A highly contagious strain of avian flu that has likely killed hundreds of birds and spread across more than two dozen states has been detected in a human for the first time in the U.S., officials said Thursday.
The man was working on a commercial farm in Colorado and was involved in culling poultry suspected to be infected when he was directly exposed to the H5N1 flu, the state’s health department said in a release.
The man, described as younger than 40, has reported only one symptom — fatigue — and was taking the antiviral drug Tamiflu, the department said.
A positive test administered this week by the state health department, which said it has been monitoring people exposed to poultry and wild birds, was confirmed Wednesday by the Centers for Disease Control and Prevention, the agency said.
The state health department described the man as a prison inmate who was working at a Montrose County farm as part of a pre-release employment program.
The affected flock was euthanized, the department said.
The state health agency and the CDC said Thursday that the risk the virus poses to people still remains low.
Although public health officials have worried that a mutation could present a threat to humans, only one other human case has been detected worldwide — a person who raised birds in the United Kingdom tested positive for the virus in December. The person was asymptomatic, the CDC said.
Earlier versions of the virus infected roughly 880 people beginning in 2003, the agency said. Although the virus rarely infects people, it can be severe when it does: According to the CDC, its mortality rate is 60 percent.
The H5N1 virus now circulating has been found in commercial and backyard birds in 29 states and in wild birds in 34 states, the CDC said.
An outbreak at a lake outside Chicago is believed to have killed more than 200 birds, and at least three bald eagles died from the virus in Georgia. Millions of chickens and turkeys have been killed to prevent the virus’s spread, prompting a surge in poultry prices.