Fish and Shellfish Poisoning
At certain times of the year, some species of fish and shellfish contain poisonous
biotoxins. This is true even if they are well-cooked. The CDC says it's an under-recognized
risk for travelers. It's a greater risk for travelers in the tropics and subtropics.
Certain fish can cause ciguatera fish poisoning. These include:
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Grouper
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Barracuda
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Moray eel
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Sturgeon
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Sea bass
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Red snapper
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Amberjack
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Mackerel
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Parrot fish
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Surgeonfish
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Triggerfish
The CDC advises never eating moray eel or barracuda. Other types of fish that may
contain the toxin at unpredictable times include sea bass and a wide range of tropical
reef and warm-water fish. Fish containing these toxins don't look, smell, or taste
bad. Cooking, marinating, freezing, or stewing does not destroy the toxin.
The risk of ciguatera poisoning exists in all tropical and subtropical waters where
reef fish are eaten. These include the West Indies, the Pacific Ocean, and the Indian
Ocean.
Here are 2 other forms of poisoning that can happen from naturally occurring toxins
in fish:
Where is the risk of ciguatera poisoning the greatest?
Reef fish from the tropical and subtropical waters of the West Indies, the Pacific
Ocean, and the Indian Ocean pose the greatest threat. Cases have been reported in
the U.S. in Hawaii, Guam, Puerto Rico, U.S. Virgin Islands, and Florida. A few isolated
cases of ciguatera poisoning have even been noted along the eastern seaboard of the
U.S.
More than 400 species of fish, particularly reef fish, are thought to contain the
toxin for ciguatera poisoning.
What are the symptoms of ciguatera poisoning?
Symptoms of ciguatera poisoning often start from a few minutes to 6 hours after eating
the toxic fish. They include many gastrointestinal, neurological, and cardiovascular
problems. Each person may have different symptoms. But these are the most common symptoms:
In more severe cases, you may have muscle pains, dizziness, and sensations of temperature
reversal, where hot things seem cold and cold things seem hot. You may also have irregular
heart rhythms and low blood pressure.
These symptoms often go away in a few days. But they may last up to 4 weeks. They
can be caused by other health conditions. Always talk with your healthcare provider
for a diagnosis.
Treatment for ciguatera poisoning
Treatment for ciguatera poisoning includes easing symptoms and treating any complications.
There is no specific antidote for the toxin itself. Generally, recovery takes from
a few days to a few weeks.
What is tetrodotoxin?
Tetrodotoxin is also called pufferfish poisoning or fugu poisoning. It's a much rarer
form of fish poisoning. It may be very serious. It's almost exclusively linked to
eating pufferfish from waters of the Indo-Pacific regions. There have also been cases
of poisonings from pufferfish from the Atlantic Ocean, Gulf of Mexico, and Gulf of
California. Some of these include deaths. Pufferfish poisoning is a continuing problem
in Japan.
What are the symptoms of pufferfish poisoning?
Symptoms often start between 20 minutes and 3 hours after eating the poisonous pufferfish.
Each person may have different symptoms. But these are the most common symptoms:
Death can happen within 4 to 6 hours of poisoning. Get medical care right away.
Treatment for pufferfish poisoning
Treatment for pufferfish poisoning consists of limiting how much of the toxin the
body absorbs. It also includes easing symptoms and treating life-threatening complications.
There is no known antidote for tetrodotoxin.
What is scombrotoxin?
Scombrotoxin is also called scombroid poisoning or histamine poisoning. It happens
after eating fish that have high levels of histamine due to incorrect food handling.
It's one of the most common forms of fish poisoning in the U.S. and worldwide.
Certain fish have high amounts of histidine. As a result of poor refrigeration or
preservation, bacteria turn the histidine into histamine. This leads to scombroid
poisoning. Contaminated fish may look and taste fresh. But some may taste peppery,
spicy, or bubbly. The toxin may form even if the fish has been stored at too high
a temperature for only a short time.
This form of fish poisoning happens worldwide in temperate and tropical waters. It
can happen after eating:
What are the symptoms of scombroid poisoning?
Symptoms often start within minutes to an hour after eating affected fish. They typically
last 3 hours. But they can last for a few days. Each person may have different symptoms.
But the most common symptoms are:
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Tingling or burning feeling in the mouth
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Rash on the face and upper body
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Wheezing or shortness of breath
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Drop in blood pressure
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Throbbing headache
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Hives and itching of skin
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Nausea
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Vomiting
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Diarrhea
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Itching
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Heart palpitations
These symptoms can be caused by other health conditions. Many cases of fish allergy
are actually scombroid poisoning. Always talk with your healthcare provider for a
diagnosis.
Treatment for scombroid poisoning
Treatment for scombroid poisoning is generally not needed. Symptoms often go away
without treatment within 12 to 48 hours. This poisoning is rarely life-threatening.
Treatment could include antihistamines, such as diphenhydramine and cimetidine.
Specific treatment for all fish and shellfish poisoning is based on:
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Your overall health and medical history
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Extent of the disease
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Your tolerance for certain medicines, procedures, and therapies
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Your opinion or preference