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.

Bird flu was first confirmed in U.S. dairy cattle in March, and high levels of the virus have been found in the milk of infected cows.

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.