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Defining Incidents Leading to Changes in Food Safety Policy
This session defined incidents leading to changes in food safety policy. Four case studies— vegetable sprouts, meat and poultry hazard analysis and critical control points (HACCP), Escherichia coli O157:H7 and Listeria monocytogenes, and the implementation of the 1996 Food Quality Protection Act—were presented. The purpose was to look at the evolution of knowledge, including lessons learned, and to think about what was done and what could have been done differently.
VEGETABLE SPROUTS
Presented by Robert L. Buchanan, Ph.D.
Senior Scientist, Center for Food Safety and Applied Nutrition
Food and Drug Administration
The microbiological safety of sprouted seeds is a unique problem for the Food and Drug Administration (FDA). It emerged as an issue in 1994 when the National Advisory Committee on Microbiological Criteria for Food—a multi-agency committee that evaluates scientific issues related to the microbiological safety of foods—identified it as a vector for food-borne disease in a white paper on the microbiological safety of fresh produce.
Sprouts represent a distinct problem as the conditions in which the seeds are germinated foster the growth of bacteria. The presence of pathogens on the seeds or seed surfaces during germination, even at extremely low levels, can be amplified by the sprouting process causing an increased health hazard. To date, no technique exists that can completely sterilize the seeds without destroying them.
Despite the risks associated with sprout consumption, shifts in consumer trends towards more healthful lifestyles over the past decade have resulted in increased consumption of raw sprouts and subsequently a dramatic increase in the incidence of outbreaks due to sprouts. These outbreaks continue in the United States, Europe, and other locations throughout the world.
Historically, sprouts have been implicated in a number of food-borne outbreaks since 1973. However, it was not until 1995 that an elevation in the number of food-borne outbreaks raised FDA concerns about the safety of sprouted seeds. At that time, FDA and the Centers for Disease Control and Prevention (CDC) met with the sprout industry to inform them of government
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concerns about recent sprout outbreaks and discuss ways to address the problem. Three years later, in 1998, FDA issued an interim advisory for high-risk persons about the consumption of sprouts and initiated rapid approval of potential interventions. The same year, FDA also issued a nationwide field assignment to determine current sprout industry practices from seed to final product. Also, they held several public meetings on the safety of sprouts to provide a forum for discussion of the current situation, consumer perspectives, agricultural practices, the state of the science, and possible intervention methods.
One of the immediate concerns that FDA had to deal with in combating the problem was that most of the sprout producers were and remain extremely small businesses, around five employees or less. An inherent problem with this is the fundamental lack of available intellectual or fiscal resources to conduct research or to purchase improved technologies to conquer the problem. In addition, few sprout production facilities are actually registered and thus are hard to locate. To overcome these problems, a formal task force was set up through the National Center for Food Safety and Technology, the FDA, and the U.S. Department of Agriculture's Agricultural Research Service to coordinate research and develop a mechanism of pooling money from sprout producers to fund the research necessary to solve the problem.
In 1999, the National Advisory Committee on Microbiological Criteria for Foods, at the request of FDA and CDC, completed a thorough safety evaluation and assessment of the current state of science associated with sprouts. Specific recommendations provided by the committee include:
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Expansion of education programs on the microbiological safety of sprouts for those groups in need of information, ranging from the seed producer to the consumer.
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Increased efforts and more in-depth evaluation on how to limit the potential for contamination at the seed milling stage.
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Multiple treatments of seeds to reduce the levels of pathogenic bacteria prior to sprouting.
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Classification of all sprout production facilities as food processing operations.
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Requirement for testing of sprouts for pathogenic activity with irrigation water prior to harvest.
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Development of technologies appropriate to industry.
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Establishment of an expedited review process to assess the different interventions that have been developed to help seeds or treat sprouts.
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Creation of improved trace-back mechanisms and recalls.
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Development of methods to prevent or retard pathogen growth during germination.
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More comprehensive evaluation of seed characteristics.
This review of the current science associated with sprouts illustrates the general framework that FDA uses to deal with many emerging health problems. First, the agency focused on the primary goal of safeguarding public health. Second, the agency gathered the best science and scientists available to evaluate the problem and identify solutions. Third, FDA responded to the problem by creating solutions appropriate for the level of risk and resources involved. Finally, FDA actively involved stakeholders at all levels, and encouraged innovation.
Currently, FDA continues to resolve the distinct food safety and resource issues of the sprout industry. As surveillance and evaluation of sprout facilities continues, the agency will keep generating alerts to the industry and consumers about emerging risks associated with sprouts, provide guidance on ways to reduce those risks, and maintain involvement with stakeholders on a routine basis in order to foster new ideas and solutions. The FDA recognizes the complexity of
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dealing with food safety hazards and will continue to provide the public with the safest food supply possible through application of science-based solutions to emerging food safety problems.
MEAT AND POULTRY HAZARD ANALYSIS CRITICAL CONTROL POINTS
Presented by Thomas J. Billy
Administrator, Food Safety and Inspection Service
U.S. Department of Agriculture
The Hazard Analysis Critical Control Point (HACCP) approach is a system of preventative process controls that is widely recognized by scientific authorities nationally and internationally and used throughout the food industry to produce products in compliance with health and safety requirements. About five years ago, the U.S. Department of Agriculture (USDA) decided to apply HACCP to meat and poultry products as a result of a major policy change that focused USDA efforts more effectively on risks associated with pathogens. The implementation of the system is expected to be complete in January 2000. Since the establishment of this rule, the incidence of food-borne illness associated with meat and poultry products continues to be monitored and impacts thus far appear favorable.
The need to focus more heavily on pathogenic microorganisms, and to implement preventive approaches such as HACCP, was established and supported by studies conducted over the past 15 years by the National Academy of Sciences, the Government Accounting Office, and the USDA. In 1994, the Council for Agricultural Science and Technology estimated that 6.5 to 33 million cases of food-borne illness and up to 9,000 deaths occur each year because of food-borne illness and related problems. However, public support for change in the food safety system did not truly begin to emerge until the 1993 outbreak of food-borne illness associated with Escherichia coli O157:H7 in undercooked hamburgers. Thus, a comprehensive strategy for change was developed with HACCP and pathogen reduction as the centerpiece.
The pathogen reduction and HACCP rule consists of four mandatory provisions. First, it requires all plants to have standard operating procedures for sanitation. The second provision requires slaughter plants to test carcasses for generic Escherichia coli, an indicator of fecal contamination. Third, all meat and poultry plants must implement HACCP systems as a means of preventing or controlling contamination from pathogens, as well as other hazards. Under HACCP, plants identify and evaluate the hazards that could affect the safety of their products and institute controls necessary to prevent those hazards from occurring or at a minimum, keep them within the acceptable limits. Finally, to make sure HACCP systems are working as intended, the rule mandates performance standards for salmonella at slaughter and grinding plants.
One of the key guiding principles of the rule was the clarification that industry is responsible for producing and marketing products that are safe, unadulterated, and properly packaged and labeled. With industry assuming its proper responsibility, federal agencies can use limited resources more efficiently and effectively. Another key concept was the combination of HACCP and performance standards for pathogen reduction. HACCP has to be combined with objective means of verifying food safety compliance. Up until this time, microbial performance standards for raw products, with the exception of Escherichia coli O157:H7 in ground beef, had not been established. The development of these rules was broadly supported by the public through numerous public meetings soliciting input.
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Although the implementation of HACCP is still underway, preliminary data indicates positive results. Salmonella prevalence in broilers, swine, ground beef, and ground turkey was significantly lower after HACCP implementation than in the baseline studies that were conducted before implementation. Data released this year from the FoodNet Active Surveillance System for food-borne illness show that during 1998, the rate of campylobacter, salmonella, and cryptosporidium infections declined nationwide, and that Salmonella enteritidis infections declined in all states but Oregon.
Concurrent with HACCP and its implementation within meat and poultry slaughter and processing establishments, USDA's broad food safety strategy addresses every step in the food production process, from animals on the farm, to slaughter and processing, and to product distribution and preparation. The USDA is working through the Partnership for Food Safety and Education and the Fight BAC!™ Campaign to ensure that consumers know how to properly prepare, handle, and store foods. Additionally, USDA is implementing many regulatory reform initiatives to convert traditional regulations to performance standards, thus clarifying the roles and responsibilities of industry and allowing them more flexibility to develop and introduce new technologies to improve food safety.
Many lessons have been learned throughout this process. First is the need to base changes on the best science available and then make adjustments as new information becomes available. Second is the importance of making HACCP mandatory for all plants to ensure that consumers receive safe food regardless of the size of the establishment from which it originates. The third lesson learned is the need to implement HACCP in the context of a broad farm-to-table strategy to enable the far-reaching changes that are necessary to effectively reduce the incidence of food-borne illness. Finally, it is important to have public participation in the process to ensure the discovery and application of the best possible scientific solutions available.
HACCP, as part of a broad-based food safety strategy, is working as intended to reduce the incidence of food-borne illness associated with meat and poultry products. Although many scientific gaps continue to exist that prevent the establishment of “pure” public health standards, revisions in the standards will occur, as new data becomes available. For the future, USDA plans to improve efforts to quantitate the public health risks associated with certain pathogens and foods and ensure that ongoing research will provide sufficient and accurate information on which to base regulatory decisions and develop new preventative procedures. To the extent possible, regulators must continue to focus efforts on designing policies and focusing resources on the most immediate and significant public health risks.
ESCHERICHIA COLI O157:H7 AND LISTERIA MONOCYTOGENES
Presented by Michael P. Doyle, Ph.D.
Regents Professor of Food Microbiology and Director of the Center for Food Safety and Quality Enhancement, University of Georgia
Over the past two decades, the Centers for Disease Control and Prevention (CDC), the Food and Drug Administration (FDA), and the U.S. Department of Agriculture (USDA) have been conducting investigative studies to determine the origin and methods of prevention for two food-borne pathogens, Escherichia coli O157:H7 and Listeria monocytogenes. Many technologies have been developed, preventive processes implemented, and lessons learned throughout this process. Following are case studies on these pathogens, with brief overviews of what the
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agencies discovered, how they responded to these findings, and ideas about what should be done in the future to prevent and reduce the incidence of these and other food-borne illnesses.
Escherichia coli O157:H7
The human pathogen Escherichia coli O157:H7 emerged as threat in 1982 when it was identified by CDC in two outbreaks (see Table 3-1 for history of significant outbreaks) associated with ground beef sandwiches. In a series of similar outbreaks over the next 10 years, CDC was able to determine several characteristics about the organism, most importantly that cattle were a principal source or host carrier and that contaminated cattle manure was likely the source of many infections. Studies also revealed that Escherichia coli O157:H7 caused hemorrhagic colitis, had no unusual heat tolerance and could be controlled by proper cooking temperatures, had a very unusual acid tolerance, and could survive fermentation of meat.
However, it was not until 1993, after a serious outbreak involving more than 700 illnesses and four deaths from eating undercooked hamburgers, that FDA changed the Food Code, which previously recommended cooking temperatures for ground beef that were insufficient to kill large populations of Escherichia coli O157:H7. The new Food Code criteria indicated that ground beef patties be cooked to an internal temperature of 155 degrees for 15 seconds. In addition, USDA required that safe handling labels be used for raw meat and poultry products. A year later, USDA declared Escherichia coli O157:H7 an adulterant in raw ground beef, established a zero tolerance, and initiated end product testing for raw ground beef. However, food-borne illness continued to increase and it was clear that further action was necessary.
Consequently, between 1995 and 1997, USDA published a rule on pathogen reduction, FDA approved irradiation of red meat, and CDC introduced the FoodNet system, an active surveillance system that monitors the occurrence of illnesses associated with selected food-borne pathogens. Additionally, CDC, USDA, and the food industry initiated the Fight BAC!™ campaign, a program which educates consumers about proper food handling techniques in the home. In 1998, USDA published a document recommending that a thermometer be used to measure the temperature of cooked ground beef patties. Currently, regulatory agency efforts to reduce food-borne illness due to Escherichia coli O157:H7 continue, with USDA planning to implement HACCP in all meat processing plants by the year 2000.
Listeria monocytogenes
In the mid-1980s, CDC published a case-control study on sporadic cases of listeriosis which revealed that about 20 percent of the cases were attributed to consumption of hot dogs or undercooked chicken (see Table 3-2 for history of significant outbreaks). In addition, inoculation studies revealed that Listeria monocytogenes can multiply rapidly in certain ready-to-eat processed meat products at refrigeration temperatures and that growth is prevented or delayed in highly acidic foods such as summer sausage. As a result, USDA initiated an end-product testing program for ready-to-eat meats. This program was shown to be ineffective as a case of listeriosis
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|
Year |
Noteworthy Events |
Action Taken |
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1982 |
CDC conducts investigative studies to identify E. coli O157:H7 and its association with two outbreaks from ground beef sandwiches. |
CDC identifies E. coli O157:H7 as a human pathogen and determines that it causes haemorrhagic colitis. |
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1984 |
Studies indicate that E. coli O157:H7 has no unique or unusual heat tolerance. |
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1985 |
Several women handling manure-encrusted potatoes become ill. |
Outbreak points to manure as a possible source of the pathogen. |
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1986 |
CDC investigates a farm identified as source of E. coli O157:H7 outbreak associated with unpasteurized milk. |
CDC isolates E. coli O157:H7 in cattle, the first evidence that cattle can be a reservoir or carrier of this organism. |
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1992 |
Studies conducted to evaluate fate of E. coli O157:H7 in raw fermented salami. |
Determined that organism has some very unusual acid tolerances and could survive sausage-making process. |
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1993 |
23 cases of E. coli O157:H7 infection associated with dry, cured salami in California. |
USDA requires that processing techniques used in salami production implement critical control points. No outbreaks have occurred since. |
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Outbreak involving more than 700 cases, four deaths associated with undercooked ground beef served by a fast-food restaurant chain on the West Coast. |
Determined that patties cooked less than 140° F were the source. FDA responds by changing Food Code to require patties are cooked to an internal temperature of 155° F for 15 seconds. |
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USDA issues a rule requiring that safe handling labels be used for raw meat and poultry products. |
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1994 |
USDA declares that E. coli O157:H7 is an adulterant in raw ground beef and establishes a zero tolerance. |
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USDA initiates end-product testing for raw ground beef. |
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1995 |
CDC introduces FoodNet system, an active surveillance system that enables monitoring of many of the illnesses attributed to food-borne pathogens. |
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1996 |
USDA publishes rule on pathogen reduction that includes the HACCP program. |
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FDA approves irradiation of red meat. |
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1997 |
CDC, FDA, USDA, and food industry initiate the Fight Bac Campaign to educate consumers on proper food handling practices. |
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1998 |
USDA requires implementation of HACCP for large meat processing plants. |
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USDA publishes a key facts document recommending that a thermometer be used to measure the temperature of cooked patties. |
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CDC FoodNet results reveal that E. coli O157:H7 infections increased in 1998, slightly above 1996 levels. |
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1999 |
USDA implements HACCP for small meat processing plants. |
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Year |
Noteworthy Events |
Action Taken |
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1986–1987 |
CDC publishes case-control study results revealing that about 20 percent of listeriosis cases were attrib-uted to consumption of hot dogs or undercooked chicken. |
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1987 |
USDA initiates finished product testing program for ready-to-eat meats. |
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1987–1989 |
266 cases of illness in U.K. out-break associated with pate. |
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1988 |
Listeriosis case in woman who had eaten a turkey frank. |
Continual evidence that frankfurters may be a source of L. monocytogenes. Therefore, USDA expands its finished product testing to more products and increases sample size in testing from 1 to 25 grams of food. |
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1989–1999 |
During this time period, USDA tests 24,500 samples with positive rate of 3.1 percent of L. monocytogenes. Results of extensive testing indicate that certain foods, such as bratwurst and frankfurters, enable the growth of this organism at refrigeration temperatures. |
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1992 |
Outbreaks in Europe associated with meat, pate, and jellied pork tongue. |
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1998 |
101 cases of listeriosis associated with frankfurters and possibly some deli meat. |
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1999 |
USDA advises meat processors to reassess HACCP plans and critical control points to identify the levels of L. moncytogenes on source materials, the validation of processes that kill Listeria, steps to control environmental contamination, growth characteristics of Listeria in products and also finished product. USDA also provided guidance to meat processors recommending environmental and end-product testing and increased educational efforts targeted at high-risk consumers. |
expanded its finished product testing to more products and increased the sample size of the foods from 1 gram to 25 grams. By May 1999, USDA had tested 24,500 samples of product with a positive contamination rate of 3.1 percent.
In 1998, a major outbreak of listeriosis occurred involving 101 cases associated with frankfurters and possibly deli meat. As a consequence, USDA advised meat processors to reassess their HACCP plans and critical control points to include measurement of Listeria monocytogenes levels on source materials, further classification of growth characteristics of the pathogen, and re-evaluation of processes thought to kill Listeria. USDA also provided guidance to meat processors, recommending both environmental contamination and end-product testing as well as increased educational efforts targeted at high-risk consumers.
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Lessons Learned
Listeria monocytogenes and Escherichia coli O157:H7 are dangerous food-borne organisms requiring the institution of many preventive efforts. Many lessons have been learned and will continue to be discovered from trying to control such pathogens. Many opportunities for improvement emerged upon evaluation of the regulatory actions taken to reduce the incidence of food-borne illness in these two cases. These include: addressing the limitations of end-product testing, defining critical control points that have the greatest impact on product safety, applying the majority of inspection resources at these critical control points, increasing safety efforts at processing facilities where critical control points are not well-defined, and identifying more effective ways to educate consumers.
Although many of the preventive efforts that were implemented previously are beginning to appear effective, there are still many opportunities to improve the current state of food safety. These include: introducing HACCP from the farm to the table, developing and implementing effective and practical critical control points for on-farm use by producers, and overcoming the major limitations with end product testing. End product testing is a particular problem because if entire lots of product are not retained by food producers, a major portion of the contaminated lot will have been consumed by the time the product is recalled. Furthermore, because of the sporadic distribution and low level prevalence and concentration of pathogens in these foods, end-product testing may frequently not detect contaminated product. However, advancements in technology and science will facilitate further improvements in these areas.
Items to consider for the future include: defining the level of danger at which corrective federal action should be initiated, identifying and developing the roles and responsibilities of industry in solving the pathogen problem, and finding out what treatments or practices are useful for food processors and food service establishments to substantially reduce the risk of pathogen contamination of foods. Most importantly, agencies need to determine the level of responsibility consumers are willing to take in adopting safe food handling practices. It is only through the implementation of preventive approaches from farm-to-table that food safety hazards will be eliminated.
1996 FOOD QUALITY PROTECTION ACT
Presented by Joyce A. Nettleton, Ph.D.
Director of Science Communications, Institute of Food Technologists
A brief review of the statutory history indicates that the first time health was mentioned in relationship to food safety occurred in the 1954 Miller amendment to the Federal Food Drug and Cosmetic Act (FDCA). This amendment required manufacturers to submit health and safety data prior to the registration of a pesticide used on raw agricultural commodities. In 1958, the Food Additives Act was passed to regulate pesticides in processed foods. In 1993, the National Academy of Sciences (NAS) published its report, Pesticides in the Diets of Infants and Children, a significant event leading up to the Food Quality Protection Act. In this report it was pointed out that children differ from adults quantitatively and qualitatively in their toxicologic responses to synthetic chemicals and exposure to pesticides. It was also suggested that estimates of exposure to chemical pesticides should include both dietary and nondietary exposures and that tolerance-setting for agricultural chemicals should consider both health and agricultural factors.
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In 1996, Congress passed the Food Quality Protection Act (FQPA), which amended the FDCA and the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA). The FQPA made major changes in the regulation of pesticides. FQPA adopted the FIFRA definition of a pesticide chemical, which is anything that will prevent, destroy, repel, or mitigate any pest. It mandated that tolerances for pesticide residues would be established on the basis of safety, defined as a reasonable certainty that no harm will result from aggregate exposure to a pesticide by not only adults. FQPA also provided for the Environmental Protection Agency (EPA) to add an additional ten-fold safety factor to protect infants and children. Further, it required the screening of agricultural pesticides for effects on endocrine disruption.
FQPA also extended the concept of pesticides to include both raw agricultural commodities and processed foods. It restricted the consideration of the benefits of using pesticides in the process used to establish pesticide tolerances. Tolerances, the legal safe limit for pesticide residues, would be established on the basis of safety and safety meant reasonable certainty that no harm will result from exposure to the pesticide chemical residue, including all anticipated dietary exposures and all other exposures for which there is reliable information. Aggregate exposure to pesticide residues includes food, water, and residential use.
The FQPA further mandated the review of the registration of all pesticides over the next 15 years and allowed EPA to require new data at any time in the consideration of the registration of any given pesticides. EPA must also review the tolerances for all of the more than 9,000 registered pesticides within 10 years, with a third of these reviews coming in the first 3 years and two-thirds of the total completed in 6 years.
So great was the concern from the agricultural community about the potential loss of an array of agricultural chemicals upon which the agricultural system has become highly dependent, that pressure was brought to bear on the government to ensure that there would be adequate transition time. In April 1998, a memorandum from Vice President Gore to EPA Administrator Browner and U.S. Department of Agriculture (USDA) Secretary Glickman, requested EPA to consult and work with USDA to ensure that the implementation of FQPA conformed with sound science. It allowed for transition time and integration with evolving integrated pest management techniques. It mandated a transparent decision-making process and it requested that both USDA and EPA consult with the public and other stakeholder groups in the implementation of FQPA.
Many questions have been raised because the FQPA is fairly new and implementation is just beginning. The FQPA will stimulate the accumulation of large amounts of data for the reregistration of pesticides, the registration of new pesticides, and the reassessment of tolerances. Stiffer data requirements for registration and the cancellation of existing registrations will stimulate the search for more environmentally friendly, less risky pesticides. Revisions to the application rates of pesticides, for example, are another approach that could markedly reduce exposure to and levels of residue. Developments in agricultural biotechnology will allow plant breeders to develop pest resistant varieties that express their pest resistant properties for only a short time or under limited circumstances. The encouragement of biocontrol measures and agricultural biotechnology holds immense promise to further reduce dependence on synthetic chemical pesticides. The FQPA is likely to accelerate research and development.
The opportunities for science to inform the legislative and policy environment and the whole spectrum of food production from farm-to-table are enormous. Science can contribute importantly to the implementation of policy, not just FQPA, but other food safety policies as well. Science can help develop better models for estimating exposures to and risks from chemical pesticides, develop alternative use patterns for existing and emerging chemical
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pesticides, and provide data on the environmental fate of pesticides and hazards associated with breakdown products of agricultural chemicals. Science is already providing impetus for the development of safer pesticides, with lower risks to health and the environment. Finally, science is providing umbrella opportunities for greater harmonization of food safety policy among regulatory agencies.
