The US Department of Agriculture's Agricultural Marketing Service (AMS) buys ground beef from suppliers that must meet mandatory process, quality, traceback and handling controls plus comply with strict limitations on the amounts of bacteria in the meat, such as E. coli and Salmonella. AMS then distributes the ground beef to federal programs, including food banks, emergency feeding programs, Indian reservations and disaster-relief agencies.
In assessing AMS's ground-beef purchase program, the committee that wrote the report said validated cooking processes provide greater assurance of ground beef's safety than would additional testing for pathogens. Testing alone cannot guarantee the complete absence of pathogens because of statistical implications associated with how beef is sampled during testing.
The committee's analysis of the number of illnesses since 1998 linked with AMS ground beef provided to schools suggests outbreaks were rare events before AMS requirements became more stringent in February, implying controls already in place were appropriate for protecting public health. No recorded outbreaks of E. coli or Salmonella associated with AMS ground beef have occurred in more than a decade.
Prevention of future outbreaks will depend on eliminating contamination during production and ensuring meat is properly handled, stored and cooked before it is served, the committee said.
The committee also attempted to compare the AMS specifications with those of large industry purchasers of ground beef. Among purchasers, the committee found considerable differences in testing and safety standards and suspected that the intended use of the ground beef could account for the variations.
For example, all raw AMS ground beef is distributed in frozen form, but distributors of fresh meat products may require different standards designed to improve shelf-life. Although AMS safety requirements appear comparable to or more demanding than those of commercial companies on the surface, the lack of information detailing the science used for corporate specifications prevented the committee from making direct comparisons.
Other specifications under the AMS program call for testing food samples and surfaces at the suppliers to look for the presence of "indicator" microorganisms that could denote unsanitary conditions, improper hygiene and processing techniques, post-processing contamination and storage-temperature abuse. Although reducing the number of indicator organisms implies a reduction in the amount of pathogens, the presence of an indicator does not guarantee that a pathogen is also present, the committee said.
For an indicator to be an effective predictor of a pathogen's presence, a statistical association needs to be established. Therefore, the committee recommended that AMS assess the usefulness of its microbiological data as a scientific basis for testing for indicators.
"The report encourages AMS to strengthen its established specifications and requirements for ground beef by utilizing a transparent and clearly defined science-based process," said Gary Acuff, chair of the committee and professor and director of the Center for Food Safety at Texas A&M University, College Station.
The committee recommended AMS base its requirements on standards supported by the International Commission on Microbiological Safety of Foods, the Codex Alimentarius Commission and the Research Council report An Evaluation of the Role of Microbiological Criteria for Foods and Food Ingredients.