Human infection with avian influenza A(H7N9) virus – China
On 11 November 2016, the National Health and Family Planning Commission (NHFPC) of China notified WHO of two additional cases of laboratory-confirmed human infection with avian influenza A(H7N9) virus.
Details of the cases
- A 77-year-old female who lived in Zhejiang Province developed symptoms on 6 October 2016. She had an exposure history to live poultry before the onset of symptoms. She was reported to be in a severe condition.
- An 89-year-old male who lived in Jiangsu Province developed symptoms on 20 October 2016. He had no known exposure history to live poultry. He was reported to be in a severe condition.
A total of 800 laboratory-confirmed human cases with avian influenza A (H7N9) virus infection have been reported through IHR notification since early 2013.
Public health response
The Chinese Government has taken the following surveillance and control measures:
- Strengthen surveillance and assessment analysis.
- Further enhance medical care of the cases.
- Conduct public risk communication.
WHO risk assessment
Most human cases had history of exposure to the A(H7N9) virus through contact with infected poultry or contaminated environments, including live poultry markets. As long as the virus continues to be detected in animals and environments, further human cases can be expected. Although small clusters of human cases with influenza A(H7N9) viruses have been reported including those involving healthcare workers, current epidemiological and virological evidence suggests that this virus has not acquired the ability of sustained transmission among humans. Therefore further community level spread is considered unlikely.
Human infections with the A(H7N9) virus are unusual and should be monitored closely in order to identify changes in the virus and/or its transmissibility in humans which may have a serious public health impact.
WHO advises that travellers to countries with known outbreaks of avian influenza should avoid, if possible, poultry farms, contact with animals in live bird markets, entering areas where poultry may be slaughtered, or contact with any surfaces that appear to be contaminated with faeces from poultry or other animals. Travellers should also wash their hands often with soap and water, and follow good food safety and good food hygiene practices.
WHO does not advise special screening at points of entry with regard to this event, nor does it currently recommend any travel or trade restrictions. As always, a diagnosis of infection with an avian influenza virus should be considered in individuals who develop severe acute respiratory symptoms while travelling in or soon after returning from an area where avian influenza is a concern.
WHO encourages countries to continue strengthening influenza surveillance, including surveillance for severe acute respiratory infections (SARI) and influenza-like illness (ILI) and to carefully review any unusual patterns, ensure reporting of human infections under the IHR (2005), and continue national health preparedness actions.