Ciguatera halmérgezés

What is Ciguatera fish poisoning?

Ciguatera fish poisoning is caused by eating reef fish contaminated with ciguatoxins. The toxin is produced by a microalgae (Garbierdiscus toxicus) that is living attached to seaweed, and corals in tropical, subtropical waters. When these are consumed by reef fish, the toxin also gets into them. 

Which are the most affected areas? 

The most affected areas are in the Caribbean Sea, Pacific, and Indian Ocean. But ciguatera can also be present in other tropical and subtropical waters, there were even cases in Europe around Madeira and the Canary Islands.  The global annual number of Ciguatera poisonings is estimated to be between 20000 and 50000 cases.

What you can do to avoid it?

There are over 400 fish species that can potentially carry ciguatoxin. It is accumulating in the food chain, so the carnivorous fish, which are eating the herbivorous fish contaminated with the toxin, will have a higher concentration of the toxin at the end.

In general, bigger size carnivorous reef fish (like grouper, barracuda, red snapper, etc.) have the highest probability to carry a considerable amount of toxin accumulated in them. There is no perfect recipe for avoiding ciguatera poisoning, but not consuming exactly these fishes in areas where there were multiple cases reported in the previous period will reduce the risk.

What are the symptoms and how it is treated?

Ciguatera poisoning can cause various symptoms that appear on the first or second day after poisoning. The most common are slight gastrointestinal or neurological symptoms (abdominal pain, nausea, vomiting diarrhea, paresthesia of the hands, legs, or lips). Sometimes more severe symptoms, like muscle weakness, blurry vision, low blood pressure, and slight bradycardia can also occur. It happens very rarely that somebody dies from the toxin, and when yes, it is due to its cardiac effects. But the symptoms can take a long time to resolve, and some of the neurological symptoms can persist for up to weeks or even months. There is no antidote or specific treatment existing for ciguatera poisoning, but some of the symptoms can be alleviated.