Took this link from another thread b/c also relevant here:
It's the first time that highly pathogenic avian influenza H5N9 has been found in U.S. poultry.
gizmodo.com
New Strain of Bird Flu Found on California Duck Farm
It's the first time that highly pathogenic avian influenza H5N9 has been found in U.S. poultry.
“… The U.S. Department of Agriculture (USDA)
notified the World Organization for Animal Health (WOAH) about the detection of H5N9 this past weekend, though the outbreak itself dates back to last November. Worryingly, both H5N9 and H5N1 were found on the farm, located in Merced County. These are the first reported cases of H5N9 ever found in U.S. poultry.
… According to the WOAH report filed by the USDA, the outbreak was detected in late November, following increased duck deaths at the farm. Tests of the sickened birds conducted by the USDA’s National Veterinary Services Laboratory initially detected an unknown type of H5 influenza. Later genetic testing, completed by mid-January, identified cases of H5N9 and H5N1 influenza. Both strains appear to belong to the same broad clade of highly pathogenic avian influenza viruses, called 2.3.4.4b.
…
The larger implications of this outbreak are unclear at this point. One reason why influenza is dangerous is that different variants can sometimes infect the same host and mix together, producing a new strain with unpredictable properties, including changes that could make it more adaptable to human transmission. It’s possible this variant of H5N9 emerged from H5N1 mingling with other N9-carrying types of influenza (which wouldn’t be the first time such a
reassortment event has happened). The outbreak is also noteworthy because ducks are a concerning host for avian influenza, since they often don’t show signs of illness; that in turn could make them more proficient vectors of infection to other birds and animals. At the same time, this outbreak may be an isolated incident, as no additional cases of H5N9 have been detected elsewhere.
While the USDA is still talking to the WOAH, the Trump administration has
ordered all of its federal health agencies to cease most external communication for the time being. Neither the USDA nor APHIS appear to have provided a public update on the outbreak. Gizmodo has reached out to APHIS for comment but did not hear back by the time of publication.”