Human infections with a new avian influenza A (H7N9) virus were first reported in China in March 2013. Most of these infections are believed to result from exposure to infected poultry or contaminated environments, as H7N9 viruses have also been found in poultry in China. While some mild illnesses in human H7N9 cases have been seen, most patients have had severe respiratory illness, with about one-third resulting in death. No evidence of sustained person-to-person spread of H7N9 has been found, though some evidence points to limited person-to-person spread in rare circumstances. The first case outside of China was in Malaysia and was reported on February 12, 2014. The case was detected in a traveler from an H7N9-affected area of China. The new H7N9 virus has not been detected in people or birds in the United States.
CDC is currently updating some avian influenza guidance documents, which will be posted to this page as they are finalized. Where only avian H7N9 guidance is available, it is appropriate to use avian H7N9 guidance to address other avian influenza infections in people.