CIGUATERA FISH POISONING
Ciguatera fish poisoning is a foodborne illness affecting humans worldwide.
- It is the most frequent seafood poisoning reported in the world, especially in travelers.
- It occurs commonly in tropical and subtropical areas, particularly in the Pacific Ocean, Indian Ocean, and the Caribbean Sea.
- According to the CDC, around 50,000 cases occur per year, although other estimates vary up to 500,000 per year.
- There is a low risk of death from poisoning.
CAUSES
Ciguatera fish poisoning is caused by eating certain fish contaminated with certain toxins. The specific toxins involved is ciguatoxin. These toxins are made by a small marine organism, dinoflagellate Gamabierdiscus toxicus, that typically inhabits low-lying tropical shore areas and coral reefs. Herbivorous fish feed on this marine organism, and larger carnivorous fish, in turn, feed on the herbivorous fish. The toxin becomes concentrated in the larger fish ultimately causing ciguatera fish poisoning when they are consumed by humans. The toxins are concentrated in the fish heads, roe, intestines, and liver.
Any reef fish can cause the condition, but other most commonly affected species include barracuda, sea bass, amberjack, moray eel, grouper, red snapper, parrotfish, hogfish, coral trout, kingfish, and sturgeon fish.
The toxins do not affect the taste, texture, or odor of the fish and cannot be eliminated by cooking, smoking, freezing, salting or any other method of food preparation.
SYMPTOMS
Symptoms usually appear 1 to 3 hours after eating contaminated fish. This may include:
- Abdominal pain
- Nausea
- Vomiting
- Diarrhea
Neurological complications usually appear 3 to 72 hours later, and this may include:
- Itching
- Blurred vision
- A tingling sensation
- Metallic taste in the mouth
- Numbness of extremities
- Muscle aches
- Headaches
- Hallucinations
- Reversal of hot and cold sensations, where hot items feel cold and cold items feel hot
Other consequences may include:
- Depression
- Low blood pressure
- Chronic fatigue
- Irregular heartbeat
- Exercise intolerance
- Hypertension
- Hypotension
- Rhythm disorders
Healthy males and females have developed symptoms following sexual intercourse with infected partners, signifying that the toxin may be sexually transmitted.
Diarrhea has been reported in breastfed infants of infected mothers, signifying that the toxin migrates into breast milk.
Symptoms can last from weeks to years, up to about 20 years, often leading to long-term disability.
DIAGNOSIS AND TREATMENT
Diagnosis is made based on a person’s symptoms and dietary history.
If a number of those who consumed the same fish have symptoms, diagnosis becomes likely
If the remains from the consumed fish are available, it can be tested to confirm diagnosis.
TREATMENT
There is no specific cure for the condition, but symptoms can be treated until the illness resolves on its own- treatment option is symptomatic and supportive.
Nausea and vomiting must be treated with intravenous administration of fluids to avoid dehydration
PREVENTION
Since the toxin cannot be eliminated by cooking, smoking, freezing, salting or any other method of food preparation, to prevent being infected:
- Avoid eating reef fish. Travelers to endemic areas should be cautioned about the risk of contracting the condition and should be warned and cautioned when considering fish to consume.
- Do not eat the head, liver, intestines, and roe of smaller reef fish