HWN Suggests

Ciguatera Is Hot (But It Could Be Cold)

Symptoms are bizarre. It starts out like a standard case of gastroenteritis — nausea and vomiting — but since ciguatera is a neurotoxin, here’s some of the weird stuff that follows: tingling, numbness, bradycardia, hypotension, muscle cramps, tooth pain, and most famously, “paradoxical dysesthesias”, where cold feels hot and hot feels cold. You ask 100 ID doctors about that last symptom, and 99 will shout, CIGUATERA! Just don’t do it in a crowded room... We can’t prevent it. The toxin is heat- and cold-stable; our stomach acidity doesn’t touch it either. This means that fish that are perfectly handled, look and smell fresh, and are then cooked appropriately still can have high levels of ciguatera…

read full article

Featured

 How climate change poisons our food

There’s no cure for a mysterious type of food poisoning known as ciguatera. But as our planet warms, it’s likely to become much more common... According to Dr Mindy Richlen, a research specialist at Woods Hole Oceanographic Institution who studies harmful algal blooms, ciguatera poisoning comes from eating fish contaminated with ciguatoxins, which come from a tropical dinoflagellate (tiny single-cell organism) that lives on microalgae growing, mostly, on dead coral. More plainly: dead reefs breed infected fish food, and humans get sick when they eat the fish that eat it. While ciguatera initially presents itself as standard food poisoning, it eventually morphs into numbness in the fingers and toes that recurs for months or even years, and sometimes causes a switching of hot and cold sensations (a side effect I thankfully lucked out of, but which leads people to think their cold soda is burning them or causes them to drink far-too-hot coffee).

Articles of Interest

Ciguatera Fish Poisoning

People may become ill with ciguatera fish poisoning after eating certain contaminated fish. The ciguatera toxin is created by microalgae that naturally live in warm-water oceans, and this disease has been known for centuries. Ciguatera fish poisoning is probably underreported in the continental United States, since most cases are of short duration and it is not well known outside areas where it is common, such as the Caribbean and Hawaii.

Explainer: what is ciguatera fish poisoning?

Because symptoms vary greatly, CFP can easily be confused with other illnesses, making it very difficult to diagnose unless the toxins can be identified in the seafood the patient has consumed. The only therapy for CFP to have been evaluated by randomised blinded clinical trials is the diuretic drug mannitol, given intravenously. It’s recommended the drug is administered within 48 to 72 hours of the ingestion of toxic fish, and has been found to significantly alleviate symptoms in many patients.

An Insidious Poison Lurks in Some Fish

The name ciguatera (pronounced sig-wa-TEHR-a) came from an incorrect assumption that it was caused by a small sea snail that the Spanish called cigua. ctually, ciguatoxin is produced by a single-celled, free-swimming dinoflagellate, the protozoan Gambiendiscus toxicus, which attaches itself to marine algae growing on coral reefs. It is consumed by small herbivorous reef fish as they eat the algae. These reef fish are eaten by larger carnivorous fish and the fat-soluble toxin becomes more and more concentrated as it passes up the food chain.

Ciguatera poisonings: A global review of occurrences and trends

Ciguatera Poisoning (CP) is the most prevalent, phycotoxin related seafood poisoning across the globe, affecting between 10,000 and 50,000 people annually. This illness results from the consumption of seafood contaminated with lipid soluble toxins known as ciguatoxins (CTXs) that are produced by benthic dinoflagellates in the genera Gambierdiscus and Fukuyoa.

Fish Poisoning in Travelers: Ciguatera and Scombroid

Health experts urge us to eat more fish because of its beneficial health effects, but toxins in contaminated fish can cause health problems. Two common causes of fish-related food poisoning are ciguatera and scombroid, and travelers may be at risk of these illnesses.

Fish Poisoning More Common Than Believed

Ciguatera (pronounced sig-WAH-terra) is produced by algae that grow in warm water, and there is a risk of it spreading north as ocean waters warm, said Elizabeth G. Radke, an epidemiologist at the University of Florida’s Emerging Pathogens Institute and the lead author of the study. The poison is picked up by coral reef fish that eat vegetation and concentrates in larger carnivorous fish that eat them. The highest levels are found in barracuda, but it is also found in grouper, amberjack, hogfish, snapper, mackerel and mahi-mahi. Neither cooking nor freezing affects the toxin.

Fish poisoning: Spanish mackerel case a 'wake-up call' for spread of deadly toxins

It's already a serious issue in the tropical Pacific, including the Cook Islands, where Dr Murray has worked. There, as many as 70 per cent of the population has been afflicted as the microalgae spreads, with some local communities giving up spear fishing and one of their main sources of exercise and protein.

When The Fish You Eat Have Eaten Something Toxic

A case of ciguatera typically involves vomiting, diarrhea, nausea and cramps. At higher doses, the toxin triggers neurological symptoms, such as the reversal of the sensations of hot and cold. Some people report dizziness or hallucinations. The illness is rarely fatal, but symptoms can last for weeks or even years.

Resources

International Association for Medical Assistance to Travellers

Ciguatera Fish Poisoning is the most common seafood illness reported in travellers. It is caused by eating fish contaminated with ciguatoxins which are produced by dinoflagellates (small marine organisms living on or near coral reefs) belonging to the species Gambierdiscus toxicus. Herbivorous fish feed on these organisms and the ciguatoxins bio-accumulate along the marine food chain to larger predatory fish, usually over 2.7 kg / 6 lbs.

MedicineNet

Ciguatera toxin tends to accumulate in predator fish, such as the barracuda and other carnivorous reef fish, because they eat other fish that consume toxin-producing algae (dinoflagellates) that live in coral reef waters. Ciguatera toxin is harmless to fish but poisonous to humans.