Ciguatera is a fish-borne illness for which there is no treatment. It's the sort of thing that can ruin a tropical vacation, unless you know which fish to avoid at sea-side restaurants. Recognizing symptoms is the only way you can get timely treatment.
Trey and Sally had left their wedding reception directly for the airport for a dream vacation in the Bahamas. Their sey had snorkeled and sunbathed all morning, and for lunch they had a delicious meal of exotic barracuda. A few hours later they became violently ill. They experienced vomiting and diarrhea, and they had to make a trip to the emergency room that night to get treatment for dehydration. It was certainly a memorable day on their honeymoon.
What had gone wrong? It turned out that Trey and Sally had been poisoned by a tiny microorganism known as Gambierdiscus toxicus. This one-celled organism is a member of a group of marine microbes that sometimes make their own food with photosynthesis and sometimes hunt down other microbes hiding on seaweed or bleached coral. To another microbe, an encounter with Gambiercus is deadly. It is paralyzed and quickly gobbled down by the predator.
However, for many tiny fish that live in seaweeds or hide in bleached (dead) coral, Ganbiercus is lunch. They are predators of the predator microbe, at least until they are themselves eaten by larger fish, which are in turn eaten by larger fish. The toxin the microbe uses to kills its own prey is concentrated at each step of the food chain, so that it builds up to levels that can affect humans in barracuda, amberjack, snapper, parrotfish, triggerfish, moray eels, and grouper. All of these fish can accumulate toxic levels of the toxin ciguatera.
What Is Ciguatera?
Ciguatera is a poison in a class of poisons known as sodium channel agonists. It opens microscopically small channels in the surface of cells so that sodium pours in. Sodium has a positive charge. Many of the nutrients and regulator hormones that cells need are also positively charged. The poison shuts down the cell so that it effectively starves.
Because muscle cells are more active than other kinds of cells, and the heart is the most active of all the muscles in the body, the heart is the organ most vulnerable to the toxin. However, the effects of ciguatera are first noticed in the digestive tract. Its later effects are noticed in the nervous system, increasing the activity of the parasympathetic nervous system, which controls the activities we don't think about, and decreasing activity of the sympathetic nervous system, which controls the activities we do think about.
Ciguatera is a very stable chemical. Heat does not destroy it. Stomach acid does not break it down. There is no cooking method that makes affected fish safe to eat.
It is tasteless, odorless, and has no affect on the flavor of the fish. Caribbean cooks sometimes put a piece of fish on the ground to see whether ants eat it, or place a silver coin on the skin to see whether it turns black, but neither of these methods actually works.
Who Gets Ciguatera Poisoning?
Ciguatera is especially common in the West Indies, where up to three percent of tourists come down with some degree of the disease. The condition is also relatively common in Australia and in the South Pacific. St. Thomas in the Virgin Islands has an anuual rate of 4.4 percent of households, and seven percent of Puerto Ricans are poisoned with ciguatera at some time in their lifetimes.