009.
The G4 viruses “have all the essential hallmarks of a candidate pandemic virus,” according to the authors of the study, scientists from Chinese universities and the Chinese Centre for Disease Control and Prevention.
From 2011 to 2018, the researchers took 30,000 nasal swabs from pigs in slaughterhouses in 10 Chinese provinces and in a veterinary hospital, allowing the isolation of 179 swine flu viruses. The majority were of the G4 variety, which has become dominant in pigs since 2016.
Researchers then conducted a variety of laboratory experiments and experiments on ferrets. These animals are widely used in flu research because their symptoms – fever, coughing and sneezing – are comparable to those of humans.
“Serological surveillance among swine workers and general population showed that G4 EA H1N1 viruses have acquired increased human infectivity,” the researchers warned, claiming around 10.4% of swine workers were infected, as well as 4.4% of the general population.
In other words, the virus has already been passed onto humans. While there is no evidence yet that it can be transmitted from human to human, “it is of concern that human infection of G4 virus will further human adaptation and increase the risk of a human pandemic.” Surveillance of populations working in contact with pigs is urgently needed, according to the researchers.
“Right now we are distracted with coronavirus and rightly so,” Professor Kin-Chow Chang told the BBC, “but we must not lose sight of potentially dangerous new viruses.”
The Brussels Times