(Reuters) - Colorado workers who contracted bird flu were working during extreme heat and under large fans, factors that made wearing protective equipment difficult and potentially contributed to their infections, the U.S. Centers for Disease Control and Prevention said on Tuesday.
The CDC had previously confirmed four cases and a fifth presumptive positive case of bird flu among Colorado farm workers who were killing and disposing of chickens that had contracted the virus.
Four other farm workers have contracted avian flu this year from infected dairy cows in Michigan, Texas, and Colorado.
The risk to the general public from bird flu remains low, Nirav Shah, principal deputy director of the CDC, said on a call with reporters.
When workers were killing the infected chickens, it was 104 degrees Fahrenheit (40 degrees Celsius) in Colorado, and strong industrial fans made it hard for workers to keep protective gear on their faces, Shah said.
"PPE use was not optimal, particularly the masks and eye protection," Shah said, referring to personal protective equipment.
Initial analysis of the virus does not show concerning changes to the virus making it easier to spread among people, Shah said.
The CDC is not recommending that livestock workers be vaccinated against bird flu, Shah added.
(Reporting by Leah Douglas; Editing by Will Dunham)
By Leah Douglas and Julie Steenhuysen
