H5N1 bird flu was detected in pigs for the first time in the United States – Boston News, Weather, Sports

(CNN) — In the United States, H5N1 bird flu was first detected in pigs US Department of Agriculture said Wednesday.

The agency said USDA and Oregon veterinary officials are investigating cases of bird flu at a backyard farm that was raising a mix of poultry and livestock, including pigs.

“The livestock and poultry on this farm shared water sources, facilities and equipment; in other states, this combination has enabled cross-species transmission of the virus,” the press release said.

After the H5N1 virus was detected in other animals on the farm, five pigs were euthanized for testing; two tested negative and the results of two more are still pending. The farm has been quarantined and the remaining animals are under observation. However, it was not a commercial farm and “as a result of this finding, there is no concern about the safety of the domestic pork supply,” the USDA Animal and Plant Health Inspection Service said.

H5N1 is a type of flu that is rare in humans but highly contagious and deadly in several animal species, including poultry and dairy cattle, raising concerns that it could mutate and become a virus that also preys on humans.

Scientists were concerned that the H5N1 virus could spread to pigs, which are thought to be a mix of flu viruses because they have the same type of receptors on lung cells as humans and birds. Some previous flu infections in pigs have allowed flu viruses to change rapidly and develop new capabilities. The 2009 H1N1 influenza pandemic is believed to have been caused by a virus that mutated in pigs in Mexico before it jumped out at people.

Throughout the United States This year, more than twenty people have tested positive for H5N1 influenza, and almost all of them have reported contact with infected dairy cows or chickens. according to the US Centers for Disease Control and Prevention.

Some infectious disease experts said they want more transparency about the nature of the Oregon pig case. Dr. Michael Osterholm said he wondered whether the virus was detected in a pig’s nasal swab or whether there was evidence of a deeper infection in the lungs.

“I think they’re using the word ‘infection’ too early because it could very well just mean environmental contamination of the nose. So we need to get this, this data,” said Osterholm, an infectious disease expert who directs the Center for Infectious Disease Research and Policy at the University of Minnesota.

He noticed it study published in 2023in which researchers tried to infect pigs with the H5N1 virus by rubbing their noses with the virus and feeding them contaminated food was largely unsuccessful. The study authors later wrote that only one of the eight pigs given an experimental dose of the virus had signs of infection in its blood, indicating that the pigs were “highly resistant” to the infection.

Osterholm said he was pleased that in the latest case, scientists conducted additional animal studies to learn more.

Veterinarians who track infections spreading between animals and humans said it’s not too surprising that pigs would become infected on the same farm as infected birds.

“It will be important to sequence the virus, but it is likely a circulating avian strain,” Dr. Scott Weese, a veterinarian and chief of infection control at the University of Guelph in Ontario, told CNN in an email. “I would be more concerned if it was related to dairy cows because the spread of the virus between mammals would be more concerning.

“I assume this is a dead end, but it highlights potential problems” with cross-contamination of different species on farms, Weese said.

“These problems will be greater on larger commercial farms, with a greater likelihood of transmission of the virus from pig to pig” and a greater risk of other flu viruses being present and gene swapping, he added.