Colorado bird flu cases show how extreme heat may be complicating efforts to control the virus

Searing heat may have played a role in the infections of five workers who fell ill last week while culling a large flock of chickens infected with the H5N1 virus in Colorado, health officials said Tuesday.

Searing heat may have played a role in the infections of five workers who fell ill last week while culling a large flock of chickens infected with the H5N1 virus in Colorado, health officials said Tuesday. “At the time transmission is thought to have occurred, Colorado was experiencing 104-plus-degree heat,” and it was probably hotter inside the barns, said Dr. Nirav Shah, principal deputy director of the US Centers for Disease Control and Prevention. The CDC is investigating the outbreak along with the Colorado Department of Public Health and Environment. This made the use of personal protective equipment a challenge, Shah said. In addition, to bring down temperatures in the sweltering barns, large industrial fans were blowing, moving air as well as dust and feathers. Feathers from infected birds are known to carry the H5N1 virus. “We understand those large fans … were moving so much air … the workers were finding it hard to maintain a good seal or a good fit either between the mask or with eye protection,” Shah said. Four of the Colorado cases have been confirmed by the CDC. A fifth tested positive at a state lab and has been sent to the CDC for confirmation.