The disease, which researchers called the G4 virus, is genetically descended from the H1N1 swine flu that caused a pandemic in 2009. "Sure, this virus meets a lot of the basic criteria but it's not for sure going to cause a hypothetical 2020 flu pandemic, or even be a dominant strain in humans." 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. 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.