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Institute of Medicine (US) Forum on Microbial Threats. Addressing Foodborne Threats to Health: Policies, Practices, and Global Coordination: Workshop Summary. Washington (DC): National Academies Press (US); 2006.

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Addressing Foodborne Threats to Health: Policies, Practices, and Global Coordination: Workshop Summary.

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Summary and Assessment


In December 2004, at a press conference called to announce his departure as Secretary of the Department of Health and Human Services (HHS), Tommy Thompson raised both concern and controversy when he remarked that he could not understand why the terrorists had not yet attacked our food supply “because it is so easy to do” (Branigin et al., 2004). Although to date the United States has been spared such a disaster, the many documented examples of unintentional outbreaks of foodborne disease—some of which have sickened hundreds of thousands of people, and killed hundreds—provide a grim basis for estimating the impact of deliberate food adulteration (Sobel, 2005). Due to the wide variety of potential chemical and biological agents that could be introduced at many vulnerable points along the food supply continuum, contaminating food is considered an especially simple, yet effective, means to threaten large populations.

Intentional adulteration is not the only reason to be concerned about the safety of the U.S. food supply, however. Accidental foodborne illness already causes an estimated 76 million illnesses, 325,000 hospitalizations, and 5,200 deaths in the United States each year (Mead et al., 1999). The U.S. Department of Agriculture (USDA) estimates costs associated with medical expenses and losses in productivity due to missed work and premature deaths from five major types of food-borne illnesses (Campylobacter, E. coli O157:H7, Shiga toxin-producing strains of E. coli, Listeria monocytogenes, and Salmonella) at $6.9 billion annually (Vogt, 2005). This figure likely represents the tip of the iceberg, as it does not account for the broad spectrum of foodborne illnesses or for their wide-ranging repercussions for consumers, government, and the food industry.

Although specific preventions cannot be mounted against the many possibilities for foodborne bioterrorism, strategic preparations to reduce vulnerability to foodborne illness—and to anticipate and address the medical, social, and economic consequences—could mitigate foodborne threats to health, whatever their origin. To explore the nature and extent of such threats, possibilities for reducing their impact, and obstacles to this goal, the Forum on Microbial Threats of the Institute of Medicine (IOM) convened the workshop Foodborne Threats to Health: The Policies and Practice of Surveillance, Prevention, Outbreak Investigations, and International Coordination on October 25 and 26, 2005. Workshop participants discussed the threat spectrum and burden of disease associated with foodborne illness and the role that increasing globalization of food production and distribution plays in the transmission of foodborne disease. Participants also reviewed existing research, policies, and practices concerning foodborne threats in order to identify unmet needs, challenges, and opportunities for improving food safety systems, surveillance, and emergency response.


This workshop summary report is prepared for the Forum membership in the name of the editors as a collection of individually authored papers and commentary. Sections of the workshop summary not specifically attributed to an individual reflect the views of the editors and not those of the Forum on Microbial Threats, its sponsors, or the IOM. The contents of the unattributed sections are based on the presentations and discussions that took place during the workshop.

The workshop summary is organized within chapters as a topic-by-topic description of the presentations and discussions. Its purpose is to present lessons from relevant experience, delineate a range of pivotal issues and their respective problems, and put forth some potential responses as described by the workshop participants.

Although this workshop summary provides an account of the individual presentations, it also reflects an important aspect of the Forum philosophy. The workshop functions as a dialogue among representatives from different sectors and presents their beliefs on which areas may merit further attention. However, the reader should be aware that the material presented here expresses the views and opinions of the individuals participating in the workshop and not the deliberations of a formally constituted IOM study committee. These proceedings summarize only what participants stated in the workshop and are not intended to be an exhaustive exploration of the subject matter or a representation of consensus evaluation.


Ensuring the safety of food is a long-standing and critical objective of public health. The estimate that millions of Americans—whose food is among the safest on earth—are sickened by tainted food each year attests to the need to further safeguard our food supply, while the mounting threat of terrorism lends this mission a particular urgency. As a first step in assessing the spectrum of threats to the U.S. food supply, speakers and participants in the workshop reviewed a broad range of foodborne pathogens and poisons that are known to endanger human health. They also noted the dangers inherent in nonhuman pathogens that can harm crops or livestock, and along with them, the economic vitality of communities as small as farms and as large as nations.1

According to the Centers for Disease Control and Prevention (CDC), more than 250 different foodborne illnesses (including both infections and poisonings) have been described to date (CDC, 2005a). The list of major foodborne pathogens expands each year; the most recent update, presented by speaker Robert Tauxe, names 20 bacterial species, half of which have been identified within the past three decades, along with five viruses, five parasites, and prions, nearly all of which were identified after 1975 (see Chapter 3). Many of these pathogens, including most of those recently identified, have animal reservoirs—a factor that has likely contributed to their emergence, as with other zoonoses (infections or diseases transmitted from vertebrate animals to humans). These include avian influenza, severe acute respiratory syndrome (SARS), and “mad cow disease” (bovine spongiform encephalopathy or BSE; see subsequent discussion and Chapter 6).

Presenter Lonnie King observed that conditions favoring the transmission of zoonoses are at an all-time high, as are the scope, scale, and implications of such outbreaks. These include diseases that, while limited to livestock, have potentially devastating economic consequences (e.g., foot-and-mouth disease) as well as emerging infections that threaten humans (NRC, 2005). The direct and indirect economic impacts associated with the 2001 outbreak of foot-and-mouth disease among cattle and sheep in the United Kingdom has been estimated to be $25 billion, a figure that includes loss of tourism revenues, compensation to affected farmers, trade impacts, and downstream effects on associated agribusiness (e.g., slaughterhouses, auctions, transport companies, and food processors) and consumer prices (Breeze, 2004; Chalk, 2005). Crops are also currently under siege by exotic, emergent, and pesticide-resistant pathogens; workshop participants noted in passing that economically important crops represent targets for bioterrorism (NRC, 2002). Although plant pathogens do not pose a significant public health threat, their presence could trigger trade embargoes with severe consequences, particularly for those rural communities that depend on income from export of the affected crops (Cook, 2005).

Although discussions of food safety often focus on infectious disease threats, several workshop participants remarked that harmful chemicals represent an even greater risk to the food supply than those posed by biologic agents, given the huge number of potential chemical adulterants and the difficulty of detecting them in foods and/or eliminating them from the food chain (see Osterholm in Chapter 1 and Busta in Chapter 7). In Michigan, for example, the contamination of 200 pounds of ground beef with insecticide containing nicotine by a disgruntled supermarket employee sickened 111 people, including 40 children, in 2003 (CDC, 2003a). In 1985, approximately 1,000 people were poisoned by eating water-melon tainted with the highly toxic pesticide aldicarb, which was not registered in the United States for use on melons, and which had been linked to several prior episodes of food poisoning resulting from its intentional or inadvertent misapplication (CDC, 1986). Although such deliberate or incidental acts of adulteration are thought to account for a minute percentage of foodborne illness, they illustrate the potential for future catastrophe.


Food production and distribution for the developed world takes place across vast and intricate global networks. In the United States, thousands of different food items—many of them produced in other countries—pass quickly through an elaborate system of processors, distributors, and purveyors, to a public with increasingly broad tastes and immense purchasing power. This “farm-to-fork” continuum is an extraordinarily complicated industrial infrastructure. However, the system that has brought us increasingly cheaper food in greater variety carries increased risks associated with foodborne illness, whether accidental, incidental, or intentional (see Osterholm in Chapter 1).

Over the past decade, the annual output of the U.S. agricultural sector has consistently surpassed $1 trillion (USDA, 2006a). Agriculture accounts for 13 percent of the U.S. gross domestic product and employs 18 percent of the nation’s workforce (USDA, 2005a). During fiscal year 2005, the nation’s agricultural exports, at $62.4 billion, exceeded agricultural imports by $4.7 billion (USDA, 2006b). The United States is also a major importer of food, bringing in more than 75 percent of its fresh fruits and vegetables and more than 60 percent of its seafood (Hedberg et al., 1994; Khan et al., 2001). Between 2000 and 2004, the United States imported significantly greater amounts of nearly every class of commodity (Henry, 2005; see Henry in Chapter 1).

Currently more than 130,000 foreign food facilities—a number that closely approximates the number of domestic facilities—have registered with the Food and Drug Administration (FDA) as required under the Public Health Security and Bioterrorism Preparedness and Response Act of 2002 (FDA, 2002). It cannot be assumed that domestically produced food is more “wholesome” or less vulnerable to adulteration than imported products; sanitary standards at some U.S. food production facilities may be vastly inferior to others in foreign sites (see Osterholm in Chapter 1).

Most foreign and domestic foods are transported across the country from central facilities. Meat served in American homes has typically traveled 1,000 miles from its farm of origin to the ultimate point of consumption (Chalk, 2004). If that meat happens to be a take-out hamburger, it could contain as many as 300 different ingredients, each with a distinct supply chain leading from a farm of origin to the restaurant where it was prepared (Osterholm, 2005). Food distribution systems permit the rapid delivery of perishable goods, provide just-in-time restocking of nonperishable items, and take advantage of economies of scale (Sobel, 2005). These strategies, along with improvements in production and processing, have contributed to a substantial decline in food expenditures as a percentage of disposable personal income in the United States, from more than 13.5 percent in the mid-1970s to near 10 percent by 1998. Dr. Craig W. Henry (see Chapter 1) noted that a similar trend on a global scale appears in data from the USDA’s Economic Research Service, which indicates that the average percentage of income spent on major food groups had declined by approximately 3 percent between 1997 and 2003 in all but the wealthiest countries (USDA, 2005b). The efficient and widespread distribution of food permits the equally rapid transmission and propagation of foodborne illness. This situation can delay recognition of an outbreak and impede identification of adulterated food, as illustrated in recent case studies of foodborne outbreaks discussed below and detailed in Chapter 3. Even more challenging, the U.S. food supply offers countless opportunities for intentional harm (Osterholm, 2005):

  • Prefarm inputs include cattle feed, agricultural chemicals such as fertilizers and pesticides, and water supplied for irrigation.
  • Farming practices include intensive animal production (zoonoses), the raising of animals and crops in close proximity (fecal contamination of plant products), and corporate farming (products are widely distributed).
  • Transportation is critical to maintaining the U.S. food supply.
  • Processing encompasses the preparation of myriad foods in thousands of locations around the globe, any of which represent potential targets for sabotage.
  • Distribution occurs with such rapidity and over such great distances that it resembles aerosol release. In the case of some products, a terrorist could assume overnight delivery of an adulterant to many thousands, if not millions, of people—a product that would be difficult to detect and remove from the market before considerable harm was done.
  • Retail includes both groceries and prepared food: a huge and complex system of outlets for an equally vast array of foods, provided by a largely low-paid and transient workforce. This is particularly the case in restaurants, which account for nearly half of all U.S. food expenditures.

As income levels in developing countries continue to rise, it is expected that global food consumption patterns—and, concomitantly, food production and distribution methods—increasingly will resemble those of developed countries (Regmi et al., 2001). Worldwide demand for high-quality animal protein continues to grow rapidly. A recent study estimates that global consumption of meat will increase by over 50 percent between 1997 and 2020 and will nearly double in developing countries during the same period. Almost all of the increased demand is expected to be met through expanded production of poultry, pork, and beef (Rosegrant et al., 2001). The globalization of the world’s food supply will expose a greater proportion of its people to emerging and reemerging foodborne disease and contamination (Buzby, 2001). Meanwhile, in developed countries such as the United States, many consumers seek food that is not only appealing to the palate, but that is also safe, convenient, and produced or marketed in accord with their values (see Henry in Chapter 1). Although consumer demand may, over time, encourage the food industry to increase their investment in ensuring food safety, a number of workshop participants expressed the view that additional measures must be taken, and taken quickly, to address key vulnerabilities in the U.S. food supply.


The globalized food supply presents considerable difficulties to agencies charged with ensuring food safety. Conference presentations and discussions revealed opportunities and barriers to meeting these challenges in the United States, as well as at the international level, through the efforts of the World Health Organization (WHO) and other non-governmental organizations.

The U.S. Food Safety System

At least 15 federal agencies are responsible for implementing the more than 30 laws that direct food inspection in the United States (GAO, 2004, 2005a). As a reflection of their respective budgets, four agencies—USDA, FDA, Environmental Protection Agency (EPA), and the National Marine Fisheries Service (NMFS)—play central roles in overseeing the food safety “system.” In 2003, these agencies combined spent about $1.7 billion and employed nearly 15,000 people (full-time equivalents) to inspect food manufacturing, processing, and storage facilities; conduct research and develop methods to reduce the prevalence of foodborne pathogens; assess risks posed by various food contaminants; and educate industry and the public on ways to mitigate or minimize foodborne illnesses (GAO, 2005b).

To coordinate food safety activities across jurisdictional boundaries, federal agencies have entered into more than 70 agreements that specify how these disparate agencies carry out their missions in a more or less “coordinated” fashion (GAO, 2005a, 2005b). In many instances, however, the agencies either do not fully implement or do not enforce these agreements, resulting in considerable waste, confusion, and inefficiencies. In recent years, the Government Accountability Office (GAO, formerly the General Accounting Office) has documented many such problems resulting from the fragmented, balkanized nature of the federal food safety system and has recommended the streamlining of relevant statutes, as well as consolidation of all food safety activities into a single agency with a single mission (GAO, 2004, 2005b). Indeed, over the past six decades, more than 21 similar proposals have advocated a reorganization of the federal food safety system (Vogt, 1998).

Such calls for reform were amplified by a 1998 report of the Institute of Medicine and National Research Council (NRC) that recommended the integration of food safety oversight into a single, independent agency (IOM/NRC, 1998). John Bailar, the chairman of the study committee that prepared this report, discussed the committee’s findings at the workshop (see Chapter 2). The committee determined that no federal agency holds food safety as its primary mission and that this absence of focused leadership—which extends to the state and local level—results in inadequate surveillance, inconsistent and archaic regulations, insufficient resources, limited consumer knowledge, and poor adherence to even the minimum food safety standards now in place (Bailar, 2005).

Bailar noted that a similar set of circumstances led to the creation of the Environmental Protection Agency in 1970. Yet, despite the weight of the evidence for the food safety report’s findings and the clarity of its recommendations, little progress toward implementation has been made in the seven years since its publication. Speaking from personal experience, Bailar attributed this lack of action to three possible factors: bureaucratic inertia, turf battles among agencies currently responsible for ensuring food safety, and resistance to change of any sort by the food industry. Workshop participants noted that the reorganization of food safety at the federal level could also benefit state and local food safety systems, many of which mirror the disorganization of federal jurisdictions. In discussion, some participants considered this a critical connection, because state and local officials perform many activities essential to food safety, such as the inspection of food-processing plants and surveillance for foodborne disease.

At the time of the workshop, proposals for reforming the federal food safety system were under consideration by legislators in both the House and Senate; each would create a single independent U.S. food safety agency to oversee inspections, enforcement, and standard setting (DeLauro, 2005). The Senate bill, known as the Safe Food Act of 2005 (U.S. Senate, 2005), takes into account many of the aforementioned IOM/NRC report’s recommendations (Smith-DeWaal, 2005), as well as recent GAO findings describing reforms undertaken by other wealthy countries (Canada, Denmark, Ireland, Germany, the Netherlands, New Zealand, and the United Kingdom) that consolidated their food safety activities except foodborne disease surveillance (Schlundt, 2005) into a single agency (GAO, 2005a). Although these changes have proved both challenging and costly, government officials and other stakeholders in these countries report that reorganization has made their food safety systems more effective or efficient (GAO, 2005a).

Global Approaches to Ensuring Food Safety

Even the most sophisticated food safety programs cannot eliminate all risk of foodborne illness. The global nature of much of the world’s food supply and the reality that safety cannot be “tested into” food necessitate the establishment of a coherent, risk-based, international system for preventing foodborne disease, according to speaker Jørgen Schlundt (see Chapter 2), director of the food safety program of the WHO. Schlundt maintained that such an international foodborne disease prevention system should focus on identifying vulnerabilities in the food chain and the most effective preventive measures that can be taken to address them.

Establishing food safety systems in resource-poor countries will be challenging, as many of them lack the basic infrastructure upon which food safety depends. Yet the achievement of this goal is increasingly urgent, not only because food exports from developing countries are on the increase, but also to address the recent introduction into developing countries of debilitating foodborne pathogens, such as Salmonella and Campylobacter, from the better-prepared industrialized world (Schlundt, 2005). WHO, in collaboration with the Food and Agriculture Organization (FAO) of the United Nations, has responded to this need by conducting risk assessments of foodborne illness and supporting training and capacity building for countries attempting to establish and meet risk-based standards for food safety (WHO, 2002a). This effort aims to help developing countries create efficient and appropriate food safety systems from the ground up that incorporate elements of successful systems in developed countries, Schlundt said.

WHO/FAO recommendations on the necessary elements of an effective national food safety program also served as the basis for a set of food safety guidelines developed for consumer organizations around the world by the Center for Science in the Public Interest (CSPI, 2006). As described at the workshop by CSPI food safety director Caroline Smith DeWaal, the recently published guidelines focus on eight essential elements for national food safety programs:

  1. Food laws and regulations
  2. Foodborne disease surveillance and investigation systems
  3. Food control management
  4. Inspection services
  5. Recall and tracking systems
  6. Food monitoring laboratories
  7. Information, education, communication, and training
  8. Funding and affordability of the national food safety program

Timely communication is critical to protecting the food supply, particularly at the international level. The International Food Safety Authorities Network (INFOSAN), established in 2004 by WHO and FAO, links officials responsible for food safety in 144 nations (INFOSAN, 2006). These officials receive food safety information from the network and disseminate it in their countries; they also alert the network to incidents of foodborne illness of international significance. When such emergencies occur, the WHO Global Outbreak Alert and Response Network (GOARN), which played a central role in the global response to SARS, is poised to respond (IOM, 2004; Schlundt, 2005). Under the recently revised international health regulations, due to take effect in 2007, countries with confirmed outbreaks of infectious disease that pose a threat beyond their borders are required to alert WHO. Governments of affected countries are responsible for determining whether an outbreak constitutes an international disease emergency, and in the case that such an emergency exists, for informing WHO once the problem ceases to be a threat. However, Schlundt noted, international health regulations grant WHO the right to overrule a national government that is not sharing information about a disease outbreak with any country that could potentially be affected by such an emergency.


Over the past two decades, cases of accidental foodborne disease reported to the CDC have outstripped incidents of intentional food adulteration by approximately 10,000 to 1, according to speaker Robert Tauxe (see Chapter 3). Although the rarity of criminal food tampering may be reassuring, this statistic also highlights the regularity—and to a certain extent the “ordinariness” of accidental foodborne illness, even in a wealthy nation. In addition to morbidity and mortality, the burden of foodborne illness borne by the industrialized world includes medical expenses, losses in productivity due to missed work and premature deaths, and trade embargoes against affected products as well as reduced profits. Consumer anxiety sparked by the contamination of a specific food brand or item can negatively affect entire agricultural sectors or industries (Tauxe, 2005). In developing countries, where food safety presents far greater challenges, foodborne disease is a fact of daily life and a significant cause of death due to diarrheal illness (WHO, 2002a).

The true incidence of food contamination in the United States is unknown. Epidemiologists believe that many affected people do not seek medical attention; moreover, foodborne disease is difficult to diagnose. “Unknown agents” account for 81 percent of foodborne illnesses and hospitalizations in the United States and 64 percent of such deaths (Mead et al., 1999). Detecting a foodborne outbreak is even more difficult, as illustrated by the single largest salmonella outbreak in the United States, which occurred in 1994 (Osterholm, 2005; see Osterholm in Chapter 1). In that episode, approximately 224,000 people across a large area of the United States contracted salmonellosis from ice cream that became contaminated following pasteurization (Hennessy et al., 1996; Sobel et al., 2002). Because only about 1.5 percent of the thousands of people presumed to have been infected actually reported symptoms, epidemiological analysis was necessary to determine the source of the pathogen. The following case studies presented at the workshop illustrated additional challenges inherent in the recognition and investigation of food-associated outbreaks of infectious disease.

Cyclosporiasis from Imported Produce

Speaker Barbara Herwaldt recalled that little was known about the biology or epidemiology of the coccidian parasite Cyclospora cayetanensis when in the mid-1990s, large, multistate outbreaks of gastroenteritis began to occur (see Chapter 3). Cyclospora is endemic in many tropical and subtropical countries and had previously been identified in persons with AIDS and in Western travelers to developing countries (Herwaldt, 2000, 2005). Although effective treatment for cyclosporiasis is available, most laboratories lack the tools and expertise necessary for accurate diagnosis of this foodborne parasite. Herwaldt and colleagues traced the initial U.S. outbreaks of cyclosporiasis to Guatemalan raspberries, a “stealth” food often consumed as a garnish, but rarely listed on menus. Some food safety experts initially questioned whether these outbreaks could have been caused by an obscure organism borne by a mere garnish, but Herwaldt and coworkers’ conclusion was confirmed when additional outbreaks occurred much as they had predicted.

Several types of fresh produce, including mesclun (a mixture of young salad greens) and basil, have been vehicles for cyclosporiasis outbreaks. Dean Bodager described an ongoing investigation of an outbreak that occurred in Florida in early 2005 (see Chapter 3). As is typical in many foodborne outbreaks, a large number of sporadic case clusters occurred over an extended period of time (four months, in this case). The investigation, triggered by reports of an unusually large number of infections detected by a private lab, involved health departments in Florida’s 67 counties and in 28 other affected states, the three different state agencies that regulate food in Florida, and two federal agencies—the CDC, and the FDA. The investigators now believe that imported basil, served in an upscale restaurant, harbored the parasite. Such investigations constitute the best method to identify foodborne pathogens and their sources, discover how they entered the food supply, and prevent similar outbreaks from occurring in the future, Herwaldt noted.

The development of preventive measures will require a better understanding of an organism Herwaldt (2005) described as “a mystery, wrapped in an enigma, served on a bed of imported produce.” In the meantime, public health authorities must consider the potential of seemingly unrelated cases of cyclosporiasis (among other potentially foodborne illnesses) as indicators of outbreaks and pursue them to their sources through timely and thorough investigation.

Hepatitis A from Imported Green Onions

Although the pathogen involved is far better characterized than Cyclospora, investigations of foodborne illness caused by hepatitis A virus (HAV) present a similar array of challenges. Speaker Beth Bell described a series of outbreaks in late 2003, including some 600 people who ate in the same Pennsylvania restaurant over a four-day period (CDC, 2003b; Wang and Moran, 2004; see Chapter 3). This outbreak was detected when an alert clinician reported to his local health department that he had identified 10 cases of HAV within a few days, as compared with 1 case of hepatitis A in the entire previous year. Six of these recent cases had reported eating in two separate groups at the same restaurant. A case-control study suggested that all of the customers who became ill had eaten salsa containing raw green onions that had been imported from four farms in Mexico, where hepatitis A is endemic; the FDA subsequently banned imports from these farms. In response to these events, Mexico established a mandatory food safety program.

This process revealed several opportunities for improving the safety of the food supply, much as did the previously discussed investigations of cyclosporiasis outbreaks. Molecular methods for HAV detection hastened tracing the cases back to their source, but a more sensitive surveillance program could reveal an outbreak consisting of more sporadic cases, including those that occur in other countries (Bell, 2005). Preventive measures taken on the farm, such as providing access to adequate sanitary facilities for field workers and using clean water for irrigation and for the rinsing of harvested produce, could also have mitigated this outbreak. Finally, as Bell observed, simply telling the story of the outbreak can increase the public health community’s awareness of this and other food safety issues.


Despite the comparative rarity and mildness of previous incidents of intentional food adulteration, little imagination is required to conceive the possibility of a major attack featuring the U.S. food supply. Workshop participants considered accounts of intentional foodborne illness, as well as likely scenarios for food adulteration with both biological and chemical agents at vulnerable points in the U.S. food supply chain. These discussions revealed needs that must be addressed to reduce the potential for such attacks and to mitigate their consequences should they occur.

Incidents of intentional food adulteration reviewed at the workshop included the following:

  • The 1984 contamination of an Oregon salad bar with Salmonella typhimurium by members of the Rajneesh religious cult, who intended to sway an election by incapacitating voters. A limited “trial run” of their plan sickened more than 700 people (Torok et al., 1997).
  • The intentional infection of 12 employees by a coworker who left pastries tainted with Shigella dysenteriae in their break room at a large Texas medical center laboratory in 1996 (Kolavic et al., 1997).
  • Several incidents in China in which food products were contaminated with rat poison by business competitors (Osterholm, 2005). In 2001, 120 people were sickened after being poisoned by the owners of a noodle factory (Death sentence, 2002a). In 2002, a similar incident took place when a snack store owner spiked a competitor’s breakfast foods with rat poison resulting in the deaths of at least 38 people and causing over 300 to become seriously ill (Death sentence, 2002a).

The consequences of these and other actual foodborne attacks pale in comparison with the potential human (and/or animal) morbidity, mortality, and socioeconomic consequences that could unfold from an intentional act of adulteration targeting the U.S. food supply chain (Breeze, 2004; Chalk, 2005). A thwarted attempt at such an event, or even a credible hoax, would probably have severe economic repercussions for growers and processors of the affected foods, given previous consumer reaction to perceived threats such as BSE in beef (see subsequent discussion and Chapter 6) or the ripening agent Alar in apples.2

Food could provide an extremely effective vehicle for delivery of a variety of pathogens, such as anthrax (Osterholm, 2005), as well as for noninfectious, chemical agents including biological toxins (e.g., botulinum toxin) and poisons (e.g., cyanide, dioxin) directly to humans (Khan et al., 2001). To identify the likeliest combinations of foods and adulterants that might be vulnerable, the FDA employs risk management protocols, described by speaker David Acheson and detailed in Chapter 4. Characteristics of high-risk food products include large batch size, short shelf life (which implies rapid turnover), the potential for uniform mixing of a contaminant into the food, and a production process that would permit the agent to be added, undetected, in sufficient quantities for it to be effective (see also Osterholm in Chapter 1). As Acheson and other workshop participants noted, however, no food can be considered risk free, either with regard to intentional or accidental adulteration. The FDA uses these food vulnerability assessments to develop guidance documents and training for state and local regulatory officials and the food industry, to focus the agency’s emergency response planning, and to set research priorities.

Many workshop participants expressed concern about a range of potential attackers of the U.S. food supply from al-Qaeda and other foreign nonstate actors, to radical animal rights groups, to homegrown “lone wolf” perpetrators. The transient nature of the food industry workforce is particularly worrisome, according to Osterholm, who noted the ease with which members of terrorist groups could be employed within food-processing companies and obtain “insider knowledge” of the vulnerable “choke points” in the production process.

Botulinum Toxin in Milk: A Possible Bioterrorism Scenario

Three workshop presentations (see Acheson, Leitenberg, and Detlefsen in Chapter 4) addressed a single, highly publicized scenario for foodborne terrorism: the intentional contamination of the U.S. milk supply with botulinum toxin. A May 2005 New York Times op-ed essay on this subject by Lawrence Wein (2005) raised heated controversy as to the appropriateness of its publication, as well as the accuracy of its conclusion that milk represents “a uniquely valuable medium for a terrorist” (Leitenberg and Smith, 2005). Six weeks later, the controversy was further fueled by the delayed publication of a peer-reviewed paper (Detlefsen, 2005; Wein and Liu, 2005) in the Proceedings of the National Academy of Sciences (Alberts, 2005). Based on a mathematical model of a “cows-to-consumers supply chain,” the authors predicted that “if terrorists can obtain enough toxin, and this may well be possible, then rapid distribution and consumption [will] result in several hundred thousand poisoned individuals if detection from early symptoms is not timely.”

Discussants Milton Leitenberg and Clay Detlefsen disputed several claims made by Wein and Liu. Leitenberg identified what he considered were numerous inaccuracies and improperly sourced citations in their work; he also questioned the ability of terrorist groups such as al-Qaeda to prepare botulinum toxin according to the “Jihadi manual” mentioned in Wein’s op-ed essay, since it requires such technology as a refrigerated cold room, a vacuum refrigerated ultracentrifuge, and a mouse colony. Detlefsen argued that the dairy industry, in partnership with the U.S. government, have taken extensive measures to ensure the security of the milk supply following the terrorist attack of September 11, 2001. These efforts included the determination that higher pasteurization temperatures can be used to denature type A botulinum toxin while retaining milk’s familiar flavor and texture. Many milk producers have already adopted this practice, Detlefsen explained, but because it is voluntary, it is not universal.

David Acheson presented the FDA’s analysis of the milk production process and recommendations for improving its biosecurity. These include greater awareness of the threat posed by bioterrorism, locks on vulnerable production and storage facilities, thermal destruction of pathogens, and the development of cost-effective tools for the surveillance and mitigation of multiple agents. That Wein and Liu may have overstated a specific threat of foodborne bioterrorism and understated the preparations in place against it does not contradict the argument, made by several workshop participants, that the food supply must be protected without unduly burdening industry or frightening the public.

Food Safety vs. Food Biosecurity

The early detection of foodborne disease, resulting either from accidental contamination (food safety) or from deliberate attack (food biosecurity), demands sensitive surveillance systems for communicable disease at both local and national levels, and it depends on close cooperation and communication among clinicians, laboratories, and public health officials (WHO, 2002c). The particulars of these needs—for the organization of food safety systems, surveillance, reporting, and response to foodborne disease outbreaks—are discussed in greater detail below and in contributions to Chapters 2 and 57.

Preventing or mitigating the impact of deliberate food adulteration requires greater attention to such threats on the part of the food industry, according to workshop participants. Industrial food safety standards focus on accidental foodborne disease, a relatively common occurrence with mild to moderate impact on the average affected individual; bioterrorism, by contrast, is a rare, potentially high-impact event. This distinction increases the already daunting challenge of ensuring food safety, of balancing the risk of harm against the cost of protection, and of implementing and paying for cost-effective safeguards.


Two categories of tools and practices are used to detect threats to the food supply: farm-to-table food safety systems and human disease surveillance (Besser, 2005). Although theoretically capable of providing primary prevention, farm-to-table systems—which include food pathogen monitoring, animal disease surveillance, the testing of food during processing and distribution, and the analysis of consumer complaints of adulterated food—can be insensitive because of typically low pathogen loads in contaminated food, according to speaker John Besser (see Chapter 5). The presence of foodborne pathogens, symptoms of foodborne illness, and illness-related behaviors in humans are comparatively sensitive indicators of foodborne outbreaks, but usually take so long to be recognized that they afford only secondary prevention. Several workshop presentations discussing the benefits, limitations, and accomplishments of specific food and disease surveillance tools sparked discussion on obstacles to timely foodborne threat detection and how such challenges might be overcome.

Monitoring Food Safety from Farm to Fork

In framing his description of food surveillance—which focused on microbial threat agents—speaker Robert Buchanan noted its key role in verifying the effectiveness of food safety systems, as well as in preventing foodborne disease. However, he observed, effective food surveillance requires a clear understanding of its strengths and limitations, and the simultaneous use of complementary preventive strategies and public health surveillance methods. The acquisition of food surveillance data occurs through the same multi-step process of sampling and analysis regardless of whether the potential contamination is likely to be intentional or accidental. Thanks to major advances in detection technology over the last decade, several methods can now be used to identify food contaminants in “real time”—a relative term in the food industry, measured by the length of time the monitoring agency has to act upon detecting contamination. For a product that can remain in a warehouse for two weeks after it is tested for safety, “real time” is 13 days; for perishable products such as fruits, vegetables, and milk, “real time” is nearly instantaneous.

Considerably less research has gone into improving sampling methods for food surveillance, which Buchanan characterized as the heart of the surveillance process. An effective sampling plan takes into account the probability of finding a contaminated sample, known as the defect rate. Given the ability of very small numbers of certain microbes to cause foodborne illness, the detection rate for many foods is miniscule. The odds of detecting contamination in these cases can be increased by taking more samples, larger samples, or by focusing on the likeliest trouble spots in the food chain, Buchanan said. Targeted “smart” sampling techniques can be further adapted to provide information, such as baseline contamination rates, that cannot be determined by traditional batch testing methods. In addition to the defect rate, the cost and effectiveness of any food surveillance protocol depends upon the degree of confidence required to ensure safety.

Analyzing Consumer Complaints

Speaker Kimberly Elenberg described a new tool used by the USDA’s Food Safety and Inspection Service (FSIS) to rapidly track and analyze consumer complaints regarding adulterated food (see Chapter 5). The analytical component of the Consumer Complaint Monitoring System (CCMS), called Emerging Patterns in Food Complaints (EPFC), employs computational methods to detect patterns in complaints received by CCMS—data that are too voluminous and complex for the human mind to grasp. EPFC examines reports of such “adverse food events” as foreign objects in food and symptoms of illness for mathematical patterns associated with foodborne outbreaks. The system includes decision trees that can identify likely chemical or microbial contaminants from symptom descriptions and onset times, Elenberg explained.

Recent tests demonstrate that EPFC can resolve faint signals amid the flood of noisy data it encounters, permitting it to generate useful alerts based on fewer adverse reports than would be required to obtain a similarly reliable result by other means, including typical syndromic surveillance methods. For example, when presented with historical data, the system immediately identified a food-borne E. coli outbreak that had originally taken two weeks of skilled analysis to identify. In the future, Elenberg and colleagues hope to greatly expand the application of their analytical methods, and eventually to enable the real-time integration of data on animal, plant, and human disease.

Public Health Surveillance

As defined by speaker Robert Tauxe, public health surveillance is “the monitoring of health events in humans, linked to action.” Information gained from public health surveillance is used to measure the magnitude and burden of foodborne illness, to identify outbreaks, and to evaluate the impact of prevention and control efforts. In the United States, authority to conduct public health surveillance rests with state governments. Surveillance data is derived from a number of different sources including: complaints from citizens to local health departments; formal reporting systems for diseases deemed notifiable; reports from physicians and laboratories to various jurisdictions upon the identification of certain specific diseases, as required by law; microbial strains referred to state public health laboratories for characterization; and reports of outbreaks under investigation. Although voluminous, these data are highly heterogeneous and typically of limited quality.

Since 1996, public health surveillance in the United States has been substantially strengthened through the establishment of standard notifiable disease reporting in all 50 states, as well as the creation of FoodNet, PulseNet, and the electronic food outbreak reporting system known as eFORS (CDC, 2003c; Tauxe, 2005). FoodNet is an active surveillance system that collects data about sporadic cases of foodborne illness, as it is diagnosed (CDC, 2006; see Tauxe in Chapter 3). It is composed of 10 sentinel sites that collectively sample 14 percent of the U.S. population; these sites are operated jointly by state health departments, the FDA, and the USDA under the aegis of the CDC Emerging Infections Program. Information derived from FoodNet is used to estimate the burden of foodborne illness and to monitor epidemiological trends in foodborne disease. FoodNet also serves as a platform for conducting specialized studies of emerging pathogens.

PulseNet, the national molecular subtyping network for bacterial foodborne pathogens, is a digital repository for the genetic fingerprints of several pathogen strains, collected by state and some city public health laboratories and managed by the CDC (CDC, 2005b; see Tauxe in Chapter 3). The analysis and comparison of such fingerprints has greatly improved outbreak detection and investigation, particularly when contaminated foods are widely distributed and the attack rate is low, such as in the previously discussed case of nationally distributed ice cream. A complex multistate outbreak investigation generally follows such a discovery. PulseNet currently monitors five foodborne pathogens—Escherichia coli O157:H7, Salmonella, Shigella, Listeria, and Campylobacter—and more are expected to be added, as are increasing numbers of molecular subtypes of pathogens found throughout the food chain, in addition to those isolated from people with foodborne disease. Global networks for foodborne disease surveillance typically focus on human pathogens, but some programs monitor animals as well. These include the WHO Salmonella surveillance network—Global Salm-Surv (WHO, 2006) and Med-Vet-Net (Med-Vet-Net, 2005), a project of the European Union that examines foodborne infections of both humans and livestock, with a special emphasis on zoonoses (King, 2005). Global Salm-Surv, which now also covers other pathogens including Campylobacter, has accumulated data for 565,000 human and 102,000 nonhuman isolates, Jørgen Schlundt noted.

Surveillance of Foodborne Outbreaks

Approximately 1,200 outbreaks of foodborne disease are reported to the CDC each year, each of which, on average, affects 20 to 30 people (Tauxe, 2005). Better surveillance results in more outbreaks being detected, which in turn increases the possibility of preventing future outbreaks, Tauxe explained. Research on foodborne outbreaks leads to targeted prevention strategies for known and emerging pathogens on an ongoing basis. Although most outbreak investigations occur after the fact, they enable public health authorities to discover new combinations of foods and pathogens, identify gaps in the food safety system, and to develop new processes and regulations that improve the safety of the food supply.

This process of continual improvement has been expedited by eFORS, a system by which local or state health departments report foodborne outbreaks to the CDC via a Web-based interface (CDC, 2003c). Diffuse outbreaks continue to challenge surveillance systems, however. An outbreak of foodborne disease that occurs among 250 people within a one-block radius is easily detected, Tauxe observed, but if the same number of people fell ill across the United States, only a highly sophisticated surveillance system could discern the “signal” of such an outbreak from the “background noise” of unrelated, sporadic cases of foodborne illness.

Progress and Roadblocks

FoodNet data reveal that incidences of some foodborne diseases have declined since the network’s advent (Tauxe, 2005). Since baselines were established in 1996–1998, cases of Campylobacter have dropped by 31 percent, Listeria by 40 percent, E. coli by 42 percent, and there has been a marginal but statistically significant decrease in Salmonella cases. Control of E. coli O157:H7 in ground beef has improved, although it is not yet adequate, as is the control of Campylobacter in poultry, Salmonella in eggs, and Listeria monocytogenes in processed meats, Tauxe noted; control remains elusive for multi-drug resistant Salmonella in ground beef, a wide array of different pathogens and different problems in produce, and Vibrio in raw shellfish.

A variety of constraints that limit the effectiveness of foodborne disease surveillance will not be easily overcome, workshop participants acknowledged. Chief among these is that detection largely depends upon people getting ill; sometimes this occurs after a long period of incubation, further complicating the determination of an outbreak’s source. People often delay seeking medical attention, after which considerable time may elapse before a physician or a laboratory can render a diagnosis, and even more time for a public health laboratory to determine its subtype—a necessity for recognizing the “signal” of a diffuse outbreak. Once such an outbreak is suspected, investigators must trace the contaminant to its source. For some foods with many unsourced components, such as ground beef, this task is nearly impossible to perform, Tauxe said.

Improving Foodborne Threat Surveillance

Several opportunities for enhancing foodborne disease surveillance identified by workshop participants included the following:

  • Increase the capacity and resources of regulatory agencies for skilled trace-back of food contaminants.
  • Decrease the anonymity of foods to make them more readily traceable.
  • Provide the resources necessary to bring every state up to the highest current standards of foodborne disease epidemiology, and create a national network capable of real-time surveillance.
  • Expand molecular subtyping to include a broader variety of pathogens, fingerprinting pathogens derived from foods and livestock in real time, and linking these subtypes to those in human databases.
  • Use faster, automated methods for fingerprinting and the detection of illness clusters (the CDC is currently evaluating several such methods).
  • Expand global and regional networks for foodborne disease surveillance, and in particular increase funding for PulseNet, which has already expanded into Canada, Europe, Asia, and Latin America (Besser, 2005; Tauxe, 2005).

Having reflected on the inherent benefits and limitations of the various approaches for detecting and investigating foodborne illness, workshop participants affirmed the need for multiple, integrated surveillance systems. The value of such systems was demonstrated in the 2005 recalls of ice cream, packaged salad, and juice based on PulseNet findings (Besser, 2005). Increasingly sensitive detection methods are blurring the line between outbreaks and sporadic cases of foodborne disease, according to Besser, making real-time surveillance of foodborne illness an achievable goal.


Among all the resources brought to bear on the control of foodborne illness, time is perhaps the most precious. The rapid reporting of foodborne threats is therefore essential to reducing the burden of foodborne illness, but it also carries inevitable and significant costs to individuals, industry, and national economies. Initial costs such as the value of lost production and expenses associated with the destruction and containment of contaminated and potentially adulterated products (which in some cases translates into acres of crops or herds of livestock) are easily appreciated and often compensated—in which case those costs are often borne by taxpayers.

A variety of indirect costs can also result from outbreaks of foodborne illness, not all of which are incurred by the producer of the affected food. These include the loss of export markets due to restrictions on products associated with disease threats, loss of consumer confidence and market share (which may extend to related products that have never been contaminated), and multiplier effects on businesses and individuals with economic ties to the affected products, from food processors and distributors to business owners and nonfarm workers who serve farming communities (Chalk, 2005; Monke, 2005).

The balance of costs and benefits associated with reporting foodborne threats is clearly illustrated by the recent and ongoing global experience with the neurological disease of BSE. After Canada announced the discovery of BSE in cattle in May 2003, farm-level prices for Canadian beef declined by nearly half. Beef prices in the United States remained very strong until December of that year, when a cow with BSE was discovered within its borders; although U.S. beef prices did not fall as far as Canada’s, a trade model developed at Kansas State University estimated the total BSE-associated loss incurred by the U.S. beef industry in 2004 at more than $3.2 billion (Coffey et al., 2005; Hanrahan and Becker, 2005; Monke, 2005).

Although the United States and Canada have clearly incurred substantial costs associated with the reporting of BSE, the benefits of the initial report and ongoing investigation in the United Kingdom were demonstrated nearly a decade later, when the disease was linked with a human variant of Creutzfeldt-Jakob disease (vCJD) (Brown et al., 2001). The establishment of a causal association between BSE and vCJD has led to the establishment of a variety of infection control and surveillance measures, as well as efforts to determine the extent of the vCJD epidemic for the purpose of public health planning. However, it is clear that the disincentives for reporting BSE, discussed below, still greatly outweigh the incentives for doing so. Through a series of presentations, workshop participants explored the biology of BSE and its implications for food safety, international perspectives on BSE surveillance and prevention, and public health lessons learned from this disease, and its consequences.

BSE Biology and Food Safety Implications

A member of the family of diseases known as transmissible spongiform encephalopathies (TSEs, also known as prion diseases), BSE was first identified in 1986 in the United Kingdom and has since been detected in 26 countries (GAO, 2005c). In the early 1980s, speaker Stanley Prusiner proposed that the pathogens that cause two TSEs— Creutzfeldt-Jakob disease (CJD) and scrapie, a disease of sheep—consist entirely of an “infectious” change in the conformation of a protein that he termed the prion (Prusiner, 2004). Researchers have since learned that in addition to scrapie and CJD, prions apparently cause BSE and its human variant, vCJD, as well as chronic wasting disease in deer and elk (see Chapter 6).

Scientists have also discovered that the prion protein is encoded in the genome of every animal studied to date and is expressed, in its normal form, in nerve cells. Prion disease arises when a prion protein in an abnormal, disease-causing conformation induces normal prion proteins to refold (Prusiner, 2004, 2005). Abnormal prion proteins form complexes that resist heat, radiation, and chemicals that would destroy viruses and other pathogens. These complexes build up in nerve cells, causing them to rupture, and producing the characteristic plaques (masses of protein) and vacuoles (microscopic holes) found in the brains of animals with TSEs. Prion diseases may be of spontaneous, infectious, or inherited origin; in the case of BSE, both spontaneous and infectious cases appear to have occurred. Because prion diseases have incubation periods that can exceed 40 years and are invariably fatal, no exposure to prions should be considered acceptable, Prusiner argued (Prusiner, 2005).

In his workshop presentation, Prusiner described the experimental evidence for this model of TSE etiology and efforts to develop rapid, low-cost diagnostic tests for BSE (see Chapter 6). Some recently developed tests are able to detect sufficiently low levels of disease-causing prions in brain tissue to permit the identification of infected but asymptomatic cattle within hours of slaughter. A far better—and as yet unrealized—alternative would detect minute amounts of abnormal prions in the blood and urine of live animals, including humans.

International Perspectives on BSE and vCJD

Speakers Steven Collins, an Australian expert on BSE and vCJD, and Maura Ricketts, a Canadian authority on prion diseases, shared their perspectives on the response to these health threats (see Chapter 6). As a preface to his remarks, Collins described an epidemic of the prion disease kuru in the Eastern Highlands of Papua, New Guinea. The disease, recognized in the 1950s, has since been linked with the practice of ritualistic cannibalism, which was successfully outlawed 50 years ago. Nevertheless, cases are still occasionally diagnosed, suggesting that there may be no finite incubation period for kuru (and perhaps for other TSEs as well). Despite its low transmissibility compared to microbial infections, kuru produced high mortality rates in villages where the disease was endemic. The disease is now thought to be nearly eliminated.

Collins recalled the false reassurance offered in the early years of the BSE epidemic by the lack of documented evidence for the animal-to-human transmission of the related disease, scrapie, which had been recognized for more than a century. Under this mistaken assumption, approximately 200 million infected cattle reached the human food chain during the epizootic (Collins, 2005). In 1996, a researcher at the National CJD Surveillance unit in Edinburgh recognized a case of CJD of an unusual form now known as vCJD; preliminary research soon suggested a link between vCJD and BSE. Based on this experience, Collins said, it should be assumed that all TSEs are capable of breaching species barriers; thus, it is now important to determine whether chronic wasting disease has been transmitted from deer to humans.

To date, 158 cases of vCJD have been diagnosed in the United Kingdom (Collins, 2005). The mean age at onset is 26 years. Two presymptomatic cases may be linked to blood transfusions, raising the possibility that a much larger population than initially thought is at risk of developing vCJD, despite appearances that the epidemic is declining. Australia has conducted surveillance for all human forms of TSEs since 1996, taking a variety of approaches described in detail by Collins in Chapter 6. To date, no probable or definite case of vCJD has been diagnosed in Australia, nor has any endogenous case of BSE or scrapie been found.

In the course of describing the Canadian response to BSE and vCJD, detailed in her contribution to Chapter 6, Ricketts emphasized the social and political forces that shaped the public health response to this threat. Although far from cautious in their individual behaviors, the Canadian public clearly dreaded vCJD and supported the expenditure of $18 billion per year for protection from the disease. Ricketts conjectured that this support was driven in part by public outrage against agricultural and food companies that reaped huge profits selling products that made unsuspecting consumers ill.

Trade-based economies resist the disclosure of threats to public health and the adoption of preventive measures due to their short-term costs, Ricketts observed. Thus government support for disease prevention and surveillance is essential; however, it is often difficult to obtain because the affected country must acknowledge that it has a foodborne disease problem.

Lessons from BSE

Speaker Wil Hueston, of the Center for Animal Health and Food Safety at the University of Minnesota, shared insights gained from 16 years of involvement with BSE and the interface between animal and human health. He distilled this experience into the following seven lessons, summarized here and discussed in detail in Chapter 6:

  1. Detecting a new animal disease is extremely difficult, for a host of reasons ranging from the fact that animal disease is typically diagnosed and treated on the farm, where sick animals are usually sold, eaten, or buried, to the lack of support for the diagnosis of emerging animal diseases.
  2. Recognizing BSE in a low-incidence country (such as the United States) is difficult, because most countries use passive surveillance and confuse the absence of evidence for the disease with evidence for its absence. There are huge disincentives for expanding national surveillance, however: it is expensive to do, and it increases the potential for economic losses if BSE is discovered before there is a plan in place to address it.
  3. Most farmers are honest, but disincentives for reporting BSE greatly outweigh incentives. Possible incentives for reporting BSE, such as treatment or the certification of herds (rather than nations) as BSE-free, do not exist, while controls mandated by the government raise the cost of production in an economy that values cheap food. At the same time, producers that report BSE lose the market for their product and face costs associated with investigation, destruction, and disposal of infected animals.
  4. Testing can become an end unto itself unless its purpose is clarified; even then, it is not a panacea. It must be backed up with animal and public health measures to reduce the burden of disease.
  5. Effective protective measures focus on reducing the risk of infectious disease, not the presence or absence of disease in a country. Trade bans do not work because infectious diseases can cross any border.
  6. Opportunity costs. Every dollar spent on BSE is not available to address other threats to human and animal health. The cost of BSE testing is currently disproportionate to its public health benefit.
  7. High health status is a curse because, once attained, the impetus for maintaining a public health infrastructure is lost.

Hueston also presented a series of actions that could be taken to address key issues raised by BSE and that are generally applicable to improving the response to infectious disease. They included the following:

  • Surveillance strategies that reflect purpose and scientific validity, as well as the recognition that no single strategy fits all circumstances;
  • Incentives for reporting disease, rather than regulatory demands;
  • To gain a better understanding of the sociology and psychology of disease reporting and compliance, greater collaboration among biological, medical, and social scientists;
  • Replacement of the nationalistic, “zero-risk” paradigm of infectious disease response with global risk management and science-based regulation; and
  • Recognizing that all animal health issues are potential public health issues, an emphasis on transdisciplinary approaches to all animal diseases (not just zoonoses).


Previously noted workshop presentations and discussions addressed the role of food safety oversight, surveillance, and reporting in protecting the food supply. Additional research and policy opportunities for reducing foodborne threats were raised in subsequent workshop presentations on animal health, food defense, and food safety science. The emphasis on risk assessment in the latter presentation provides a framework for addressing several key challenges to food safety, as well as opportunities for protecting the food supply, identified by workshop participants.

Animal Health at the Crossroads

Following closely on the discussion of BSE and its implications for food safety, Lonnie King’s presentation highlighting the recently published NRC report, Animal Health at the Crossroads (2005), magnified and reinforced participants’ understanding of the critical linkage between animal and human health. The report, summarized in Chapter 7, used case studies of key animal diseases to evaluate existing prevention and detection systems and identify opportunities and barriers to their improvement. Many of the report’s findings directly address the reduction of foodborne illness, including the identification of the following needs:

  • Greater collaboration and integration between public health and animal health officials and between biomedical and veterinary research communities;
  • New technologies and scientific tools to detect, diagnose, and prevent animal diseases and zoonoses;
  • Expanding and strengthening the animal health laboratory network;
  • Global systems that prevent, detect, and diagnose known and emerging disease threats to animal and public health; and
  • The improved and expanded use of predictive, risk-based tools and models to develop strategies to address health threats.

Food Protection and Defense

In contrast to earlier discussion stressing the importance of a unified effort to detect and respond to both accidental and deliberate foodborne threats, speaker Frank Busta focused on research needs and opportunities that, while they might also reduce accidental foodborne illness, are specifically directed toward reducing and mitigating attacks on the food supply. This is the purpose of the National Center for Food Protection and Defense (NCFPD), which Busta directs at the University of Minnesota. The NCFPD pursues this goal through a series of strategies, including the rapid and accurate detection of attacks, the minimization of consequences, and the rapid implementation of recovery measures.

The research needs identified by Busta, detailed in his contribution to Chapter 7, involve tools and technologies necessary to answer key questions prompted by a foodborne attack. Sampling, detection, and tracing technologies can help determine how an attack was staged and what agent was involved. Studies of decontamination and disposal methods can indicate how to protect public health and food workers from the threat agent. Risk communication and economic research can inform optimum approaches to recovery from a foodborne attack. Such information is currently being pursued by many different agencies, and could be collected, coordinated, and shared—rather than duplicated—through the establishment of a multidimensional database, Busta noted.

Food Safety Science

Contending that food safety “is an intellectual concept, not an inherent biological property of a substance,” speaker Sanford Miller noted the profound influence of such nonscientific issues as politics, economics, and social values on perceptions of risks to the food supply. The clear identification of foodborne threats and the accurate estimation of the risks they present require a new approach; Miller has collected these functions into a new academic discipline that he calls food safety science. This nascent field integrates nutrition, microbiology, toxicology, molecular biology, genetics, functional biology, and conventional food science and brings these sciences to bear on the problem of ensuring a safe food supply.

Miller, along with several other workshop participants, emphasized the importance of risk assessment to the strategic protection of the food supply. “We all feel comfortable talking about science,” he observed, “but the moment comes when science has to be translated into risk and risk has to be translated into public policy. That is when we run into trouble, because we as scientists don’t really understand that process and its dynamics.” A case in point, one participant noted, is the common pursuit of food safety and security, a goal for which risk assessment provides the intellectual underpinning (Taylor, 2005).

Assessing Needs and Opportunities

The following summary comprises needs and policy opportunities for reducing foodborne threats to health that were most frequently mentioned by workshop participants. In the spirit of the discussion that followed Miller’s presentation, the items below can be most appropriately viewed through the lens of risk assessment. That paradigm is the key to appropriately prioritizing needs and anticipating the cost-effectiveness of research and policy opportunities to enhance food safety and biosecurity (protection of the food supply from deliberate adulteration).

  1. Prevention:
    1. Create positive incentives for safe food production; encourage industry to recognize and address vulnerabilities, either through regulation or through market forces.
    2. Organize responsibilities for food safety and biosecurity oversight into a single independent government agency (but maintain surveillance separately; see below).
    3. Build capacity to support food safety in developing countries.
    4. Manage risks with the understanding that zero risk cannot be achieved.
    5. Adopt multilevel (domestic) and coordinated (global) approaches to protecting the food supply.
  2. Detection:
    1. Improve the cost-effectiveness of surveillance by focusing on the greatest or most likely risks.
    2. Use common agencies, mechanisms, and resources to address accidental and deliberate foodborne illness.
    3. Make all food products more traceable, less anonymous.
    4. Separate surveillance from food safety oversight to permit objective evaluation of protective measures.
    5. Emphasize coordination, communication, and collaboration among local, state, federal, and international food safety authorities.
  3. Response:
    1. Create incentives for reporting apparent and actual threats to the food supply.
    2. Coordinate animal and public health responses to foodborne outbreaks.
    3. Use validated risk-based approaches for mitigating foodborne threats.
  4. Research:
    1. Investigate the biology and natural history of emerging foodborne pathogens such as Cyclospora and prions.
    2. Examine the ecology of foodborne diseases to inform the integration of animal and health surveillance.
    3. Advance techniques for real-time surveillance of foodborne threats to health.
    4. Define the role of water as a source of foodborne illness.
  5. Policy opportunities:
    1. Create interdisciplinary animal-public health programs.
    2. Conduct training programs in food safety for public health officials in developing countries, veterinarians, and the animal health community.
    3. Strengthen and integrate laboratory networks that diagnose food-borne and animal diseases.
    4. Enhance communication and collaboration among all geographic levels, all scientific and medical disciplines, and all public and private sectors, toward the common goal of safe food.


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It should be noted that not all foodborne illness is caused by an infection, not all foodborne disease causes diarrhea, and not all foodborne disease is acute. The cause of foodborne disease is often undefined, and, in many cases, the pathogens that cause them are not detected by routine laboratory tests.


Alar (Uniroyal’s brand name for the chemical daminozide) was sprayed on apples as a ripening agent to regulate fruit growth and color and to simplify harvest. Registered with the FDA in 1963, Alar was removed from the U.S. market by its manufacturer in 1989 in response to safety concerns. The alarm was raised by media reports of a study by the Natural Resources Defense Council that implicated Alar as a dangerous carcinogen, especially in children. U.S. apple sales and prices plummeted and the EPA moved to ban Alar; Uniroyal pulled its product from the market before the ban could take effect. Years later, the extent to which Alar constituted a public health threat continues to be debated. Some organizations, most notably the industry-funded American Council on Science and Health, contend that the Alar “scare” was unfounded. Others, including the Consumers Union, contend that Alar poses a significant public health risk according to government standards, thus the EPA’s actions were appropriate. For a more in-depth discussion of this issue see, Ashton L. 1999 (February 28). Alar scare 10 years past, but food safety debate goes on. Yakima Times [online] (excerpts.) Available: http://www​.ecologic-ipm​.com/APyw22899.html; Environmental Working Group. 1999. Ten years later, myth of ‘Alar scare’ persists. [Online] Available: http://www​​.html; and, Wikipedia, accessed March 4, 2006. Daminozide. Available: http://en​

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