Monday, November 01, 2021

Macao Govt Reports Another H5N6 Case in Mainland China (Hunan Province)



China's summer of H5N6 continues with another belated report of an H5N6 case (onset in late August), this time involving a 58 y.o. female farmer from Yongzhou City, Hunan Province. This is the 3rd case reported from Yongzhou City in the past 60 days (see here, and here).

Since if first emerged in the spring of 2014, we've seen an average of 4 to 5 human H5N6 infections reported each year out of China.  At least, until December of last year.  Over the past 10 months we've seen 26 cases officially reported, double the total from the previous 6 years. 

This recent spike is of particular concern because much of it has occurred during the summer months - typical the slowest time of the year for avian influenza transmission - and because we continue to see delayed reporting of cases from official sources. 

First today's announcement from the Macao Government Portal, then I'll have a postscript:

A human case of H5N6 avian influenza confirmed in Hunan
source:Health Service (SS)
Release date:November 1, 2021 17:47

The Health Bureau stated that according to the latest notification from the health department of the Mainland, a human case of H5N6 avian influenza has been confirmed in Hunan Province. The Health Bureau urged residents to avoid contact with poultry and birds and pay attention to personal and food hygiene.

According to data, the patient is a 58-year-old female farmer living in Yongzhou City, Hunan Province. She developed symptoms on August 29 and was admitted to the hospital on August 31. She is now in a serious condition and had a history of exposure to the live poultry market before the onset of illness.

Since April 2014, there have been confirmed cases of H5N6 avian influenza in Sichuan, Guangdong, Yunnan, Hubei, Hunan, Anhui, Guangxi Zhuang Autonomous Region and Jiangsu.

The Health Bureau will continue to maintain close contact with the health departments of the country and neighboring regions, and the World Health Organization, and closely monitor the epidemic situation in various places and in Australia. To prevent human infection with avian influenza, the Health Bureau urges the public to pay attention to the following matters:
  • Avoid contact with poultry and birds or their secretions and excrement; if there is contact, wash your hands immediately;
  • Do not buy or carry birds that have not been quarantined;
  • Do not eat poultry meat, offal, blood products and eggs that have not been thoroughly cooked;
  • Pay attention to personal hygiene and wash hands frequently;
  • If symptoms such as fever, cough, or difficulty breathing occur, wear a mask, seek medical attention as soon as possible, and detail travel history and animal contact history to the doctor.
For information on avian influenza, please refer to the Health Bureau's website ( or call the Health Bureau's Infectious Disease Enquiry Hotline 28700800 during office hours.

Over the past two months China's CDC has published two detailed outbreak reports (see below) in their CCDC Weekly. Both of which warn that HPAI H5N6 continues to mutate and reassort, and that its threat to public health is increasing. 

China CCDC Weekly: Genetic Characterization of Two Human A (H5N6) Viruses — Guangxi , China, 2021

CCDC Weekly: Outbreak Report - Five Independent Cases of Human Infection With HPAI H5N6 — Sichuan Province

While we haven't seen any obvious signs of human-to-human transmission of H5N6, this recent surge is the largest avian flu outbreak affecting humans we've seen since the spring wave of H7N9 in 2017.

To date, human infection with H5N6 has been primarily reported in China (and 1 from Laos), although the virus has been found in migratory birds in Vietnam, Laos, and Cambodia. Given the limits of surveillance, testing, and reporting in that part of the world, it is likely some cases have been missed. 

And the ability of HPAI H5 viruses to hitch a ride on (relatively) immune migratory birds, we'll be watching this winter's migration closely for any signs that H5N6 is expanding its geographic range.