The Centre for Health Protection has set up a hotline (2575 1221) to offer health advice, as the number of shellfish poisoning cases rises to 12, affecting 24 people.

The centre's Consultant Community Medicine Dr Thomas Tsang said eight men and 16 women, aged 11 to 57, have been affected.

He said the patients developed nervous-system related symptoms including dizziness, limb weakness, blurred vision and cramps 20 minutes to three hours after consuming the same type of scallops from March 13 and 15.

The scallops were brought from markets in Tuen Mun, Yuen Long, Sheung Shui, Tin Shui Wai, Chai Wan, Wan Chai, Wong Tai Sin and Tseung Kwan O.

None hospitalised

Dr Tsang said 14 affected people sought medical treatment from hospitals and one from a private doctor, but all are in a stable condition and none require hospitalisation.

The cases have been referred to the Food & Environmental Hygiene Department for follow-up action.

Dr Tsang called on people to avoid eating scallops for now, and seek medical advice immediately if they develop poisoning symptoms.

The Department of Health has received 11 reports of shellfish poisoning involving 36 people in the past five years.