Human infection with avian influenza A(H7N9) virus – China
On 30 December 2016, the Department of Health, Hong Kong Special Administrative Region (SAR) notified WHO of a case of laboratory-confirmed human infection with avian influenza A(H7N9) virus.
Details of the case
The case is a 70-year-old man with underlying chronic conditions, who travelled to Shenzhen and Zhongshan, Guangdong province from 13 to 16 December 2016. The patient reported having fever, productive cough, shortness of breath, vomiting and diarrhoea since 26 December. He visited a public hospital in Hong Kong SAR, China on 27 December and was admitted to an isolation ward on 28 December. A sputum sample taken on 28 December tested positive for avian influenza A(H7N9) virus RNA. The patient was in serious condition at the time of report.
In Zhongshan, he passed by mobile stalls selling live poultry on 14 December but reported no direct contact with the poultry. In Hong Kong SAR, he purchased a chilled chicken from a shop near a wet market on 22 December but no live poultry was sold in the shop, and he did not enter the wet market.
A total of 17 close contacts and 85 other contacts were identified as of 30 December, and put under medical surveillance. The patient’s co-traveller had a cough since 29 December and was admitted to a public hospital on the same day. His respiratory specimen tested negative for avian influenza A(H7N9) virus RNA by the hospital.
To date, a total of 809 laboratory-confirmed human infections with avian influenza A(H7N9) virus have been reported through IHR notification since early 2013.
Public health response
The Centre for Health Protection of the Department of Health has taken the following measures:
- Urged the public to maintain strict personal, food and environmental hygiene both locally and during travel.
- Issued an alert to doctors, hospitals, schools and institutions of the latest situation.
WHO risk assessment
Most human cases are exposed to avian influenza A(H7N9) virus through contact with infected poultry or contaminated environments, including live poultry markets. Since the virus continues to be detected in animals and environments, further human cases can be expected. Although small clusters of human cases with avian influenza A(H7N9) virus 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 avian influenza A(H7N9) virus are unusual and need to be monitored closely in order to identify changes in the virus and/or its transmission behaviour to humans as it 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.