Ask the Doctor: Ciguatera Is a Food Poisoning
DEAR DR. DONOHUE: In 1994, I had a reaction to fish. The Centers for Disease Control and Prevention told me I wasn’t allergic to fish but to a poison in the fish. Since then I avoid all large fish and eat only farm-raised fish or smaller fish. Is this ciguatera fish poisoning an allergy to which I can be desensitized? Does canning fish inactivate the poison? Are canned salmon and tuna safe? - M.V.
ANSWER: Ciguatera (SEE-kwah-TARE-uh) is not an allergic reaction. It’s food poisoning due to a poison made from a one-celled marine organism. The poison settles in the fish’s flesh. It makes it way up the fish food chain so the biggest concentrations of it are found in large, predatory fish. Fish that feed near coral reefs or oil rigs are the ones most often containing the poison - barracuda, snapper, shark, amberjack and some species of grouper. (Have you ever seen barracuda on a restaurant menu or in a fish market?) Most often, these fish are found in tropical or semitropical waters, but people living long distances can still come down with the poisoning. A vast transportation network for all fish varieties exists. Canadians are said to suffer 1,000 cases of this poisoning every year.
The affected fish looks and tastes normal. No method of cooking or freezing inactivates the poison. I believe canning doesn’t make the fish safe either. However, neither salmon nor tuna appears on the list of fish that cause trouble. Eat them without fear. I do.
The signs and symptoms of poisoning usually appear within one to six hours after eating the fish. There can be a delay as long as 24 hours. Nausea, vomiting, diarrhea, headache, itching and double vision are some of the signs and symptoms. Numbness may appear in various body locations, and the mouth often dries. Tooth pain is a common complaint. People recover without medicines. If the heart slows and blood pressure drops, then hospitalization is necessary. Death is rare, but it has happened.
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