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Food safety while traveling

Trying new and different cuisines is one of the interesting and enjoyable aspects of traveling. In certain parts of the world, however, both eating and drinking may carry considerable health risks. The U.S. Centers for Disease Control and Prevention offers the following guidance regarding what's safer to eat and drink while traveling — and what's not.And the U.S. Peace Corps captures essentially the same advice in a slightly different manner.Seafood poisoning can be caused by any of a number of natural toxins in seafood. Such toxicity can be inherent to the species, as is the case with the Japanese puffer fish known as fugu, or it can result from external contamination, as is the case with a neurotoxin known as ciguatera. However, gastrointestinal problems attributed to seafood poisoning are often actually the result of infections caused by ingesting harmful bacteria, parasites or viruses. Learn more about travel-related illnesses for more information on these disease agents.

Described here are three forms of what's known as ichthyosarcotoxism, a form of food poisoning resulting from ingestion of fish flesh containing natural toxins. The word "ichthyosarcotoxism" is derived from the Greek words ichthyo (meaning "fish"), sarx ("flesh") and toxism ("intoxication" or "poisoning"). The three main ichthyosarcotoxisms are ciguatera, scombroid fish poisoning and tetrodotoxism.

Ciguatera: Ciguatera is caused by a neurotoxin produced by microscopic organisms that contaminate reef-based fish. Small fish feed on these organisms, and bigger fish eat the small fish. The bigger the fish, the more toxic the meat. Large predators (such as barracudas, eels, and groupers) contain more toxins due to food-chain bioaccumulation. Symptoms are primarily neurological (such as numbness, tingling, and dizziness); gastrointestinal symptoms (such as nausea, vomiting, and diarrhea) may also occur. Symptoms may persist for many years but are rarely fatal. Infected fish appears, smells and tastes normal; for example, it has no unusually fishy odor. Cooking does not diminish the potency of the toxin. Travelers should avoid eating large reef-based predators. Learn more about Ciguatera.

Scombroid poisoning: The scombroid family of fish includes tuna, mackerel, mahimahi and jack. Scombroid poisoning is caused by eating any of these fish that have not been properly refrigerated after being caught. Once such a fish is dead, bacteria naturally present in its gut translocate and break down a component of the meat, releasing an immune-system compound called a histamine. Ingestion of large quantities of histamine-contaminated meat triggers an allergic-like reaction. Scombroid poisoning can easily be confused with and misdiagnosed as a seafood allergy. Contaminated fish looks, smells and tastes normal — perhaps with a slight peppery or metallic taste, but not unpleasant or foul. Furthermore, cooking does not eliminate histamines and will therefore not prevent symptom occurrence. While you are traveling, you should avoid eating these kinds of fish unless you are sure it was properly chilled immediately after being caught and then kept at a temperature below 40°F (4.4°C) until it was cooked. Learn more about scombroid poisoning.

Pufferfish poisoning: Pufferfish poisoning, also known as tetrodotoxism (TTX), is caused by eating a highly potent neurotoxin contained in certain fish - such as pufferfish, triggerfish, mola mola and Japanese fugu — from the order Tetraodontiformes. Initial symptoms usually involve numbness around the mouth shortly after ingestion. TTX can be deadly, because it leads to progressive systemic paralysis, which can result in respiratory failure. Cooking does not alter the potency of the toxin. Travelers should avoid eating these fish in any form or preparation.

Shellfish: Such as mussels, clams, oysters, and scallops — can also cause various forms of seafood poisoning. However, these are bivalve mollusks (meaning they have a two-part shell), not fish, so such poisonings are not considered ichthyosarcotoxisms. Learn more about red tide and shellfish poisoning.

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