Cod worms are parasites found in various seafood species including cod, mackerel, salmon, and red snapper. They will make you sick if you ingest them live from an infected fish.
Also known as anisakids or seal worms, symptoms of cod worm infection range from mild allergic reactions to severe gastrointestinal issues, sometimes requiring surgical removal.
The worms live in large marine mammals, like sea lions and dolphins, which release larvae into the ocean and infect seafood species, and thereby enter the human food chain.
The Food and Drug Administration and Centers for Disease Control advise either freezing fish or cooking it through at 145 degrees Fahrenheit or higher to kill the parasite.
Reassuringly, cod worm infection, known as anisakiasis, is rare in the U.S. and more common in countries where the cuisine favors raw fish dishes, such as Japan and Spain.