Researchers tested the ability of the H7N9 virusto infect several mammal species including ferrets and monkeys. They found that as well as readily invading the lungs, it could be spread like seasonal flu by coughing and sneezing.
Professor Yoshihiro Kawaoka, from the University of Wisconsin-Madison, US, and Tokyo University in Japan, who led the international team, said: "H7N9 viruses have several features typically associated with human influenza viruses and therefore possess pandemic potential and need to be monitored closely."
Most bird flu viruses do not infect humans. But H7N9 has so far infected at least 132 people, more than a fifth of whom have died. Several instances of human-to-human infection are suspected.
In monkeys the H7N9 virus efficiently infected cells in both the upper and lower respiratory tract, the scientists reported in the journal Nature. Most human flu viruses are restricted to the upper airway of non-human primates.
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