The World Health Organization has published an update on 7 H7N9 cases reported by the Chinese government between May 26th and Jun 23rd.
Normally, by late May, H7N9 cases have all but ended until the fall. This year Hong Kong's CHP has taken special notice of these unusual `warm weather cases' and has repeatedly warned:
"In view of additional human cases reported on the Mainland with detections of human cases in previously unaffected areas in warmer months, as well as the detections of positive sample of faecal droppings of live poultry in Hong Kong and positive environmental sample in Macao in June, the public should remain vigilant. Travellers to the Mainland and other avian influenza-affected areas in the upcoming summer vacation should not visit poultry markets, and should avoid contact with poultry and their droppings."
All seven cases were reported previously, and this report adds little, except that it confirms that during this reporting period there were no new clusters.
Human infection with avian influenza A(H7N9) virus – China
Disease outbreak news
22 July 2016
On 12 July 2016, the National Health and Family Planning Commission (NHFPC) of China notified WHO of 7 additional laboratory-confirmed cases of human infection with avian influenza A(H7N9) virus, including 4 deaths.
Onset dates range from 26 May to 23 June. The cases range in age from 52 to 68 years, with a median age of 61 years. Of these 7 cases, 4 (57%) are male. The majority (5 cases, 71%) reported exposure to live poultry, slaughtered poultry or live poultry markets. One case has no history of exposure to poultry and the remaining case worked in a market where live poultry is sold. No human to human transmission was reported.
Cases were reported from 6 provinces and municipalities: Tianjin (2), Anhui (1), Beijing (1), Jiangsu (1), Liaoning (1) and Zhejiang (1).
Public health response
The Chinese Government has taken the following surveillance and control measures:
- strengthening outbreak surveillance and situation analysis;
- reinforcing all efforts on medical treatment; and
- conducting risk communication with the public and dissemination of information.
WHO risk assessment
Most human cases are exposed to the 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 influenza A(H7N9) viruses have been reported previously 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, community level spread of this virus is considered unlikely for the time being.
Human infections with the 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.