Diarrheic Shellfish



  • Major Outbreaks Have Been Reported in North America (United States, Canada), South America (Chile, Uruguay), Europe (Scandinavia, France, Belgium, Spain, Ireland), and Asia (Japan, China)


  • Ingestion of Bivalve Mollusks (Mussels, Scallops)


  • Okadaic Acid (and Other Toxins)
    • Lipid Soluble Toxin Which Inhibits Phosphorylation in Mammalian Cells
    • Data from Animal Studies
      • In Chinese Hamster Lung Cell Animal Models, Okadaic Acid Has Been Found to Be Mutagenic
      • Okadaic Acid Promotes the Development of Skin Tumors in Mice
      • Okadaic Acid Exposure Has Been Proposed as a Risk Factor for the Development of Human Colorectal Cancer (Med Hypotheses, 2008) [MEDLINE]


  • Detection of Okadaic Acid or Other Associated Toxin in Suspected Food

Clinical Manifestations

General Comments

  • Onset: within 2 hrs of ingestion
  • Resolution: within 2-3 days

Gastrointestinal Manifestations

Other Manifestations


Supportive Care


  • Illnesses caused by marine toxins. Clin Infect Dis. 2005;41(9):1290 [MEDLINE]
  • Shellfish consumption: a major risk factor for colorectal cancer. Med Hypotheses. 2008;70(2):409-12 [MEDLINE]
  • First U.S. report of shellfish harvesting closures due to confirmed okadaic acid in Texas Gulf coast oysters. Toxicon. 2010 Jun;55(6):1138-46. Epub 2010 Jan 11 [MEDLINE]
  • Shellfish toxicity: human health implications of marine algal toxins. Epidemiol Infect. 2010 Jul;138(7):927-40 [MEDLINE]
  • Toxins in mussels (Mytilus galloprovincialis) associated with diarrhetic shellfish poisoning episodes in China. Toxicon. 2012 Sep;60(3):420-5. Epub 2012 Apr 20 [MEDLINE]
  • Diarrhetic shellfish toxins and other lipophilic toxins of human health concern in Washington State. Mar Drugs. 2013;11(6):1815 [MEDLINE]