#19,155
After an impressive run of cases between 2021-2023 (see ECDC chart below), we've gone nearly 2 years (July 2024) since the last human H5N6 case was reported by of China.
While it is certainly possible that there have been cases that were either not detected by local surveillance - or were simply not reported - we've continued to see studies coming out of China cautioning on the the evolution of this subtype.
Emerg. Microbes & Inf: Unique Phenomenon of H5 HPAI Virus in China: Co-circulation of Clade 2.3.4.4b H5N1 and H5N6 results in diversity of H5 Virus
Transboundary & Emerging Dis.: The H5N6 Virus Containing Internal Genes From H9N2 Exhibits Enhanced Pathogenicity and Transmissibility
China CDC Weekly: Infection Tracing and Virus Genomic Analysis of Two Cases of Human Infection with Avian Influenza A(H5N6) — Fujian Province, China
So it is not completely surprising that the WHO reported, in their most recent Avian Influenza Weekly Update # 1044 SitRep, on China's 93rd human infection (since 2014) with H5N6.
Once again, this case appears to be linked to the purchase of live market poultry.Human infection with avian influenza A(H5N6) virus
From 1 to 7 May 2026, one new case of human infection with avian influenza A(H5N6) virus was reported to WHO in the Western Pacific Region. The case is a 55-year-old female from Chongqing Municipality,China, with symptom onset on 16 April 2026. She developed severe pneumonia, was hospitalised on 23 April, and died on 3 May.
She had purchased, slaughtered, and consumed poultry. Samples collected from a cutting board tested positive for influenza A (H5). All close contacts tested negative and developed no symptoms. Since 2014, a total of 93 laboratory-confirmed cases of human infection with influenza A(H5N6) virus including 58 deaths (CFR 62.4%) have been reported to WHO in the Western Pacific Region.
As we've discussed previously (see Mixed Messaging On HPAI Food Safety), there is some degree of risk in the slaughtering of live birds and preparation of raw poultry; especially from birds raised at home or purchased from live markets.
In 2024 the WHO published Interim Guidance to Reduce the Risk of Infection in People Exposed to Avian Influenza Viruses, which lists a number of `risk factors', including:
- keep live poultry in their backyards or homes, or who purchase live birds at markets;
- slaughter, de-feather and/or butcher poultry or other animals at home;
- handle and prepare raw poultry for further cooking and consumption;
Although far more common in Asia and the Middle East, dozens of outbreaks of HPAI H5 in poultry markets here in the United States have been reported (see USDA Report 9 More Live Bird Markets Infected With HPAI H5).
While reports of human H5N6 infection in China have receded sharply over the past couple of years, novel influenza A viruses have a nasty habit of reinventing themselves (often via reassortment), before making dramatic returns.
Which is why we never like to say `never' when it comes to novel flu.
