|Description:||This 2013 image depicts a Centers for Disease Control and Prevention (CDC) scientist measuring the amount of H7N9 virus that has been grown and harvested in CDC’s laboratory.|
Human infections with avian influenza (AI, or “bird flu”) are rare but do occur, most commonly after exposure to infected poultry (Bird-to-human spread). Limited person-to-person spread of bird flu is thought to have occurred rarely in the past, most notably with avian influenza A (H5N1). Based on this previous experience, some limited human-to-human spread of this H7N9 virus would not be surprising. Most important, however, is that this transmission not be sustained (ongoing).