The Centers for Disease Control and Prevention on Friday confirmed highly pathogenic form of bird flu in a person in Oregon.

The infected person is linked to a previously reported outbreak tied to a commercial poultry operation in the state, where the virus has been confirmed in 150,000 birds, the state health authority said.

A total of 52 people from seven states have tested positive in the U.S. this year as the virus has infected poultry flocks and spread to more than 500 dairy herds, the CDC said.

All the cases were farm workers who had known contact with infected animals, except for one person in Missouri.

Health officials did not provide more details about the individual infected in Oregon, but said there is no evidence of person-to-person transmission and the risk to the public is low.

Last month, the H5N1 bird flu was confirmed in a pig on a backyard farm in Oregon, the first detection of the virus in swine in the country.

The CDC has instructed that farm workers who have been exposed to animals with bird flu should be tested even if they do not have symptoms.

Since 2022, the virus has wiped out more than 100 million poultry birds in the nation’s worst-ever bird flu outbreak.