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2024-05-25 -Signs, Portents, and the Weather-
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How Bird Flu in Dairy Cows got past the Safety Net
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That's the newspaper's title, not the scientists'.
[ASBMBTODAY, h/t to the Dallas Morning Snooze] In early February, dairy farmers in the Texas Panhandle began to notice sick cattle. The buzz soon reached Darren Turley, executive director of the Texas Association of Dairymen: "They said there is something moving from herd to herd."
An early indication that something had gone awry on farms in northwestern Texas came from devices hitched to collars on dairy cows. What farmers saw when they downloaded the data in February stopped them in their tracks. One moment a cow seemed perfectly fine, and then four hours later, rumination had halted. "Shortly after the stomach stops, you’d see a huge falloff in milk," Turley said. "That is not normal."
In hindsight, Turley wished he had made more of the migrating geese that congregate in the panhandle each winter and spring. Geese and other waterfowl have carried H5N1 around the globe. They withstand enormous loads of the virus without getting sick, passing it on to local species, like blackbirds, cowbirds, and grackles, that mix with migrating flocks.
On March 7, Turley called the Texas Animal Health Commission. They convened a One Health group with experts in animal health, human health, and agriculture to ponder what they called the "mystery syndrome." State veterinarians probed cow tissue for parasites, examined the animals’ blood, and tested for viruses and bacteria. But nothing explained the sickness.
They didn’t probe for H5N1. While it has jumped into mammals dozens of times, it rarely has spread between species. Most cases have been in carnivores, which likely ate infected birds. Cows are mainly vegetarian. "If someone told me about a milk drop in cows, I wouldn’t think to test for H5N1 because, no, cattle don’t get that," said Thomas Peacock, a virologist at the Pirbright Institute of England who studies avian influenza.
What finally tipped off veterinarians? A few farm cats died suddenly and tested positive for H5N1. Swinford’s group — collaborating with veterinary labs at Iowa State and Cornell universities — searched for the virus in samples drawn from sick cows. "On a Friday night at 9 p.m., March 22, I got a call from Iowa State," Swinford said. Researchers had discovered antibodies against H5N1 in a slice of a mammary gland. By Monday, her team and Cornell researchers identified genetic fragments of the virus. They alerted authorities. With that, the U.S. Department of Agriculture announced that H5N1 had hit dairy cattle.
Sometime in March, viruses appear to have hitched a ride to other states as cows were moved between farms. The limited genomic data available links the outbreak in Texas directly to others in New Mexico, Kansas, Ohio, North Carolina, and South Dakota. However, the routes are imprecise because the USDA hasn’t attached dates and locations to data it releases.
 Researchers don’t want to be caught off guard again by the shape-shifting H5N1 virus, and that will require keeping tabs on humans. Most, if not all, of about 900 people diagnosed with H5N1 infections worldwide since 2003 acquired it from animals, rather than from humans, Farrar said. About half of those people died.
Occasional tests of sick farmworkers aren’t sufficient, he said. Ideally, a system is set up to encourage farmworkers, their communities, and health care workers to be tested whenever the virus hits farms nearby.
"Health care worker infections are always a sign of human-to-human transmission," Farrar said. "That’s the approach you want to take — I am not saying it’s easy." 
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Posted by Bobby 2024-05-25 10:21||
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Posted by Skidmark 2024-05-25 10:59||
2024-05-25 10:59||
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Posted by Ebbuger Whuque4103 2024-05-25 11:04||
2024-05-25 11:04||
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