Disturbed, the family grabbed a cellphone and recorded video of the parasites, which they sent along with a letter to the San Joaquin County Department of Public Health. “It seems like shock to conscious for Costco selling this knowing they have these parasitical worms inside of their food,” John Rock told the Sacramento-area station. Environmental Health Specialist Lisa Medina said that Costco mostly repackages the fish, and does not do any of the main processing, according to KCRA.