Avian Flu Diary: CHP Reports Mainland H5N6 Infection

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After two years of enhanced activity (see map above), reports of human infection with H5N6 from the Chinese government have declined sharply in 2023, with the last case reported on March 1st which occurred in December of 2022.

In last week's weekly report from the Chinese National Influenza Center, however, there was a cryptic 1-line mention (buried on page 10) of a new H5N6 case in Sichuan Province which (translated) read:

In the 21st week, Sichuan Province reported a case of human infection with H5N6 avian influenza virus

No other details were provided, but today Hong Kong's CHP has published the following notice that - while mostly boilerplate - provides some additional details on the case.

CHP closely monitors human case of avian influenza A(H5N6) in Mainland

The Centre for Health Protection (CHP) of the Department of Health is today (June 5) closely monitoring a human case of avian influenza A(H5N6) in the Mainland, and again urged the public to maintain strict personal, food and environmental hygiene both locally and during travel.

The case involves a 54-year-old female living in Nanchong, Sichuan, who had exposure to live domestic poultry before the onset of symptoms. She developed symptoms on May 19 and was admitted for treatment on the same day. She is in serious condition.

From 2014 to date, 84 human cases of avian influenza A(H5N6) have been reported by Mainland health authorities.

"All novel influenza A infections, including H5N6, are notifiable infectious diseases in Hong Kong," a spokesman for the CHP said.

Travellers to the Mainland or other affected areas must avoid visiting wet markets, live poultry markets or farms. They should be alert to the presence of backyard poultry when visiting relatives and friends. They should also avoid purchasing live or freshly slaughtered poultry, and avoid touching poultry/birds or their droppings. They should strictly observe personal and hand hygiene when visiting any place with live poultry.

Travellers returning from affected areas should consult a doctor promptly if symptoms develop, and inform the doctor of their travel history for prompt diagnosis and treatment of potential diseases. It is essential to tell the doctor if they have seen any live poultry during travel, which may imply possible exposure to contaminated environments. This will enable the doctor to assess the possibility of avian influenza and arrange necessary investigations and appropriate treatment in a timely manner.

While local surveillance, prevention and control measures are in place, the CHP will remain vigilant and work closely with the World Health Organization and relevant health authorities to monitor the latest developments.

The public should maintain strict personal, hand, food and environmental hygiene and take heed of the advice below when handling poultry:
Avoid touching poultry, birds, animals or their droppings;
When buying live chickens, do not touch them and their droppings. Do not blow at their bottoms. Wash eggs with detergent if soiled with faecal matter and cook and consume the eggs immediately. Always wash hands thoroughly with soap and water after handling chickens and eggs;
Eggs should be cooked well until the white and yolk become firm. Do not eat raw eggs or dip cooked food into any sauce with raw eggs. Poultry should be cooked thoroughly. If there is pinkish juice running from the cooked poultry or the middle part of its bone is still red, the poultry should be cooked again until fully done;
Wash hands frequently, especially before touching the mouth, nose or eyes, before handling food or eating, and after going to the toilet, touching public installations or equipment such as escalator handrails, elevator control panels or door knobs, or when hands are dirtied by respiratory secretions after coughing or sneezing; and
Wear a mask if fever or respiratory symptoms develop, when going to a hospital or clinic, or while taking care of patients with fever or respiratory symptoms.
The public may visit the CHP's pages for more information: the avian influenza page, the weekly Avian Influenza Report, global statistics and affected areas of avian influenza, the Facebook Page and the YouTube Channel.

Ends/Monday, June 5, 2023

In the six years between 2014 and late 2020, China reported only 25 human cases of H5N6. In the past three years, 59 new cases have been announced. While the outcomes of these infections are not always divulged, many have proved fatal.

Reporting from China is sporadic at best, with delays or weeks or even months common. We've no idea, really, of how many cases might go unreported.

Recent studies (see Study: Influenza A (H6N6) Viruses Isolated from Chickens Replicate in Mice and Human lungs Without Prior Adaptation) suggest the H5N6 virus continues to adapt to mammalian hosts. Last summer, the Lancet published Resurgence of H5N6 Avian Influenza Virus in 2021 Poses New Threat to Public Health.

However, between a reluctance to report cases, limited testing and surveillance (particularly in remote regions), and belated reporting, it is difficult to accurately gauge the current threat posed by H5Nx in China.

While H5N1 is currently atop our pandemic worry list - and globally is the most active novel virus on our radar - China's H5N6 (along with swine EA H1N1, and avian H3N8, H3N6, and others) are all credible pandemic contenders. Some recent blogs on these threats include: