Study says H7N9 could spark global flu outbreak

The H7N9 avian influenza virus responsible for at least 37 deaths in China has traits that could result in a global outbreak of influenza, according to a study published on Wednesday in Nature. An international research team by Yoshihiro Kawaoka of the University of Wisconsin at Madison and the University of Tokyo analyzed two of the first human isolates of the virus from patients in China. Kawaoka’s team determined that the H7N9 virus’ ability to infect mammals and transmit in ferrets suggests the viruses could become a worldwide human threat. “H7N9 viruses have several features typically associated with human influenza viruses and therefore possess pandemic potential and need to be monitored closely,” Kawaoka said. The study suggests the H7N9 virus is able to infect and replicate in human cells because of a few amino acid changes in its genetic sequence. “These two features are necessary, although not sufficient, to cause a pandemic,” Kawaoka said....