CHP investigates suspected ciguatoxin poisoning case

     The Centre for Health Protection (CHP) of the Department of Health is today (June 23) investigating a suspected ciguatoxin poisoning case affecting two people.

     The case involves one male and one female, aged 72 and 55 respectively, who developed symptoms of ciguatoxin poisoning including vomiting, diarrhea, nausea, limb weakness and perioral numbness about six hours after consuming a marine fish for dinner at home on June 21. The female patient also developed facial numbness. Both attended the Accident and Emergency Department of North District Hospital yesterday (June 22) and none required hospitalisation. They are in a stable condition.
       
     Initial enquiries revealed that the fish consumed was bought from a fish stall in Po On Road Market, Cheung Sha Wan, on June 21.

     "We have informed the Food and Environmental Hygiene Department of the incident and investigations are ongoing," a spokesman for the CHP said.

     Ciguatera fish poisoning is not uncommon in tropical areas. It is mainly associated with the consumption of big coral reef fish which have accumulated the toxin in the body, particularly in internal organs, through eating small fish that consumed toxic algae in coral reef seas.
      
     A 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 whether it contains the toxin.
      
     People affected may have symptoms of numbness of the mouth and limbs, vomiting, diarrhoea, alternating sensations of coldness and hotness, and pain in the joints and muscles.
      
     "Most people affected by ciguatoxin will recover without long-term health effects, but if excessive toxins are consumed, the circulatory and nervous systems can be affected. The toxin cannot be destroyed by cooking," the spokesman said.
      
     To prevent ciguatera fish poisoning, the public should:

• Eat less coral reef fish;
• Eat small amounts of coral reef fish at any meal and avoid having a whole fish feast in which all dishes come from the same big coral reef fish;
• Avoid eating the head, skin, intestines and roe of coral reef fish, which usually have a higher concentration of toxins;
• When eating coral reef fish, avoid consuming alcohol, peanuts or beans as they may aggravate ciguatoxin poisoning;
• Seek medical treatment immediately should symptoms of ciguatoxin fish poisoning appear; and
• Coral reef fish should be purchased from reputable and licensed seafood shops. Do not buy the fish when the source is in doubt.