Washington (AFP). Researchers from China have discovered a new type of swine flu that can cause a pandemic, according to a study published Monday in the American scientific journal PNAS.
Called G4, it is genetically derived from the H1N1 strain that caused a pandemic in 2009.
It has “all the main signs of high adaptability to infecting people,” say authors, scientists from Chinese universities and the Chinese Center for Disease Control and Prevention.
From 2011 to 2018, researchers took 30,000 swabs from pigs from pigs in slaughterhouses in 10 provinces of China and in a veterinary hospital, which allowed them to isolate 179 swine flu viruses.
Most of them were of the new type, which has been dominant among pigs since 2016.
Researchers then conducted various experiments, including ferrets, which are widely used in flu research because they experience symptoms similar to humans – mainly fever, coughing and sneezing.
G4 was found to be highly infectious, propagating in human cells and causing more severe symptoms in ferrets than other viruses.
Tests have also shown that any immunity that people get from exposure to seasonal flu does not provide protection against G4.
According to blood tests that showed the presence of antibodies created by exposure to the virus, 10.4 percent of the working pigs were already infected.
Tests showed that 4.4 percent of the general population was also affected.
Thus, the virus is already transmitted from animals to humans, but so far there is no evidence that it can be transmitted from person to person – the main concern of scientists.
“It is worrisome that a human G4 virus infection will contribute to human adaptation and an increased risk of a human pandemic,” the researchers write.
When asked about the virus on Tuesday, Chinese Foreign Ministry spokesman Zhao Lijian said at a regular press briefing that China was “paying close attention to its development” and would take all necessary measures to prevent its spread and any outbreaks.
The authors of the study called for urgent measures to monitor people working with pigs.
“This work is a useful reminder that we are constantly at risk for new zoonotic pathogens, and that farm-raised animals that humans have more close contact with than wild animals can provide important pandemic viruses,” said James Wood. Head of Department of Veterinary Medicine, University of Cambridge.
Zoonotic infection is caused by a pathogen that has jumped from a non-human animal into a human being.