Background and summary of human infection with avian influenza A(H7N9) virus

Overview

 

 

The influenza A(H7N9) virus is one subgroup among the larger group of H7 viruses, which normally circulate among birds. Human infections with other subgroups of H7 influenza viruses (H7N2, H7N3, and H7N7) have previously been reported in Australia, Canada, Italy, Mexico, the Netherlands, the United Kingdom and the United States of America. Most of these infections occurred in association with poultry outbreaks. The infections mainly resulted in conjunctivitis and mild upper respiratory symptoms, with the exception of one death, which occurred in the Netherlands. Since the first notification at the end of March 2013, China has been reporting to WHO cases of human infection with H7N9 virus. This is the first time infection with this virus has been found in humans.