Ciguatera Poisoning

If you or someone you know has ingested a fish that you suspect might be contaminated with ciguatera toxin call the National Poison Control Center (1-800-222-1222) for guidance.

Ciguatera is a type of food poisoning. The ciguatera toxin may be found in large reef fish, most commonly barracuda, grouper, red snapper, eel, amberjack, sea bass, and Spanish mackerel. These fish live in coral reef waters between latitudes of 35 degrees south to 35 degrees north, corresponding to the area located between the Tropic of Cancer and the Tropic of Capricorn. These geographic lines ring the earth north and south of the equator and make up the tropics. These areas include the Caribbean Sea, Hawaii, and coastal Central America.

Ciguatera toxin tends to accumulate in predator fish, such as the Barracuda and other carnivorous reef fish because they eat other fish that consume toxin-producing algae (dinoflagellates) that live in coral reef waters.

Ciguatera toxin is harmless to fish but poisonous to humans. The toxin is odorless and tasteless, and it is heat-resistant, so cooking does not destroy the toxin. Eating ciguatera-contaminated tropical or subtropical fish poisons the person who eats it.

Ciguatera fish poisoning is caused by the consumption of reef fish that contain accumulated ciguatoxins. These toxins are produced by dinoflagellates, which are small marine organisms (microalgae) that belong to the species Gambierdiscus toxicus. Typically, they live in the coral reefs in tropical or subtropical areas.

Small herbivorous fish feed on these dinoflagellates. The ciguatoxins bio-accumulate in the marine food chain and contaminate larger predatory fish, usually weighing over 6 lbs. When humans consume the contaminated fish, it causes ciguatera fish poisoning.

More than 400 different species of fish have been associated as the cause of ciguatera fish poisoning and such fish are said to be ciguatoxic fish.

Ciguatera toxin may be found in any large reef fish but is mostly found in the following:

• Barracuda
• Grouper
• Red snapper
• Moray eel amberjack
• Perch Spanish mackerel
• Parrotfish
• Hogfish
• Sturgeon fish
• Kingfish
• Coral trout
• Sea bass

Symptoms of ciguatera poisoning generally begin six to eight hours after eating the contaminated fish.

Symptoms may include:

• Nausea
• Vomiting
• Diarrhea
• Muscle pain
• Numbness
• Tingling
• Abdominal Pain
• Dizziness
• Vertigo

The hot and cold sensation may be reversed.

Severe cases of ciguatera poisoning may result in the following:

• Tearing of the eyes
• Chills
• Skin rash
• Itching
• Shortness of breath
• Drooling
• Paralysis

Death due to heart or respiratory failure occurs in rare cases.

Severe cases of ciguatera poisoning require hospitalization for intravenous fluids. If you think you may have ciguatera poisoning, seek immediate medical attention.

A doctor should be consulted in every case about treatment for ciguatera poisoning, including available medications.

If you or someone you know has ingested a fish that you suspect might be contaminated with ciguatera toxin, and you or they have signs or symptoms, such as nausea, vomiting, pain, trouble breathing, seizure, confusion, or abnormal skin color, call either an ambulance or the National Poison Control Center (1-800-222-1222) for guidance.

• The National Poison Control Center's phone number is 1-800-222-1222. This number is routed to the poison control center that serves your area.
• Place the telephone number (along with police, fire, and 911 or equivalent) near your home phones.
• Do not induce vomiting or give syrup of Ipecac.
  • Ipecac was formerly used to induce vomiting in poisoned patients where there was a chance to get the toxin out of the body. Several advisory bodies such as the American Association of Poison Control Centers and the American Academy of Pediatrics have recommended that Ipecac NOT be used and that it should not even be kept in the household. For more information on this subject go to: https://www.poison.org/prepared/ipecac.asp
• Do not give activated charcoal at home. Allow medical personnel to decide if this treatment is appropriate.

The poison control center will instruct you on what to do.

• Maintain hydration. Intravenous fluids may be necessary for uncontrollable nausea and vomiting.
• There is no specific antidote for ciguatera poisoning.
• Diphenhydramine (Benadryl) may help relieve itching. Give 25-50 mg every 6 hours.
• Alcohol, fish, nuts, and nut oils should be avoided after exposure to ciguatera poisoning because they may trigger recurrent symptoms.

Severe cases of ciguatera poisoning may result in breathing difficulties, muscular paralysis, coma, itching, skin rash, stiff neck, sweating, chills, tearing of the eyes, or drooling.

Death due to heart or respiratory failure may occur in rare cases within 24 hours.

Ciguatera food poisoning may be prevented by:

• Avoid eating reef fish that weigh 6 lbs or more.
• Avoid eating the liver, intestine, head, and roe of smaller reef fish.