Overview of shellfish and pufferfish poisoning
- Erin N Marcus, MD, MPH, FACP
Erin N Marcus, MD, MPH, FACP
- Associate Professor of Clinical Medicine
- University of Miami Miller School of Medicine
- Section Editors
- Daniel F Danzl, MD
Daniel F Danzl, MD
- Section Editor — Environmental Emergencies
- Professor of Emergency Medicine
- University of Louisville School of Medicine
- Michele M Burns, MD, MPH
Michele M Burns, MD, MPH
- Section Editor — Pediatric Toxicology
- Assistant Professor of Pediatrics and Emergency Medicine
- Harvard Medical School
- Stephen J Traub, MD
Stephen J Traub, MD
- Section Editor — Toxicology
- Associate Professor of Emergency Medicine
- Mayo Medical School
- Deputy Editor
- James F Wiley, II, MD, MPH
James F Wiley, II, MD, MPH
- Senior Deputy Editor — UpToDate
- Deputy Editor — Adult and Pediatric Emergency Medicine
- Deputy Editor — Primary Care Sports Medicine (Adolescents and Adults)
- Clinical Professor of Pediatrics and Emergency Medicine/Traumatology
- University of Connecticut School of Medicine
As world travel and trade grow, physicians are increasingly likely to encounter patients poisoned by marine toxins. The world's oceans harbor hundreds of different types of marine toxins, and the epidemiology and clinical manifestations of these toxins vary widely. Several of these toxins are produced by dinoflagellates or phytoplankton during algae or marine diatom blooms. Shellfish and pufferfish poisoning arise from consumption of seafood that is contaminated by various toxins (table 1) [1-3]. In most instances the ingested seafood smells, appears, and tastes normal. Clinical features of the most common forms of shellfish or pufferfish poisoning typically develop within minutes to hours of ingestion. A food history that identifies ingestion of seafood commonly associated with the specific toxin, clinical features consistent with the specific poisoning, and detection of elevated levels of the toxin in the ingested seafood provides the diagnosis. Treatment is supportive.
An overview of paralytic shellfish poisoning, neurotoxic shellfish poisoning, diarrheic shellfish poisoning, and pufferfish poisoning is provided here. Scombroid (histamine) poisoning, ciguatera fish poisoning and marine envenomations, such as coral abrasions and sea urchin injuries, are discussed separately. (See "Scombroid (histamine) poisoning" and "Ciguatera fish poisoning" and "Marine envenomations from corals, sea urchins, fish, or stingrays".)
PARALYTIC SHELLFISH POISONING
●Epidemiology – Paralytic shellfish poisoning (PSP) occurs after ingestion of shellfish contaminated with neurotoxins formed by algae, primarily saxitoxins . It has been linked to algal blooms called "red tides," even though it can occur in the absence of red tides. PSP primarily occurs in temperate climates, although it has been described in shellfish from tropical waters . Potential vectors for PSP include bivalve mollusks (eg, cockles, salt- and fresh-water mussels, or butter/little neck clams), gastropod mollusks (eg, whelk, moon snails, or abalone), crustaceans (eg, Dungeness crabs, shrimp, or lobsters), pufferfish (saxitoxin pufferfish poisoning), and zooplanktivorous fish (eg, Atlantic salmon, herring, and mackerel) [4,6]. Of these, outbreaks of human disease are most commonly associated with salt-water bivalve mollusks, especially mussels or clams.
PSP has been described worldwide . In the United States, PSP primarily occurs in seafood harvested from the Northeast, Pacific Northwest, and Alaskan waters . As an example, from 2010 to 2011, there was a marked increase in the number of PSP cases in southeast Alaska, all of which stemmed from the ingestion of non-commercially harvested shellfish (specifically, cockles, blue mussels, butter/little neck clams, and Dungeness crabs) . A subsequent CDC report noted that non-commercially-harvested Alaskan shellfish can have high levels of PSP toxin at any time of year . Clinicians were urged to report suspected cases to health officials and to collect and freeze patient urine and shellfish samples (if available) for testing. In contrast, commercial shellfish are routinely monitored for PSP toxin in Alaska and are safe to consume .
●Pathophysiology – The toxins that cause PSP are formed by dinoflagellates of the genus Alexandrium and are collectively known as saxitoxins [4,9,10]. These toxins are taken up by seafood vectors, most commonly, bivalve mollusks such as mussels, clams, scallops, and oysters, as well as by crabs and snails, with no apparent ill effect. The PSP toxins are not destroyed by heat, marinating, or freezing. Contaminated seafood smells, tastes, and appears normal.
- Mines D, Stahmer S, Shepherd SM. Poisonings: food, fish, shellfish. Emerg Med Clin North Am 1997; 15:157.
- Sobel J, Painter J. Illnesses caused by marine toxins. Clin Infect Dis 2005; 41:1290.
- James KJ, Carey B, O'Halloran J, et al. Shellfish toxicity: human health implications of marine algal toxins. Epidemiol Infect 2010; 138:927.
- Etheridge SM. Paralytic shellfish poisoning: seafood safety and human health perspectives. Toxicon 2010; 56:108.
- Hartigan-Go K, Bateman DN. Redtide in the Philippines. Hum Exp Toxicol 1994; 13:824.
- Deeds JR, Landsberg JH, Etheridge SM, et al. Non-traditional vectors for paralytic shellfish poisoning. Mar Drugs 2008; 6:308.
- Centers for Disease Control and Prevention (CDC). Paralytic shellfish poisoning --- southeast Alaska, May--June 2011. MMWR Morb Mortal Wkly Rep 2011; 60:1554.
- State of Alaska Epidemiology Bulletin. Paralytic Shellfish Poisoning in Juneau, Kodiak, and Haines, June 2010. http://www.epi.alaska.gov/bulletins/docs/b2010_17.pdf (Accessed on December 22, 2011).
- Fleming L, Stinn J. Shellfish poisonings. Shoreland's Travel Medicine Monthly 1999; 3:1.
- Cusick KD, Sayler GS. An overview on the marine neurotoxin, saxitoxin: genetics, molecular targets, methods of detection and ecological functions. Mar Drugs 2013; 11:991.
- Morris PD, Campbell DS, Taylor TJ, Freeman JI. Clinical and epidemiological features of neurotoxic shellfish poisoning in North Carolina. Am J Public Health 1991; 81:471.
- Poli MA, Musser SM, Dickey RW, et al. Neurotoxic shellfish poisoning and brevetoxin metabolites: a case study from Florida. Toxicon 2000; 38:981.
- Milian A, Nierenberg K, Fleming LE, et al. Reported respiratory symptom intensity in asthmatics during exposure to aerosolized Florida red tide toxins. J Asthma 2007; 44:583.
- Fleming LE, Kirkpatrick B, Backer LC, et al. Aerosolized red-tide toxins (brevetoxins) and asthma. Chest 2007; 131:187.
- Morris JG Jr. Pfiesteria, "the cell from hell," and other toxic algal nightmares. Clin Infect Dis 1999; 28:1191.
- Aune T, Yndestad M. Diarrhetic shellfish poisoning. In: Algal Toxins in Seafood and Drinking Water, Falconer IR (Ed), Academic Press Ltd., 1993. p.87.
- Trainer VL, Moore L, Bill BD, et al. Diarrhetic shellfish toxins and other lipophilic toxins of human health concern in Washington State. Mar Drugs 2013; 11:1815.
- Deeds JR, Wiles K, Heideman GB 6th, et al. First U.S. report of shellfish harvesting closures due to confirmed okadaic acid in Texas Gulf coast oysters. Toxicon 2010; 55:1138.
- Li A, Ma J, Cao J, McCarron P. Toxins in mussels (Mytilus galloprovincialis) associated with diarrhetic shellfish poisoning episodes in China. Toxicon 2012; 60:420.
- Manerio E, Rodas VL, Costas E, Hernandez JM. Shellfish consumption: a major risk factor for colorectal cancer. Med Hypotheses 2008; 70:409.
- Centers for Disease Control and Prevention (CDC). Tetrodotoxin poisoning associated with eating puffer fish transported from Japan--California, 1996. MMWR Morb Mortal Wkly Rep 1996; 45:389.
- Cole JB, Heegaard WG, Deeds JR, et al. Tetrodotoxin poisoning outbreak from imported dried puffer fish--Minneapolis, Minnesota, 2014. MMWR Morb Mortal Wkly Rep 2015; 63:1222.
- Watters MR. Organic neurotoxins in seafoods. Clin Neurol Neurosurg 1995; 97:119.
- Baden DG, Fleming LE, Bean JA. Marine Toxins. In: Handbook of Clinical Neurology, deWolff, FA (Eds), Elsevier Science B V, New York 1995. p.149.
- Centers for Disease Control and Prevention (CDC). Neurologic illness associated with eating Florida pufferfish, 2002. MMWR Morb Mortal Wkly Rep 2002; 51:321.
- Advisory on Puffer Fish. Industry advisory. October 17, 2007. http://www.fda.gov/Food/RecallsOutbreaksEmergencies/SafetyAlertsAdvisories/ucm085458.htm (Accessed on October 20, 2013).
- Islam QT, Razzak MA, Islam MA, et al. Puffer fish poisoning in Bangladesh: clinical and toxicological results from large outbreaks in 2008. Trans R Soc Trop Med Hyg 2011; 105:74.
- Liu SH, Tseng CY, Lin CC. Is neostigmine effective in severe pufferfish-associated tetrodotoxin poisoning? Clin Toxicol (Phila) 2015; 53:13.
- Andjelkovic M, Vandevijvere S, Van Klaveren J, et al. Exposure to domoic acid through shellfish consumption in Belgium. Environ Int 2012; 49:115.
- Perl TM, Bédard L, Kosatsky T, et al. An outbreak of toxic encephalopathy caused by eating mussels contaminated with domoic acid. N Engl J Med 1990; 322:1775.
- Teitelbaum JS, Zatorre RJ, Carpenter S, et al. Neurologic sequelae of domoic acid intoxication due to the ingestion of contaminated mussels. N Engl J Med 1990; 322:1781.
- Jeffery B, Barlow T, Moizer K, et al. Amnesic shellfish poison. Food Chem Toxicol 2004; 42:545.
- Friedman MA, Levin BE. Neurobehavioral effects of harmful algal bloom (HAB) toxins: a critical review. J Int Neuropsychol Soc 2005; 11:331.
- Hilborn ED, Roberts VA, Backer L, et al. Algal bloom-associated disease outbreaks among users of freshwater lakes--United States, 2009-2010. MMWR Morb Mortal Wkly Rep 2014; 63:11.
- Grattan LM, Oldach D, Perl TM, et al. Learning and memory difficulties after environmental exposure to waterways containing toxin-producing Pfiesteria or Pfiesteria-like dinoflagellates. Lancet 1998; 352:532.
- Shoemaker RC, Hudnell HK. Possible estuary-associated syndrome: symptoms, vision, and treatment. Environ Health Perspect 2001; 109:539.