The U.S. Department of Agriculture (USDA) announced on Wednesday that a pig at a backyard farm in Crook County, Oregon, has tested positive for the bird flu virus, marking the first instance of this infection being detected in swine in the United States. The finding has raised alarms about the potential for the virus to pose a human health risk.
The infection was discovered after poultry at the same farm were confirmed to have the virus last week. Following this initial finding, testing revealed that one of the farm’s five pigs had also contracted the virus. As a precaution, the farm has been placed under quarantine, and all five pigs were euthanized to facilitate further testing. Officials have stated that the farm is not commercial, and there are currently no concerns regarding the safety of the national pork supply.
Experts are expressing concern about the implications of this finding. Jennifer Nuzzo, a pandemic researcher at Brown University, explained that pigs can harbor various types of influenza viruses, which may allow them to serve as a conduit for bird viruses to adapt to human hosts. “If we’re trying to stay ahead of this virus and prevent it from becoming a threat to the broader public, knowing if it’s in pigs is crucial,” Nuzzo emphasized.
The USDA has conducted genetic analyses on the infected poultry and has not identified any mutations that would suggest an increased risk of transmission to humans, indicating that the current public health risk remains low. Nonetheless, the existence of a different strain of bird flu in pigs has been documented internationally without triggering a human pandemic.
Troy Sutton, a researcher at Penn State who studies flu viruses in animals, stated that while the Oregon pig infection is noteworthy, it does not fundamentally change the assessment of the threat level. “If the virus starts spreading more widely among pigs and if there are ensuing human infections, then we’re going to be more concerned,” Sutton added.
The Type A H5N1 bird flu virus has been widely circulating in the U.S. among wild birds, poultry, and other animals, heightening the potential for human exposure. So far this year, nearly 40 human cases have been reported across several states, including California, Colorado, and Michigan, primarily among individuals who have had contact with infected animals. Most of these cases have exhibited mild symptoms.
Experts caution that while the detection of bird flu in pigs is significant, it is essential to monitor the situation closely to assess any potential health risks.