Food Safety Focus (178th Issue, May 2021) – Food Incident Highlight

Ciguatoxin Poisoning and Coral Reef Fish Consumption

Locally, there is a recent case of suspected ciguatera fish poisoning (CFP). The victims had diarrhoea, nausea and abdominal pain after eating a yellow-edged lyretail (Variola louti) at home. The fish, around 3 catties in weight, was purchased from a local market fish stall.

Ciguatoxins are produced by Gambierdiscus toxicus, a type of toxic marine plankton, and are more concentrated in the viscera, liver and gonads of coral reef fish. The coral reef fish involved in CFP usually weighs more than 2 kg (3 catties). The clinical manifestations of CFP include gastrointestinal symptoms like vomiting and abdominal pain, and neurological symptoms such as tingling of lips and fatigue. Ciguatoxins are heat-stable and cannot be removed by cooking.

To reduce the risk of CFP, the public are advised to consume less coral reef fish in terms of frequency and the amount consumed in each meal. Avoid eating the head, skin, intestines and roe of the fish. Trades such as fish importers should avoid sourcing fish from areas knowingly at risk of having fish contaminated with ciguatoxins.