Douglas J Lanska MD FAAN MS MSPH (

Dr. Lanska of the University of Wisconsin School of Medicine and Public Health, the Medical College of Wisconsin, and IM Sechenov First Moscow State Medical University has no relevant financial relationships to disclose.

Originally released January 17, 1994; last updated October 21, 2020; expires October 21, 2023


Ciguatoxin, which was first isolated from a dinoflagellate from the Gambier Islands (a small group of islands, remnants of a caldera, in French Polynesia in the Pacific Ocean) and termed Gambierdiscus toxicus, is the most common nonbacterial food toxin related to seafood ingestion in the United States, Canada, and more recently, Europe. Ciguatoxin represents a number of lipid-soluble polyethers that are acid and heat stable; tasteless, colorless, and odorless; and have a number of pharmacologic effects. The clinical syndrome, termed “ciguatera,” is a serious, although rarely lethal, human food toxicity related to the consumption of tropical reef fish. Because fish is eaten in such abundance and distributed throughout the world, ciguatera can occur most anywhere and should be familiar to treating physicians. Soon clinicians may be able to directly test for ciguatoxins in patients to verify that they have been exposed to ciguatoxin, as opposed to relying solely on the clinical presentation.

Key points


• Ciguatera fish poisoning is a prevalent environmental toxic exposure found, for the most part, in tropical areas.


• Patients may be diagnosed in non-tropical areas if there is a history of travel in endemic areas or of eating tropical reef fish shipped to nonendemic areas.


• Chronic ciguatera symptoms are prevalent after acute exposure and can be exacerbated by foods containing alcohol and serotonin.


• Inverted sensory symptoms ("hot-cold") are common in ciguatera fish poisoning.

Historical note and terminology

Ciguatera poisoning is a serious, though rarely fatal, condition related to the consumption of tropical reef fish. Ciguatoxins are odorless, tasteless, and colorless neurotoxins that accumulate in many tissues of the fish, including the muscles, head, viscera, and roe. Ciguatoxins retain toxicity despite cooking and freezing (Klekamp et al 2015).

A naming system has been proposed for the various ciguatoxins. CTX is used to indicate toxins that accumulate in fish to levels likely to cause ciguatera poisoning in humans. A letter code indicates the ocean or sea of origin of toxic fish (eg, Pacific Ocean is P-CTX) and a number code indicates the chronological order of reporting of the specific toxin (eg, P-CTX-1) (Vernoux and Lewis 1997).

One of the first recorded outbreaks of ciguatera poisoning occurred in 1774 on His Majesty's Ship Resolution during Captain James Cook's (1728-1779) second voyage to the Pacific (Cook 1777).

British explorer Captain James Cook Image: British explorer Captain James Cook (1728-1779)
On July 23, 1774, off of Malicolo island in the New Hebrides island group in the South Pacific (now the nation of Vanuatu), the ship's surgeon William Anderson (1750-1778) recorded a clear account of ciguatera poisoning (Anderson 1776).

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