The Chinese Center for Disease Control and Prevention reported on July 7 that a recent study in China has confirmed the presence of an influenza virus strain that has the potential to spread from pigs to humans.
The study was published by the School of Public Health of the University of Hong Kong. It claimed to have found zoonotic potential in an H9N2 avian influenza virus, which primarily infects pigs only. Zoonotic means the virus can transmit from animals to humans.
In the new study, the researchers gathered nasal swab samples from pigs over different time intervals to compare the isolated influenza A viruses. They then found natural reassortment of influenza viruses.
Among them, the September 2021 sample was an influenza A virus with gene segments of avian H9N2 origin. This means they have found a human influenza virus with H9N2 viral genes that might aid zoonotic transmission.
Previous research has warned that avian and human influenza A viruses can co-infect pigs and result in the development of novel zoonotic illnesses with pandemic potential.
The Hong Kong study also found 7 other samples of influenza A virus that required further risk assessment on pandemic potential.
The researchers collected samples from a local Hong Kong slaughterhouse. The 7 samples came from pigs that were imported from two Southern Chinese provinces.
The researchers theorize that influenza transmission may have occurred between pigs outside Hong Kong before import because the imported animals were butchered within 24 hours.