California declares state of emergency over bird flu outbreak affecting cows

California has declared a state of emergency due to a bird flu outbreak affecting milk cows and causing some illnesses in people. The virus, H5N1, has spread to about one-third of U.S. states since it was first identified in cows in March. The CDC reports that the general public is at low risk, with no person-to-person transmission detected. However, one severe case was reported in Louisiana, marking the first known severe illness linked to backyard birds in the U.S. Health officials are increasing testing of raw milk to contain the virus. They advise those in contact with infected animals to take precautions, as the virus can also spread through unpasteurized milk.