• A pig tested positive H5N1 bird flu On a backyard farm in Oregon.
• Pigs can harbor both avian and human flu viruses, making them a dangerous “mixing bowl.”
• Flu season may also increase the risk of mutation and ultimately the risk of human transmission of H5N1.

Bird flu virus spread to one species closer to human epidemic.

H5N1 bird flu The first case of swine infection in the United States was detected in a pig in Oregon, officials announced Wednesday.

Pigs pick up both bird flu viruses and human flu viruses, making them a genetic mixing bowl from which H5N1 could win genetic mutations It helps spread among people.

It’s not inevitable, but St. “I would say there is some increased concern because of this swine infection,” said Stacey Schultz-Cherry, a virus expert at St. Jude Children’s Research Hospital and a hospital deputy director. World Health Organization The animal and bird flu center told Business Insider.

‘Animal epidemic’ that could spread to humans

This strain of bird flu has killed tens of millions of birds worldwide and more than 40,000 sea lions and seals in South America since 2020. World Health Organization chief scientist Jeremy Farrar describes this as “animal epidemic“

An unexpected event occurred at the beginning of this year Jumping on US cattle herds.

Since then even H5N1 few people were infected They work closely with animal husbandry in the USA. However, there is no evidence of sustained human-to-human transmission. Pigs could change that.

Meet the first infected pig

US Department of Agriculture reported He said the infected pig was currently living in a quarantined “backyard farming operation.”

Two other pigs on the farm tested negative for H5N1, while the results of the other two pigs are still awaited. poultry There were people who tested positive there too.

The USDA stated that the pigs on this farm were not intended for commercial use and added, “There are no concerns about the safety of the nation’s pork supply as a result of this finding.” food supplies.

Because of the backyard setting, this case does not pose the same risk of a major outbreak as an infection. commercial pig farm.

“If it starts spreading from pigs to pigs, that’s a much bigger problem,” said Florian Krammer, an influenza virologist at the Icahn School of Medicine at Mount Sinai in New York. ISTAT News. “If large populations of pigs, similar to cows, emerged in the United States, I think it would be a disaster.”

Why pig infection could be a tipping point

pigs It hosts both bird flu viruses and human flu viruses. This makes them a dangerous playground for the duo to swap genes.

inside a pigThe H5N1 bird flu virus can acquire genetic mutations that help the human body better adapt to infection.

The more pigs are infected, the greater this risk. But “we don’t need to see pig-to-pig transmission to worry about this mixing bowl or mixing bowl effect,” Schultz-Cherry said.

St. Richard Webby, a virologist at St. Jude and director of the WHO animal and avian influenza center, told BI in June that no other animal was “at the top of the list” with pigs.

This may be due to gaps in our understanding of animal influenza. After all, he added: “A few months ago I would have told you that cows don’t get the flu.”

Bad timing: Flu season is in full swing

Schultz-Cherry said the timing of this development was “not ideal” because it was in the middle of it. flu seasonand pigs can contract influenza strains circulating among humans.

If this season’s flu strains overlap with H5N1 infection in swine, the risk of gene mutations that help bird flu adapt to humans will increase.

“It actually only takes one pig,” Schultz-Cherry said.

However, it may be helpful to get the seasonal flu vaccine, especially if you are in contact with cows, pigs or poultry. Schultz-Cherry said that’s because the vaccine reduces the amount of flu circulating in the community.

Genomic detective work

Schultz-Cherry was surprised by the pig news, but said, “I guess I shouldn’t be surprised.”

virus circulates in cattleThere are chickens, wild birds and cats all over the country. The mice tested positive.

Even sharing a drinking water source with these animals can put the pig at risk. Livestock and poultry on Oregon farms share water supplies, shelter and other equipment, the USDA said.

Now that authorities have samples of the virus that infected the pig, they can sequence its genome. This may give a clue as to which animal it came from in the first place.

Scientists will likely look for mutations in the virus that could help the virus infect humans more easily; such as a tweak that allows the virus to bind to more mammalian-type receptors on the cells of a host animal.

“It was a single pig,” Schultz-Cherry said. “But this is something that will lead to further monitoring of the situation.”