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#18,472
While LPAI (low path) H5N9 viruses have been around for decades, it was not quite 10 years ago in J. Virol: Emergence Of AN HPAI H5N9 Virus In China that we learned of an emergent HPAI H5N9 virus resulting from a reassortment between H5N1, H7N9, and H9N2 avian viruses.
Half a world away - during a brief 2015–2016 avian flu epizootic - southwestern France detected outbreaks of HPAI H5N9, along with H5N1 and H5N2 in poultry, albeit of a different (European) lineage than the virus reported in China.
During the 2016-2017 H5N8 Epizootic in Europe, that virus spun off several short-lived reassortments, including H5N5, H5N9, and H5N6 as it mingled with local (European) LPAI viruses (see HPAI H5N5 Detected In German Poultry Operation).
Somewhat unexpectedly, 3 months ago we saw a report from WOAH: California Reports New H5N9 Reassortant In Ducks at a duck farm in Merced County, California. This HPAI subtype was last reported during the 2016/2017 H5N8 epizootic in Europe (see DEFRA: Update On HPAI & LPAI Avian Flu Outbreaks in France).
Today, the Philippines DOA has released the following announcement. I'll have a bit more after the break.
BAI confirms first case of HPAI H5N9 in Camarines Sur
Author: DA Press Office | 8 May 2025
The Bureau of Animal Industry (BAI) confirms the detection of the country’s first case of High Pathogenicity Avian Influenza (HPAI) Type A Subtype H5N9 in Camaligan, Camarines Sur. On April 30, 2025, the BAI-Animal Disease Diagnosis and Reference Laboratory (BAI-ADDRL) reported positive results from duck samples collected during a routine surveillance by DA Regional Field Office V (DA-RFO V). Subtype H5N9, while highly pathogenic in birds, poses low risk to humans based on current global assessments.
BAI promptly endorsed disease control measures to DA-RFO V, including immediate quarantine, culling, surveillance and coordination with local authorities and notified the Department of Health (DOH) to monitor any potential human exposure.
DA-RFO V, led by Regional Executive Director Rodel Tornilla, activated its Command Center and convened its Regional Quick Response Team to enforce control protocols. Coordination meetings with Regional DOH, the Provincial Government of Camarines Sur and the Municipality of Camaligan have also been conducted to streamline actions.
Culling and proper disposal of the remaining ducks in the affected farms are done on May 6, 2025. Intensive surveillance within the 1-kilometer quarantine zone will begin today, May 7, 2025, followed by monitoring and disinfection measures.
Moving forward, DA RFO V, in close coordination with the BAI and local government units, will implement sustained disease control operations including surveillance within 1-km and 7-km zones and thorough cleaning and disinfection of affected sites to prevent further spread.
While HPAI H5N1 has remained the dominant H5 subtype around the globe for the past 4 years, we've recently seen inroads made by an HPAI H5N5 subtype in Canada and parts of Europe (see The Continued Expansion of HPAI H5N5).Rest assured that BAI is committed to protecting the Philippine’s poultry industry from the threat of avian influenza and will maintain close cooperation with other government agencies and stakeholders. We encourage the public to remain vigilant and report any unusual poultry deaths or signs of illness to local authorities for immediate action. ### (DA-BAI Press Statement)
Whether this HPAI H5N9 virus has `legs', and can compete successfully against H5N1, remains to be seen.
