The disease, which researchers called the G4 virus, is genetically descended from the H1N1 swine flu that caused a pandemic in 2009. Chinese researchers based at several institutions, including Shandong Agricultural University and the Chinese National Influenza Center, discovered the G4 virus during a pig surveillance program. But the G4 virus kept showing up in pigs, year after year -- and even showed sharp increases in the swine population after 2016. Surveillance and discoveryIn 2009, the H1N1 swine flu pandemic killed an estimated 151,700 to 575,400 people globally. Swine flu occurs in people that are in contact with infected pigs.

Source: CNN June 30, 2020 06:56 UTC