The U.S. Department of Agriculture (USDA) confirmed on Wednesday that the H5N1 bird flu has been detected in a pig on a backyard farm in Oregon, the first known case of the virus in swine in the U.S. 

Although officials emphasized that the risk to the country's pork supply and public health remains minimal, the discovery has raised concerns among experts due to the potential of pigs to host mixed infections that could facilitate viral gene exchange, creating a more dangerous strain transmissible to humans.

Richard Webby, a virologist at St. Jude Children's Research Hospital and advisor to the World Health Organization, noted that the detection of the virus on a small backyard farm makes it less concerning than if it had appeared on a larger commercial farm. However, he cautioned that if the virus begins to spread between pigs, it could raise more serious concerns.

The Oregon farm is currently under quarantine and all poultry and swine on the premises have been culled to prevent potential spread. Additional testing on two remaining pigs is ongoing, according to the USDA. Other animals on the farm, such as sheep and goats, are under close surveillance as a precaution.

Experts pointed out that the farm's setup, where pigs and poultry shared resources like water, shelter and equipment, likely facilitated the transmission of H5N1, a pattern observed in other instances of animal-to-animal transmission.

Marie Culhane, a professor at the University of Minnesota, highlighted that this detection serves as a warning for pig farmers to stay vigilant for further infections, stressing the need for preparedness as pigs are particularly prone to flu viruses.

Meanwhile, lean hog futures saw a downturn at the Chicago Mercantile Exchange after the USDA's confirmation of the H5N1 case. Although the USDA clarified that the Oregon pigs were not intended for commercial food production, the detection has nevertheless impacted market sentiment.

The H5N1 virus has been a persistent threat globally, with 36 human cases identified this year alone, primarily in farm workers exposed to infected animals. Since the outbreak began in 2022, it has led to the culling of over 100 million poultry birds across the U.S.

(With input from Reuters)