The Centers for Disease Control and Prevention has confirmed the first human case of highly pathogenic avian influenza in Oregon, according to the Oregon Health Authority.

The person is linked to a previous outbreak that affected 150,000 birds at a commercial poultry operation in Clackamas County from Oct. 23.

There have been 52 human cases of HPAI in the U.S. as of Nov. 15, according to the CDC, with California leading the nation with 26 instances, all with cattle as the source.

Washington was second with 11 human cases, all from poultry.

Mild illness, recovery

Oregon officials are not providing additional details about the individual or operation.

There is no evidence of person-to-person transmission and the risk to the public is low, according to the OHA.

“Clackamas County Public Health Division has been closely monitoring people exposed to the animal outbreak, which is how this case was identified. The individual experienced only mild illness and has fully recovered,” said Dr. Sarah Present, Clackamas County public health officer, in the news release.

The person received treatment with the antiviral medication oseltamivir and household contacts were prescribed oseltamivir prophylaxis.

Education and monitoring

When an outbreak in animals occurs, the Oregon Department of Agriculture provides personal protective equipment and training to affected farmworkers, and public health agencies provide symptom education and monitoring.

To reduce the risk of highly pathogenic avian influenza, people should avoid contact with sick or dead birds or animals, or their droppings or litter, and should not eat unpasteurized or raw dairy products.

Recent farm outbreaks

The multiyear bird flu outbreak has affected 4.26 million birds in commercial and backyard flocks in the United States.

Oregon’s most recent farm outbreak of avian influenza was confirmed in Malheur County on Nov. 13 and 20 birds were euthanized, according to the CDC.

From Nov. 12 to 14, California had outbreaks that affected nearly 2.5 million birds.

The most significant of these was from a commercial table egg layer in Kern County on Nov. 12 that had nearly 2.16 million birds.

Pig, cattle cases

In late October, highly pathogenic avian influenza was confirmed in a pig at a small farm in Crook County, Ore., in the first instance of the virus infecting pigs in the U.S.

Bird flu also infected a backyard flock at that property.

Officials expressed concern about the development, as pigs are susceptible to viruses from both birds and humans, which could cause intermingling and mutations of the disease.

The virus also has been reported in 508 herds of cattle during the outbreak, with 294 in California dairy herds.

Idaho has had 35 instances in dairy herds.

Wild birds, other animals

Avian influenza cases are higher in fall and spring as the virus is widespread among wild birds, which spread the disease through migration.

Bird flu has been found in domestic cats and several different types of wild mammals in the Pacific Northwest and California, including bobcats, cougars, skunks, raccoons, red foxes, fishers, a marten and a harbor seal.

More bird flu coverage

Bird flu hits SE Oregon for first time

California shell egg prices surge as bird flu spreads

Bird flu confirmed in pig at small Oregon farm

WSDA: Migratory birds spreading avian influenza

Bird flu infects four Washington farmworkers

Bird flu blues: Highly pathogenic avian influenza hits dairy herds without warning