Ciguatera is a dietary illness caused by eating fish contaminated with a toxin called “ciguatoxin”. This neurotoxin acts on the calcium channels of the nervous system. It alters the balance of neurons and causes digestive and cardiac complications. This results in the hours following its consumption by abdominal pain, accompanied by nausea, vomiting or diarrhea. Other symptoms, such as dizziness, paralysis or hypersalivation may occur. Ciguatera disease warrants a medical consultation. Treatment is symptomatic.

The term Ciguatera comes from the Cuban name “cigua” of a small mollusk Cittarium pica, also called the Antilles troch. Ciguatera’s disease, or “itchy” because of the itching it causes, has been known since the XNUMXth century. It is caused by eating large carnivorous tropical and subtropical fish, such as barracuda, contaminated with a toxin called “ciguatoxin”, secreted by microscopic algae growing in polluted coral reefs.

Ciguatera disease is rife in all seasons in the tropics and intertropics (Oceania, Polynesia, Indian Ocean, Caribbean). The waters must be warm and shelter coral reefs. The risk of contamination is higher after a cyclone.

Ciguatoxin, responsible for this disease, is produced by microscopic algae, called Gambierdiscus toxicus, which develop in the skeleton of dead corals. This is ingested by fish in polluted coral reefs, and, as the food chain progresses, it can concentrate in carnivorous fish, which are themselves eaten by larger than them. The latter, like the moray eel or barracuda, are then fished by humans who consume them. Ciguatoxin levels are of the order of a hundred nanograms or even micrograms, sufficient to trigger symptoms in humans.

There is thus a risk of poisoning for consumers of these fish, especially since the toxin is resistant to cooking. This is the reason why certain species are prohibited from fishing according to their weight and or according to their fishing zone. To prevent Ciguatera disease, it is recommended, when staying in areas where the toxin is present, to adhere to the following recommendations.

Avoid consuming fish “bigger than your plate”.

Such as:

• grouper;
• barracuda ; 
• parrot fish;
• shark ;
• surgeonfish;
• lutjan ;
• lever; 
• crab;
• overcast ;
• loche ;
• bécune
• napoleon fish, etc.

Other recommendations

It’s important to :

• never eat the liver or viscera of fish from these regions;
• not to eat the fish that the natives do not eat;
• always show your catch to a local fisherman before consuming it.

Ciguatoxin is a neurotoxin that acts in the calcium channels of the nervous system. It alters the balance of neurons and can cause many symptoms. Most often, the signs appear between 1 to 4 hours after ingestion, more rarely beyond 24 hours:

Digestive symptoms

The signs often begin with digestive symptoms:

• nausea;
• vomiting;
• diarrhea;
• abdominal pain ;
• hypersalivation or dry mouth.

Cardiovascular signs

Cardiovascular signs reflect the severity of the poisoning:

• brachycardia (slow pulse);
• arterial hypotension.

Other signs

Neurological signs:

• paresthesias (tingling) especially in the extremities and face, especially the lips;
• feelings of numbness;
• burning sensations or electric shocks on contact with cold objects;
• coordination and balance disorders;
• confusion ;
• hallucinations ;
• headache;
• dizziness;
• paralysis, etc.

Skin signs:

• itching (pruritus) especially on the palms of the hands and the soles of the feet;
• redness.

Other symptoms:

• muscle and joint pain;
• sweats;
• tired.

Ciguatera disease can be very serious and even fatal if there is paralysis of the respiratory muscles or heart failure. The development of “hypersensitivity” to fish and foods of marine origin is possible.

There is no cure for Ciguatera disease, which goes away on its own within days. On the other hand, drug management aims to reduce symptoms, especially heart problems, by far the most dangerous. Symptomatic treatments are as follows.

Against itching:

• antihistamines (Teldane, Polaramine);
• local anesthetics (lidocaine gel).

For the correction of gastrointestinal disorders:

• antispasmodics;
• antiemetics;
• antidiarrheal.

In the event of cardiovascular disorders, it is recommended to hospitalize the patient who may be placed under:

• corticosteroids to prevent the onset of shock;
• atropine sulphate in poorly tolerated bradycardias;
• cardiac analeptics in hypotension.

In case of neurological disorders: 

• vitamin therapy B (B1, B6 and B12);
• amitriptyline (Laroxyl, Elavil) ;
• Tiapridal combined with dexamethasone;
• salicylic acid associated with colchicine.

As respiratory depression is one of the main causes of death from Ciguatera disease, ventilatory assistance is part of the emergency treatment of certain severe forms with respiratory paralysis.

Finally, patients should also avoid consuming fish in the days following the onset of the disorder so as not to further increase their ciguatoxin level. Alcoholic beverages are also not recommended, as they can exacerbate the symptoms.