A man who worked on a commercial poultry farm in Colorado has tested positive for avian influenza A(H5) virus, better known as H5 bird flu, the CDC announced on April 28.
This is the first case of H5 bird flu in humans in the United States and only the second case in the world, the CDC said in a news release. The first case was detected last December in a man who raised birds in the United Kingdom. That man had no symptoms.
The only symptom the man in Colorado reported was fatigue, the Colorado Department of Public Health and Environment (CDPHE) reported. He has recovered and is isolating and being treated with oseltamivir, an antiviral drug.
The CDC said the man was helping kill poultry that likely had the H5N1 bird flu.
He is a state prison inmate who was working on a commercial poultry farm in Montrose County in a prerelease employment program, the CDPHE said. The flock he was working with has been euthanized, and the response team and other inmates working on the farm were given protective equipment, the CDPHE said.
“Repeat testing on the person was negative for influenza,” the department said. “Because the person was in close contact with infected poultry, the virus may have been in the person’s nose without causing infection.”
This CDC said the case does not change the risk of bird flu for the general public, which is considered low. People who work with birds should continue to take safety precautions, such as wearing gloves when handling birds and avoiding birds that appear to be dead or ill, the CDC said.
“We want to reassure Coloradans that the risk to them is low,” said Rachel Herlihy, MD, state epidemiologist with the CDPHE. “I am grateful for the seamless collaboration between CDC, Department of Corrections, Department of Agriculture, and CDPHE, as we continue to monitor this virus and protect all Coloradans.”
The federal government says the H5N1 virus has been found in commercial and backyard birds in 29 states and in wild birds in 34 states since the first cases were detected in late 2021.
The CDC says it has tracked the health of 2,500 people exposed to birds infected with H5N1 and only found one case of human infection, in Colorado.
A version of this article first appeared on WebMD.com.