The Centre for Health Protection has confirmed two cases of food poisoning involving 17 people suspected to have been caused by fish containing ciguatoxin.

The first involved five men and seven women, aged 28 to 57, who developed limb numbness, diarrhoea and abdominal pain after eating hump-head wrasse in a Sai Kung restaurant on October 22.

Their symptoms were generally mild and five of them sought medical attention from a private hospital in Kowloon and another consulted a private doctor. They are all in a stable condition and none required hospitalisation.

The second was an imported case in which a 33-year-old woman and four of her Mainland relatives developed symptoms after eating moray eel in Dongguan on October 21.

They were admitted to a local hospital. The woman returned to Hong Kong yesterday and was admitted to Prince of Wales Hospital. She was discharged today.

To prevent ciguatera fish 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 small amounts of coral reef fish at any one meal and avoid having a whole fish;

* avoid eating the head, skin, internal organs and roe of coral reef fish which usually have a higher concentration of the toxin;

* when eating coral reef fish, avoid consuming alcohol, peanuts or beans as they may aggravate ciguatoxin poisoning; and,

* seek medical treatment immediately should symptoms appear.