Identification of avian influenza mutations in humans

According to RCO News Agency, The continued spread of bird flu in the United States has experts worried, not only because of the increase in human cases that cause severe illness, but also because of the alarming new cases being detected in cats.

A sample of the virus found in a critically ill patient in the United States showed signs of a mutation that is more compatible with the human airways, researchers reported, although there was no indication that it had spread from that person to others. be transferred

Earlier this month, researchers announced that an elderly patient from Louisiana, USA, was in “critical condition” with a severe H5N1 infection.

A newly released analysis by researchers at the US Centers for Disease Control and Prevention (CDC) found that a small percentage of the virus in the patient’s throat has genetic changes that could alter the virus’s ability to bind to specific cell receptors in the human upper respiratory tract. to increase

Importantly, the CDC noted that these changes have not been detected in birds, including domestic poultry, which are believed to have been the source of the disease’s initial infection.

Instead, the mutations likely arose as the virus replicated in a patient with advanced disease, the researchers said, noting that no transmission of the mutated strain to other humans had been detected.

Several experts cautioned that it is too early to determine whether these genetic changes in the virus make the virus more transmissible or more deadly in people.

Angela Rasmussen, a virologist at the University of Saskatchewan in Canada, explained that while the mutation may help the virus enter cells more easily, other evidence, such as animal testing, is needed to confirm any effect on its infectivity.

In addition, similar mutations have occurred in previously critically ill patients without leading to a more widespread outbreak.

“It’s good to know that we should be careful, but it doesn’t really tell us that we’re close to a pandemic now,” Rasmussen says.

Thijs Kuiken of the Erasmus University Medical Center in the Netherlands also agrees with Rasmussen’s opinion.

He says: efficient connection to the cells of the human upper respiratory tract is a necessary condition for more effective transmission between people, but it is not sufficient.

He added that this process is only one of several steps required for successful replication of the virus.

Instead of exacerbating disease and affecting the lower respiratory tract leading to more severe pneumonia, such adaptations may actually lead to milder infections by supporting cells in the upper respiratory tract, causing symptoms such as a runny nose or sore throat, Quicken noted.

Rapid evolutionary leaps

Rasmussen expressed larger concerns about the massive amount of bird flu currently circulating.

The CDC has so far reported 65 confirmed human cases in 2024, and many may be undetected among dairy and poultry workers.

Rasmussen warned that this wide circulation increases the chance of the virus mixing with seasonal flu, potentially triggering “rapid evolutionary jumps” similar to the events that triggered the 1918 and 2009 flu pandemics.

Researchers are also monitoring increasing cases of bird flu infection in cats.

A cat in Oregon died after consuming raw pet food that was approved but contaminated with the H5N1 virus, prompting a recall of a certain brand of raw and frozen pet food.

Ryan Scholz, a veterinarian, said: This cat was completely a domestic cat and had not been exposed to the virus in its environment. The genome sequence of the virus showed that the virus in the pet food was an exact match to the strain found in the cat.

An animal shelter in Washington state also announced that 20 big cats at a shelter were recently euthanized after contracting bird flu.

Rasmussen warns that infected outdoor cats can return indoors and expose people to the virus through close contact.

“If you have an outdoor cat that gets H5 from eating a dead bird, and that cat comes back to your house and you hold it and sleep with it, that puts you at risk,” he explained.

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