The U.S. Department of Agriculture (USDA) Agricultural Marketing Service (AMS) purchases and distributes food for various federal food and nutrition programs, which include the National School Lunch Program (NSLP), food banks, emergency feeding programs, Indian reservations, programs that serve the elderly, disaster-relief agencies, and a variety of other institutions that serve the food-insecure. Thus, the AMS commodity program serves members of society who may be most vulnerable to foodborne illness and its consequences, including children, the elderly, and the immunocompromised.
As part of its Federal Purchase Ground Beef Program, AMS buys ground beef from more than 15 suppliers that are required to meet specifications (food safety requirements) that exceed those mandated by the USDA Food Safety and Inspection Service (FSIS) for all federally inspected meat processing plants, such as those which supply meat to retail stores and restaurants. However, in December 2009, a news article in USA Today suggested that some large-scale purchasers of ground beef in the corporate sector have more stringent requirements than AMS. That and other news stories and a letter from U.S. Senator Kirsten Gillibrand (D-NY) to Secretary of Agriculture Tom Vilsack about perceived deficiencies in the Federal Purchase Ground Beef Program led to a review of the AMS ground beef purchase specifications by the Agricultural Research Service (ARS) and FSIS concurrent with the USDA Office of the Inspector General (OIG) audit that was being conducted at that time; the revision—based on recommendations from ARS, FSIS, and OIG—of the AMS ground beef purchase specifications that are found in the Technical Requirements Schedule for ground beef; and a request for an independent body (the National Research Council) to review the current Federal Purchase Ground Beef Program.
In response to this request, the National Research Council of the National Academies created an ad hoc Committee on An Evaluation of the Food Safety Requirements of the Federal Purchase Ground Beef Program. On the basis of the statement of task that AMS provided to the National Research Council, the committee considered its charge to be to evaluate the scientific basis of the AMS technical documents that describe the food safety requirements for beef suppliers (July 2010 Technical Requirements Schedule for ground beef) and testing procedures for AMS-accredited laboratories (June 2010 Statement of Work for AMS-accredited laboratories), to examine how the AMS safety requirements compare with those used by large retail and commercial food service purchasers of ground beef, and to provide recommendations to AMS for conducting periodic evaluations of the Federal Purchase Ground Beef Program.
The AMS purchase specifications for frozen ground beef specifically include limits on the pathogens Escherichia coli O157:H7 and Salmonella, which are recognized hazards in raw ground beef products (ICMSF, 2005). To assess the extent of the risk to schoolchildren posed by the presence of those pathogens in AMS purchased ground beef, the committee reviewed foodborne-illness outbreaks that occurred in schools and were associated with ground beef and products containing ground beef. Although most foodborne illnesses do not occur as part of recognized outbreaks, in school settings large groups of students may be exposed to a contaminated food item simultaneously. Because clustering of cases in a school makes it more likely that a common source of exposure would be recognized, outbreak data constitute a useful tool for evaluating the presence of E. coli O157:H7 and Salmonella associated with ground beef in schools.
The Centers for Disease Control and Prevention (CDC) received reports of 263 confirmed foodborne outbreaks of E. coli O157:H7 infection in the United States from 1998 to 2007. Ground beef was identified as the likely contaminated food in 69 (26%) of the reported outbreaks, of which three were found to have occurred in schools (two in 2000 and one in 2003). Two of those three may have involved ground beef that was purchased by the schools through the Federal Purchase Ground Beef Program. In one, in 2000, students at a private school in Minnesota became ill after eating apparently undercooked ground beef in a baked casserole known as hot dish that was prepared at the school. A review of ground beef handling procedures at the school indicated that thawing, cooking, and cooling of the ground beef may have been inadequate. However, the packing plant of origin and the packing date for the ground beef
used in the hot dish could not be conclusively identified, so it is unclear whether the ground beef was obtained through the Federal Purchase Ground Beef Program. The other outbreak, in 2003, involved beef burritos that were distributed in restaurants and schools in Nebraska. On the basis of the details of those incidents and the institutions involved, the committee thought it unlikely that the two outbreaks involved AMS purchased ground beef and did not consider them relevant to the discussion of the safety of ground beef in the Federal Purchase Ground Beef Program.
An outbreak in 1998 was entered into the CDC database with the location “other”, and no food vehicle was identified. However, investigation of the outbreak revealed that students became ill apparently after eating undercooked ground beef in tacos prepared in a school in Washington state. The ground beef was obtained through the NSLP, and this was the only confirmed outbreak of E. coli O157:H7 infection linked to the Federal Purchase Ground Beef Program.
It is noteworthy that the two E. coli O157:H7 outbreaks (in 1998 in Washington state and in 2000 in Minnesota) occurred because undercooked ground beef was served to students and before FSIS issued a requirement that establishments reassess their Hazard Analysis and Critical Control Point (HACCP)1 plans in 2002 (USDA-FSIS, 2002). Successful implementation of HACCP plans in the industry has been widely credited with substantially improving the quality and safety of ground beef.
CDC also received reports of 1,152 confirmed foodborne outbreaks of Salmonella infection in the United States from 1998 to 2007. Ground beef and products containing ground beef were identified as the likely contaminated foods in 36 (3.1%) of the outbreaks. Of the 36, one outbreak was associated with beef lasagna that was prepared at home and eaten in a school; the other outbreaks were not associated with schools. The CDC database indicates that the key ingredient in the lasagna that contributed to the outbreak was eggs, and ground beef was not the likely source of the Salmonella Enteritidis contamination. Hence, no confirmed Salmonella outbreaks in schools during 1998–2007 were associated with ground beef obtained through the Federal Purchase Ground Beef Program or any other source.
The finding that no outbreaks of either Salmonella or E. coli O157:H7 associated with AMS-purchased ground beef have been recorded in more than a decade strongly suggests that existing AMS purchase specifications have been protective of public health. It is possible that sporadic cases and small outbreaks have gone unrecognized. However, the attention given to E. coli O157:H7 infections and school food safety since 2000 makes it unlikely that any sizable outbreaks have occurred. Prevention of such outbreaks depends on continuing to ensure the low likelihood that ground beef is contaminated by pathogens during its production and continuing to ensure that it is properly handled, stored, and cooked before being served.
Food safety requires a system of multiple interventions and controls throughout production and processing. Even when producers and processors minimize or reduce contamination, thorough cooking of ground beef is essential to protect the health of students served by the AMS program regardless of the stringency of purchase specifications.
In response to its charge, the committee detailed several findings and recommendations regarding the AMS Federal Purchase Ground Beef Program. The major findings and recommendations are presented below.
The scientific basis of the current purchase specifications for ground beef is unclear. Some specifications were based on industry practices, but the scientific basis of the industry practices cannot be ascertained by the committee. Other specifications appear to have been based on information that was gathered through informal, ad hoc expert consultation. The Agricultural Marketing Service is encouraged to develop a systematic, transparent, and auditable system for modifying, reviewing, updating, and justifying science-based purchasing specifications.
In developing the current purchase specifications for ground beef, the AMS procedure did not follow the scientific principles for establishment and implementation of microbiological criteria described by the National Research Council, the International Commission on Microbiological Specifications of Foods, and the Codex Alimentarius Commission. It is recommended that future revisions of the specifications be based on such principles.
The recent update of the AMS purchase specifications relied heavily on informal ad hoc expert opinion, which the committee determined to be the least preferred form of evidence. To strengthen the scientific basis of the Agricultural Marketing Service purchase specifications, it is recommended that the Agricultural Marketing Service use resources that yield more reliable evidence (such as the use of reports based on data, internal reports based on Agricultural Marketing Service data, formal expert consultation, and peer-reviewed reports and risk assessments) and that are consistent with the entire context of the service’s need to develop a cohesive program.
As part of its program to ensure the safety of the ground beef that it purchases (that is, compliance with FSIS and AMS requirements), AMS routinely collects microbiological testing data from its suppliers. The committee recommends that the Agricultural Marketing Service look into appropriate methods of analyzing these data because they could be useful for process control and improvement and could enable the service to evaluate and guide future revisions of the ground beef purchase program specifications.
The July 2010 Technical Requirements Schedule for ground beef (TRS-GB) contains specifications that increase the testing requirements for ground beef. However, increased testing might not increase the safety of the product. Process control is a well-established method for improving food safety and is the basis of HACCP. The Agricultural Marketing Service should ensure that suppliers in its purchase program are responsible for the safety of their products and for the management, performance, and improvement of their processes. It is recommended that the Agricultural Marketing Service develop a strong supplier evaluation program that is based on statistical process control techniques and that encourages suppliers to improve both process and product performance.
The committee examined and found considerable variations in the microbiological standards set by 24 large purchasers of ground beef in the corporate sector. Substantial differences were found among the specifications of the corporate purchasers in criteria for aerobic plate counts, coliforms, generic E. coli, Staphylococcus aureus, Salmonella, Listeria monocytogenes, and E. coli O157:H7. The committee believes that the intended use of the ground beef is a likely factor in the variations. For example, although all raw AMS-purchased ground beef is distributed in frozen form, distributors of fresh products may require different standards designed to improve shelf-life. In addition, little information was available to the committee on the scientific (or any other) basis of the corporate specifications. The committee was therefore unable to compare AMS specifications with those of the corporate purchasers directly.
The July 2010 TRS-GB specifications apply to all ground beef purchased by AMS. Ground beef not compliant with these specifications may not be made into cooked products eligible for purchase by the AMS, even if they are handled and cooked according to FSIS guidelines in a USDA-inspected facility. Yet, proper cooking kills pathogens in ground beef, making those products safe to eat. Moreover, USDA food and nutrition program participants may purchase commercially available cooked ground beef products outside of the AMS procurement system. While these products must meet all FSIS requirements, their source materials do not necessarily have to meet AMS ground beef specifications. As a result, there is no apparent health benefit supported by the current AMS policy, especially since indications of unwholesomeness are always grounds for rejection of both raw and cooked
products. Therefore, the committee recommends that Agricultural Marketing Service consider permitting July 2010 TRS-GB noncompliant products to be used in cooked meat products purchased through USDA food and nutrition programs if they meet FSIS requirements.
The overall procedures in the June 2010 Statement of Work for the testing of supplier samples by AMS-accredited laboratories appear to be appropriate. However, the committee found one inconsistency involving the reporting of E. coli O157:H7 between procedures in the AMS June 2010 Statement of Work for AMS-accredited laboratories and the USDA FSIS Microbiological Laboratory Guidebook, which it referenced. The committee recommends that the Agricultural Marketing Service address that inconsistency.
The committee recommends that the Agricultural Marketing Service—through partnerships with the Agricultural Research Service, the Food Safety and Inspection Service, and the Centers for Disease Control and Prevention—follow developments associated with pathogens of current concern and other emerging pathogens to develop strategies for the protection of vulnerable consumers (such as schoolchildren and the elderly). The Agricultural Marketing Service outreach for advice should continue and be expanded by considering the use of existing advisory committees, such as the National Advisory Committee on Microbiological Criteria for Foods.