Ciguatera Fish Poisoning: An Emerging Syndrome in Italian Travelers

Abstract

Ciguatera is an acute or chronic intoxication syndrome associated with the consumption of marine tropical reef fish. The illness has a short incubation period, and the symptoms typically affect the gastrointestinal and nervous systems. Ciguatera poisoning has been extensively reviewed. 1‐5 It is endemic in many tropical and subtropical regions, also in the United States, 5,6 and Mexico, 7 where it accounts for more than half of all outbreaks related to ingestion of fish. In the Caribbean and Indo-Pacific islands, regions where coral reefs are present, the disease is the most common seafood-borne illness.Ciguatera poisoning can occur after the consumption of a wide variety of predatory tropical fish including barracuda,surgeon fish,red-snapper,amber-jack,red-grouper, and king-mackerel. These fish contain heat resistant and acid-stable toxins, mainly ciguatoxin, a lipid-soluble toxin, and maitotoxin, a water-soluble toxin. Both poisons belong to a newly described class of toxins, chemically polycyclic ether compounds, produced by tropical marine microalgae that become attached to the epiphytes of macroalgae, which herbivorous fish consume while foraging. Many small fish succumb to ciguatoxin and are eaten by other fish. Hence ciguatera toxin becomes more bioconcentrated as it passes up through the food chain from large carnivorous fish to larger predatory reef fish and ultimately to humans. Whereas the toxins are harmless in the host fish, in humans they produce illness. The earliest and commonest symptoms to appear are watery diarrhea, nausea and vomiting, abdominal pain, typically lasting about 12 hours. Usually, 24‐48 hours after ingesting the toxic fish, neurologic symptoms follow, including numbness, lip, tongue, and limb paresthesias, severe itching, and cold-to-hot temperature reversal (considered a pathognomonic sign). The illness generally subsides within a week. Neurologic symptoms may last for months or subside and then recur. Prompted by the growing number of Italian travelers returning from the Caribbean who present to our unit after experiencing symptoms of ciguatera poisoning, we designed this clinical study to assess the clinical outcome in our patients.We also sought to know whether they had received information before departure on the potential risks of ciguatera fish poisoning. Methods