Ciguatera fish poisoning is a severe food poisoning caused by eating the meat of some marine fish (big barracuda, surgeonfish, unicorns, etc.).

This pathology has long been known in tropical regions. In the 7th century, a Chinese physician of the Tang dynasty, Chen Tsang-Shi, described a case of fatal poisoning after eating yellowfin tuna. Around 1520, Pedro Martire D'Angera, a chronicler at the Spanish court, recorded the poisoning of sea fish during the expeditions of Columbus, Vasco da Gama and Magellan. In 1601 Hermensen described a similar case in Mauritius, and in 1609 de Quiros in the New Hebrides. In 1675, the English philosopher John Locke gave the first detailed clinical description of this type of poisoning in the Bahamas. Finally, in 1866, the Cuban physician Felipe Poey used the term ciguatera to describe poisoning by ingestion of what is known in Cuba as shellfish.

Chemical structure of ciguatoxin-CTX1B

The disease is caused by the consumption of reef fish that accumulate a toxin produced by dinoflagellates such as Gambierdiscus toxicus, which live in tropical and subtropical waters. These organisms live near corals, algae and marine plants, where they become food for herbivorous fish, which in turn feed on large predatory fish such as barracuda, sea bass, moray eels, etc. Fish and shellfish are much less sensitive to the toxin than warm-blooded fish. Ciguatoxin is very heat stable, so normal cooking will not remove it from food.

The ingested toxin selectively disrupts the function of sodium channels in the membranes of nerve and muscle cells, affecting signal transmission at synapses.