Dairy cows in Nevada have been infected with a new form of bird flu form different from the edition that has spread through the herds over the last year, the US Department of Agriculture announced on Wednesday.
The finding shows that the virus, known as H5N1, has been spilled by birds into cows at least twice – leading to these two sets of infections – and that it could continue to do so. It also suggests that the virus can put a constant risk for cows and people who work closely with them.
Before last year, scientists did not know that the cows were sensitive to this type of flu.
“That’s what no one wanted to see,” said Louise Moncla, an evolutionary biologist who studies bird flu at the University of Pennsylvania. “We now have to look at the possibility that cows are widely prone to these viruses than we initially thought.”
The news was announced in a press release by the Animal and Plant Inspection Service, a section of the Department of Agriculture. The federal services did not inform news about bird flu since President Trump took over.
The virus that has spread to the Nation’s dairy is a version of the H5N1 known as B3.13, which has contaminated over 950 flocks in 16 states. Scientists believe that he initially jumped into cows from birds about a year ago, somewhere in Texas Panhandle. This transition took scientists by surprise, and this news even more.
“I was a bit under the conviction that the bird movement towards the cow was a pretty rare event,” said Richard Webby, influenza expert at St. Jude.
The fact that happened again is “a little of a” wow “for me,” he added.
The cows in Nevada were infected with a version of the virus known as D1.1, which has spread to wild birds and poultry. It was originally found in milk collected from a silo as part of a national milk test strategy announced by USDA at the end of last year.
H5N1 D1.1 format has also been proven dangerous to humans. Of the 67 Americans who are known to have become ill with H5N1 so far, the only one who died was infected with this edition. This person, a resident of Louisiana over 65, had taken care of sick and dead birds and died in early January.
In November, a 13 -year -old Canadian girl also became infected with D1.1, but it is not clear where she could get it. Her only risk factor was obesity, but she too became seriously ill and placed in support of life due to the failure of the organs. Eventually it was recovered.
Bird influenza is so called because it is better adapted to bird contamination. But in both of these people, the virus gained mutations during the infection that could allow it to better infect people.
“It is possible that the virus is more permissible for human adaptive mutations,” said Scott Hensley, an immunologist at the University of Pennsylvania.
Reassuringly, the virus did not seem to spread from anyone else. Still, his evolution showed that he was able to gain the ability to effectively spread to people.
So far, at least, the spread of D1.1 to cows “does not change the life of the average person,” said Dr. Moncla. However, it endangers dairy and dairy industry, experts said. It also suggests the possibility that cows have already been infected once with B.3.13 could get sick for the second time with D1.1, Dr. Webby said.
“It’s no longer just a virus,” he said. “This, for me, suggests that it is going to be a prolonged problem.”
Since January 2022, when H5N1 was detected in wild aquatic birds in the United States, the virus has affected more than 153 million commercial, courtyard and wild birds, resulting in record prices on eggs.
It has also hit dozens of mammal species, including cats both wild and domesticated, raccoons, bears and marine lions.
