The United States has reported its first bird flu-related death in a year after a Washington state resident contracted the H5N1 virus following exposure to infected cattle at a dairy farm in Yakima County. The case has drawn attention to the ongoing spread of the virus among dairy herds in the state.

According to Yakima County health officials, the individual had underlying health conditions and was hospitalized before dying on Sunday. The death is the first reported in the country in 12 months and the third since bird flu became a national public health concern in 2024.

Washington Dairy Herds Record 40 Infections

The outbreak has affected dairy cattle in two Washington counties, with the majority of reported detections concentrated in Yakima County.

Data from the Washington State Department of Agriculture's tracker showed 39 infected herds in Yakima County and one in neighboring Benton County as of October 30. A separate Yakima County dashboard, updated November 1, reported 33 affected herds through October 29. The difference reflects six additional Yakima County herds confirmed by the state on October 30.

The state's first two cattle detections were confirmed in Yakima County on October 8. Further cases were subsequently recorded in the same county, followed by a detection in Benton County on October 23.

The figures identify affected counties rather than individual farms. State authorities say infected herds are placed under quarantine and must follow biosecurity measures.

Differences in Reported Human Cases

Publicly available data also show discrepancies in the number of confirmed human infections.

Yakima County's dashboard lists three confirmed human cases, while the Washington State Department of Health's online table records one confirmed dairy-associated human case in 2026. The state figures may not include the county's most recent updates.

Newsweek said it had contacted the Centers for Disease Control and Prevention, Washington health and agriculture officials, representatives of the dairy industry and an infectious disease expert for comment.

How H5N1 Spreads Among Dairy Cattle

The spread of the virus is not limited to direct contact between infected animals. According to information from Washington's agriculture department, transmission can occur through infected cattle and contaminated milk, equipment, vehicles, clothing and footwear.

Dr. Peter Rabinowitz, a professor at the University of Washington, told Newsweek that the strain circulating among dairy cattle appears particularly well adapted to spreading from one cow to another.

He explained that the virus can become concentrated in milk and the udders, allowing it to move between animals through contaminated milking machines and other equipment. The movement of cattle between farms may also contribute to transmission.

The outbreak therefore highlights the importance of monitoring infected herds and applying biosecurity measures across dairy operations.

Editorial note: The supplied source excerpt ends during Dr. Rabinowitz's explanation. It does not provide further details about the deceased individual's identity, the full public health assessment, or subsequent developments in the outbreak.