The latest alternative to bird influenza that recently hit the Albanian livestock in Nevada has a genetic change that is believed to help the virus copy itself in mammals – including humans – more easily, according to what is mentioned new. Artistic summary From the inspection service on the health of animals and agriculture of the US Department of Agriculture.
It is not clear whether these viruses are a greater threat to people. The H5N1 risk to the public says is still low, although people working on farms or who have herds of the backyard are at greater risk.
The US Department of Agriculture’s report comes as a dairy farm in Nevada, has a positive appeared for H5N1, the first human infection identified in the state. Symptoms of the worker include red or inflamed eyes or conjunctivitis, according to a source familiar with the details that were not authorized to speak to the media. Disease control and prevention centers emphasize the initial positive test.
Scientists closely monitor the new infections in Nevada because the sequence of genes from infected livestock showed that it is a sub -type of H5N1 virus, D1.1, which has been associated with severe human infections in North America, including one death.
The affected herds, in the same valley in Churchill County, are the first known cases of indirect effects from D1.1 to livestock. The strain was already found in birds and people.
Most bird flu infections in dairy cattle in the United States were the B3.13 alternative, or what is known as “Clade Clade”. The researchers are not sure how the D1.1 variable is transferred to the Nivada cows. Dairy farmers who have herds of a large death of wild birds were informed near their farms before they got their cows, according to the US Department of Agriculture.
This led to the investigators believed that cows faced the affected birds, or perhaps their waste, and the virus caught in this way. It is difficult to control wild birds on farms, where the grain -filled nutritionist like giant birds can appear.
The genetics sequence of these D1.1 viruses found a boom that helps the virus to copy itself more efficiently in mammal cells, including people.
This change was not seen in another D1.1 infection in wild birds or poultry, according to the US Department of Agriculture. It raises the possibility that another animal, perhaps a cat or fox, will bring the virus to these farms.
Dr. Sima Lakdaoula, a microbiologist and immunologist at Emory University, who was studying how H5N1, is a microbiologist and immunologist at Emory University, who was studying how H5N1 was, a microbiologist and immunologist at Emori University, who was He studies how H5N1, a microbiologist and immunologist at Emory University, was studying how H5N1, a microbial scientist and immunologist at Emory University, who was studying how H5N1, is the microbial world and immunologist at Emory University, “this boom.” … provides the virus with improved repetition, which poses a threat to humans who are exposed to these cows. ” Spread in dairy herds.
Follow D1.1 assets
When viruses change, or think, they do so in two ways: erosion or transformation.
The erosion indicates a slight change in the genome, and it is usually wrong, that the virus is committed when he copies itself in a cell. Most of the time, these changes are harmful to the virus or have no effect. Sometimes, a slight change can help the virus become more convenient and overcome those around it, which helps it become a more dominant variable.
The transformation is a greater change. Influenza viruses have eight slices of their genome. When different influenza viruses affect a cell at the same time, they can switch whole parts of their genomics to create hybrid viruses that may have significant different properties.
D1.1 is a new clutch created by a transformation, so it is a hybrid virus. Half its slices, including the “H” chip, comes from the very ill H5N1 virus that was transferred to North America by wild birds traveling from Asia at the time after April 2022. The other half, including part “N” comes From a low physical influenza virus that was already present in birds in North America.
D1.1 was first discovered in wild birds in September 2024, according to the US Department of Agriculture, which is now the dominant H5N1 strain in wild birds in North America.
In late October, The D1.1 sub -type has been confirmed In workers who were separated from birds on a farm with infected poultry in Washington state. Although these workers have developed the symptoms of the respiratory system, their infection was described as mild.
A few weeks later, in early November, a 13 -year -old girl in British Colombia, Canada, proved also positive for the H5N1 D1.1 breed and suffered severe disease and witnessed multiple failure in the organs. I survived, but just weeks Intensive care. Public health officials have conducted an intense investigation, but they still do not know how it was exposed to the virus.
When scientists holed the H5N1 virus, they found signs that they started developing the types of mutations that would need to become more efficient human pathogens.
Then, in December, a 65 -year -old person was injured in Louisiana, who was also exposed to sick birds in the backyard as well as a serious disease with D1.1 and was taken to the hospital. This person died in the end, and he became the first influenza death in the country.
The genome sequence of samples that was collected from this patient is also revealed in relation to changes in the virus, which is likely to help him storm human cells.
Searching for evidence about severe infections
Researchers are urgently looking for evidence to try to understand the reason for the connection of D1.1 with severe human infection.
The “H” symbol of Hemggglinnin Virus protein, which helps it to infect cells, while its “N” part icons of the enzyme called Neuraminidase, helps the virus out of the cells and spread to others.
Scientists call high or low flu viruses depending on their illness. These designations have no great relationship with the severity of these infections in humans.
One of the theories about the cause of B3.13 infection, for example, is that experiments in rodents have shown that people may have some cross -protection against B3.13 infection because our immune devices have faced part “N” of this virus of this virus. Seasonal flu.
Dr. Louise Monla, a Veterinary Medicine School at the University of Pennsylvania, who studies how viruses appear in the human population and transmitted between them, says the N. of the D1.1 virus is completely said about the n -B3 part. 13 virus. She said, “It is really different.”
This change in part N of the virus may help him evade any immunity that people have seasonal influenza viruses, which increases the possibility of more severe injuries. This theory is currently being investigated.
Dr. Scott Hinsley, a microbiologist at the University of Pennsylvania, has another theory.
After seeing similar changes in H proteins from viruses that caused two severe human states in Canada and Louisiana, scientists began to wonder if this might be a sorting of the H5N1 virus that could easily adapt to humans.
Hinsley says that H and N of the virus should work together in a sensitive dance. The protein H helps the virus storming a cell, while the NGOM symbols help it escape from all the same copies that are returned to the body. Changes on protein N usually come at the expense of H Part, which makes the virus less efficient in infected cells. Hensley D1.1 believed it may be an exception.
His laboratory performs experiments to see if the N N of D1.1 viruses may allow protein H to change and affect humans more easily.
“This genetic pattern appointed to the virus can be more likely to adapt to human cells,” Hinsley said. “We just don’t know yet.”
CNN’s Meg Tirrell contributed to this report.
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