If you choose to eat fish, you should be aware of the dangers that can come with consuming certain species. This is particularly true if you choose to travel to the South Pacific and other tropical destinations, where many unusual fish make their way to the dining table. Here, we’ll take a look at Ciguatera poisoning. You’ll learn what it is, where it comes from, and how to avoid it.
What is Ciguatera Poisoning?
Ciguatera poisoning is a form of foodborne illness. It is caused by eating the flesh of reef fish contaminated with toxins produced by microorganisms called dinoflagellate, which cling to seaweed, algae, and coral, where herbivorous fish consume them. When larger carnivorous fish consume the herbivorous species, the toxin passes on to them, eventually bioaccumulating up the food chain. Many predatory species near the top of the food chain harbor Ciguatera.
Symptoms of Ciguatera Poisoning
Ciguatera is odorless and tasteless. It is also heat resistant, so fish harboring ciguatoxin cannot normally be detoxified by cooking. Symptoms normally start between fifteen and thirty minutes after contaminated fish has been consumed. They include nausea and vomiting, abdominal pain, tooth pain, throat and tongue numbness, and occasionally, difficulty breathing. In addition, diarrhea, blurred vision, difficulty walking, itching and skin rashes, teary eyes, twitching muscles, and difficulty sleeping can occur. Finally, a hallmark of Ciguatera poisoning is the reversal of cold and hot sensations or general hypersensitivity to hot or cold temperatures.
Heart problems, peripheral and central nervous system deficiencies, low blood pressure, and collapse can also occur. These symptoms can persist for weeks or even months in the most severe cases.
Treatment for Ciguatera Poisoning
Treatment for Ciguatera poisoning is generally dependent upon symptoms. Intravenous mannitol may be administered to counteract heart arrhythmias or nervous system abnormalities, however, there is no specific antidote. If you think you may have been exposed, be sure to seek medical attention immediately. During recovery, you should avoid all fish and fish sauces, shellfish and shellfish derivatives, nuts, nut oils, and alcoholic beverages.
Avoiding Ciguatera Poisoning
The easiest way to avoid Ciguatera poisoning is to avoid eating any questionable fish. Species that tend to harbor the toxin include jack, snapper, barracuda, and snapper; moray eels, parrotfish, and triggerfish are also known to have caused outbreaks. If you have the opportunity to see the entire fish before consuming it – for example, if you’re on a liveaboard and someone lands a fish that’s going to be prepared for dinner – question whether very large fish might be carrying Ciguatera. The larger the fish, the greater the chances it’s going to be toxic.
Finally, even though folklore says that if flies are attracted to a fish it won’t be toxic, that is misinformation. Ciguatera is common throughout the Pacific and Caribbean, and is found in more than 400 reef fish species. Avoiding consumption of reef fish is the only certain way to avoid exposure. Know what you are eating, and if in doubt, choose something else. This sickness doesn’t normally cause death, but the symptoms are horrible, and can be long-lasting.