ESTABLISHING PRODUCT STANDARDS AND CERTIFICATION SYSTEMS Iddya Karunasagar Fish Utilisation and Marketing Service FAO, Rome
SPS AND TBT AGREEMENTS Introduce new disciplines that govern trading practices at international level Set out rights and responsibilities of WTO members That wish to take action to restrict imports in order to protect human, animal or plant health When applying technical regulations and standards and conformity assessment procedures for traded goods
SPS AGREEMENT RIGHT: to ensure that consumers are being supplied safe food Safe by the standards the country considers appropriate OBLIGATION: to ensure that strict health and safety regulations are not being used as an excuse for protecting domestic producers
SPS AGREEMENT Restrictions should be minimum necessary to human, animal or plant health They should be based on scientific principles and not maintained without sufficient scientific evidence Governments must notify each other of SPS measures in the course of preparation
SPS AGREEMENT Members are encouraged to adhere to international standards where they exist Higher standards can be enforced, if there is scientific justification provided in accordance with internationally accepted risk assessment techniques
SPS AGREEMENT Members should accept SPS measures of other countries as equivalent, even if different, where they provide the same level of protection as their own regulations Control, inspection and approval procedures should be undertaken in no less favourable manner for imported products than for similar domestic products
SPS AGREEMENT With regard to food safety measures, members should base their national measures on international standards, guidelines adopted by Codex Alimentarius Commission (CAC) For Animal life and health, measures should be based on standards and guidelines adopted by the International Office of Epizootics (OIE)
SPS AGREEMENT Article-1 General Provisions Annex A Definitions Sanitary/Phytosanitary Measures Any measure applied to Protect Human and Animal Life or Health from Risks from improper use of food additives contaminants toxins disease causing organisms in foods, beverages or feedstuffs
SPS AGREEMENT Article-1 General Provisions Annex A Definitions Sanitary/Phytosanitary Measures Any measure applied to Protect Animal or Plant Life within the territory of the Member from risks related to the entry, establishment or spread of: Pests or diseases Disease carrying organisms Disease causing organisms
SPS AGREEMENT Annex A - Definitions Sanitary/Phytosanitary Measures include all laws, decrees, regulations, requirements and procedures related to end product criteria processes production methods testing inspection certification approval procedures quarantine treatments statistical methods sampling procedures risk assessment packaging labelling
DEFINING PRINCIPLES OF SPS AGREEMENT (Article 2) ADEQUACY: measures should only be applied to the extent to protect the health JUSTIFICATION: measures should be based on scientific evidence NON DISCRIMINATION: measures should not arbitrarily or unjustifiably discriminate, where identical or similar conditions prevail.
TBT AGREEMENT Tries to prevent standards becoming obstacles for trade Products imported from any WTO member receiving no less favorable treatment given to similar product of national origin or originating in any other country Standards should be based on legitimate objectives, be drafted in terms of performance rather than design
TBT AGREEMENT Governments should notify each other of standards in the course of preparation Members are encouraged to adhere to international standards, where possible Accept standards of other countries as equivalent, even if different, where they meet objectives of their own regulations Foreign suppliers should have access to conformity assessment procedures on terms no less favourable than domestic producers
TBT AGREEMENT Covers all types of consumer products including foods Does not apply to requirements covered by SPS agreement Covers measures designed to protect consumer against deception and fraud
TBT AGREEMENT States that all technical standards and regulations must have a legitimate purpose The impact or cost of implementing a standard must be proportional to the purpose f the standard If there are two or more ways of achieving the same objective, the least trade restrictive alternative should be followed
Technical Barriers to Trade Agreement (TBT) Annex 1. Definitions Technical regulation Document which lays down product characteristics or their related processes and production methods, including the applicable administrative provisions, with which compliance is mandatory. It may also include or deal exclusively with terminology, symbols, packaging, marking or labelling requirements as they apply to a product, process or production method.
Technical Barriers to Trade Agreement (TBT) Annex 1. Definitions Standard Document approved by a recognized body, that provides, for common and repeated use, rules, guidelines or characteristics for products or related processes and production methods, with which compliance is not mandatory. It may also include or deal exclusively with terminology, symbols, packaging, marking or labelling requirements as they apply to a product, process or production method.
Technical Barriers to Trade Agreement (TBT) Annex 1. Definitions Conformity assessment procedures Any procedure used, directly or indirectly, to determine that relevant requirements in technical regulations or standards are fulfilled.
Implications of the SPS and TBT agreements in Fisheries
SPS/TBT Agreements General Principles Sovereignty Harmonization Equivalency Scientific basis Transparency Technical Assistance Special and differential treatment Consultation and dispute settlement
SPS/TBT Agreements General Principles Sovereignty Harmonization Equivalence Scientific basis Transparency Technical Assistance Special and differential treatment Consultation and dispute settlement SPS AGREEMENT Annex A Definitions Appropriate Level of Protection Each country is sovereign to establish SPS measures it terms necessary to protect human and animal health and plants The level of protection deemed appropriate by the Member to protect human, animal or plant life or health “Acceptable Level of Risk”
SPS/TBT Agreements General Principles SPS AGREEMENT Article 2 Basic Rights Sovereignty Harmonization Equivalence Scientific basis Transparency Technical Assistance Special and differential treatment Consultation and dispute settlement Recognizes the rights of Members to establish appropriate levels of protection Outlines the application of scientific evidence in establishing sanitary/phytosanitary measures Prohibits discriminatory, disguised or unnecessary restrictive trade measures
SPS/TBT Agreements General Principles Sovereignty Harmonization Equivalence Scientific basis Transparency Technical Assistance Special and differential treatment Consultation and dispute settlement The TBT Agreement establishes rights of Members: to ensure the quality of its exports, to protect human, animal or plant life or health to protect the environment or for the prevention of deceptive practices, at the levels considered appropriate
SPS/TBT Agreements General Principles SPS AGREEMENT Annex A Definitions Harmonization Sovereignty Harmonization Equivalence Scientific basis Transparency Technical Assistance Special and differential treatment Consultation and dispute settlement Establishment, Recognition and Application of Common Sanitary/Phytosanitary Measures by Members
SPS/TBT Agreements General Principles SPS AGREEMENT Annex A Definitions: Harmonization Codex Alimentarius Commission Sovereignty Harmonization Equivalence Scientific basis Transparency Technical Assistance Special and differential treatment Consultation and dispute settlement Standards, Guidelines, and Recommendations for Food Safety Food Additives Veterinary Drug and Pesticide Residues Contaminants Methods of Analysis and Sampling Codes /Guidelines of Hygienic Practices
SPS/TBT Agreements General Principles SPS AGREEMENT Annex A Definitions: Harmonization Sovereignty Harmonization Equivalence Scientific basis Transparency Technical Assistance Special and differential treatment Consultation and dispute settlement Standards, Guidelines, and Recommendations for Animal Health and Zoonoses International Office of Epizootic Standards, Guidelines, and Recommendations for Plant Health International Plant Protection Convention
SPS/TBT Agreements General Principles SPS AGREEMENT Annex A Definitions: Harmonization Sovereignty Harmonization Equivalence Scientific basis Transparency Technical Assistance Special and differential treatment Consultation and dispute settlement For matters not covered by the identified Organizations Standards, guidelines, and recommendations promulgated by other international organizations, open for membership to All WTO members, as identified by the SPS Committee may be applied
SPS/TBT Agreements General Principles SPS AGREEMENT Article 3 Harmonization Sovereignty Harmonization Equivalence Scientific basis Transparency Technical Assistance Special and differential treatment Consultation and dispute settlement Members shall base Sanitary and Phytosanitary Measures on international standards, guidelines and recommendations Measures which conform to international standards are consistent with Agreement Higher level of protection may be used
SPS/TBT Agreements General Principles Sovereignty Harmonization Equivalence Scientific basis Transparency Technical Assistance Special and differential treatment Consultation and dispute settlement SPS AGREEMENT Article 3 Harmonization Members are to fully participate in relevant international organizations WTO to monitor progress of international harmonization
SPS/TBT Agreements General Principles SPS AGREEMENT Article 4 Equivalence Sovereignty Harmonization Equivalence Scientific basis Transparency Technical Assistance Special and differential treatment Consultation and dispute settlement Members shall accept other Member measures as equivalent, if final results are the same Members shall consult to achieve bilateral and multilateral agreement (Mutual Recognition Agreements)
SPS/TBT Agreements General Principles SPS AGREEMENT Article 5 Risk Assessment Sovereignty Harmonization Equivalence Scientific basis Transparency Technical Assistance Special and differential treatment Consultation and dispute settlement Risk Assessment should take into account available scientific evidence relevant processes and production methods inspection/sampling/testing methods prevalence of specific diseases or pests existence of pest/disease free areas ecological/environmental conditions quarantine or other treatment SPS Measures are to be based on an assessment of the risks to Human, Animal and Plant life and health using internationally accepted Risk Assessment Techniques
SPS/TBT Agreements General Principles SPS AGREEMENT Article 5: Risk Assessment Sovereignty Harmonization Equivalence Scientific basis Transparency Technical Assistance Special and differential treatment Consultation and dispute settlement SPS Measures should minimize negative trade effects Arbitrary or unjustified measures shall not be considered Members may provisionally adopt international Standards Protection level shall not be trade restrictive Explanations may be requested by Members
SPS/TBT Agreements General Principles SPS AGREEMENT Article 7 Transparency Sovereignty Harmonization Equivalence Scientific basis Transparency Technical Assistance Special and differential treatment Consultation and dispute settlement Publication of regulations and provide lead time for comment Establish Enquiry Point Establish Notification Procedures General Reservations (related to Confidential information)
SPS/TBT Agreements General Principles SPS AGREEMENT Article 7 Transparency Emergency circumstances Sovereignty Harmonization Equivalence Scientific basis Transparency Technical Assistance Special and differential treatment Consultation and dispute settlement Bypass publication Immediately notify Members through SPS Committee Secretariat Allow Members to comment and take comments into account
SPS/TBT Agreements General Principles SPS AGREEMENT Article 7 Transparency Notification Procedures Sovereignty Harmonization Equivalence Scientific basis Transparency Technical Assistance Special and differential treatment Consultation and dispute settlement Prompt publication Provide information on effected products, objectives and rational Provide copies of regulation on request Allow Members to comment and take comments into account
SPS/TBT Agreements General Principles SPS AGREEMENT Article 9 Technical Assistance Sovereignty Harmonization Equivalence Scientific basis Transparency Technical Assistance Special and differential treatment Consultation and dispute settlement Members agree to facilitate technical assistance, especially to developing countries If substantial investment is needed, technical assistance should be provided (WTO is not a funding organization)
SPS/TBT Agreements General Principles Sovereignty Harmonization Equivalence Scientific basis Transparency Technical Assistance Special and differential treatment Consultation and dispute settlement SPS AGREEMENT Article 10: Special and Differential Treatment Members are to consider needs of other Member countries Time limit exception (granted by SPS Committee upon request) Longer time frames for compliance with this agreement Developing countries should actively participate in international organizations
SPS/TBT Agreements General Principles SPS AGREEMENT Article 11 Consultations and Dispute Settlement Sovereignty Harmonization Equivalence Scientific basis Transparency Technical Assistance Special and differential treatment Consultation and dispute settlement Rules established by GATT (Article XXII and XXIII) Technical/Scientific - advise from experts, advisory panels or relevant international organizations Other existing international agreements may be used
SPS/TBT Agreements General Principles SPS AGREEMENT Article 11 Administration The SPS Committee was established to Sovereignty Harmonization Equivalence Scientific basis Transparency Technical Assistance Special and differential treatment Consultation and dispute settlement encourage the use of International Standards maintain contact with international organizations develop procedures to monitor harmonization monitor for duplication of procedures examine specific standards review operational procedures after3 years
SPS/TBT Agreements General Principles The Committee on TBT Sovereignty Harmonization Equivalence Scientific basis Transparency Technical Assistance Special and differential treatment Consultation and dispute settlement Meets as necessary, at least once a year To enable members to consult on the operations of the agreement Committee can establish working parties or other bodies as appropriate Committee to ensure duplication with other technical bodies is prevented
Achievements and Challenges Harmonization Equivalence Scientific basis Special and differential treatment/Technical assistance
Achievements and Challenges HACCP-based systems widely accepted Codex Alimentarius Commission accepted as the international standards setting body Harmonization Equivalence Scientific basis Special and differential treatment/ Technical assistance Shortcomings: Different inspection and control schemes Different fish standards applied High rates of detentions/rejections
Achievements and Challenges Harmonization Equivalence Scientific basis Special and differential treatment/ Technical assistance Achievements: “Food chain” and “Control at source” approaches Cost-effectiveness of these approaches Shortcomings: Very few agreements Obligation of means vs. obligation of results
Achievements and Challenges Harmonization Equivalence Scientific basis Special and differential treatment/ Technical assistance Risk analysis widely accepted National and International work undertaken Shortcomings: Needs exceed by far activities undertaken Lack of resources in developing countries Many standards not scientifically based
Achievements and Challenges Harmonization Equivalence Scientific basis Special and differential treatment/ Technical assistance Achievements: Regional and national initiatives (SIDA, EC-ACP) STDF (Standard and Trade Development Fund) Trust Fund for CAC Shortcomings: Developing countries obliged to meet market requirements Needs exceed by far initiatives Lack of resources in developing countries Many standards not scientifically based
Risk Analysis Components (Quantitative) Risk Assessment How big is the risk, what factors control the risk? Scientific process Risk Communication How can we talk about the risk with affected individuals? Social and psychological process Risk Management What can we do about the risk? Political process
'risk assessment' means a scientifically based process consisting of four steps: hazard identification, hazard characterisation, exposure assessment and risk characterisation; 'risk management' means the process, distinct from risk assessment, of weighing policy alternatives in consultation with interested parties, considering risk assessment and other legitimate factors, and, if need be, selecting appropriate prevention and control options;
'risk communication' means the interactive exchange of information and opinions throughout the risk analysis process as regards hazards and risks, risk-related factors and risk perceptions, among risk assessors, risk managers, consumers, feed and food businesses, the academic community and other interested parties, including the explanation of risk assessment findings and the basis of risk management decisions;
MICROBIOLOGICAL RISK ASSESSMENT A scientific process which consists of determining the likelihood and severity of an adverse health effect in a population exposed to a certain pathogen/food combination
PURPOSE OF MICROBIOLOGICAL RISK ASSESSMENT Facilitate and support decision making by risk managers This may be achieved by providing: - Estimates of risk of illness by consumption of certain food/pathogen combination - Estimates of risk reduction that may be achieved by certain control measures
ACCEPTABILITY OF RISK IS NOT EXPRESSED IN MRA A risk estimate does not provide information whether the risk associated with the level (prevalence and/or concentration) of microbe in food is acceptable or not. This is a decision that society (stakeholders: Government agencies, industry, academicians, consumers, politicians) should take
RISK ASSESSMENT AREAS Microbiological Chemical Biotechnological
Microbiological hazards vs chemical hazards Usually acute effect Single exposure Pathogen/commodity combination Living hazards - numbers can change up or down Dynamic and adaptable - different characteristics & variable response Difficult to define acceptable levels Chemical hazards: Usually cumulative effect Multiple exposures One chemical - many foods Toxic levels stable or decrease during storage Processing has minimal effect Acceptable levels defined for many chemical hazards In this slide a comparison is made between chemical and microbiological hazards. For people who are more familiar with chemical risk assessment this may help explain the differences in approaches when assessing risk from microbial compared to chemical hazards. With microbial hazards, most adverse effects are acute; vomiting and choking may occur within minutes or hours, gastro-intestinal disorders often within one to three days. On top of these effects, secondary lesions may occur later. They are called sequelae, examples are Haemolytic Uraemic Syndrome (HUS) as a consequence of an E. coli O157 infection, and Guillain-Barré Syndrome (GBS) as a consequence of Campylobacter infections. However, most chemical hazards do not provoke acute effects; many may cause lesions in organs, cancer and all kind of other debilitating conditions. This does not take away that some may indeed provoke acute effects, particularly when they are taken in high doses. The point here is that microbiological hazards do more frequently cause acute effects rather than long-term effects. With microbes a single exposure is sufficient to cause an effect however with chemicals the adverse effect is more commonly due to exposure over a period of time. With microbial hazards control measures tend to focus on pathogen commodity combinations while with chemical hazards exposure to a particular hazard can come from a very broad range of foods which results in a different approach to hazard control. Many chemical hazards however, such as antibiotic residues, hormones, pesticides and mycotoxins, can be more effectively controlled at the farm level than later in the food-chain. Many microbiological hazards cannot be very well controlled at the farm level, but there are also good examples of eradication or containment programmes. Microbial hazards are living organisms. This means that their numbers can increase as well as decrease between harvest and consumption. Furthermore, they can adapt to different environmental conditions and may become resistant to certain treatments used to reduce their numbers over time. With many chemical hazards there tends to be little change although some processing steps will decrease the hazard, e.g. ocratoxin in coffee if decreased during the roasting process. Manufacturing has a great effect on microbiological hazards, but very little on chemical ones. Human response to microbiological hazards can vary greatly; for example, for certain population groups (e.g. immunocompromised, pregnant women) Listeria monocytogenes can cause very serious illness whereas for the rest population it has no adverse effect. This can make it difficult to establish any acceptable limits for microbiological hazards. Codex Alimentarius has an extensive list of chemicals in foods and their acceptability, related to use and level. Acceptable levels for microbes are less well established. For most microbiological hazards, no acceptable levels have been defined, although for instance a low number of Listeria monocytogenes (L.m.) in certain foods is accepted in a number of countries. (Throughout this course L.m. will be used as an example to illustrate some of the points which will be made.)
MICROBIOLOGICAL RISK ASSESSMENT Microbiological risk assessment is a science based process driven by Governments to assess the severity of illness and the probability of its occurrence as a consequence of the exposure to certain pathogen/food combination
Risk Assessment - Codex Hazard identification Exposure assessment Hazard characterization Risk characterization MRA consists of four distinct components: Hazard identification Hazard characterization Exposure assessment Risk characterization These will be addressed in detail in the following two lectures. An important point made in this slide is the continuous interaction between risk managers and risk assessors, as part of the risk communication component.
Step in Risk Assessment Hazard Identification What microbe, food(s) and people are involved? Hazard characterisation Characteristics of pathogen, food, public health outcomes Exposure Analysis What is the chance of exposure? How many cells? Dose-Response Analysis What is the human health effect of the exposure? Risk Characterization Complete picture of the assessed risk
HAZARD IDENTIFICATION HAZARD CHARACTERISATION “THE IDENTIFICATION OF KNOWN OR POTENTIAL HEALTH EFFECTS ASSOCIATED WITH A PARTICULAR AGENT” HAZARD CHARACTERISATION “THE QUALITATIVE AND/OR QUANTITATIVE EVALUATION OF THE NATURE OF THE ADVERSE EFFECTS ASSOCIATED WITH BIOLOGICAL, CHEMICAL AGENT WHICH MAY BE PRESENT IN FOODS. A DOSE-RESPONSE ASSESSMENT SHOULD BE MADE IF DATA IS AVAILABLE”
Hazard Identification Epidemiological data linking Foods Pathogens Human illness Special considerations Disease complications Acute vs. chronic disease Specific sensitive consumer populations Characteristics of the organism Organisms mode of action
Exposure - Simple Example Initial number of organisms follows a Poisson distribution Growth rate is normally distributed Product composition and storage temperature are fixed The product becomes unsafe when it contains 100,000 organisms/gram
Initial number - Poisson
Growth rate is normal
Simulation Results
Dose-Response Analysis Translates exposure analysis output in to a measure of human health If “quantitative” Use dose-response curve Estimate probability of infection and illness from dose
Dose response curve
Dose-Response factors Statistical model(s) to analyze or quantify dose- response relationships Threshold vs. non-threshold models Dose response data Human Animal Outbreak or intervention data
Dose-Response factors Source and preparation of challenge material or inoculum Organism type and strain Virulence factors or other measures of pathogenicity Characteristics of the exposed population Age, immune status, etc.
RISK CHARACTERISATION EXPOSURE ASSESSMENT “THE QUALITATIVE AND/OR QUANTITAIVE EVALUATION OF THE THE DEGREE OF INTAKE THAT IS LIKELY TO OCCUR” RISK CHARACTERISATION “INTEGRATION OF HAZARD IDENTIFICATION, HAZARD CHARACTERISATION AND EXPOSURE ASSESSMENT INTO AN ESTIMATION OF THE ADVERSE EFFECT LIKELY TO OCCUR IN A GIVEN POPULATION INCLUDING ATTENDANT UNCERTAINTIES”
If “quantitative” assessment Exposure Analysis Estimate likelihood of consumption likely number (dose) of the pathogen If “quantitative” assessment Modeling Simulation
Risk Characterization Final task in risk assessment Combines the information from Hazard identification Exposure analysis Dose-response analysis Produces a complete picture of the assessed risk
Inputs to MRA Science (multidisciplinary) Infrastructure Tools Data Knowledge Experts Tools Statistics Ranking Simulation (e.g. Monte Carlo) Knowledge elicitation Infrastructure Epidemiology Food consumption Outbreak investigation Consumer behaviour Framework Risk analysis In this slide a number of inputs are mentioned. Their use will become apparent during this course and particularly in the next lecture (Topic 3 Lecture 2).
Iterative process of MRA Run simulation Review results Need more data? Assumptions not suitable? Revise model Estimate risk Validate YES NO Collect data Define assumptions Develop model The purpose of this slide is simply to illustrate the iterative nature of MRA. This is discussed further in other presentations. However, here we just want to illustrate that and MRA evolves in the course of its development. It will not be perfect on the first attempt but when the model is built it can be modified according to the data available, the assumptions that are made and if in some cases some critical data are missing an effort may be made to get such data in the course of doing the MRA. The other aspect of this iterative process is that it allows the involvement of various stakeholders at various steps of the process.
Codex principles for MRA (1) MRA should be soundly based on science There should be a functional separation between risk assessment and risk management MRA should be conducted according to a structured approach that includes hazard identification, hazard characterization, exposure assessment and risk characterization MRA is a scientific process. It must be carried out by risk assessors who have a functional separation from risk managers. This separation does not mean that there should not be continuous interaction between the two groups. It means that the risk assessors should take into account only scientific data; the political and societal aspects of risk assessment are the responsibility of the risk managers. The risk assessors have to adhere to a strict procedure; the components (mentioned in slide 14) are mentioned in this slide again.
Codex principles for MRA (2) An MRA should clearly state the purpose of the exercise, including the form of risk estimate that will be the output The conduct of an MRA should be transparent Any constraints that impact on the MRA, such as cost, resources or time, should be identified and their possible consequences described It has already been shown that different forms of risk estimate can be presented to the risk managers. Before an MRA starts, the purpose of the exercise and the form of the output should already have been decided upon. Risk assessors work in a glasshouse: whatever they do or do not do, and why this is the case, should be open to anyone who is interested. The assumptions should be clearly identified and the models should be available for peer review. The data, their sources and reliability should be open to use by others, unless they are strictly confidential data. In this case, their existence and use should be noted, and the reason for this confidentiality mentioned. Point 6 speaks for itself.
Codex principles for MRA (3) The risk estimate should contain a description of uncertainty and where the uncertainty arose during the risk assessment process Data should be such that uncertainty in the risk estimate can be determined; data and data collection systems should, as far as possible, be of sufficient quality and precision that uncertainty in the risk estimate is minimized Variability and uncertainty are unavoidable aspects of any MRA. The uncertainties and where the uncertainties arose during the MRA should be described. The openness around data has already been mentioned. Point 8 highlights some aspects of data collection and their possible influence on the quality of the risk assessment.
Codex principles for MRA (4) An MRA should explicitly consider the dynamics of microbiological growth, survival and death in food and the complexity of the interaction (including sequelae) between human and agent following consumption as well as the potential for further spread Wherever possible, risk estimates should be reassessed over time by comparison with independent human illness data An MRA may need re-evaluation, as new relevant information becomes available Point 9 refers to the product/pathogen/pathway (PPP) analysis and the diversity in human reactions to the agent. It also mentions the potential for further spread, not only of the disease, but also within the food preparation environment itself (e.g. cross-contamination from raw poultry to salad). Contrary to chemical risk assessments, where human disease data can seldom be related to the correct use of chemicals, in MRA, epidemiological data may be very useful, also for the validation of the risk estimates. In fact, outbreak data have already been incorporated in the risk assessments on Listeria monocytogenes and Salmonella. Principle no. 10 underlines the importance of the use of epidemiological data to improve or to confirm MRAs already performed. This is also a part of the monitoring and review component of MRM as described in the previous lecture. Clearly if new relevant information becomes available, an MRA may be re-evaluated.
Different applications of MRA One pathogen/one food One pathogen/multiple foods Introduction of hazard into a region Comparison of different control measures Comparing risks in more than one domain (e.g. use of chlorine versus risk of water-borne diseases) A product/pathogen/pathway MRA considers one pathogen associated to one food product type. The assessment determines the risk of a specific pathogen in a specific food product, e.g. Salmonella Enteritidis in eggs. A risk-ranking MRA studies one pathogen in a range of food products with a similar trait. The assessment compares the exposure of a population to one pathogen through the various different foods, e.g. Listeria in ready-to-eat retail foods (USA). A geographical MRA estimates the risk of a hazard to being introduced in a new region, as has been studied recently for BSE/TSE outside the countries where the hazard emerged. One of the most useful applications of risk assessment is to compare the effect in terms of relative risk reduction of different control measures. This allows risk managers to get a clearer picture of the impact of specific control measures and this information can be used in conjunction with information on economic and technical feasibility or consumer acceptance to determine the most effective and appropriate control measures to implement. A risk/risk trade-off MRA compares safety risks in one domain (e.g. microbiology) with risks in other domains (e.g. toxicology, occupational). An example is the risk of toxic compounds formed by chlorination of drinking water and the risk of cholera or other water-borne diseases by abstention from chlorination.
Outcomes of MRAs The chance of a person falling ill by consuming a food The estimated number of cases of a certain illness (e.g. per 100 000 per year in a country) due to consumption of a specific food The relative risk posed by a pathogen in different food products or uses Risk estimates for different processing, distribution and consumer use conditions and risk reduction scenarios Several outcomes of MRA are possible; only four are mentioned here. This list is not exhaustive and different outcomes will result depending on what the risk manager requested of the risk assessment in the first place. In the next slides these examples will be illustrated.
VIBRIO VULNIFICUS RISK ASSESSMENT Validated approaches for post-harvest processing of oysters to achieve end point criterion of <3 MPN/g mild heat treatment (50C) freezing with extended frozen storage high hydrostatic pressure In US, three methods have been validated for achieving a criterion of <3 V. vulnificus/g oysters. These are mild heat treatment, freezing with extended frozen storage and high hydrostatic pressure.
Illnesses due to Vibrio parahaemolyticus have been attracting more attention because of the reports from areas such as Alaska and Chile, where illnesses due to this pathogen were largely unknown. FAO/WHO risk assessment for this pathogen has been now completed. Basically, this RA uses the US-FDA model for this organism to predict illnesses in countries like Japan, Australia, Newzealand and Canada, from where data on prevalence of this organism in oysters was available.
HARVEST MODULE OF RA MODEL Regional, seasonal and yearly variation Water temperature Water salinity Total Vp/g Pathogenic Vp/g In the case of V. parahaemolyticus, it is now well understood that only a small proportion of the natural population is pathogenic to man. The clinical strains are capable of producing a thermostable direct hemolysin (TDH) or a TDH-related hemolysin (TRH). It is presumed in this RA that a certain proportion of natural population is pathogenic and the numbers taken are based on US data. The harvest module of the risk assessment considers regional and seasonal variation in levels of total Vp, the effect of water temperature and salinity on the prevalence and levels of total Vp. From this, the level of pathogenic Vp is estimated. HARVEST MODULE OF RA MODEL
POST HARVEST MODULE OF RA MODEL Vp/g at harvest Vp/g at first refrigeration Time to refrigeration Air temperature Vp/g at cool down Vp/g at consumption Cool down time Storage time The postharvest module considers the level of total Vp at harvest, the air temperature, the time taken for refrigeration, the cool down time, storage time and the effect of these parameters on levels of total Vp. From these data, the level of total Vp at the time of consumption is estimated. POST HARVEST MODULE OF RA MODEL
FACTORS USED TO MODEL EXPOSURE Level of pathogenic V. parahaemolyticus in oyster at harvest Effect of postharvest handling and processing Ability of the organism to multiply to an infective dose Number of pathogenic V. parahaemolyticus consumed Based on the harvest and post harvest factors, the ability of Vp to multiply to an infective dose is estimated and the number of pathogenic Vp consumed is derived. Integrating this with the dose response data, the number of illness is predicted.
The model predicts 38 cases in Japan, 27 cases in Australia (Wallis lake alone), 186 cases in Canada (British Columbia).
When the number of predicted illness is compared with actual illness being reported, it is evident that the US-FDA model over predicts cases in other regions. For example, in Australia, only 2 cases have been reported in 18 years from oysters, while the model predicts 27 cases in Wallis lake and 91 cases annually for Australia.. In Canada, 212 cases have been reported in a decade, while the model predicts 186 cases annually
Factors influencing the output in the model Under reporting of illness (20:1 in US model) Levels of pathogenic V. parahaemolyticus ( In US, Pacific coast, 2%-4%; overall, 0.1% to 0.3%) Growth of V. parahaemolyticus in various oyster species (no growth in Sydney rock oyster at 30C for seven days) There are number of reasons for this over prediction. The US FDA model presumes that for every reported case, there are 20 unreported cases. Under reporting to this extent may not occur in other countries. The proportion of pathogenic Vp in US and other countries may vary. Further, the model uses data on growth of Vp in broth and applies this to oysters with a correction factor.Hoever, growth of Vp may not occur to the same extent in different oyster species. For eg, data from Australia suggests that Vp does not grow in Sydney rock oysters even at 30C in 7 days. Very low number of illness reported from Australia may be due to this factor.
The RA also estimated the effect of regulating oysters for raw consumption based on level of Vp at 100/g, 1000/g and 10,000/g. The data shows that 96-99% reduction in illness can be brought about if the level of total Vp in oysters for raw consumption is regulated at 100/g. But this would result in diversion of 16-67% oysters fron the “raw”market
THANK YOU