A person in Yakima County, Washington, has died after contracting bird flu through exposure to infected dairy cows, county health officials said Sunday. The patient suffered a severe illness and had underlying health conditions that officials did not identify.

The death is the first known US fatality from complications of avian influenza in 2026. It is also the third US bird flu death since February 2024, when the virus first jumped into dairy cattle.

The Yakima County Health District reported on October 31 that the person had been hospitalized with a severe case of bird flu after contact with infected cattle. The county reported the death on November 1.

County health officials are closely monitoring the patient’s contacts to determine whether the infection spread to anyone else. No transmission between humans has been documented in the United States, and health officials continue to describe the threat to the general public as low.

The US Centers for Disease Control and Prevention has recorded bird flu infections in more than 70 people nationwide since 2024. Most patients worked on farms with infected cattle or poultry, and most experienced mild illness.

Officials have characterized the cases as so called dead end infections, meaning the virus moved from an animal to a person but did not spread farther. The Washington death followed occupational exposure to infected dairy cattle.

Three human cases have been identified in the Yakima County Health District this year. They include a mild case found last month, the patient who died and a third infection reported over the weekend.

All three Washington cases have occurred since mid October and were connected to exposure to infected cows. The third patient, like the first, has mild symptoms and has not been hospitalized, according to county health district officials.

Washington health officials reported all three infections to the CDC. However, the federal agency had not yet included them on its bird flu dashboard.

Since October 8, Washington has reported 33 dairy herds infected with the H5N1 bird flu virus. State officials are urging dairy workers to use personal protective equipment and report symptoms if they become ill.

Dr. Dave Atteberry, public health officer for the Yakima health district, said infected herds were identified in early October through milk testing conducted by the Washington State Department of Agriculture and the US Department of Agriculture. County public health workers then contacted the affected farms.

Workers were enrolled in a daily screening tool delivered by text message that checks for symptoms including cough, fever and red eyes. When a worker reports symptoms, the health department follows up with additional questions.

“We’re throwing a large net so that we capture everybody that that potentially could be getting exposed, and then we’re able to focus our attention on those individuals that are exposed, and then we get them treated,” Atteberry told CNN last month.

On October 15, a dairy worker in the county tested positive for a mild H5N1 infection. It was the first human case reported in nearly a year.

Monitoring practices differ among states. ProPublica reported that Utah’s Department of Agriculture and Food agreed to share information about farm outbreaks as long as health officials did not take steps to track workers’ health.

Dr. Jennifer Nuzzo, director of the Pandemic Center at Brown University’s School of Public Health, expressed concern about that patchwork approach. “I just think that our our picture of H5N1 is the murkiest it’s ever been,” Nuzzo said.

Nuzzo said the increase in bird flu activity at Washington dairies has coincided with very early seasonal influenza circulation on the Pacific Coast. She said that overlap creates an opportunity for H5N1 to exchange pieces of its genome with seasonal flu viruses, potentially helping it infect humans more effectively.

“That is the bad scenario. So when you have an uptick in bird flu activity corresponding with human flu season, that just increases my worry even more that we could have a mix that we don’t want to have,” Nuzzo said.

Atteberry said farm workers who test positive receive antiviral medication to treat their symptoms and lower their viral load, reducing the chance they might infect others. “Even though we haven’t seen that biologically be possible yet,” Atteberry said. “We’re doing it out of an abundance of caution.”