食物 安全焦點

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Message from the Editor-in-chiefIncident in Focus

Recall of Salmonella Contaminated Chocolate Products in the United Kingdom

Summary of Risk CommunicationWorkFood Safety Platform

Hazard and Risk in Food Safety (Part I)

Food Incident Highlight Food Poisoning Cases Traced to Raw Sea Urchins from the Same Supplier

New Zealand Food Safety Authority (NZFSA) Advised the Public not to Consume Uncooked Oysters Imported from Korea

Editor-in-chief

Dr. Y Y HOConsultant (Community Medicine)(Risk Assessment and Communication)

Executive EditorDr. Priscilla KWOKPrincipal Medical Officer(Risk Assessment and Communication)

Editing Member

Dr. Tina MOKPrincipal Medical Officer (Risk Management)

Dr. Y H CHONGHead (Risk Communication Section)

Dr. Shirley CHUKSenior Veterinary Officer(Veterinary Public Health)

Dr. Scott CRERARFood Safety Officer (Risk Management)

Mr. W C LEESenior Superintendent(Food Surveillance & Certification Section)

Dr. K S LEUNGSenior Chemist (Food Chemistry)

Dr. Samuel YEUNGHead (Risk Assessment Section)

(Salmonella Montevideo)

Reported by Arthur YAU, Research Officer, Risk Communication Section, Centre for Food Safety

Summary of IncidentOn 23 June 2006, the Food Standards

Agency (FSA) of the United Kingdom (UK)announced that Cadbury recalled seven types ofchocolate products in the UK due to possiblecontamination with an unusual strain of salmonellanamed “Salmonella Montevideo”. As the productsof the Company are readily available locally, theCentre for Food Safety (CFS) promptly contactedthe sole agent of Cadbury products, major foodretailers and the British Consulate-General in HongKong. A small number of one of the affectedproducts were found locally but were immediatelywithdrawn from sale by the concerned supermarketchain. It was subsequently concluded that eatingparticular Cadbury chocolate products was themost likely cause for the recent outbreak of thisunusual strain of salmonella in the UK. On 1August 2006, the FSA was notified by Cadburythat it intended to restock five types of products thathad been recalled on 23 June 2006 due topossible contamination with salmonella. Theinvestigation in the UK was still in progress as ofearly August 2006.

Health EffectSalmonella is a group of bacteria that can be

found in the intestinal tract of humans as well as

Recall of Salmonella Contaminated Chocolate Products in the United Kingdom

Incident in Focus

Message from the Editor-in-chief

W elcome to the first issue of “Food SafetyFocus”! “Food Safety Focus” provides a

new channel of communication between theCentre for Food Safety (CFS) and the generalpublic. Its main objectives are to arouse theawareness of the community on current foodsafety issues, both local and overseas, as wellas the actions undertaken by the CFS in relationto these issues; to provide professional andeasy-to-understand information on various foodhazards and their public health risks and topromote food safety through enhancingcommunication with the food trade and public.This is an electronic monthly newsletteravailable on the CFS homepage on the thirdWednesday of each month. Enjoy reading!

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Food Safety Focus• •

both wild and domestic animals including poultry, pigs andpets like dogs, cats and reptiles. A variety of salmonellaspecies can cause food poisoning in humans. In food,salmonella is more commonly found in beef, pork, poultry,milk, eggs and their products. By eating raw or under-cooked food that contains the bacteria or by consumingcooked ready-to-eat (RTE) food that had been cross-contam-inated with salmonella from other foods or infectedhumans, food poisoning can occur. The incubation periodis from 6 to 72 hours, usually about 12 to 36 hours. Thesymptoms include nausea, fever, abdominal pain,diarrhoea and sometimes vomiting. The symptoms aremore severe in infants and the elderly. Salmonella presentin raw food can be destroyed by cooking thoroughly.However, cooked food must be handled carefully in orderto prevent re-contamination by salmonella.

Microbiological CriteriaUnder the CFS food surveillance programme, RTE

food samples collected from the market are analyzed andtheir safety are assessed using the microbiological criteriaset out in the Microbiological Guidelines for RTE Food.The guidelines specifies that no salmonella bacteria shouldbe detected in 25 grams of the RTE food sample tested.

Follow-up ActionsThe CFS has been closely monitoring the development

of the issue and follow up actions were undertakenimmediately. The CFS contacted the sole agent ofCadbury products, major food retailers and the BritishConsulate-General in Hong Kong. The agent informed thatno affected products had been imported through them anda hotline had been set up by them to answer questionsfrom concerned customers. Of the major food retailers, themanagement of a major supermarket chain informed theCFS that one of the affected products had been importedinto Hong Kong through their own channels. Theconcerned products were immediately withdrawn fromsale. The CFS also informed concerned members of thefood trade of the issue and reminded them that they shouldensure that all foods sold are fit for human consumption.Since the UK authority was still conducting further investi-gations, the CFS would continue to monitor thedevelopment of the incident. In Hong Kong, the CFS hasliaised with the Centre for Health Protection (CHP) tomonitor the pattern of salmonella infection. Preliminarydata from the CHP showed one laboratory isolate ofSalmonella Montevideo in the first two quarters of 2006through the Salmonella Surveillance System. CHPwould continue to monitor the situation.

Further InformationFor readers who are interested to know more about

the incident, they can visit the FSA website. In fact, thesalmonella group of organisms in general are a commoncause of food poisoning outbreaks. The number of foodpoisoning cases confirmed to be caused by salmonella ispresented in the attached graph. For further informationon salmonella food poisoning, please visit the CFSwebsite.

Number of confirmed salmonella food poisoning outbreaks and persons involved,1995-2006 (as of 30 June 2006)

Incident in Focus

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Hazard and Risk in Food Safety (Part I)

Food Safety Focus• •

Food SafetyPlatform

Reported by Anna TANG, Research Officer, Risk AssessmentSection and Mary WONG, Research Officer, Risk CommunicationSection, Centre for Food Safety

Risk is part of everyone's life. For example, there is arisk of injury due to traffic accidents when we go out ontothe street. Also, when we put money in a bank, there is arisk of not being able to retrieve it if the bank goesbankrupt.

Hazard ≠ Risk This article introduces the concepts of hazard and

risk, within the framework of food safety control.Identification of hazards and estimation of the riskconcerned are central components in ensuring food safetyand safeguarding public health.

“Hazard” and “risk” are terms commonly used inscenarios where possible adverse outcomes are expected.Though these two terms are related to each other, they aredistinct entities with different meanings.

Hazard is a factor or agent which may lead toundesirable effects, whereas, riskrefers to the probability that theeffect will occur. The table on theleft compares the estimated risk ofcer tain events that we mayencounter within the population.

In the context of food safety,a “hazard” can be classified as asubstance or agent present infood that has the ability or thepotential to cause an adverse

health effect to the consumer. The substance can be abiological, chemical or physical agent. For example,salmonella, a biological agent, may be present in raweggs. Ingestion of salmonella may result in foodpoisoning. Therefore, salmonella in food is considered abiological hazard and may also pose a potential risk to theconsumer. Mercury, a natural contaminant that may bepresent in some foods, is regarded as a chemical hazardand could also pose a potential risk to the consumer.

In determining whether there is a “risk” posed tohumans from exposure to a specific hazard through food,there must be a consideration of the likelihood ofconsumption and the nature or severity of the adversehealth effect posed by a certain hazard if consumed.While “risk” already implies the existence of a hazard, ithas the addit ional component of the “chance” or“probability” of that happening to the individual or thepopulation as a whole, as well as taking into account theseverity and impact of the health effect that may occur as aresult of being exposed to the hazard. For example,although salmonella may be present in raw eggs, the riskof getting salmonella food poisoning is minimal when theegg is thoroughly cooked before consumption to eliminatethe hazard and thus minimizing the chance of exposure.However, if the eggs are eaten raw, the health risk fromsalmonella in eggs will be higher as a result of the higherlikelihood that the hazard will be present and consumed.Similarly, mercury may be present in food and could posea potential risk to the consumer. However, as in the casesof most chemical hazards, if the amount of mercury in thefood is low, the risk to the consumer will also be low asoccasional exposure to low levels of mercury will usuallynot cause adverse health effects in humans. Also in foodsafety assessment with respect to chronic toxicity, exposureand health effects of a chemical usually refer to the intakeof that chemical over a lifetime. Transient excursion abovethe safety reference value would have no healthconsequences provided that the average intake over longperiod is not exceeded.

Risk in qualitative source Annual riskInjury due to traffic accident 1 in 460Death due to heart disease 1 in 1,170Liver cancer from all causes 1 in 4,130Death due to traffic accident 1 in 43,300Death due to lightening strike 1 in 2,000,000Death due to plane crash (airliner) 1 in 52,600,000

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Food Safety Focus• •

Aflatoxin as an ExampleAflatoxin is a food hazard and the concern is on its

ability to cause liver cancer when people are exposed tohigh levels over an extended time. Its level in food istherefore regulated by law to prevent excess exposure. Thefollowing hypothetical scenario shows the estimated risk ofoccurrence of liver cancer due to aflatoxin intake.

According to the average pattern of peanut consumptionin Hong Kong and assuming that peanuts contain aflatoxin ata level two times the legal limit, a healthy person who eatspeanuts every day of their life would have a risk of cancerdue to aflatoxin intake of 1 in 2,300,000 per year. Thislevel of risk is very low and is comparable to the risk of deathdue to lightening strike.

In general, an exceedance of the level of a food hazardover the regulatory standard does not necessarily cause harmto health. The individual impact should depend on the riskassessment result.

Food Poisoning Cases Traced toRaw Sea Urchins from the Same Supplier

In July 2006, there were a number of Vibrioparahaemolyticus food poisoning outbreaks related toconsumption of raw sea urchins at several food premises. TheCentre for Food Safety (CFS) conducted prompt investigations andfound that the raw sea urchins concerned all sourced from thesame supplier. The supplier was immediately requested to stopdistribution of the affected products, and to recall and destroy anyremaining sea urchins. In addition, over 40 food outlets wereinspected to confirm that the affected products had been removedfrom the market. At the same time, since the supplier claimed thatthe sea urchins were supplied from Shenzhen, the CFS informedthe relevant authority on the Mainland to take further action. Nofurther cases occurred after control measures taken by the CFS.

Vibrio parahaemolyticus is one of the most frequentlyisolated food poisoning organisms and can be destroyed byheating at 75°C or above for several minutes. Incubation periodis from 4 to 30 hours and usually 12 to 24 hours. The symptomsinclude abdominal pain, diarrhoea, vomiting, occasionally withmild fever.

The food trade and consumers are advised to purchase allfood, especially shellfish, from reliable and reputable suppliers,check the quality of the food and store food at appropriatetemperatures. Please visit the CFS website for further details onthe incident.

New Zealand Food Safety Authority (NZFSA)advised the public not to consume uncookedoysters imported from Korea

The NZFSA issued a reminder to the public on 6 July2006 of not to consume uncooked oysters imported fromKorea. The statement was made in response to severalreported outbreaks in New Zealand that had been linked tothe consumption of uncooked Korean oysters. Although allbags of frozen Korean oysters were clearly labelled asrequiring cooking before consumption, this practice has notbeen consistently observed by the catering industry in NewZealand. Raw oysters are known to sometimes carrynorovirus, which can cause gastrointestinal illness.

Norovirus is commonly found in sewage-contaminatedwater. Ingestion of raw or inadequately cooked foods,including shellfish, salad and raw vegetables can pose ahigh risk of norovirus infection. Symptoms caused bynorovirus may include nausea, vomiting, non-bloodydiarrhoea and abdominal cramps.

The key to the prevention of norovirus infection is strictobservance of food, personal and environmental hygiene.Vulnerable population, which include the elderly, children,pregnant women and persons with lower immunity, shouldbe careful when choosing foods especially high risk food.Products that pose a high risk of being contaminated withnorovirus, such as shellfish, should also be cookedthoroughly before consumption. Please visit the CFSwebsite for further educational materials on norovirus andsafe consumption of shellfish.

Food SafetyPlatform

Food IncidentHighlight

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