A highly contagious strain of avian flu that has led poultry farmers to kill millions of birds across the country has now been detected in a human in the United States for the first time.
An adult male under 40 who was working at a commercial poultry farm in Montrose County, Colorado, tested positive earlier this week for influenza A (H5) virus, according to a news release by the Colorado Department of Public Health and Environment. The Centers for Disease Control and Prevention confirmed the positive test on Wednesday.
The person is an inmate at a correctional facility in Delta County who was working on a commercial poultry farm as part of a pre-release employment program, according to the agency. The affected poultry flock has been euthanized.
The man reported fatigue for a few days as his only symptom, has since recovered and is being treated with the influenza antiviral drug oseltamivir (Tamiflu). He was involved in culling birds presumed to have H5N1 bird flu, according to the CDC.
Public health experts consider the risk for humans to be low from this strain of the avian flu. The CDC has monitored more than 2,500 people exposed to birds infected with H5N1 virus and has only found the one case in Colorado. There are currently no cases of H5 viruses spreading from person to person.
A person who raised birds in the United Kingdom, who tested positive in December, is the only other human found to have been infected with this strain of avian flu. More than 880 human infections of other H5N1 viruses have been reported since 2003, but the current viruses circulating among birds are different from the earlier ones, according to the CDC.
In the U.S., the H5N1 viruses have been found in commercial and backyard birds in 29 states and in wild birds in 34 states, according to the CDC.
The spread of the avian flu viruses to farms in more than half the country has resulted in farms killing millions of egg-laying birds, which has contributed to the rise of the price of eggs to historic levels this spring.