CIGUATERA OR ICHTHYOSARCOTOXISM

In Polynesia, after having consumed grouper or "surgeon fish", a person experiences tingling on the face and around the lips, general discomfort and a cold sweat. A few hours later, there are burning sensations and electric shocks over the whole body, a numbness in the lower limbs, shivering, etc... This person is a victim of ciguatera. Recovery will take several weeks. A heart attack resulting in death is exceptional but possible : 1 to 2 % of the cases.

Described by the great navigators of the Seventeenth Century, from Queiros, Locke in 1675 in the Bahamas, and raging in the hot seas of the tropics, this sort of food poisoning is observed in the waters surrounding islands : in the Pacific, notably in Polynesia; in the Atlantic, among other places in the Caribbean Islands and the West Indies; and in the Indian Ocean, round the Archipelago of the Mascareignes.

Colonial physicians distinguish this phenomenon from food poisoning by eating rotten fish and, with ichthyologists, they suspect the intervention of a toxin of undetermined nature and origin. It is noted that the same species of fish can be dangerous or harmless, depending on its size, the place where it was caught but also the date.

Three research centres attempt to elucidate this mystery: the Americans in Honolulu, the Japanese in Tokyo and the French in Tahiti.

Bagnis*, the Director of the Mallardé Institute in Papeete, makes a list of the fish that cause ciguatera in the Indo-Pacific zone, all of them big and carnivorous.

In 1977 he discovers, in the Gambier Islands a microscopic blue-green alga, one of the dinoflagellata, called Gambierdiscus Toxicus, identified by Adachi and Fukuyo as the agent responsible for the synthesis of the toxins in ciguatera, especially ciguatoxin.


Lagoon

This alga abounds in underwater coral reefs, especially when they have been recently undermined by ground swelling or work in a neighbouring port. Baignis* describes the physio-pathological cycle : herbivorous fish become toxic by feeding on these algae. By eating the herbivores, the big carnivorous fish become toxic in their turn, while remaining unharmed. The flesh and, above all, the intestines of the latter are toxic, whence the term "Ichthyosarcotoxism".

The toxin resists cooking heat. There is no specific treatment for this food poisoning.



For further information :

- Bagnis R. : Les empoisonnements par le poisson en polynésie française. Rev. Hyg. et Méd. Soc.1967,15,7,619-646.
- Bagnis R. : L'ichtiosarcotoxisme de type ciguatera en Nouvelle Calédonie. Rev. Epid. 1979,27,1,29.
- Bagnis R. : Etude morphologique, biologique, toxicologique et écologique de l'agent causal "princeps" de la ciguatera, le péridien "Gambierdiscus toxicus". Thèse Doctorat Biologie humaine, 1981, Université de Bordeaux II, n°26.
- Le Coq Saint-Gilles, Sankale M. : Les poissons toxiques. L'ichtiosarcotoxisme de type ciguatera. Conc. Méd. 1983,105,21,2353-2368.


Page publiée le 11/01/2017.