A strain of bird flu new to the U.S. has been found in samples collected from a commercial duck farm in Merced County, Calif., according to a report from the World Organisation for Animal Health.
Both H5N9 and H5N1 strains of avian influenza were identified in sampling that began Nov. 23, 2024, at the duck meat facility. More than 118,950 susceptible birds were killed.
The report, based on data from the World Animal Health Information System (WAHIS), said testing came after increased mortality rates among the affected flock in the county just east of San Jose. WAHIS data reflect validated information on diseases in domestic animals and wildlife as well as on emerging diseases and zoonoses reported by veterinary services around the world.
The report is the first emergence of H5N9 in the United States, according to the Center for Infectious Disease Research and Policy.
The most recent national data on bird flu from the Centers for Disease Control and Prevention (CDC) confirm 67 human cases of H5N1 in the U.S. since the outbreak began last April, with 1 death reported Jan. 6 in Louisiana. The CDC’s bird flu briefing page states the risk to public health is low.
Public communications from the CDC were paused last week by Dorothy Fink, M.D., acting secretary for the U.S. Department of Health and Human Services, until at least Feb. 1, pending review and approval by a presidential appointee.
The CDC recommends parents keep their children away from sick or dead animals; properly cook poultry, eggs and beef; and not provide raw or unpasteurized milk products to their children.
Robert W. Frenck Jr., M.D., FAAP, advises parents to caution children against touching, handling or moving a sick or dead bird. Such birds should be reported to an adult.
Children who live on or visit farms should be supervised and reminded not to rub their eyes or touch their nose or mouth after being around birds or bird droppings. Any children who may have touched birds or their byproducts should wash their hands with soap and water.
People who work with animals, tend backyard flocks or hunt are at higher risk of exposure to H5N1, according to the CDC. Viruses may be shed in birds’ saliva, mucus and feces, and in other animals’ respiratory secretions or bodily fluids, including raw milk.