Advice on Treatment to Remove Worries of Contracting Shellfish Poisoning

Centre for Food Safety: Eviscerated shellfish before cooking and discard all cooked juices

The Centre for Food Safety reminds the public to avoid shellfish viscera to prevent shellfish poisoning. "CiCi's Food Paradise" on NTD Television

According to data from the HK Centre for Food Safety, the incidence of paralytic shellfish poisoning (PSP) cases around the world seems to be on the rise in recent decades.

In Hong Kong, according to the records of the Centre for Health Protection, between 2007 and 2011, there were 34 suspected PSP cases affecting 68 people. Epidemiological studies at that time showed a higher risk of discomfort from the ingestion of gonads of scallops.

A case of paralytic shellfish poisoning (PSP) occurred in Hong Kong in June last year (2021). A man and a woman experienced blurred vision, dizziness, and fatigue 10 to 30 minutes after eating conch at home. The follow-up investigation declared it as PSP poisoning.

The Centre for Health Protection pointed out that the symptoms of PSP are mainly related to the nervous system and usually appear within minutes to a few hours after eating shellfish. Initial symptoms include tingling, numbness of the mouth and limbs, headache, dizziness, and gastrointestinal discomfort. In most cases, symptoms will disappear completely within a few days. However, in severe cases, swallowing and difficulties in speaking, paralysis, respiratory arrest, and even death may occur.

The HK Centre for Food Safety reminded the public again that they should pay attention to four points when eating shellfish to avoid possible poisoning:

1. Wash and brush clean the outer shell before cooking
   Wash, and even better, brush clean the shell with clean water, and discard the shellfish if the shell is found to be broken or already exposed prior to being cooked.
2. Remove all viscera from shellfish
   Once the shellfish are contaminated during their growth, toxins, such as paralytic shellfish toxin, could accumulate within the shellfish, especially inside the viscera. Shellfish toxins are generally resistant to heat and cannot be removed even by high-temperature cooking. Therefore, it is wise to remove all the viscera and gonads of shellfish before cooking. For example, for popular shellfish like scallops, or fan scallops, you should just eat the clear white meat portion.
3. Avoid eating the cooking juice
   Some shellfish toxins are soluble in water, so avoid drinking cooked shellfish juices.
4. Do not overeat
   Cooked shellfish should also be eaten in moderation with an amount following the principle of a balanced diet.