The good news about ciguatera is that you are not likely to die (less than 1% mortality rate). The bad news is that during the run of it, you’ll wish you were dead.
Ciguatoxin originates from toxic algae in coral reef areas and is passed up the food chain through reef fish feeding on the toxic algae and humans feeding on the toxic reef fish. Ciguatera food poisoning is a phenomenon common in tropical reef waters generally falling between latitudes 35° south and north. It is impossible to predict precisely from where, when and which species of reef fish would carry ciguatoxin. Contaminated fish look, smell and taste normal, and the toxins are not killed by heating, freezing or drying.
Symptoms usually begin 10 minutes to 12 hours, but can occur up to 36 hours, after eating a poisonous fish. Typical symptoms include nausea, vomiting, diarrhea, generalized weakness, a decreased sensation to pain or touch, unusual or painful sensations produced by ordinary stimuli, a burning or tingling of the hands and legs or around the mough, muscle pain and temperature reversal sensation (hot things feel cold and vice versa). Other less common symptoms include chills, itching, sweating, headache, and taste disturbances.
Gastrointestinal symptoms last for about 1 or 2 days. Other symptoms may last for up to 1 week. Sensitization may occur after an incident of ciguatera fish poisoning – meaning the victime experiences recurrences when they consume reef fish again.
Victims should be treated with rest and lots of fluids. Cool showers and antihistimines may help, as may analgesics such as Tylenol and Panadol. During recovery victims should avoid and fish or shellfish product, alcohol, nuts and nut oils.
The only really effective way to prevent ciguatera fish poisoning is to not eat reef fish. Since this isn’t practical, you can reduce the rish by avoiding fish larger than 5 – 7 pounds and by not eating the head, viscera, skin, roe and gonads as the toxins accumulate in greater concentration in these areas. Children may be more susceptible, so they should be given smaller portions of reef fish.
Buy yourself a good fish identification book for the area you will be cruising. Make sure the book lists if the fish is edible, a good book will list the food value from excellent to bad. If you can’t identify the fish and it’s not in the book, try asking a local or another cruiser. Keep in mind, locals sometimes eat anything that moves. If you’re uncertain, toss it. In the long run another can of tuna is better than a case of fish poisoning.
Detection: If you suspect a fish is toxic, touch the fish liver to your lips or tongue. If you feel a tingling or numbing sensations, throw out the fish. Ciguatera testing kits are available, but they are expensive and hard to find. To buy them online, check out www.cigua.com.