Antimicrobial resistant bacteria have become a global threat to public health. The World Health Organization has warned the world is headed for a "post-antibiotic era" in which common infections can become untreatable because of abuse of antibiotics in medical treatment and farming. According to some studies from Europe and the United States, 20-50% of infected cases of ESBL (extended-spectrum beta-lactamase)-producing bacteria, could have come from chicken which were regularly eaten. This cannot be ignored and ought to strengthen monitoring.
The Consumer Council, for the first time, tested chicken products sold in the market, to study whether they contained ESBL-producing bacteria in order to gauge the likelihood that chickens consumers commonly buy carry antimicrobial resistant bacteria. Over 60% of chickens among the 100 tested models were found to contain ESBL-producing bacteria, with models from Mainland China and Hong Kong reaching 80% or higher. Hong Kong people tend to cook chicken "just right" to maintain its tender texture, but it is necessary for consumers to change this eating habit, besides having to cook chicken thoroughly, consumers are advised to remain vigilant when buying, cleaning, storing, marinating and cooking chicken, to minimise the risk of cross-contamination in the consuming environment.
The Council emphasises that emergence of antimicrobial resistant bacteria is a complicated issue. The whole process from raising to selling chicken in the market involves numerous segments, including regional prevalence of bacteria, health status of chickens, day-old chicks, feed, poultry farming methods, husbandry environment, transportation, slaughter, packaging and chilling and freezing process, which make it hard to trace and verify the origin of bacteria. Consumers should also be aware that "organic" certification accredits the raising or production process of chicken, but not the final quality of the product. The product could become contaminated after being slaughtered.
The 100 tested models included whole chickens and chicken wings, comprising live chicken freshly slaughtered on site (24), daily slaughtered fresh chicken (6), chilled models (30), previously frozen models (12) and frozen models (28). Based on their packaging or on the explanations of salespersons at retail stores, the products originated from Mainland China (29), Hong Kong (25), Europe (13), North America (13), Australia and New Zealand (9), South America (8) and other regions in Asia (3). Among which, 16 of the models were claimed or labelled "organic".
The sampling was conducted with reference to the Guidebook of United States Department of Agriculture. Test methodology referred to the literature published by the European Food Safety Authority and Clinical Laboratory Standards Institute to test for the presence of Enterobacteriaceae which were resistant to third generation cephalosporins (3GC). ESBL Phenotypic Test was then applied to detect whether the bacteria possessed ESBL. ESBLs are enzymes that inactivate many in the group of beta-lactam antibiotics. They are impervious to 3GC – an antibiotic commonly used to treat infectious diseases with bacterial origin. As a result, diseases should be treated with other unconventional antibiotics, or even by applying multiple antibiotics at one time.
Among the 100 models, bacteria in 6 models could be killed by the antibiotics 3GC effectively, 22 did not contain Enterobacteriaceae, while the remaining 72 were confirmed to contain Enterobacteriaceae. Among them, 68 models were found resistant to 3GC, from which 62 were found to carry ESBL-producing Enterobacteriaceae. Of the models claimed to be "organic", 6 were found to have ESBL-producing Enterobacteriaceae.
All 6 models (100%) of daily slaughtered fresh chicken were found to contain ESBL-producing Enterobacteriaceae, followed by live chicken freshly slaughtered on site (92%) and chilled models (70%). By contrast, 33% and 32% of the previously frozen models and frozen models were found to contain such bacteria respectively. This may be attributed to slaughter time, storing temperatures and processing. According to responses of some suppliers, the slaughtering environment has to be kept at 8-12°C to avoid affecting the texture of the meat of fresh chicken. Frozen models and previously frozen models are placed in an environment with temperature close to or below freezing point, which may account for the lower proliferation or growth of the bacteria. In addition, these models were handled by many stages during which some of the bacteria could be eliminated.
Divided by regions of origin, among the 62 models found to have ESBL-producing Enterobacteriaceae, 96% of the local models were found with the bacteria, followed by Mainland China (79%), South America (63%), Europe (46%), other regions in Asia (33%), North America (15%) and Australia and New Zealand (11%).
Models from Europe, North America and Australia and New Zealand had relatively lower percentages of ESBL-producing Enterobacteriaceae. According to Australian laws, most antibiotics for animals must be prescribed by a veterinarian; since 2001, the Europe Union has progressively banned the use of antibiotics in animals without medical justification; the United States has proactively launched campaigns to combat the problem of antimicrobial resistant bacteria in recent years.
Hong Kong has no such regulation against antibiotic use. Although the Harmful Substances in Food Regulation and the Public Health (Animals and Birds) (Chemical Residues) Regulation list 2 antibiotics as banned farming pesticides, and veterinary chemicals and harmful substances, as well as set maximum concentration limits of some antibiotics in tissues of food animals and maximum residue limit for relevant harmful substances in food, but the 2 regulations do not specify how to use antibiotics properly. Fish, however, is yet to be classified as a food animal. These regulations are apparently insufficient to control abuse of antibiotics during the process of raising food animals.
The Council hopes the High-level Steering Committee on Antimicrobial Resistance formed by the Government could make pragmatic suggestions and take a three-pronged approach, to review the current legislation in respect of regulations, healthcare and hygiene, and the raising of food animals. The authority should gradually cease to issue permits for the regular use of antibiotics, so as to eventually restrict the use of antibiotics to situations in which they have been prescribed for medical reasons by veterinarians.
During the transition period of changing application for Antibiotics Permits, the authority should also continue to provide assistance and relevant education to farmers. This would include inspection of hygienic conditions of the rearing environment on farms and a review of guidelines of farm move, and offer advice on improvement when necessary. Assistance also includes introduction of preventive vaccines; making available sufficient number of veterinarians with relevant experience when farms need antibiotics prescribed by a veterinarian in cases of sickness among poultry stocks. The Government should also strengthen periodic spot checks on food animals and edible meat from farms, food import check points and retail outlets. These measures will help in monitoring antimicrobial resistant bacteria.
The Council will continue to support the global campaigns against antimicrobial resistant bacteria initiated by the World Health Organisation and Consumers International in order to raise concern and awareness of this issue in society and improve the situation collectively.
Following is advice to consumers:
To combat the problems arising from antimicrobial resistant bacteria, consumer can express their demand on food safety to catering chains, by changing consumption choices and strengthening their knowledge on this issue, hence help change the merchandising policy adopted by catering chains to provide non-antibiotic ingredients to consumers. In the daily life, consumers should not eat foods not thoroughly cooked to minimise the chances of becoming infected by antimicrobial resistant bacteria. Other tips are provided below:
- Raw and cooked meat should be packed properly and kept in the refrigerator separately, raw meat should be placed below cooked meat;
- Be careful when handling raw meat and maintain proper hygiene at all times to reduce risks of getting infected and remember to wash hands;
- Use different chopping boards, knives and cooking utensils to handle raw and cooked food. Cleanse thoroughly with hot water and dishwashing liquid after use, and diluted bleach to clean the kitchen;
- Wounds should be properly bandaged if the person needs to handle food, avoid getting in touch with raw meat. People with gastrointestinal disorders should not handle food;
- Antimicrobial resistant bacteria can be killed under high temperature, and cooking the meat thoroughly can reduce chances of consuming antimicrobial resistant bacteria. Hot food should be kept at 60°C or above, and it is not suitable for eating after being kept in room temperature for more than 2 hours;
- Wash hands with soap and running water before eating, or rub hands with instant hand sanitiser.
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