Lonnie J. King, D.V.M.
National Center for Zoonotic, Vector-bourne, and Enteric Diseases, CDC
Findings from CDC’s Foodbourne Diseases Active Surveillance Network (FoodNet)
The Committee on Agriculture
Subcommittee on Horticulture and Organic Agriculture
United States House of Representatives
Thursday May 14, 2009
Thank you for the opportunity to submit testimony for the record on CDC’s activities related to the prevention of foodborne disease and CDC’s role in collecting and reporting FoodNet data.
Diseases spread by contaminated foods continue to challenge the public health system. Large foodborne outbreaks are often attributed to fresh produce and processed foods, as well as foods of animal origin. Numerous factors are responsible for these large outbreaks such as changing production systems, changing ecologies, and changing food consumption patterns.
As an agency within the Department of Health and Human Services (HHS), CDC leads federal efforts to gather data on foodborne illnesses, investigate foodborne illnesses and outbreaks, and monitor the effectiveness of prevention and control efforts. CDC relies on local and state health departments, which have varying capacity to detect and respond to food-related illnesses.
CDC is not a food safety regulatory agency, but CDC works closely with the food safety regulatory agencies, in particular with HHS’ Food and Drug Administration (FDA) and the Food Safety and Inspection Service within the United States Department of Agriculture (USDA/FSIS). CDC also plays a key role in building state and local health department epidemiology, laboratory, environmental health, and communication capacity to support foodborne disease surveillance and outbreak response. CDC surveillance data can help attribute the burden of foodborne illness to specific food commodity groups to support regulatory risk-based inspection efforts and help document the effectiveness of prevention interventions
Much of what CDC does to detect and monitor foodborne illness depends on critical partnerships with state and local public health departments that collect surveillance data, conduct laboratory testing, investigate most outbreaks, and take public health action. CDC has worked with the Association of Public Health Laboratories (APHL) and the Council of State and Territorial Epidemiologists (CSTE) to develop networks for foodborne disease surveillance. For example, PulseNet, the national network for molecular subtyping of foodborne bacteria coordinated by CDC, allows every state health laboratory to test strains of bacteria from sick persons in that state and to compare them with DNA “fingerprint” patterns in the national database at CDC. This has greatly improved the ability to detect clusters of illness that may be related, even if they are dispersed across multiple states. Similarly, other related networks [OutbreakNet team] help coordinate the investigation of the large, multistate clusters detected by PulseNet, facilitate state reporting of outbreaks to CDC [National Outbreak Reporting System], develop baseline information on what foods are commonly consumed and trends in foodborne illness [FoodNet], and assess policies and practices of retail foodservice establishments that could lead to or prevent foodborne outbreaks [Environmental Health Specialist Network]. These networks and systems, among others, provide data to help CDC and our regulatory partners better understand foodborne disease in the United States.
CDC also works with a broad range of other partners to improve capacity and knowledge regarding foodborne disease control and prevention. In collaboration with the National Environmental Health Association (NEHA), CDC conducts team training programs for local and state health department officials including specialists in environmental health, laboratory science, and epidemiology. CDC works with the World Health Organization (WHO) and a variety of other international partners to conduct similar training programs in other countries. CDC supports the Council to Improve Foodborne Outbreak Response (CIFOR), which was created to help develop model programs and processes that will facilitate the investigation and control of foodborne disease outbreaks. CSTE and the National Association of County and City Health Officials (NACCHO) are co-chairing CIFOR, and it includes representatives from CDC, FDA, USDA, APHL, NEHA, the Association of State and Territorial Health Officials, the Association of Food and Drug Officials, and industry.
The Foodborne Diseases Active Surveillance Network (FoodNet) of CDC's Emerging Infections Program collects data from ten U.S. sites, representing approximately 15 percent of the U.S. population. Sites locations include Connecticut, Georgia, Maryland, Minnesota, New Mexico, Oregon, Tennessee, and selected counties in California, Colorado, and New York. FoodNet is an active, population-based surveillance system for laboratory-confirmed infections caused by pathogens transmitted commonly through food. Preliminary data for 2008 were released last month and show that the estimated incidence of infections caused by Campylobacter, Cryptosporidium, Cyclospora, Listeria, Shiga toxin-producing Escherichia coli (STEC) O157, Salmonella, Shigella, Vibrio, and Yersinia did not change significantly when compared with the preceding three years.
The lack of significant change in recent years is in contrast to trends from 1996, when FoodNet surveillance began, to 2004. Models show that rates of infection with Yersinia, Shigella, Listeria, Campylobacter, and STEC O157 had decreased 25 to 48 percent. However, Vibrio had increased 47 percent. The estimated incidence of infection with Cryptosporidium and Salmonella did not change significantly over this period.
Despite ongoing activities aimed at preventing foodborne human infections, progress toward the national health objectives has plateaued, suggesting that fundamental problems with food contamination persist. Although significant declines in the incidence of certain pathogens have occurred since establishment of FoodNet, these all occurred before 2004. The lack of recent progress toward national health objective targets and the occurrence of large multistate outbreaks caused by E. coli in shredded lettuce, frozen pizza, and ground beef; Salmonella in tomatoes, peanut butter, cantaloupe, and jalapeños; and botulinum toxin in carrot juice and canned chili sauce point to gaps in the current food safety system and the need to continue to develop and evaluate food safety practices as food moves from the farm to the table.
Enhanced and food-specific measures are needed to 1) control or eliminate pathogens in domestic and imported food; 2) reduce or prevent contamination during growing, harvesting, and processing; and 3) continue the education of restaurant workers and consumers about risks and prevention measures. In particular, continued efforts are needed to understand how contamination of fresh produce and processed foods occurs and to develop and implement measures that reduce it. More outbreaks can be recognized and their causative foods identified with rapid and complete subtyping of pathogens and with rapid standardized interviews of ill persons and appropriately selected controls.
Consumers can reduce their risk for foodborne illness by following safe food-handling and preparation recommendations and by avoiding consumption of unpasteurized milk, raw or undercooked oysters, or other raw or undercooked foods of animal origin such as eggs, ground beef, and poultry. Risk also can be decreased by choosing pasteurized eggs, high pressure-treated oysters, and irradiated meat and produce. Everyone should wash hands before and after contact with raw meat, raw foods derived from animal products, and animals and their environments.
There is a continued need for robust public health surveillance at all levels—local, state, and federal—to ensure prompt recognition, response, and investigation of foodborne illness. CDC will continue its efforts to:
- focus on research, education, and training that will assist with federal strategies to prevent foodborne illnesses;
- incorporate food industries into prevention, response and information sharing; and
- bolster state health infrastructures to effectively and promptly identify and respond to outbreaks.
This will entail continued cooperation between regulatory authorities, state and local partners, food and environmental microbiologist scientists, and the food industry to prevent future foodborne illness outbreaks. CDC is working closely with the White House Food Safety Working Group established by President Obama and is strongly committed to strengthening our national food safety system. President Obama established the working group to coordinate the efforts of federal agencies and to advise the President on improving coordination throughout the government. Thank you again for the opportunity to submit written testimony for the record.
Last revised: June 18, 2013