A pig was infected with bird flu in Oregon, the U.S. Department of Agriculture reported Wednesday. It’s the first time bird flu, also known as the H5N1 virus, infected a pig in the United States — a troubling development, as this gives the pathogen another mammalian reservoir that could raise the risk of a pandemic.
Meanwhile, six bird flu cases were confirmed in humans in Washington and three more human cases were reported in California this week, bringing the national total of human infections to 36 cases since April 2024, the Centers for Disease Control and Prevention (CDC) reported Tuesday. The rate at which humans are being infected with the virus is accelerating, with more than half of the confirmed cases in humans thus far reported in the past two weeks.
All human cases since the outbreak began, apart from two people in Missouri, occurred when workers came into direct contact with farm animals. An investigation in Missouri could not determine how the two individuals, who shared a home, infected there came into contact with the virus. However, it did confirm that no healthcare workers who cared for the patients were infected, calming concerns that the virus had developed the ability to spread between humans.
The CDC maintains the risk of contracting bird flu for the general public to be “low,” but many public health experts are concerned that as the virus continues to spread, it has more chances to evolve into a form that can better infect humans.
Pigs, in particular, are sometimes called a “mixing vessel,” for flu viruses because they can pool together human and bird flu viruses at the same time, STAT reported. The fear is that various viruses could coexist in the body, swap genes, and produce a new strain that can more efficiently spread between people.
“If it doesn’t spread from pigs to pigs and it just happened on that one farm, it’s not a big deal," Florian Krammer, a flu virologist at Mount Sinai’s Icahn School of Medicine in New York, told STAT.
"If it starts to spread from pigs to pigs, then it’s much more of a problem,” he said. “If it ends up in large pig populations in the U.S. similar to cows, I think this would be a disaster.”
