Can I get sick from eating raw seafood?

Originally Published: February 20, 2004 - Last Updated / Reviewed On: September 9, 2011
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Alice,

I love Sushi/Sashimi, and oysters on the half shell. I apparently am uneducated (ignorant) when it comes to the health risks associated with eating raw seafood. I read in an article that a person could contract Hepatitis A, and worms. Is Hepatitis A something that is "curable"? Are ANY of the diseases/problems associated with eating raw fish NOT "curable?"

Dear Reader,

Raw fish and seafood can certainly be tasty delectables. Many a consumer has wondered about the health risks. They are generally minimal — lower than compared to other means of transmitting food borne illnesses. Though most are indeed incurable, many of them go away on their own, though this also depends somewhat on other health conditions of the consumer.

The hepatitis A virus can be found in some raw shellfish, but it is not common in other seafood. Hepatitis A, unlike types B and C, does not cause long-term or chronic illness. Hepatitis A causes inflammation of the liver and interferes with liver function. Mild cases require no treatment. Once the infected individual heals, s/he will then have immunity for life. Symptoms of hepatitis A can include:

  • fever
  • tiredness
  • loss of appetite
  • abdominal discomfort
  • dark urine
  • jaundice (yellow skin)
  • nausea
  • no symptom at all

Hepatitis A's incubation period (the time it takes from eating the food until beginning to exhibit symptoms) ranges from 15 to 50 days. Infected individuals can be sick for up to 6 months, but the liver usually heals on its own within a month or two. You can take a blood test to see if you've already been exposed to hepatitis A, and you can also receive a vaccine, which may be something you want to consider. If you're a Columbia student, you can call Medical Services at x4-2284 for an appointment, or see your own health care provider for either the antibody test or vaccine. Hepatitis A is killed by heat, so it is not a concern for those enjoying cooked shellfish dishes.

Worms (and worm eggs) can be a concern when consuming raw fish. They are preventable and treatable. Your health care provider can prescribe oral medication that is toxic to the worms. Worms are killed when the fish is cooked or completely frozen, but can be passed on in the raw state. This includes not just sashimi or sushi, but also some other popular dishes, such as partially raw seared fish fillets and ceviche — raw fish marinated in lime or other citrus juice. Most worms will pass through the digestive system without causing any problems, but two can cause infections: roundworm larvae and a type of tapeworm species, diphyllobothrium. Infection by either of these two parasites can result in abdominal discomfort, diarrhea, fatigue, and feelings of weakness in the arms and legs. Though the risk is low, it can be further reduced by purchasing fish from reputable stores and also eating at reputable restaurants. Trained sushi chefs have learned how to identify worms or worm eggs in fish, and reputable packing houses use a process called candling (quite simple: holding the fish to light) to check for worms in the fillets.

For all of the above reasons, people with the following conditions should check with a health care provider before eating raw fish or shellfish:

  • liver disease
  • HIV/AIDS
  • diabetes
  • stomach disorders
  • inflammatory bowel disease
  • cancer
  • abnormal iron metabolism
  • other autoimmune disorders

There are toxins found even in cooked foods, so when you take this into account, the risks posed by eating raw or undercooked seafood are actually relatively low, but raw fish and seafood still sometimes get a bad rap. Hopefully this information will help you in weighing the risks of feasting on the bounties of the sea.

Bon appétit!

Alice