The first human case of bird flu in the United States has been reported by a Colorado prisoner involved in a pre-release program. In October 2015, cage-free chickens walk in a fenced pasture at an organic farm.

Charlie Neibergall/AP

The first human in the US to test positive for bird flu is a man in Colorado.

The H5N1 bird flu poses a low risk to humans while leading to the deaths of millions of birds. The majority of the birds are being culled to stop the spread of the disease.

The patient, who is younger than 40, was involved in the slaughter of poultry at a commercial farm in Colorado. He was working with poultry as part of a pre-release employment program while he was in prison.

The affected flock has been euthanized because members of the response team were given personal protective equipment while working on the farm.

The patient recovered after he reported fatigue for a few days. He was treated with the medication oseltamivir.

According to a statement from Colorado authorities, the virus was found on a single specimen and could have been present in the patient's nose without causing infections.

The first human case associated with this group of H5 viruses occurred in the UK in December 2021, according to the CDC. According to the World Health Organization, the first patient lived with a large number of birds that had been exposed to H5N1.

The human risk of bird flu is low for the general public, according to the CDC. People who work with birds are at higher risk for infections.

Dr. Rachel Herlihy, the state epidemiologist, said in the statement that the risk to Coloradans is low.

Birds are contracting bird flu. More than 35 million birds have been affected.

The latest data from the U.S. Agriculture Department shows that 58,070 birds have been affected in Colorado. More than 13 million birds have been affected in Iowa, which is one of the worst-hit states.