Minnesota boards report H5N1 detections in dairy herds and poultry; no confirmed human infections

State and federal animal-health officials on Thursday told the Minnesota Board of Animal Health that the H5N1 avian influenza virus has been detected in both poultry premises and dairy cattle in the state, triggering quarantines, expanded testing and updated milk-management controls.

Stacy, the state public health veterinarian at the Minnesota Department of Health, said public-health monitoring has covered thousands of potentially exposed people and that "No human infections of h 5 11 were detected." The board and its agency partners have provided personal protective equipment from the Strategic National Stockpile to poultry and dairy workers and initiated voluntary symptom monitoring for people with occupational exposure.

State veterinarians described how the outbreak has presented differently in cattle than in poultry. Dr. Katie Corneal, senior veterinarian on the board, summarized the Minnesota response for dairy: affected herds have been placed under quarantine, and the state now requires three consecutive negative bulk-tank tests collected at least seven days apart (including sampling of lactating animals) before a quarantine is lifted. She said those requirements and milk-management plans have guided decisions to release quarantines.

Sandy Larson of the Minnesota Department of Agriculture said epidemiologic evidence and genomic sequencing point to cattle movement and shared personnel as major drivers of spread between premises. "We learned that the spread of H5N1 interstate and intrastate is linked to cattle movements," she told the board, adding that under-reporting and untested herds have left gaps in investigators' ability to reconstruct transmission chains.

Federal and state officials described laboratory capacity and surveillance efforts. Dr. McCarty, a laboratory representative, reviewed testing volumes and sequencing work that has helped link cases across species and counties. USDA and state lab partners are accepting sequencing samples and have begun limited approvals for vaccine trials; officials said only killed (inactivated) injectable products have been authorized for experimental or limited use so far.

The board heard that, nationally, public-health partners have monitored more than 14,000 people since February 2022 for potential exposure and that, as of the most recent reports presented, there have been human H5N1 cases identified in other states. Minnesota's health officials emphasized the risk remains occupational and that the immediate priority is protecting workers through PPE, monitoring and outreach. "We offered N95 respirators, safety goggles, nitrile gloves and face shields to anyone who works in dairy and poultry production," the state public-health veterinarian said.

Officials cautioned that questions remain about environmental routes of spread, including the role of contaminated milk, manure or equipment. The board and agency partners said they will continue targeted surveillance, genomic analysis and outreach to encourage case reporting and testing by producers and veterinarians. The board did not take a new regulatory vote at the meeting on declaring H5N1 reportable in dairy; staff said such a change would require additional statutory or federal action.

Next steps: agencies will continue testing and sequencing, enforce quarantine and milk-management requirements where needed, distribute PPE, and maintain public-health monitoring of potentially exposed workers. The board reminded producers that pasteurization inactivates influenza in milk intended for commercial processing.