Wilderness: Shellfish Poisoning, Gastrointestinal

Medically Reviewed by Carol DerSarkissian, MD on May 14, 2022
2 min read

Shellfish poisoning is caused by eating shellfish contaminated with bacteria or, more commonly, viruses. Contaminated shellfish include shrimp, crabs, clams, oysters, dried fish, and salted raw fish. Contaminated fish may have a tainted odor or taste.

Symptoms of shellfish poisoning begin 4-48 hours after eating and include:

A person who has blood in the stool and a fever may have a bacterial infection.

 

Follow these steps for someone with shellfish poisoning:

  • Do not induce vomiting.
  • Help the person stay well-hydrated.
    • Encourage the person to drink frequent sips of clear fluids.
    • IV fluids may be necessary if nausea and vomiting cannot be controlled.

There is no specific cure available for shellfish poisoning, and antibiotics do not shorten the illness.

Drugs used to control diarrhea, vomiting, and stomach cramps should not be used except for bismuth (Pepto-Bismol). These drugs are referred to as antimotility drugs since they decrease stomach and intestine motion. Antimotility drugs other than bismuth preparations can worsen or lengthen the illness because the infectious agent is not expelled from the body as rapidly.

 

Seek medical treatment immediately if the person is unable to tolerate oral fluids, if fever is present, if there is blood in the stool, or if other concerning symptoms develop.

For all other cases of shellfish poisoning, seek medical treatment as soon as possible.
 

wilderness: shellfish poisoning, gastrointestinal; food poisoning; diarrhea; abdominal cramps; vomiting; nausea