It seems that H5N1 is not the only kind of bird flu that Americans have to be careful. Federal officials recently reported finding a very pathogenic H5N9 flu between ducks at a commercial meat shop in California.
The US Department of Agriculture (USDA) notified The World Organization for Animal -Holl (WOAH) on the detection of H5N9 this -last weekend, although the explosion itself dates from last November. Carefully, both H5N9 and H5N1 were found on the farm, located in Merced Prefecture. These are the first reported cases of H5N9 ever found in American birds.
H5N1 bird flu has become serious care of public health in the past few years, thanks to ongoing explosions in wild birds and birds, as well as the more recent appearance of H5N1 in milk cows beginning early last year. More than 60 human cases of H5N1 in the United States have been documented since 2024, most linked to contact with infected cows or birds. Most of these human cases were mild and the risk of bird flu to the general public is still considered low, although there was a recent death linked H5N1 in Louisiana Reported Earlier this month.
As this recent duck shows, yet H5N1 is not the only variant of the very pathogenic influenza A -virus circulating in the world (very pathogenic refers to the potential of the virus to cause severe disease in birds specifically). According to the WOAH report presented by the USDA, the explosion was detected in late November, after increased deaths from a duck on the farm. Tests of the sick birds conducted by the National Veterinary Service Laboratory of USDA initially detected an unknown type of H5 flu. Later genetic testing, completed in mid-January, identified cases of H5N9 and H5N1 flu. Both tensions seem to belong to the same wide clade of very pathogenic aviation flu viruses, called 2.3.4.4B.
“This is the first confirmed case of HPAI H5N9 in birds in the United States,” Woah’s report said.
According to the report, civil servants quarantined the farm after the explosion detection. At the beginning of December, a slaughter of the nearly 120,000 birds of the farm was done. Officers with the animal and plant health -inspection of USDA (APHIS), along with state animal health and wild officials, reportedly conduct “extensive epidemiological surveys and improved surveillance” from the affected area.
The larger implications of this blast are unclear at the time. One of the reasons why influenza is dangerous is that different variants can sometimes infect the same host and mix together, producing a new stress with unpredictable properties, including changes that could make it more adaptable to human transmission. It is possible that this variant of H5N9 came out of H5N1 mixing with other N9-bearing types of flu (which would not be the first time such reassorm There was an event). The explosion is also noticeable because ducks are concerned host for aviation flu, because they often do not show signs of disease; This in turn could make them more skilled vectors of infection to other birds and animals. At the same time, this explosion can be an isolated incident, as no additional cases of H5N9 have been detected elsewhere.
While the USDA still talks with the WOAH, the Trump administration has ordered All of its federal health agencies to stop external communication for the moment. Neither the USDA nor APHIS seems to have provided a public update on the blast. Gizmodo reached APHIS for comment but did not hear back in the time of publication.
