The Overview of Human Infection Caused by Avian Influenza A (H7N9) Virus

Yung-Ching Lin, Yi-Chun Lo

2013 Vol.29 NO.8

Correspondence Author: Yung-Ching Lin

  • Office of Preventive Medicine, Centers for Disease Control, Taiwan


        On March 31, 2013, China announced the first known human case infected by avian influenza A (H7N9) virus. By April 15, the total number of human H7N9 influenza cases reached 60 in China, including 13 deaths, 38 with severe illness, and 9 with mild illness, which were reported from Shanghai, Jiangsu, Zhejiang, Anhui, Beijing and Henan. Several cases had poultry contact history or had butchered bird meat before the onset of illness. The genome sequencing of the isolated viruses indicated a triple reassortment virus with avian origin. The first family cluster of human H7N9 infection was reported in Shanghai on April 13, suggesting that limited human-to-human transmission might occur. Currently, no human H7N9 influenza confirmed case has been reported in Taiwan. Human H7N9 influenza was listed as Category V Notifiable Infectious Disease since April 3. By April 15, 68 suspected cases were reported. Of them, 67 were excluded (including 13 H1N1, 5 H3N2 and one influenza B) and one was pending diagnostic tests. To cope with the emerging human H7N9 influenza outbreak in China, the Central Epidemic Command Center for H7N9 influenza was established on April 3 for prompt infection control and prevention measures, such as gathering latest infection information, strengthening border quarantine, coordinating medical systems and stockpiles, and managing risk communication.