Ciguatera Fish Poisoning

Ciguatoxins that cause ciguatera poisoning are produced by microscopic sea plant-like forms that grow in reefs of warm tropical waters. They are unicellular algae and algae-like organisms called dinoflagellates. Small fish that eat the algae become contaminated. If larger fish eat many smaller, contaminated fish, the poison can build up to a dangerous level. In this issue of Heart Views (2011 Oct-Dec Issue 4/Vol. 12) Senthilkumaran et al., in their article, “Cardiovascular Complications in Ciguatera Fish Poisoning: A Wake-up Call” raise our awareness about this phenomenon.

As the authors state, ciguatoxin is lipid soluble, heat resistant, and not affected by freezing. Since the toxin is heat stable, cooking does not destroy the toxin, no matter how well the fish is cooked. Contaminated fish, when consumed, will cause poisoning.

Dinoflagellates are present in the whole of the Arabian Gulf and have been scientifically reported to be present along Kuwait's shores[1,2] when large numbers of dead fish were seen along its shores. To my knowledge, no human ciguatera poisoning has been reported in the Gulf.

Human ciguatera fish poisoning in the Gulf may be underreported or not diagnosed yet. The toxin is no doubt present in the Gulf. Dinoflagellates are implicated in causing the “red tide” phenomenon in the Gulf, also known as an algal bloom. The photosynthetic pigment in the algae gives it the red coloration. This is commonly seen in the summer throughout the Arabian Gulf. We, in the Gulf, refer to this phenomenon locally as “sea menstrual period.” It causes death of large numbers of fish due to the toxins and depletion of dissolved oxygen. A report on ciguatera fish poisoning may raise our clinical suspicion of such poisoning in the future.