Advisory Council on Food and Environmental Hygiene



Food surveillance involves the on-going collection, analysis and interpretation of data on food hazard. It is important for both assurance of regulatory compliance, and evaluation and planning of food safety programmes. This paper examines the surveillance results of 2000, with particular emphasis on trends.


2. Every year, around 43 million chickens, 510 000 ducks and geese, 2.3 million pigs, 57 000 cattle, 4 000 goats and 710 000 tonnes of vegetables were consumed in Hong Kong. In 2000, our mid-year population was 6.8 million.


3. In 2000, we have collected around 59 000 food samples for chemical, microbiological and radioactivity analysis. Highlights of the 58 133 test results available so far are discussed in the following paragraphs.

Chemical Tests

4. Of the 58 133 food samples collected, 37 550 were for chemical testing. 339 food samples failed the chemical tests, with a failure rate of 0.9%. This figure was encouraging when compared with those in the previous two years (Fig. 2).

5. The number one culprit was pesticides (除害劑) (Fig. 3). 96 failures were found. Notwithstanding this, the trend was in fact a decreasing one when compared with figures of 1998, 1999 and 2000 (Fig. 4). The falling trend assures the public that various preventive and control measures in place indeed provide a secure safety net against pesticide residues in food.

6. The second problematic group was preservatives (防腐劑). There were 83 failures related to this group. The most conspicuous contaminant-food combination was sulphur dioxide in fresh meat. Some meat sellers purposely abused the use of preservative sulphur dioxide, by adding it to fresh meat for colour enhancement and shelf-life prolongation. The use of sulphur dioxide in fresh meat is, however, prohibited by law. There were 36 related failure cases. All sellers involved were prosecuted and convicted, with fines ranging from HK$1,500 to HK$15,000.

7. There were 62 beta-agonist (乙類促效劑) failures. The major clustering occurred in the second half of the year and coincided with the 35 food poisoning outbreaks in October. To curb the problem, raids on illegal slaughtering, urine surveillance in slaughterhouses and food surveillance at markets were all stepped up. In order to tackle the problem at source, legislative proposals to ban the use of clenbuterol and to tighten control of other veterinary and agricultural chemicals in farms have been put forth by Agriculture, Fisheries and Conservation Department under Public Health (Animals and Birds) Ordinance, Cap 139. Related legislative amendments will be introduced later this year.

Microbiological Tests

8. There were 18 748 food samples taken for microbiological tests in 2000. 59 food samples failed the test, giving a failure rate of 0.3%. Again, there was a decreasing trend when compared with statistics in the past three years (Fig. 5).

9. Amongst the list of incriminated pathogens, the most prominent one was Salmonella spp. (沙門氏菌)(Fig. 6). It is found not only in raw oysters, clams and salads, but also in sandwiches, barbecue pork and even meat congee. Although primarily sourced from poultry and eggs, salmonella can cross contaminate virtually any food. Indeed, it has always been Hong Kong's top three food poisoning causing bacteria. For this reason, we have published special pamphlets to arouse public awareness and to promote better observance of food safety measures and personal hygiene (pamphlet A).

10. The next group of microbiological hazard was hepatitis A (甲型肝炎病毒)in shellfish. The virus was found in 13 of the 240 samples examined during the year. Further analysis showed that the first two quarters were higher risk seasons (Fig. 7). Therefore, we have highlighted the importance of thorough cooking in our risk communication and food safety education programme.

11. A newcomer in the list of incriminated pathogens was Bacillus cereus (臘樣芽胞桿菌). This organism is commonly found in the environment and causes food poisoning by production of toxins. It grows particularly well in cooked food. The involved food categories found included rice vermicelli, dim sum, vegetable and hot dog. Control is by prevention of toxin production. This can be achieved by discouraging the germination and multiplication of bacterial spores in cooked foods through proper storage. Specific advice is given in our publicity pamphlet (pamphlet B).

12. In the first half year of 2000, we have found 5 out of 34 salad samples contaminated with Listeria monocytogenes (李斯特菌). After stepping up our publicity efforts through public announcement and health education given last August, no new failures were recorded from the 39 samples taken in the second half of 2000. In view of the possible severe health sequelae in vulnerable population sub-groups, we have targeted our publicity efforts to expectant mothers, the young, the elderly and those chronically ill. We were encouraged by the general press/media coverage given to our health advice.

Overall Results

13. In summary, there were 398 failures out of the 58 133 laboratory tests carried out, giving an overall failure rate of 0.7%. The overall situation is satisfactory as there was a general falling trend for failure rates in the past three years (Fig. 1).


14. To complement our efforts in surveillance and public education, taking enforcement action and prosecuting offenders is also an integral part of our food safety control work. A total of 488 food surveillance prosecutions were laid in the year. Of these, 343 cases had been heard with 335 convicted. The range of fines was between HK$300 and HK$10,000. Follow up prosecutions in connection with food poisoning outbreaks were also initiated. Of the 25 prosecution cases we had taken, 15 were related to beta-agonists and 10 microbial food poisoning. Of the 11 cases heard thus far, all were convicted, with fines ranging from HK$1,500 to HK$15,000.

Food and Environmental Hygiene Department
February 2001

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