In the old days, we worried about H5N1 reaching the Americas. Now, without much fanfare, it's very much here. Via Reuters: Bird flu kills close to a record number of poultry in the U.S. Excerpt:
A near-record number of U.S. chickens and turkeys have died in this year's outbreak of avian flu, as a different form of the virus than farmers battled before has infected more wild birds that then transmit the disease, officials said.
More than 47 million birds have died due to infections and cullings. This has spurred export bans, lowered egg and turkey production, and contributed to record prices of the staples ahead of the U.S. holiday season. The outbreak exacerbates economic pain for consumers grappling with soaring inflation.
In 2015, 50.5 million birds died in the deadliest U.S. outbreak, the nation's worst animal-health event to date.
Farmers are fighting a subtype of the H5N1 strain of the virus that survived over the summer, when rising temperatures typically reduce avian flu, said Rosemary Sifford, chief veterinary officer for the U.S. Department of Agriculture (USDA).
The same subtype, known as the goose/Guangdong lineage, is spreading in Europe, she said in an interview. Europe is already suffering its worst avian flu crisis, with nearly 50 million poultry culled.
Officials are finding the subtype in a broader range of wild birds, such as ducks, than in the past and it seems to live in the birds longer, Sifford said. An elevated threat for infections may persist until summer 2023 as they migrate, she said.
The United States is monitoring wild birds for avian flu in four migration paths known as flyways, up from two previously, and plans to do the same next year.
"This virus could be present in wild birds for the foreseeable future," Sifford said. "This one is certainly different."
The outbreak has infected flocks in 42 states since February, twice as many as in 2015, USDA records show. Infections slowed over the summer this year but did not stop as they did in 2015.
The tenacity of the virus surprised some producers, who have boosted cleaning and security in barns since the 2015 outbreak.
"Unfortunately what we've done probably hasn't been enough to protect us from this high load of virus in the wild bird population," Sifford said.
