Human infection with a novel avian influenza virus, A(H7N9), China - 2nd update, 8 May 2013

Risk assessment

On 31 March 2013, Chinese authorities announced the identification of a novel reassortant A(H7N9) influenza virus isolated from three unlinked cases of severe respiratory disease in eastern China. This marked the first time that human infection with avian influenza virus A(H7N9) was identified.

Since then, human cases have continued to be reported from eastern China. Cases occur sporadically, without obvious epidemiological links.

This second update to ECDC's initial risk assessment concludes that the risk of the disease spreading to Europe via humans or through poultry is still low at this time.

Executive summary

As of 1 May, there were 128 laboratory-confirmed cases, including 26 deaths reported from eight neighbouring provinces (Anhui, Fujian, Henan, Hunan, Jiangsu, Jiangxi, Shandong, and Zhejiang) and two municipalities (Beijing and Shanghai). One case who acquired his infection in Jiangsu travelled to Taiwan before developing illness.

A few small clusters were detected but almost all cases have occurred sporadically, without obvious epidemiological links. While occasional human-to-human transmission in the clusters cannot be ruled out, there is certainly no confirmation of sustained human-to-human transmission.

ECDC stresses that EU citizens living or working in China should avoid live-bird markets. It is likely that travellers who become infected in China may import the disease to Europe. However, the occurrence of imported cases would not change ECDC’s risk assessment