After a new study showed that bird flu has spread to dairy farm workers more often than previously known, the US Centers for Disease Control and Prevention is expanding its recommendations for testing and treatment of workers on farms where animals have tested positive.

To date, 46 people have been diagnosed with bird flu, also known as H5N1, in the United States this year. All but one of those patients had been exposed to sick cattle or poultry on farms. Most cases have been reported in California (21), Washington (11 ...

Federal officials said Thursday that farmworkers exposed to bird flu should be tested for the virus even if they are not showing any symptoms, especially if they were not wearing the proper