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.