For the second time in roughly the span of a week, Santa Clara County Department of Public Health officials tested store-bought raw milk and found evidence of the virus. The sample was collected and tested on Nov. 26.

The detection of bird flu virus this week in a batch of unpasteurized milk sold in California underscores what health experts say are the known and potential risks of the products.

Bird flu virus has been found in a batch of raw milk sold in California, and consumers should not drink it, the state Department of Public Health warned Sunday.