Seafood safety: Ciguatoxin and paralytic shellfish poisoning toxin are natural toxins, and their presence and levels in coral reef fish and shellfish can be very unpredictable.

Hong Kong's food safety standard is high, with only 0.2% of the 29,000 samples taken in the first half of this year failing Food & Environmental Hygiene Department tests, including three failed samples for ciguatoxin and one for paralytic shellfish poisoning.

Assistant Director of Food & Environmental Hygiene Dr Thomas Chung said the trend was reassuring, with an overall failure rate at a consistently low level of 0.2%, against 0.4% and 0.3% over the same period in 2002 and 2003.

Only 0.04% of 11,500 food samples failed microbiological tests, improving on the 0.07% recorded in the two previous years.

Pathogen pairs

The five pathogen-food pairs were:

* staphylococcus aureus found in a siu-mei, pork chop rice and sandwich sample;

* listeria monocytogenes found in a barbecued spare rib sample; and,

* Norovirus found in a raw oyster.

"The first four cases reflect the importance of proper food handling, while the last one is a common risky combination," Dr Chung said.

He called on food handlers to be vigilant in maintaining good environmental, food and personal hygiene as improper handling is conducive to the breeding of pathogens.

Fifty-five of 17,800 chemical test samples failed tests, giving a failure rate of 0.3%, compared to 0.6% and 0.4% in the last two years.

Of the 2,170 samples taken for preservative analysis, 26 or 1.2% yielded unsatisfactory results, compared with 24 failures (1.3%) out of 1,870 samples in 2002 and 43 failures (2.5%) out of 1,700 samples last year.

Sulphur dioxide in fresh meat

The most conspicuous contaminant-food combination found was abusive use of sulphur dioxide in fresh meat, which accounted for seven unsatisfactory samples.

Dr Chung said the use of preservatives in food like fresh meat is prohibited. For other foods, only permitted preservatives can be used. The amount added should follow good manufacturing practices and be permitted by the relevant regulations.

"To strive for further improvement, we will provide more health education to the trade and impress upon them the consequences of indiscriminate use of preservatives on public health and their legal liability. This will couple with our strict enforcement action against offenders of food safety regulations," he said.

There were eight failures out of about 8,700 samples tested for pesticides, showing a significant improvement over the 41 and 13 failures in the same period in 2002 and 2003.

Caution issued on seafood

There were three failed samples for ciguatoxin and one for paralytic shellfish poisoning toxin, compared to just one ciguatoxin and no paralytic shellfish poisoning cases for the same period in both 2002 and 2003.

"We must continue to be on the alert as ciguatoxin and paralytic shellfish poisoning toxin are natural toxins, and their presence and levels in coral reef fish and shellfish can be very unpredictable," Dr Chung said.

"While the Government will continue to promote and regulate food safety, the public and the trade also have an important part to play. Penalties alone cannot uphold our excellent record, without each of the three parties fulfilling its own role.

"This is also the most proactive and cost-effective model advocated by international authorities like the Food & Agriculture Organisation and the World Health Organisation."