Volume 7, Number 7—June 2001
International Conference on Emerging Infectious Diseases 2000
Conference Panel Summary
Teaming Up to Prevent Foodborne Disease
Preventing foodborne disease requires the efforts of different segments of our "global" society. This session featured presentations on emerging issues across the spectrum of food safety activities, from science and technology to policy development and regulation.
Norwalk-like caliciviruses (NLV) are increasingly recognized as a significant cause of food-related illness. In recent years, The Netherlands has conducted four NLV studies: i) a physician-based case-control study, 1996-99; ii) a population-based cohort study with a nested case-control design, 1999; iii) NLV testing of stools obtained from patients who became ill during gastroenteritis outbreaks reported through municipal health services; and iv) NLV testing in samples from animal surveillance systems. NLVs were the causative agent in 5% of patients with foodborne illness seen by a general practitioner and 16% of patients in the community cohort. In the past 6 years, NLVs have caused more than 80% of all gastroenteritis outbreaks. Multiple NLV variants cocirculate in the population, and their diversity allows researchers to trace outbreaks to a common source. Highly related viruses have been found in herds of calves and swine, suggesting that animals may be a reservoir. A project has been initiated to study transmission patterns of these viruses across Europe.
Under Hazard Analysis and Critical Control Point (HACCP) systems, food manufacturers identify points where contamination is likely to occur and implement process controls to prevent it. A current limitation of the HACCP is that very few CCP practices are available for on-farm use, although several interventions appear to have promise. These practices include probiotic bacteria (benign bacteria that can be used to out-compete pathogenic bacteria) that prevent colonization by pathogens, edible vaccines that stimulate IgA production in an animal's gut, and improved farm management practices, such as reducing pathogen contamination in watering systems. Food processors have a larger array of current and promising control measures available, but most measures have limitations. For example, irradiation may cause undesirable "off" flavors in meat and poultry or undesirable texture characteristics in vegetables such as lettuce.
Some treatments such as probiotic bacteria may be especially useful for protecting high-risk populations, such as the immunocompromised. Inevitably, consumers must also play a role in preventing foodborne disease. Consumers must be more active in such practices as avoiding undercooked and uncooked high-risk foods, refrigerating perishable foods, and disposing of hazardous foods that have been recalled.
The food industry bears responsibility for providing safe foods for consumption. A framework of laws, regulations, and an inspection system facilitates production of safe foods. Food safety regulations fall into two basic classes: process-based and performance-based. Future legislative and regulatory requirements will focus more on performance-based standards, leaving the specifics of how the standard is achieved to individual processors, although most will likely develop HACCP programs. Future regulations, however, will also consider international agreements, such as those that enable the World Trade Organization to impose obligations that nations must fulfill to enter into free trade.
Both international and domestic policy will increasingly rely on the discipline of risk analysis for decision-making. The need for better data to conduct risk assessment will spur increased emphasis on foodborne illness surveillance systems like FoodNet (1) and PulseNet (2). Results of risk assessments must be analyzed through the risk management process to yield food safety policies that lead to development of performance criteria that the food industry can use to develop safer food processes.
There has been a globalization of the food supply. Although no evidence supports the idea that imported food is less safe than domestic food, the Food and Drug Administration's (FDA) imported foods plan recognizes that some food safety issues, such as lack of regulatory authority and basic infrastructure, are specific to developing nations. Along with important surveillance and sampling activities, FDA provides international training and fosters technical cooperation aimed at prevention at the source of production. FDA's international partners are often from industry, nongovernment institutions, and universities. Other key partners include Food and Agricultural Organization, Pan American Health Organization, Instituto Interamericano de Cooperacion para la Agricultura, as well as the Centers for Disease Control and Prevention and the Foreign Agricultural Service. In 1999, FDA tested 1,000 samples of imported celery, cantaloupe, cilantro, green onions, parsley, loose-leaf lettuce, strawberries, and broccoli for Salmonella, Shigella, and Escherichia coli O157:H7. To date, 95.4% of these samples have been free of contamination. FDA has worked closely with several countries (e.g., Costa Rica, Trinidad and Tobago, Honduras, and Jamaica) to determine their needs and capacities. Examples of training and outreach include a Regional Outreach Meeting on Food Safety in Mexico City, Mexico, and one in Santiago, Chile.
To paraphrase The Future of Public Health, the 1988 Institute on Medicine report, food safety is not just what government regulators or industry quality assurance managers do. Food safety is what society does to ensure the conditions under which people can consume food that is safe, as well as wholesome and nutritious. Safe food requires the work of producers and consumers; industry and government; local, state, federal, and, increasingly, international partners.
- Mead PS, Slutsker L, Dietz V, McCaig LF, Bresee JS, Shapiro C, Food-related illness and death in the United States. Emerg Infect Dis. 1999;5:607–25.
- Swaminathan B, Barrett TJ, Hunter SB, Tauxe RB, and the CDC PulseNet Task Force. PulseNet: the molecular subtyping network for foodborne bacterial disease surveillance, United States. Emerg Infect Dis. 2001;7:382–9.