HK CHP Reports 3 H9N2 Cases On Mainland

 

#19,266

Although it received brief mention (see below) in the July 17th WPRO avian flu update, Hong Kong's CHP acknowledged 3 recent H9N2 cases in their weekly avian flu report today.  

As usual, details are scant, but we get a little more from the following WHO WPRO report:

Human infection with avian influenza A(H9N2) virus

From 10 to 16 July 2026, three new cases of human infection with avian influenza A(H9N2) virus were reported to WHO in the Western Pacific Region. All three cases were from China. 

The first case is a 4-year-old male from Guangxi Province, with symptom onset on 26 June 2026. The second case is a 4-year-old male from Jiangsu Province, with symptom onset on 22 June 2026. The third case is a 44-year-old male from Guangdong Province, with symptom onset on 26 June 2026. 

All three cases had exposure to live poultry. The first and second cases had mild symptoms and now recovered; the third case had underlying comorbidities and is curently receiving treatment in the intensive care unit.

Since 2015, a total of 173 cases of human infection with avian influenza A(H9N2), including two deaths(both with underlying conditions), have been reported to WHO in the Western Pacific Region. Of these,170 were reported from China, two were from Cambodia, and one was from Viet Nam.

While most human H9N2 cases have been reported out of China (see below), this year Europe saw its first (imported) human infection with H9N2 in Italy (see WHO DON: Avian Influenza A(H9N2) - Italy (Ex Senegal)).

It is assumed that most cases go unreported, since human infections tend to be mild or moderate (but occasionally severe), and very rarely are non-hospitalized patients tested for novel flu. 

Although there is currently no evidence of sustained or efficient human-to-human transmission of H9N2, the virus remains poorly controlled in poultry, and appears on a path towards greater mammalian adaptation.

While trying to predict the source of the next influenza pandemic is a mug's game, H9N2 shows up twice the top 10 zoonotic influenza A viruses the CDC has pegged as having at least some pandemic potential, with the Y280 lineage having a higher emergence score than H5N1.

Given that we've already seen 2 modern influenza pandemics (1957 & 1968) caused by avian viruses spilling over from birds to humans in China, H9N2's continued evolution and spread is very much worthy of our attention.