SALEM, Ohio — A rare subtype of the bird flu has been found in the United States at a commercial duck farm in California, according to the Paris-based World Organization for Animal Health (WOAH).
“This is the first confirmed case of HPAI H5N9 in poultry in the United States,” the U.S. Department of Agriculture said in a report to the World Organization for Animal Health.
The USDA also discovered the more prevalent H5N1 strain of the disease on the same farm in Merced County.
The U.S. Department of Agriculture’s Animal and Plant Health Inspection Service, in collaboration with state animal health and wildlife officials, first alerted WOAH of the discovery of the strain on Jan. 24. The USDA is continuing to investigate and monitor the outbreak, the WOAH report said.
State officials quarantined the premises and culled 119,000 birds in early December to prevent the disease from spreading.
Research from the U.S. National Library of Medicine, which initially identified the virus subtype at live bird markets in China in 2015, cautions that “whether this novel H5N9 virus will cause human infections from its avian host and become a pandemic subtype is not known yet. It is therefore imperative to assess the risk of emergence of this novel reassortant virus with potential transmissibility to public health.”
In recent months, health officials have closely monitored the spread of the H5N1 type of bird flu, which has resulted in the deaths of more than 145 million birds since the current outbreak began in the U.S. in February 2022.
The strain has also infected dozens of mammal species including dairy cows in the U.S. There have been 67 reported human cases of the bird flu, resulting in one death. An elderly man in Louisiana died earlier this month after developing serious illness following his exposure to the H5N1 strain.
Since the bird flu moved into mammals, veterinary and human health researchers have raised concerns about the possibility of the H5N1 bird flu strain reassorting or mutating, which could lead to more severe human infection.
