• Decrease font size
  • Return font size to normal
  • Increase font size
U.S. Department of Health and Human Services

Animal & Veterinary

  • Print
  • Share
  • E-mail

Assessment of Risk: Pathogens on Meat

Kenneth Petersen, Ph.D.

DR. PETERSEN: Thank you and good morning. It is a pleasure to be here to present some of the risk assessment activities within the Food Safety and Inspection Service. For those of you who are not familiar with us, basically we regulate the meat, poultry and egg products industries.

So to return to this issue of food safety, because it is an issue that unites all of us whether we produce food, regulate its safety, or simply consume it, for all of us, food safety has become increasingly complex.

Not only do we have more issues to debate, technology, irradiation and microbes just to name a few, but these issues are being debated in public forums as never before. Just look at the attention paid to food safety by the media during the past decade.

The globalization of food trade has presented new and difficult challenges in minimizing food-borne diseases. Although the globalization of food trade has made public debate more contentious, it has not been easy for the public to separate fact from fiction.

So how exactly do we base food safety decisions on science In countries worldwide, we need to make these decisions. We need a structured way of organizing and analyzing the scientific information that exists, as well as that to be developed in the future. To support major policy-making within USDA, we employ a quantitative farm-to-table approach.

Although our regulatory activities primarily target the post-harvest rather than the on-farm end of the spectrum, we identify whenever possible the best point or points in the food production chain in which to control risks. The scope of our risk assessments and the scientific data utilized is transparent to all interested parties. We emphasize a public process.

The concept of risk analysis is certainly not limited to the food safety arena. In fact, the structure is universal. And its value lies in the fact that it is a fluid process. As new scientific information becomes available, it can be applied in the risk assessment and strategies can be re-evaluated.

In fact, risk assessment is a good way of determining what gaps exist so that we can target needed research. So it also provides a feedback loop to enable the risk to be better defined as new information comes along.

Risk analyses play an important role in managing health hazards in food and, thus, improving food safety. Once hazards are identified, the risk managers can weigh options to address these hazards. Options may include decisions by food companies to modify their process controls or regulatory action when necessary.

A broad range of voluntary options also exist such as activities on the part of industry to modify production, processing or labeling approaches. So there is much support for using risk analysis as a means of making science-based food safety decisions. Risk assessment supported by quantitative data has been used for many years in evaluating the safety of chemicals as we heard already this morning.

But we are significantly lacking in similar data related to food-borne pathogens. In our risk assessments, we assume that high levels of uncertainty are the rule, not the exception. Part of the challenge relates to the fact that biological population dynamics may be unpredictable.

We must consider survival, growth and decline of microbial populations throughout the farm-to-table continuum. We must assess both the potential for human illness resulting from consumption of food, as well as illness resulting from cross-contamination.

We acknowledge evolutionary changes in pathogens, for example, virulence acquisition. Another challenge relates to the many data gaps that limit the precision of risk assessments. The final assessment is only as good as the data that is currently available.

But despite these methodologic challenges, we have made some progress in conducting risk assessments. Our microbiological risk assessments incorporate the previously mentioned steps of hazard identification, exposure assessment, dose response assessment and risk characterization.

USDA has completed a risk assessment on Salmonella enteritidis in eggs and egg products which was our first farm-to-table quantitative microbial risk assessment. This was completed in June of 1998.

The risk assessment is being used to develop a strategy to address egg safety. In fact, the President's Food Safety Council, which is conducting strategic planning for food safety, will soon release an action plan to improve food safety in the United States.

We are also conducting a risk assessment for E. coli 0157:H7 in ground beef and carcass trimmings. Consistent with the farm-to-table approach, the exposure assessment addresses on-farm production to include transportation, slaughter inputs from hide removal to carcass chilling, and product preparation from grinding to consumption.

We have also entered into a cooperative agreement with Harvard University for a risk analysis of bovine spongeiform encephalopathy, or BSE. And FDA and FSIS are jointly carrying out a risk assessment for Listeria monocytogenes in a variety of ready-to-eat foods.

So although we prefer to the extent possible quantitative risk assessments, we also believe in risk assessment in the right proportions. That is, the level of detail considered in a risk assessment and included in a risk characterization should be commensurate with the importance of the problem. Salmonella enteritidis, E. coli 0157, Listeria and concerns relating to BSE all reflect important problems.

We also utilize risk analysis to deploy our valuable inspection resources based on food safety risks. This risk base deployment forms the basis for the HACCP-based inspection models project. For this project, in volunteer plants that slaughter young, healthy classes of animals, industry conducts on-line carcass sorting activities under FSIS oversight and verification. These new inspection activities enable us to concentrate on food safety risks, whether they be visual or microbial.

Beyond the formal risk assessments for major policy decisions, we have also made progress in implementing various risk management strategies. When quantitative data do not exist, we then base our regulatory management strategies on qualitative data.

HACCP, the Hazard Analysis and Critical Control Point Systems, are a risk management tool because they enable the user to identify hazards that are reasonably likely to occur and to develop a plan to prevent or control the hazard. As more quantitative risk assessments are conducted and hazards become more accurately characterized, HACCP plans become more effective.

Right now, we are in the final stages of implementing HACCP in meat and poultry plants. And HACCP is being implemented in other commodities, as well, such as seafood. Performance standards for pathogen reduction are another risk management tool that we use today.

Along with mandatory HACCP, we have in place pathogen reduction performance standards for Salmonella that slaughter plants much meet. And we test products to ensure that these standards are, in fact, met.

Such standards provide a basis for plants to calibrate their process control measures. So far, testing indicates that plants are meeting the challenges, significantly reducing the prevalence of Salmonella in many raw products. Thus, this risk management tool is working to improve food safety.

And for the future, we will consider establishing pathogen reduction performance standards for other pathogens of public health concern. An additional non-regulatory tool is food safety education. For consumers, we have the "Fight Bac" campaign, the result of a public-private partnership for food safety education begun as the result of the President's Food Safety Initiative.

Food safety education is an important risk management tool because everyone has a responsibility for food safety. And consumers have an important role in handling, preparing and storing food properly to reduce the risk of food-borne illness. In fact, education is needed all along the farm-to-table chain.

The recent public health education activities include communicating the recommended hamburger cooking temperature of 160 degrees Fahrenheit and identification of meat color as an unreliable indicator of doneness.

So in closing, there are tangible benefits to including food safety standards based on risk assessment. Among the many long-term benefits are improving food safety, maintaining and improving consumer confidence in the safety of the food supply, and facilitating trade. We would like to see more involvement by the industry, consumer groups and others interested in food safety risk assessment to achieve science-based food safety systems both here and abroad.

To maintain confidence in the safety of the food supply and avoid the chaos that would result if we did not, we must see that science wins out of rhetoric; that science guides our food safety policies. By doing so, the consumer will benefit from the food supply that is as safe as possible. It will also facilitate the harmonization of food safety standards and will in turn facilitate trade between nations. Thank you very much.


DR. STERNER: Questions for Dr. Petersen We are scheduled for a break due to the absence of Dr. Bolger. We will break for 15 minutes and reconvene in 15.

(Whereupon, a brief recess was taken.)

DR. STERNER: They say in sporting circles you can't start the program without the players. And Dr. Angulo was missing, but we have located him and he is ready to speak. Fred is well known in veterinary circles for the role that he plays at the CDC and investigating clinical outbreaks of microbial disease that affect humans.

Fred, I am not going to belabor your background or your history since we don't have much of the room. If you will go ahead and get us started, we will stay on time.