China—WHO Joint Mission on Human Infection with Avian Influenza A(H7N9) Virus, 18 – 24 April 2013

Overview

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. The team’s findings, assessment and recommendations were formed on the basis of the  data available, site visits and discussions. These are presented in this report.