On 31 March 2013, in accordance with the International Health Regulations (2005) [IHR],
the Government of China reported the detection of three cases of human infection with a
novel influenza A(H7N9) virus (hereafter, H7N9) in Shanghai and the province of Anhui. At
the same time, the Chinese Center for Disease Control and Prevention (China CDC) posted
full genome sequences of viruses isolated from the first three cases in a publicly accessible
database. Over the next two weeks additional cases were confirmed in the municipalities of
Shanghai and Beijing, and in the provinces of Anhui, Jiangsu and Zhejiang. Most cases were
marked by severe pneumonia and a substantial number of deaths followed. Investigations
identified live bird markets as a possible source of human infection.
In response to this situation and at the invitation of the National Health and Family Planning
Commission of China, a China─WHO Joint Mission on Human Infection with Avian Influenza
A(H7N9) Virus was formed to assess the outbreak and provide guidance on its management
(see terms of reference in Annex 3. The Joint Mission was composed of experts from China
and WHO and four from Australia, Europe, Hong Kong, Special Administrative Region of
China, and the United States of America. The team visited Beijing and Shanghai over 6 days,
19 – 24 April 2013, meeting with senior officials and many experts from the human and
animal health sectors involved in the continuing outbreak investigation, following an agreed
method of work (see Agenda in Annex 6).