The Centre for Health Protection is investigating three suspected cases of paralytic shellfish poisoning affecting three men and three women aged 29 to 60.

Two men and a woman, aged 30 to 60, developed numbness in the mouth after eating scallops at home on April 26. Their symptoms were mild and no medical attention was required. The scallops were bought from a Wong Tai Sin market.

A 42-year-old woman developed numbness, headache and tiredness after eating scallops at home on April 27. She attended Yan Chai Hospital's Accident & Emergency Department and did not require hospitalisation. The scallops were purchased from a Tsuen Wan fish stall.

A 29-year-old man and a 30-year-old woman developed limb and oral numbness, dizziness, weakness and abdominal pain after consuming scallops, coral reef fish skin and geoduck in a Tuen Mun restaurant on April 28. They attended Tuen Mun Hospital's Accident & Emergency Department. The man was admitted and has been discharged. He is now in stable condition.

Paralytic shellfish poisoning toxin is a natural toxin sometimes found in bi-valve shellfish. It is heat-stable and cannot be destroyed through cooking.

Forty-two suspected paralytic shellfish poisoning cases were reported to the centre in 2005, and three in 2006.