A fourth dairy worker in the U.S. has been infected with bird flu. Health officials said Wednesday that the worker in Colorado had an eye infection and has since recovered. The man worked on a farm in Colorado where dairy cows tested positive for the virus. Three previous cases of human infection linked to cows were reported in dairy workers in Texas and Michigan this year. As of Wednesday, the Agriculture Department says more than 135 dairy herds in a dozen states had reported infections with bird flu that originated in poultry.
