Bird flu in U.S. dairies

Bird flu turned up in five more Idaho dairy herds this month, the first new U.S. cattle cases confirmed in 2026. (capitalpress.com) The Idaho detections were confirmed April 13 through routine monthly surveillance, Idaho state veterinarian Scott Leibsle said. The U.S. Department of Agriculture has reported 1,093 confirmed cattle cases in 19 states since the dairy outbreak began. (capitalpress.com) Bird flu is an influenza virus that usually circulates in wild birds and poultry, but this strain was first reported in U.S. dairy cows on March 25, 2024. The Centers for Disease Control and Prevention says the virus is now causing outbreaks in poultry and U.S. dairy cows, with sporadic human cases in dairy and poultry workers. (cdc.gov) The main public-health line has not changed: the Centers for Disease Control and Prevention still says the risk to the general public is low. The agency says people with job-related exposure to infected birds or animals, including cows, face higher risk and are being monitored through flu surveillance systems. (cdc.gov) The Idaho cases were found under a broader federal testing regime built after the virus jumped into cattle. The U.S. Department of Agriculture’s National Milk Testing Strategy, announced in December 2024, requires raw milk samples to be collected and shared for testing, alongside mandatory testing for interstate movement of lactating dairy cows. (aphis.usda.gov) Federal officials say those rules are meant to catch silent spread, because the virus can move between farms on cattle, equipment, vehicles, and people. The U.S. Department of Agriculture says the April 2024 movement order has helped limit spread to new states. (aphis.usda.gov) Food-safety guidance has also stayed steady. The Food and Drug Administration says milk from sick cows is diverted or destroyed, and pasteurization inactivates H5N1 in milk, so officials say the commercial pasteurized milk supply remains safe. (fda.gov) Health officials are still watching workers closely because human infections have occurred during the dairy outbreak. The Centers for Disease Control and Prevention says several U.S. human cases have been identified and says most recent U.S. cases have been linked to animal exposure rather than sustained person-to-person spread. (cdc.gov) Drugmakers are now testing vaccines against the H5 strain in people as the cattle outbreak drags into a third calendar year. Moderna said April 21 that it had started a Phase 3 trial of its investigational mRNA-1018 pandemic influenza vaccine, with funding support previously announced by the Coalition for Epidemic Preparedness Innovations. (newswire.com) (cepi.net) For now, the new Idaho herd detections fit the pattern officials have been describing for a year: more surveillance, more farm-level positives, and no change in the federal assessment that the broader public risk remains low. (cdc.gov)