Avian Flu Diary: South Korea Detects HPAI H5N8 & H7N9 (Pathogenicity To Be Determined) In Wild Birds

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With the fall bird migration well underway, both South Korea and Japan have recently reported outbreaks and detections of avian flu in wild birds (including environmental samples) and/or in poultry. For the most part, these reports have involved HPAI H5N8 and a variety of less worrisome low path (LPAI) H5 and H7 viruses.

Today in addition to confirming additional HPAI H5N8 detections, South Korea's MAFRA has announced the detection of H7N9 in an environmental sample as well.

It would obviously be a significant development if this H7N9 virus turns out to be closely related to the LPAI/HPAI H7N9 subtype that infected hundreds of people, and killed millions of birds, in China between 2013 and 2017.

But not all H7N9 viruses are created equal, and twenty-two months ago (Jan 2019), in South Korea Detects LPAI H7N9 In Environmental Samples - Cheonan, Chungnam province, we saw a similar report which turned out to have `low similarity' to China's H7N9 virus.

Additional tests must be performed to determine the pathogenicity and lineage of this H7N9 virus. The following (translated) report is from South Korea's Ministry of Agriculture.

H7N9 type avian influenza (AI) antigen detection in wild bird feces in Buan, Jeollabuk-do (algae)

November 10, 2020 13:37:02 Office

□ The Ministry of Agriculture, Food and Rural Affairs (Minister: Hyun-Soo Kim, hereinafter referred to as'Ministry of Agriculture and Food') announced that the H7N9 type avian influenza (AI) antigen was detected as a result of an interim test on wild bird feces collected (11.3.) in Buan, Jeollabuk-do.

※ It is expected to take one day to determine whether it is highly pathogenic
.

① Access control at the relevant wild bird fecal collection point (initiated by the initial response team at the Defense Control Headquarters)
② Set a 10km radius as a “ wild bird bird watchdog area”, restrict movement and strengthen surveillance and inspection for poultry farms within the area
③ Migratory bird sites and nearby Reinforcing prevention and prevention of poultry farms such as disinfection

Between 2016 and 2017 North America saw three novel avian H7 reassortants jump from wild birds to poultry. While all were North American reassortants, and not related to the Asian H7N9 virus, all now reside on the CDC's Influenza Risk Assessment Tool (IRAT) list of pathogens with pandemic potential.

H7N8 [A/turkey/Indiana/1573-2/2016]
H7N9 [A/chicken/Tennessee/17-007431-3/2017]
H7N9 [A/ chicken/Tennessee /17-007147-2/2017]

While China's massive poultry vaccination campaign of 2017 has dramatically reduced both H5 and H7 avian flu activity across the Mainland, H7N9 still circulates at low levels (see EID Journal: Evolution and Antigenic Drift of Influenza A (H7N9) Viruses, China, 2017–2019), and LPAI and HPAI H7N9 viruses remain at the top of the CDC's IRAT list.

So the results of the viral characterization of this sample will be of considerable interest.

Meanwhile MAFRA reports three additional avian flu detections today.

Highly pathogenic avian influenza in wild birds in Byeongcheoncheon, Cheonan, Chungcheongnam-do, issued a risk advisory by the Ministry of Agriculture and Food

Chungnam Asan (Gokgyocheon), Jeonbuk Buan (Algae) Wild bird fecal examination results, low pathogenic avian influenza (AI) confirmation, press release (11.10, at the time of distribution)