A Colorado prison inmate who had direct exposure to poultry infected with avian flu is the first person in the U.S. to test positive for the current strain.

The man, who is an inmate at a state correctional facility in Delta County, has shown mild symptoms of fatigue, the Centers for Disease Control and Prevention and the Colorado Department of Public Health and Environment said.

“This case does not change the human risk assessment for the general public, which CDC considers to below,” the CDC said in a statement.

According to the Colorado health department, the man who tested positive is isolated and being treated with an antiviral drug. He was working at a commercial farm with infected poultry as part of a correctional pre-release employment program.

“Because the person was in close contact with infected poultry, the virus may have been present in the person’s nose without causing infection,” the Colorado department said. Still, the CDC said it was appropriate to contain and treat the case as an infection.

The CDC recommends that people who work in direct contact with poultry take increased precautions, including wearing gloves, masks, and eye protection and washing hands.

While the H5N1 virus can spread between an infected person and a close contact only very rarely, based on previous outbreaks, it does not lead to sustained spread among humans, the CDC said.

Only one other person is known to have tested positive with the current strain; a person in the UK who raises birds became infected but did not have any symptoms in December 2021.