Cows infected by lethal bird flu strain showing respiratory symptoms, Nevada says
At least four herds of Nevada have tested positive for H5N1 bird flu strains that cattle have never seen before, and respiratory symptoms such as coughing and sneezing have been reported, state agriculture officials confirmed Wednesday.
Scientists call D1.1 avian flu strains also linked to deadly human cases In Louisiana After exposure to sick birds last year. In recent months, the D1.1 strain has emerged to predominate the infection of wild birds and poultry flocks in North America.
The symptoms seen in humans infected with D1.1 are more severe than the avian flu strains that have previously been transmitted in dairy cows. This strain is called B3.13 and can only cause mild symptoms such as pink eyes and fever in humans infected after contact with sick cows.
Research suggestion Unlike other influenza strains of birds overseas, this B3.13 is unlikely to cause serious disease in humans. The risks of other animals are different, e.g. Pet catThese often die after exposure to B3.13 contaminated food and milk.
The discovery of D1.1 bird flu strains in dairy cows also subverts the previous theory proposed by U.S. health and agriculture officials that the virus spills the virus into wild birds is a rare one-time event.
Since the spillover in Texas in late 2023, all cases of influenza in birds have previously been linked to b3.13, and officials believe new variants of these viruses have not been repeatedly spread into bird cattle.
USDA Animal and Plant Health Inspection Services explain Wednesday, citing plans for the federal government in recent years to stop unprecedented highly morbid avian influenza or HPAI.
In addition to the human health threat posed by the virus Unprecedented tolls D1.1 The overflow sound from wild birds to chickens drives Egg price Nationwide.
So far, nearly a thousand cows have been confirmed to have bird flu explaintested in 16 states. The most recent case was in California.
Four new cattle herds infected with D1.1 were reported in Churchill County, Nevada.
The bird flu also reportedly came from a herd of cattle in New York County, the state in December, although the cows ended up positive for the virus’s B3.13 strain.
Two other herds in Churchill County are now also quarantined, a Nevada spokesman said.
“The symptoms of H5N1 D1.1 are similar to those of B3.13. These symptoms include fever, reduced feed consumption, reduced milk production and mild respiratory tract (cough, sneezing, runny nose), “Ciara Ressel), a spokesperson for the Nevada Department of Agriculture spoke about the symptoms of cattle.
The herds were confirmed to be infected due to state investigations because they received silos of milk in milk that was positive for the virus, the USDA said.
“USDA Aphis continues to work with the Nevada Department of Agriculture to better understand this test and limit further disease transmission by conducting other farm surveys, testing and collecting other epidemiological information,” the USDA said.
It is not clear how many workers in the state may be under pressure from D1.1 after working with those sick cows.
A spokesperson for the Nevada Department of Health forwarded the request to the Central Nevada Health District, which did not immediately respond to a request for comment.
CDC says 40 confirmed cases of influenza since 2024 Linked Cows exposed to the virus. Most others are the result of exposure to infected poultry.
exist Press release Last month, the Nevada Department of Agriculture said the CDC “stands that the risk to humans remains low” and “works with state and county health officials to protect human health and safety.”
When asked whether the D1.1 spillover would change the risk assessment, a CDC spokesperson did not immediately respond to a request for comment.
“It is crucial to strengthen animal health biosafety practices to prevent the spread of disease and protect the safety of animals and workers,” state veterinarian Peter Rolfe said.
