Sushi Lovers! These Dangerous Worms are Probably Inside You. Here’s What You Should Do

by in Food, Health, Other April 3, 2017

Sushi is a favorite among many and has been consumed for hundreds of years. However, there are some dangers to eating sushi that contains raw fish.

Specifically, certain species of worms can stay alive in sushi and infest the person who eats it. Some worms can get into the eyes and the central nervous system, creating serious complications. Don’t get me wrong, I love sushi but after doing all the research I did for this article I will only be eating cooked rolls and I suggest that you do the same.

The general rule is that fish served raw in the United States must be flash-frozen before you eat it. The FDA requires that all fish (except for tuna) destined to be served raw in the U.S. be frozen at a minimum of four degrees Fahrenheit for 7 days or minus thirty-one degrees for 15 hours. Either process kills parasites inside of the fish and keeps it fresh.

The FDA’s requirement means that most sushi in the U.S. is likely to be free of parasites, but there are some exceptions. Some diners, for instance, may be sensitive to even dead parasites and can suffer from stomach pain and vomiting if they eat them in sushi. In other cases, the fish may not have been frozen at all and may be contaminated with parasites. This may occur in some specialty shops that pride themselves on serving “fresh,” raw fish. It is always good to ask or just go for the cooked rolls instead.

What Kind of Worms are Found in Sushi?


Nematodes are worms that are usually round, and an infestation with them contracted from eating raw or undercooked saltwater fish is known as anisakiasis. These worms find their way into sushi when marine mammal feces enter the ocean. These feces often contain the eggs of these worms, which hatch and become larvae. The larvae are eaten by fish and other animals in the ocean.

When the fish that has consumed, the nematodes are caught and made into sushi, the worms don’t die. They remain in the sushi until they are ingested by the consumer. In some cases, people have reported a “tingling” feeling after consuming sushi. This feeling is a worm, and some people who have experienced this feeling have successfully extricated the worm from their mouth.


While the worms causing anisakiasis are primarily found in saltwater fish, tapeworms are usually found in freshwater fish (or fish who spend a part of their lives in freshwater). Salmon are a common carrier.

Gnathostomiasis: The Most Dangerous

Anisakiasis and tapeworm infestations can be inconvenient and painful, and they may cause the sufferer to need surgery. However, gnathostomiasis, or an infection with a worm (nematode) from the genus gnathosoma, is often much worse. These parasitic worms are most commonly seen in southeast Asia and parts of Africa, but they are rare in the Americas. These worms resemble small lampreys, and they are contracted much like anisakiasis is.

Though eating uncooked seafood is a common way to contract a gnathostome worm, eating undercooked or uncooked freshwater animals (including birds who drink from freshwater) can put a person at risk. And while the worms responsible for anisakiasis generally are confined to the digestive tract, these worms can travel into many areas of the body.

Most commonly, gnathosoma worms are seen as small swellings under the skin. These swellings, unlike most skin bumps, move. This is because the worm moves right beneath the skin. If you do see a moving swelling, it’s imperative that you see a doctor immediately, as many of these worms move deeper into the body.

A gnathosoma worm may work its way into the liver and into the central nervous system and eyes. Though the worm is not poisonous, it can cause pain, paralysis, coma, and death. This is because it travels along nerves, causing excruciating pain. If the worm gets to the eyes, it can cause permanent blindness.

How to Protect Yourself

  1. Cooked Sushi

The number one way to protect yourself is to order cooked or vegetable based rolls.

  1. Wasabi

If you just refuse to stop eating raw sushi then opt for Wasabi, it naturally kills parasites.

  1. Saltwater fish

Saltwater fish are less likely to be infected that fresh-water fish. Choose albacore, Atlantic cod, rockfish, eel, flounder, grouper, halibut, Pacific Bluefin tuna, and swordfish to raise your odds of avoiding parasites.

  1. What Ocean?

Choose fish from the Atlantic Ocean over those from the Pacific Ocean, number one reason being to avoid radiation but the Pacific has a higher population and can spread more parasites

  1. Ask for Sashimi based fish

These fish go through all the FDA measures to guarantee safety. They are inspected and found to be at least very low in parasites, and then are frozen to the point that parasites cannot survive. The fish is also cut thinner, making it easier to spot a worm with the naked eye.