The Centre for Health Protection has confirmed two reports of ciguatoxin poisoning involving six people who ate at the same Sai Kung restaurant.

On November 10, three men developed symptoms, including limb numbness and diarrhoea, after eating humphead wrasse. Two of them, aged 32 and 39, were admitted to private hospitals in a stable condition.

Meanwhile, the second case occurred on the same day and involved two men and a woman, aged 49 to 70, who developed similar symptoms after consuming the same type of fish at the same place. One, a 57-year-old man, was hospitalised and all are in stable condition.

Ciguatera fish poisoning is common in tropical areas. It is mainly associated with the consumption of a big coral reef fish which has accumulated the toxin in its body. Larger fish are more likely to carry higher amounts of the toxin. However, it is not easy to tell from the appearance of the fish if it contains the toxin.

Cooking cannot destroy the toxin. Most people affected by ciguatoxin will recover without long-term health effects. However, if excessive toxin is consumed, the circulatory and nervous systems will be affected.

To prevent ciguatera poisoning:

* coral reef fish should be purchased from reputable and licensed seafood shops. Do not buy from doubtful sources;

* eat less coral reef fish, and especially avoid fish weighing over three catties;

* eat only small amounts of coral reef fish at any one meal;

* avoid eating the head, skin, internal organs and roe, which usually have higher concentrations of the toxin;

* when eating coral reef fish, avoid consuming alcohol, peanuts or beans which can aggravate the poisoning; and,

* seek medical treatment immediately should symptoms of ciguatoxin fish poisoning appear.