The outbreak hit California dairy farms in the late summer, and shortly thereafter, some dairy workers handling the raw milk began to fall ill with avian influenza themselves. Today in the state, more than 400 dairy farms are suffering outbreaks of avian influenza.

California health officials are warning not to drink another lot of raw milk from Fresno-based Raw Farm after it tested positive for bird flu virus. More testing of Raw Farm products is underway, the state said.