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.

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.

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.