Microbiological Hazards and Their Control
1.4 Historical Development of Modern Food Safety Management
Microbiological criteria for foods in international trade are addressed in the joint Food and Agriculture Organization of the United Nations/World Health Organization (FAO/WHO) food standards program, as implemented by the Codex Alimentarius Commission (CAC 1997, 2013). The program, established in 1962 (the same year as the establishment of the ICMSF), was the direct result of conflict between national food legislation and the general requirements of the main food markets of the world. Serious non-tariff obstacles to trade were caused by differing national food legislation. At that time, the Commission’s objectives were to develop international food standards, codes of practice and guidelines, anticipating that their general adoption would help to remove and prevent non-tariff barriers to food trade.
Since the 1990s, risk analysis has developed within the Codex Alimentarius Commission (CAC) as the agreed framework for its work. In the process, FAO and WHO convened expert consultations for instance to address the three components of risk analysis (i.e., risk assessment, risk management and risk communication) and to develop specific guidance on the various stages of risk assessment (i.e.
hazard characterization, exposure assessment and risk characterization). Risk analysis is now consid-ered to be an integral part of the decision-making process of Codex. In 1999, the CAC adopted the Principles and Guidelines for the Conduct of Microbiological Risk Assessment (CAC 1999) and sub-sequently adopted the Principles and Guidelines for the Conduct of Microbiological Risk Management (CAC 2007a).
Codex develops and reviews standards and codes on an ongoing basis. Several aspects of food control are covered in Codex standards and Codes of Practice, including composition, labelling, additives, and hygiene. Subsidiary bodies of the Commission, the Codex committees, develop the standards and codes.
Although the period from drafting a standard or code to its adoption at times is rather lengthy, the system has worked well, and many robust international food standards and codes of practice have been estab-lished. The Codex Committee on Food Hygiene (CCFH) has the major responsibility for all provisions on food hygiene in Codex documents, including microbiological criteria and codes of hygienic practice (effectively, good hygienic practices (GHPs)). The CCFH needs expert advice in dealing with highly spe-cialized microbiological matters and especially in developing microbiological criteria. Over the 50 years of its existence, such advice has been extensively provided by the ICMSF through its many publications on sampling plans and microbiological criteria, HACCP, the principles for the establishment and applica-tion of microbiological criteria for foods, microbial ecology in foods and many other expertise areas rel-evant for Codex work.
The microbiological safety of food is principally assured by selection of raw materials, control at the source, product design and process control, as well as the application of prerequisite programs and HACCP during production, processing, distribution, storage, sale, preparation, and use. This compre-hensive preventive system offers much more control than relying solely on end-product testing.
Examples of measures that have successfully controlled foodborne hazards are given in Table 1.2.
Microbiological testing is time-consuming, often lacks sensitivity and specificity, and the levels of sampling routinely applied have a low probability of detecting defective lots when the proportion of defective servings within the lot is low (see Chaps. 6 and 7). Recognizing the limitations of end-product testing to ensure microbiological safety at port-of-entry, the ICMSF proposed a system of verification based on the use of prerequisite programs in combination with the HACCP system as a more reliable means of assuring product safety in the modern food industry (ICMSF 1988).
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Much of the information needed in HACCP to judge whether microorganisms grow, survive, or die during food processing, distribution, and use is contained in the scientific literature, but this informa-tion is not organized in a way that is convenient for those in the food industry needing to use that information. Hence, the ICMSF compiled published information that was judged by experts to be reliable in a series of easily used tables (ICMSF 1996). This was a conscious step towards promoting
Table 1.2 Measures That Have Successfully Controlled Foodborne Hazards
Hazard Control measures Other measures
Bacteria B. cereus Time-temperature control during cooking, cooling, and storage, retorting, acidification, low water activity
Brucella Eradication of brucellosis Animal health
Campylobacter (thermophilic)
Raw material selection, avoid cross- contamination, cooking GHP Cronobacter Raw material selection, avoid recontamination, storage and
consumer education
GHP, HACCP C. botulinum
(proteolytic strains)
Retorting, acidification, low water activity HACCP C. botulinum
(non-proteolytic strains)
Cooking, time-temperature control, pH and aw of products HACCP
C. perfringens Time-temperature control during cooking, cooling, and storage HACCP E. coli (pathogenic) Cooking, controlled fermentation and aging, avoid
recontamination
GHP L. monocytogenes Cooking, controlled fermentation and aging, chilled storage,
avoid recontamination
GHP M. bovis Eradication of TB in cattle, pasteurization of milk
Salmonella (non-typhoid)
Cooking, controlled fermentation and aging, avoid recontamination
GHP
S. typhi Personal hygiene
Shigella Cooking, water quality, waste water management, personal hygiene
S. aureus Cooking, controlled fermentation and aging, chilled storage, avoid recontamination
GHP V. cholerae Water quality, waste water management, personal hygiene GHP V. parahaemolyticus Raw material selection, avoid eating raw fish, cooking GHP, HACCP V. vulnificus Avoid certain foods, cooking
Y. enterocolitica Separation of raw from ready-to-eat, extra hygiene at slaughter GHP Viruses Hepatitis A Water quality, personal hygiene, consumer education, cooking Controls at
harvesting Norovirus Water quality, personal hygiene, consumer education, cooking Controls at
harvesting Parasites Trichinella spiralis (at farms) limit access to farms, rodent control, freezing,
cooking control at slaughter for anim als at risk (outdoor farmed pigs, game esp. wild boars), freezing, cooking
Animal health
Toxoplasma gondii Meat: freezing, cooking; vegetables: wash thoroughly Toxigenic
fungi Aspergillus Raw material selection, sorting, dry storage, dehydration GAP, HACCP Fusarium Raw material selection, sorting, dry storage, dehydration GAP, HACCP Penicillium Raw material selection, sorting, dry storage, dehydration GAP, HACCP Seafood
toxins
Ciguatera Controls on harvesting, consumer education GHP
Scombroid poisoning Hygiene, temperature control GHP, HACCP
Shellfish intoxication Controls on harvesting, consumer education GHP 1.4 Historical Development of Modern Food Safety Management
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the newly emerging concept of food safety management systems, based on Codex documents. The ICMSF then recognized that much of the information in ICMSF Book 3 (1980a, b) was out of date and did not consider the newly emerged pathogenic bacteria, such as Listeria monocytogenes and Campylobacter jejuni/coli, or many of the newer processes used in food manufacture. Consequently, the ICMSF updated its reviews of commodities in ICMSF Book 6 (1998b, 2005), but deliberately omitted consideration of sampling plans and microbiological criteria to emphasize that food manage-ment systems were replacing the earlier approach of end-product testing and offered better control of microbiological hazards.
That evolution of management systems continued with the first publication of Book 7 (ICMSF 2002) of which the current book is an updated edition. Book 7 aims to re-emphasize that end-product testing is merely one of several components of that, in concert, help to ensure food safety. Different types of sampling plans are considered, some more intensive than the “attributes plans” traditionally used at ports-of-entry, as they are intended for use when attempting to identify a problem and its source. Since production and processing methods and technical abilities continue to evolve at a rapid pace and new/re-emerging hazards reinforce the need for tailored food safety management of ade-quate stringency, ICMSF updated ICMSF Book 2 part 2 by publishing Book 8 (ICMSF 2011). Book 8 is linked to the commodity specific management considerations and emphasizes the benefits of vari-ous types of testing for food safety management other than end-product testing, such as environmental monitoring, in-line samples, shelf-life evaluation, etc. Over the years, ICMSF published various opin-ion documents and studies regarding modern food safety management, for instance on the use of epidemiologic data to measure the impact of food safety control programs as well as on the relation-ship between microbiological criteria and control measures with the new risk-based risk management metrics (ICMSF 2005; van Schothorst et al. 2009; Zwietering et al. 2010).
During the last 40 years, Codex Alimentarius Commission programs have gradually shifted from providing a basis for national standards to providing the point of reference in standards, guidelines and codes of practice for international trade. Subsidiary bodies of the CAC, the Codex committees, develop the standards and codes. Codex also, as a policy, adopted a sound-science and risk-based way of working in which expert bodies provide the risk assessment information and other pertinent scien-tific insight/data for the risk managers in the subsidiary bodies to make decisions when compiling standards, codes of practice or guidelines. At its 32nd session convened in 1999, CCFH identified 21 combinations of pathogens and commodities of significant public health concern. CCFH prioritized these according to criteria such as the significance of the public health problem, the extent of the problem in relation to geographic distribution and international trade and the availability of data and other information with which to conduct a risk assessment. CCFH suggested that FAO and WHO convene ad hoc expert consultations to provide advice on microbial risk assessment. This resulted in the creation of the Joint FAO/WHO Meetings on Microbiological Risk Assessment (JEMRA) as a key expert body for CCFH. JEMRA works under the auspices of FAO and WHO with the primary role to provide risk assessments and other relevant information to CCFH for consideration when CCFH develops its standards, codes and guidelines.
The charge to JEMRA for conducting risk assessments comes from CCFH in the form of a scoping document, risk profile or set of specific risk manager questions. Since its inception, JEMRA provided scientific advice on a broad range of pathogen and commodity combinations, including “Microbiological hazards associated with fresh produce,” “Viruses in foods,” “Enterohaemorrhagic Escherichia coli (EHEC) in meat and meat products,” “Salmonella in eggs and broiler chickens,” “Listeria monocto-genes in ready-to-eat foods,” “Vibrio spp. in seafoods,” “Campylobacter spp. in broiler chickens,”
“Enterobacter sakazakii and other micro-organisms in powdered infant formula,” and “Foodborne parasites” (FAO/WHO 2015).
Much of the work done by CCFH since 2000 has received JEMRA input, either through their inter-national risk assessments or expert consultations, in addition to input from specialist observer organiza-tions such as ICMSF. The risk-based Codex guidance developed since that time includes: “Principles and Guidelines for the Conduct of Microbiological Risk Management” (CAC 2007a), “Code of Hygienic
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Practice for Eggs and Egg Products” (CAC 2007b), “Guidelines on the Application of General Principles of Food Hygiene to the Control of Listeria monocytogenes in Ready-to-Eat Foods” (CAC 2007c),
“Code of Hygienic Practice for Powdered Formulae for Infants and Young Children” (CAC 2008b),
“Guidelines on the Application of General Principles of Food Hygiene to the Control of Pathogenic Vibrio Species in Seafood” (CAC 2010), “Guidelines for the Control of Campylobacter and Salmonella in Chicken Meat” (CAC 2011), “Guidelines on the Application of General Principles of Food Hygiene to the Control of Viruses in Food” (CAC 2012), “Principles and Guidelines for the Establishment and Application of Microbiological Criteria Related to Foods” (CAC 2013a), “Guidelines for the Control of Taenia saginata in Meat of Domestic Cattle” (CAC 2014) and “Guidelines for the Control of Trichinella spp. in Meat of Suidae” (CAC 2015). As an “international non-governmental observer (INGO)” to CCFH, ICMSF has played an active role in the development of these international standards.