Ciguatera Poisoning

Ciguatera is a form of poisoning that occurs when the tropical reef fish you eat have ingested algal toxin.  The toxic effects have been known for centuries, but what is responsible for the poisoning has only been understood for the last 40 to 50 years.  An estimated 50,000 to 200,000 cases are reported annually.  The case mortality rate is less than 1% but the effects of the poisoning may cause significant morbidity.

In 1774 Captain Cook and his crew experienced a bout of poisoning while visiting New Hebrides (now Vanuatu).

Ciguatera poisoning occurs in tropical regions where it is mostly related to coral reefs. It is believed that some aspect of reef damage is usually responsible – a cyclone, human or agricultural pollution or coral bleaching as is happening with climate change.  A much higher prevalence has been noted with ocean temperatures above 28C, also a feature of climate change.

It is thought the toxin is released by the environmental disturbance and then settles on the sea floor. It is then picked up by bottom feeding fish which are then part of the food chain. Ultimately it is consumed by humans.

Ciguatera poisoning is likely underdiagnosed and underreported with fewer than 10% cases being reported.

Be careful if you are buying fresh fish from local fisherman to cook yourself. Suspect this toxin if there is any numbness of the hands or stinging sensation after skinning or filleting the fish.

Cooking does not destroy the toxin and you can become seriously ill.

• Be aware of specific locations where ciguatera has been reported
• Avoid casseroles using fish cutlets
• Eat fish of less than 2-3 kg rather than portions of the larger pelagic fish
• Avoid the liver, roe and viscera of tropical fish
• Be aware of the link between environmental disturbances and ciguatera
• Do not consume moray eels
• Avoid: barracuda, chinaman fish, coral cod, coral trout, groper, paddy tail, red bass, red emperor, spanish mackeral, spotted mackeral, trevally