The bird flu is spreading on hundreds of dairy farms this season in the Central Valley. More than 100 dairies are under quarantine in Stanislaus County because of cows infected with the H5N1 virus, which in rare cases is transmitted to people. Stanislaus County health officials on Monday reported a single case of bird flu in a county resident who had contact with infected dairy cattle. In response to this strain of avian flu, the state has established quarantines at 680 infected dairy farms in California, most of them in the Central Valley. In all but one of the 37 human cases in the state, the person was exposed to dairy cattle. State and county health agencies are not seeing the illness spread person-to-person. Read more