Avian Influenza A (H7N9) Virus
http://www.cdc.gov/flu/avianflu/h7n9-virus.htmHuman infections with a new avian influenza A (H7N9) virus continue to be reported in China. The virus has been detected in poultry in China as well. While mild illness in human cases has been seen, most patients have had severe respiratory illness and some people have died. No cases of H7N9 outside of China have been reported.?? The new H7N9 virus has not been detected in people or birds in the United States.
An investigation by Chinese authorities is ongoing. Many of the people infected with H7N9 are reported to have had contact with poultry. However some cases reportedly have not had such contact. Close contacts of confirmed H7N9 patients are being followed to determine whether any human-to-human spread of H7N9 is occurring. No sustained person-to-person spread of the H7N9 virus has been found at this time.
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).
Influenza viruses constantly change and it’s possible that this virus could become able to easily and sustainably spread between people, triggering a pandemic. CDC is following this situation closely and coordinating with domestic and international partners. CDC takes routine preparedness actions whenever a new virus with pandemic potential is identified, including developing a candidate vaccine virus to make a vaccine if it were to be needed. CDC also has issued guidance to clinicians and public health authorities in the United States, as well as provided information for people traveling to China. This is an evolving situation and there is still much to learn. CDC will provide updated information as it becomes available. Page last updated: April 23, 2013
