Influenza A virus subtype H5N1
  • This Monday, April 15, 2013 electron microscope image provided by the Centers for Disease Control and Prevention shows the H7N9 virus which can take on a variety of shapes.

    A new strain of bird flu that emerged in China over the past month is one of the "most lethal" flu viruses so far.

    LAST UPDATE : Apr 24, 2013, 6:03 PM EDT
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