California has declared a state of emergency due to the spread of the H5N1 bird flu virus in dairy farms, with over 650 herds infected. The CDC confirmed severe symptoms in a case, raising concerns about potential human transmission. Experts emphasize the need for preventive measures to protect workers and animals. Testing protocols for milk deliveries have been strengthened to ensure consumer safety. The state aims to manage the outbreak and prevent a dangerous mutation of the virus that could lead to human-to-human transmission.