Researchers in China have discovered a new flu virus in pigs capable of triggering a pandemic, according to a study published Monday in the US science journal PNAS.
Named G4, it is genetically descended from the H1N1 strain that caused a pandemic in 2009. It possesses ‘all the essential hallmarks of being highly adapted to infect humans’ say the authors, scientists at Chinese universities and China’s Center for Disease Control and Prevention.
From 2011 to 2018, researchers took 30,000 nasal swabs from pigs in slaughterhouses in ten Chinese provinces and in a veterinary hospital, allowing them to isolate 179 swine flu viruses. The majority were of a new kind, which has been dominant among pigs since 2016.
The study’s authors called for urgent measures to monitor people working with pigs. “Farmed animals, with which humans have greater contact than with wildlife, may act as the source for important pandemic viruses,” said James Wood, head of the veterinary medicine department at Cambridge University.
According to blood tests that showed antibodies created by exposure to the virus, 10.4 percent of people who work with pigs had already been infected. The tests also showed that as many as 4.4 percent of the general population also appeared to have been exposed.
The virus has passed from animals to humans but there is no evidence yet that it can be passed from human to human — the scientists’ main worry.
“It is of concern that human infection of G4 virus will further human adaptation and increase the risk of a human pandemic,” the researchers wrote.
Asked about the virus on Tuesday, Chinese foreign ministry spokesman Zhao Lijian said that China has been paying close attention to its development and will take all needed action to prevent its spread and any outbreaks.
A zoonotic infection is caused by a pathogen that has jumped from a non-human animal into a human.