About Ciguatera

Have you heard about Ciguatera? I don't mean to scare you all and put you off catching fish, but ciguatera poisoning must be considered in some places.  This is one of the most common causes of fish related illness within the United States.  It has been a problem for centuries. Captain William Bligh of the Bounty described similar symptoms in his log back in 1789 after having a meal of Mahi Mahi, and Captain James Cook seemed to come across it while sailing the Resolution in the South Pacific in 1774.

This is still a relatively rare and normally non-fatal but debilitating fish poisoning that occurs from eating some reef fish in tropical areas. Two to three percent of severe cases are fatal and caused by respiratory system paralysis and failure. The problem is caused by fish feeding on others that have consumed an organism called dino-flagellates (dinoflagellate Gamabierdiscus toxicus) that grow on specific algae, notably blue-green.  Years ago I received an email rom a lady called Marianne, who informed me that she has suffered and still suffers from the results of the ciguatoxin, which is toxic neurotoxin involved in ciguatera. She advised that she ended up in a hospital for 5 days and cost a massive $8000 in medical bills.  In her message she advised that one doesn’t necessarily have to be in an area of reef disturbance to pick up the toxin in fish.  The toxin is 1,000 times more toxic than arsenic by volume, scary isn’t it?  So be vigilant with Ciguatera and Ciguatera Poisoning.

Ciguatera Sources

There are approximately 400 fish species suspected of causing poisoning. Ingestion of contaminated tropical and subtropical fish where the ciguatoxin is at high levels can cause problems. Statistics show that at least 50,000 people every year who either live in or visit  these areas contract ciguatera around the world. The CDC says that only about 2-10% of case actually get reported in the United States. Many put it down to food poisoning in general. The principal fish species include the Surgeon Fish, Coral Trout, Coral Cod, Red Snapper, Spanish Mackerel, Queen Fish, Red Emperor, Sweet Lip, Trevally, Yellowtail Kingfish, Wrasse, Red Bass, Barracuda and Grouper. Current research shows that fish above 5lb (2.2kg) are worst as the toxins concentrate and are stronger the larger the fish becomes. Any area where major reef disturbances have or are occurring there is a significantly increased risk of poisoning. This is after cyclones and hurricanes, pollution and any major natural reef disturbance when these fish consume more algae.  Most common advice suggest not eating large fish, so don’t eat a Spanish Mackerel exceeding about 12 kg, as the larger the fish the greater concentration of toxins that will have accumulated within the fish.  Research has shown that the amount of toxins within the fish liver and roe can be some 50 times greater than the actual flesh. Can’t say I am a fan of those buts but some do and use them along with fish frames as a soup stock base.

Ciguatera Risk Areas

The list of areas where it is endemic include Southern Florida, Hawaii and the South Pacific in general that includes American Samoa, Papua New Guinea, Virgin Islands, Bahamas, Guadeloupe and Northern Australia.  The primary areas looking at statistics are Marshall Islands, French Polynesia, Tuamotos, Puerto Rico. Other research I have found is that certain crabs in Asia are also susceptible to poisoning. On the Madagascan East Coast the highest mortality rate occurs from consumption of a shark specific to there.

Fish to be wary of. Fish that have been caught within areas where typhoons, cyclones and hurricanes or serious storm events should be suspect. In addition any area where coral reefs are being disturbed by channel construction and so on can lead to dead or damaged coral. Always seek local advice as they are more aware of recent events that can lead to outbreaks. I have read that fish caught in the more exposed weather side of islands or atolls are more likely to be contaminated, as the weather side results in more dead and damaged coral. There are other factors that can cause a rise in ciguatera. Increases in water temperature, areas where there is sediment runoff from farming activities, and as is common, areas with increased water nutrients emanating from sewage and fertilizers, and as also observed, water pollution from trash dumping. Just remember that as fish have bigger ranges than you might expect, fish that are relatively close and not around the immediate reef areas can also be contaminated. 

Ciguatera Symptoms

In a statement of the obvious Ciguatera is a toxin, and the onset of poisoning symptoms generally starts to manifest within a couple of hours up to 24 hours after fish consumption. Usually the fish is good tasting and shows no signs it’s a problem. These symptoms can be severe diarrhea, nausea, vomiting, abdominal cramps, itching and breathing issues. Also you might get a red skin rash (pruritus). Then you might also see some generalized weakness, or signs of restlessness, perhaps some dizziness, or abnormal sensitivity to light (photophobia), plus other symptoms. Most symptoms resolve within 1 to 4 days.

 The first stage lasts around 40 hours and is also characterized by tiredness and fatigue and possibly profuse sweating. Another Ciguatera symptom is some tingling and numbness in your fingers, toes, around the lips, the tongue, mouth and throat. Evidently the toxin does not allow fluids to pass through your kidneys and so no urination. If you are really sick then getting on a saline drip is an urgent thing to do.

More Ciguatera Symptoms

Then there are longer lasting effects that include blurred vision and sore eyes, tight chest pains, lack of muscular coordination and blood in the urine. There are long term effects that may last years that include tingling or numbness of the lips, hands and feet, aching joints, severe headaches and aching teeth. You might experience muscle and joint pain and some muscular weakness. Some experience severe headaches, chronic fatigue and fainting.  The nervous system also can be affected. Another strange side effect is of temperature sensory reversal, which means hot feels cold and vice versa.  This is characterized by a burning sensation when contacting cold water.  You need to be careful when taking a shower as you can’t gauge the temperature properly.  You also may suffer from irregular heart rhythms and low blood pressure. There have been cases of temporary blindness and in fatal cases cardiac arrest. How long does ciguatera poisoning last? Good question! Ciguatera poisoning symptoms will typically resolve after 7-10 days and in some cases persist for up to 4 weeks.  I have also read that ciguatera poisoning symptoms can sometimes resemble other medical conditions, so getting some medical advice is recommended. All about ciguatera poisoning and how to cook seafood.