CHP investigating suspected ciguatera fish poisoning cases

The Centre for Health Protection (CHP) of the Department of Health today (September 22) urged people to be extra cautious when consuming large coral reef fish as they could contain ciguatoxin which may cause food poisoning.

The advice followed reports of five food poisoning cases suspected to have been caused by fish containing ciguatoxin. A total of 16 people, aged from 5 to 63, were affected.

The people developed symptoms of ciguatoxin poisoning, such as mouth and limbs numbness and diarhoea, after eating large coral reef fish , including flowery grouper and grouper-like fish, on September 19 and 20.

Their symptoms were generally mild and some of them sought medical attention from hospital. One of them, a 63-year-old woman is in a stable condition in a private hospital in Kowloon.

A CHP spokesman said ciguatera fish poisoning was not uncommon in tropical areas. It is mainly associated with the consumption of a big coral reef fish which has accumulated the toxin in its body, in particular internal organs, through eating small fish that consumes toxic algae in coral reef seas.

The larger fish is therefore 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.

People affected may show symptoms of numbness of the mouth and the limbs, vomiting, diarrhoea, reversal of sensation of coldness and hotness and pain of the joints and muscles.

The spokesman said that most people affected by ciguatoxin would recover without long term health effects. However, if excessive toxin was consumed, the circulatory and nervous systems would be affected.

"The toxin cannot be destroyed by cooking", the spokesman said.

To prevent ciguatera fish poisoning, the spokesman advised that the following should be observed:
*Avoid consuming large coral reef fish; the bigger the fish, the higher the risk of ciguatera poisoning.
*Avoid eating the internal organs especially liver and gonads of big coral reef fish because the toxin tends to accumulate there;
*Eat only a small quantity of coral reef fish at any one meal;
*Do not consume coral reef fish together with alcoholic beverages and nuts, and,
*Seek medical care when symptoms appear.

Ends/Wednesday, September 22, 2004