CDC Expands Bird Flu Fight as Infected Workers Go Undetected

US health officials said high-risk farm workers should be more widely tested and treated for bird flu based on evidence suggesting some contracted the infection without showing signs of illness.

The agency updated its guidance Thursday after a study found that 7% of 115 farm workers exposed to the virus in Michigan and Colorado had evidence of a recent infection, even though some didn’t recall having symptoms.

The agency said farm workers should get tested if they were exposed to animals infected with bird flu, even if they don’t have symptoms, especially if they weren’t wearing protective equipment. The CDC ...