MARINE POISONINGS

CIGUATERA

  • Epidemiology: The most common fish-associated nonbacterial food poisoning in the United States, with most cases occurring in Florida and Hawaii
    • In all, 20,000–50,000 people are affected annually, although 90% of cases may go unreported.
    • Three-quarters of cases involve barracuda, snapper, jack, or grouper found in the Indian Ocean, the South Pacific, and the Caribbean Sea.
  • Pathogenesis: Ciguatera toxin acts on neuron voltage-gated sodium channels and is created by marine dinoflagellates, whose consumption by fish allows the toxin to accumulate in the food chain. Three major ciguatoxins—CTX-1, -2, and -3—are found in the flesh and viscera of ciguateric fish, are typically unaffected by external factors (e.g., heat, cold, freeze-drying, gastric acid), and do not generally affect the fish (e.g., odor, color, or taste).
  • Clinical features: Pts typically develop symptoms within 2–6 h, with virtually all pts affected within 24 h. The diagnosis is made on clinical grounds.
    • Symptoms can be numerous (>150 reported) and include diarrhea, vomiting, abdominal pain, neurologic signs (e.g., paresthesias, weakness, fasciculations, ataxia), maculopapular or vesicular rash, and hemodynamic instability.
    • A pathognomonic symptom—reversal of hot and cold tactile perception—develops within 3–5 days and can last for months.

Treatment: Ciguatera Poisoning

  • Therapy is supportive and based on symptoms.
  • Cool showers, hydroxyzine (25 mg PO q6–8h), or amitriptyline (25 mg PO bid) may ameliorate pruritus and dysesthesias.
  • For 6 months after disease onset, the pt should avoid ingestion of fish (fresh or preserved), shellfish, fish oils, fish or shellfish sauces, alcohol, nuts, and nut oils.

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