Wilderness: Shellfish Poisoning, Gastrointestinal

Shellfish Poisoning Overview

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.

Shellfish Poisoning Symptoms

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.

 

Shellfish Poisoning Treatment

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.

 

When to Seek Medical Care

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.
 

Synonyms and Keywords

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

WebMD Medical Reference Reviewed by Carol DerSarkissian on May 15, 2018

Sources

SOURCES:

Author: Scott H Plantz, MD, FAAEM, Research Director, Assistant Professor, Department of Emergency Medicine, Mount Sinai School of Medicine.

Editors: Ivette Motola, MD, Staff Physician, Department of Emergency Medicine, Harvard Medical School; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine; James Kimo Takayesu, MD, Staff Physician, Department of Emergency Medicine, Brigham and Women's Hospital/Massachusetts General Hospital.

CHC Medical Library and Patient Education: :Fish and shellfish poisoning."

SailNet: "Dangerous Seafood."

CDC: "Marine Toxins."

 

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