IN light of recent fish
poisoning cases where few people lost their lives and some ended up in hospital, The Fiji Times North Bureau reporter LUKE RAWALAI had an interview via electronic mail (email) with the Ministry of Health on the issue
Q: What is ciguatera fish
poisoning and where does it
occur?
A: Ciguatera fish poisoning (CFP) is a common food-borne disease related to the consumption of subtropical and tropical marine finfish, which have accumulated naturally occurring toxins through their diet. The concerned — ciguatoxic — fish are either feeding on small algae species known as dinoflagellates or feeding on toxic herbivore fish. The main toxic dinoflagellate is found primarily in sub and tropical areas where it lives in association with other algae on dead corals.
Q: Are all tropical area and
coral reefs toxic?
A: No. The majority of coral reefs are not ciguatoxic. Outbreaks of ciguatera are limited in distribution and time and are usually much localised. Thus knowledge of toxic areas is usually based on local experience from fishermen and consumers. Toxic fish may be found in the Pacific and Indian Ocean regions and in the tropical Caribbean.
Q: How to detect ciguatera fish poisoning?
A: Clinical symptoms vary widely, but are characterised by gastrointestinal, neurological and cardiovascular disturbances often within 10 min, but also up to 24 hours after ingestion of toxic fish. The initial symptoms are similar to any other food poisoning (abdominal pain, nausea, vomiting and diarrhoea).
The most common neurological symptoms are tingling and numbness in the mouth and the extremities, muscle cramping and sensation of temperature reversal (a sensory inversion whereby hot or warm objects feel cold and cold objects may feel warm). Other symptoms include headache, vertigo, hallucinations, salivation, and perspiration. The disease is generally non-fatal and of short duration. However, in a few severe cases, symptoms can persist for months or even years.
Q: What to do in case of a
suspected ciguatera fish
poisoning case?
A: In case of a suspected ciguatera fish poisoning, consult a medical doctor.
Unfortunately, there is no single specific remedy for the treatment of ciguatera fish poisoning. The most successful management of the disease has been accomplished by supportive and symptomatic treatment, such as induced vomiting. It is important to try to obtain portions of the meal and in particular the fish to assist in confirming the diagnosis. These portions should be packaged and frozen for any subsequent analysis.
Q: What can be done to prevent or avoid ciguatera fish poisoning?
A: The ciguatoxin is very heat stable. Normal household cooking (e.g boiling, steaming, frying) will not reduce or eliminate the toxin. Consumers should exercise caution in areas of concern for particular tropical species.
Q: Which fish can be
ciguatoxic ?
A: Ciguatoxin is produced initially by microscopic algae and is stored in the tissues of fish species consuming these algae, increasing in concentration in large carnivorous fishes. Fish from some reef areas may be toxic, while those from others may not be.
The same species of fish that is ciguatoxic in one area may be safe in another. By talking to local fishermen one can learn which areas to avoid and which fish may be dangerous to eat. It is the location where a fish is caught, more than its species that determines whether a fish is ciguatoxic. Therefore, a comprehensive list of non-ciguatoxic fish cannot be provided.
About 300 to 400 species of fish have been implicated in ciguatera fish poisoning. If no information is available, it is wise not to eat any large reef fish, since such specimens may have accumulated sufficient toxin during their lifetime. However, among the large reef fish only very few have been found to be poisonous.
