Ciguatera fish poisoning is endemic wherever coral reef fishes are a food source. In South Florida, this includes the local coral reef fishing grounds as well as all of the Caribbean. It is the most frequently reported seafood-related disease.
Ciguatera results from the eating of reef fish affected with ciguatoxin. Ciguatoxin originates from a dinoflagellate name Gambierdiscus toxicus which colonizes coral beds. The toxin first affects the coral-grazing fish and is then passed up and through the food chain to the piscivorous fish (i.e., snapper, grouper, amberjack, barracuda) and finally to man. The toxin is not affected by either cooking or freezing, and the affected fish, cooked or raw, is not tainted by bacteria in any way. Typically, the victim states, “It was the best fish I ever tasted.” Ciguatera symptoms were first described in the 1500’s by the Spanish explorers to Cuba and were attributed to the ingestion of a small snail which they called cigua.
A typical scenario of Ciguatera fish poisoning would include a delicious family fish dinner at the evening meal, perhaps applauding the successful fisher person and the culinary skills of the cook. Several hours later the rather sudden onset of gastrointestinal complaints awakens one after another of the fish-feasters. Nausea, vomiting, cramping, abdominal pain, and diarrhea suggest that perhaps the fish was spoiled.
Intense itching, joint and muscle pain, tingling of the lips, burning or pain when cold liquids are touched or drank will usually bring at least the more affected victims to the emergency room, later to find most if not all the others who also enjoyed the fish were variably affected. With the exception of ice applied to the tongue or fingertips being interpreted as a burning sensation, there are no clinical signs. There is no diagnostic laboratory test. Diagnosis rests with the history of ingestion of reef fish followed by gastrointestinal and bizarre neurological complaints all within a few hours’ time frame.
Some of the symptoms can recur hours after treatment, suggesting further ciguatoxin absorption from the gastrointestinal tract; retreatment has been successful in these cases. Untreated, ciguatera is usually a self-limited disease lasting one to two months. However, symptoms can persist months to years, causing great anguish.
Treatment has traditionally been supportive and disappointing. This has included antihistamines, amitriptyline, calcium gluconate, pyridoxine, corticosteroids, atropine and vitamin B. Recently ciguatera has been successfully treated with IV mannitol.4 The usual dose is 1 gram of mannitol per kilogram victim’s body weight infused intravenously either as a 20 percent mannitol solution or added to .9 NaCl or Ringer’s solution. For help with this treatment, call the Ciguatera Hotline at (305) 361-4619 or (305) 661-0774.
There is currently no test for Ciguatera, thus, avoidance of potentially toxic fish makes sense. This includes large predatory reef fish (greater than 5 pound snappers, greater that 10 pound grouper or amberjack or greater than 2 pound hogfish). Many old timers say that “fish shorter than your arm means no harm,” however, the age and weight of a fish is more determinative of any possible toxicity then the length. A fish small enough to fit on your plate is probably safe. Yellowtail snapper and dolphin (mahi-mahi) are safe fish to eat at any size in the South Florida and Caribbean areas.
David Avellar Neblett has handled a number of Ciguatera poisoning cases and is happy to provide legal assistance relating to this or other maritime matters.