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Food Safety and Inspection
Service United States Department of Agriculture Washington, D.C. 20250-3700 |
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Food Safety and Inspection
Service United States Department of Agriculture Washington, D.C. 20250-3700 |
Speeches
Food Safety and Inspection
Service
U.S. Department of Agriculture
Remarks for delivery by Dr. Kaye Wachsmuth, Deputy Administrator for the Office of Public Health and Science, FSIS, USDA at “Applied Epidemiology and Other Vital Public Health Tools to Inform Food Safety Actions” January 29, 2002 in Atlanta Georgia.
I’ll start with a strong personal conviction that food safety is an essential part of public health. A public health system that ignores the contribution of food to the occurrence and spread of illness is not protective of our population. Similarly, a food safety program that does not focus on the potential human health consequences of consuming certain foods is not protective of the public, and, as such, will not serve the food industry in the long term.
It has amazed me that, in the past, public health practitioners and food safety experts have not consulted one another more often, either at the federal or state level or even at the international level. Most often the two disciplines are located in separate departments, have separate budgets and report to separate ministries. It was a rare occasion when the Infectious Diseases Society of America, Council of State and Territorial Epidemiologists, or the World Health Organization highlighted food safety at their annual meetings.
Things are different today for many reasons. Among them, one of the most important, I believe, has been the advent of FoodNet. Not just because it is giving us unprecedented data and insights, but also because it is a collaborative effort between the food safety arms of the government (FSIS and FDA) and that citadel for public health surveillance, the Centers for Disease Control and Prevention. It is also a strong collaboration with the state health departments, which are the FoodNet sites. All participants have recognized the importance of prevention and the need for controls along the food production chain. We have also learned the need to respond in a more coordinated way when the unanticipated occurs and harmful products are in commerce.
Many countries besides the United States, have recognized the importance of foodborne illness not only as an issue of public health but also for its impact on trade and commerce. Governments have toppled in response to large and devastating outbreaks of E. coli O157:H7 disease and the spread of BSE throughout Europe. In May of 2000, for the first time in its 54 year history, the World Health Assembly adopted a food safety initiative requesting renewed efforts and resources from WHO to support international food safety activities such as Codex Alimentarius. Additionally, the proposed new International Health Regulations will be based on reports of any significant cluster of illnesses and will surely mean that more foodborne diseases will be reported and investigated worldwide.
I’m going refocus my comments back to home base, the FSIS experience today. However, I would like for all of you to remember that the public health awareness and the perception that we need to do more to prevent foodborne illnesses is much more universal. The public health imperative to prevent foodborne illness is international in scope.
Since this is an epidemiology meeting, I am going to show you a conceptual graph to illustrate how we might interpret and respond to epidemiological data. I’d like to apply this to E. coli O157:H7 and Listeria moncytogenes (Lm).
To recognize that E. coli O157:H7 was a pathogen in 1982, it took the exposure of thousands of people to a contaminated food vehicle, fast food hamburgers and the occurrence of a unique disease, hemorrhagic colitis. It took much more experience to recognize its public health importance. A decade later, fast food hamburgers and E. coli O157:H7 were the cause of over 700 illnesses and the deaths of 4 children in a large outbreak in the western United States. This tragic event was the turning point for one of America’s favorite food industries and for FSIS; both felt the imperative to be more protective of the public health. Today, FSIS is a public health regulatory agency with access to the best available epidemiology data and tools, and consumption of fast food hamburgers was found to be protective in the latest FoodNet study of O157 infections.
Now let’s look at the graph plotting the number of illnesses against time. This is just a fictional curve but you could imagine that those 700-plus illnesses in the western states are under the curve. You’ll learn about the actual epidemiology tools from our next speakers and also learn why we are now able to better distinguish problems or outbreaks when they are small… so small they would have been part of the background of sporadic illnesses until a few years ago. In the western states outbreak, public health action was taken before the pathogen was isolated from ground beef, averting an estimated 800 illnesses in Washington state. One major factor was the use of molecular finger printing to identify outbreak patient isolates and, subsequently, to implicate the ground beef. With the recall of that product, at the peak of this curve, the outbreak began to abate.
In 1996, the application of new epidemiological tools, including PFGE, and the quick actions of investigators and of Hudson Foods prevented a similar situation. The Colorado State Health Department initiated the investigation, which resulted in an outbreak curve containing 14 reported cases and no reported deaths. The recall of 25 million pound of product (equivalent to approximately 100 million frozen patties) is remembered as one of the largest to this day, but the outbreak, which ended with the recall is often forgotten.
Once the Agency learns that people are ill or dying, the public health imperative is for all responsible parties to act as quickly as possible to prevent further illness and death; in the short term it is an emergency response. In the long term, it is for us to identify issues and to apply lessons learned to outbreak investigations and to controls (e.g., cooking temperatures, safe food handling labels, E. coli O157:H7 as an adulterant in ground beef, HACCP/PR, rework, etc.) and turn those lessons into prevention steps. Although the fast food industry learned a hard lesson and put controls in place, hamburgers prepared in other food services and at home are still associated with sporadic E. coli O157:H7 illness. There is more to do to get the desired “flat line graph.”
Using this same bell shaped curve, let’s imagine a different pathogen-food combination which resulted in over 100 illnesses and 20 deaths in 1998 and 1999. This was another wake-up call for industry and FSIS. Again, a popular and widely distributed, high volume food, hotdogs, and a deadly pathogen, L. moncytogenes. The emergency response was not as rapid as we would have liked, but the issues raised are still being addressed (e.g, construction within the processing facility, shelf life, product flow, persistent environmental contamination, etc.).
The public is told that these products are ready-to-eat. That should mean that they are also safe to eat without further cooking, with no risk of illness and death. Although it’s said quietly, it is said that only the susceptible population is at risk of Lm infections, or that Lm is probably not infectious at low levels in food, or that not all strains of Lm are pathogenic. Well, these observations may be true, but the public health imperative will not allow the Agency to ignore those vulnerable individuals at the extremes of age, those with compromised immune systems, or pregnant women. Education can go only so far, and many of those who are susceptible may not recognize themselves as being in such a population. The years pass rather quickly as we approach retirement age, and when does one slip into susceptibility? We also have more and more people with malignancies and post transplant, whose treatment can blunt a healthy immune response, leaving them more susceptible.
Back to the graph, if the bigger bell-shaped curve is the 1998 outbreak, then imagine the small curve represents the 2000 outbreak with 29 cases, 4 deaths, and 3 miscarriages/stillbirths. As with E. coli O157:H7, the epidemiological tools improved, and everyone was able to respond more quickly. Both of these outbreak investigations identified a strain of Lm, which was resident in, and unique to, the establishment producing the RTE meats. One strain may have been harbored for years in one establishment. What you don’t see on this graph is the 2001 outbreak which did not occur, because a third establishment producing large volumes of RTE meats, detected a resident Lm strain, recalled product, and took action to prevent further contamination. Tomorrow, you will hear a scenario about the sequential detection of Lm in RTE products from a fictional plant. At that point, you may want to remember the public health imperative in the context of this graph.
I hope that everyone can understand that at times, the Agency may need to respond to an emergency, to listen to the victims and act appropriately, i.e., as best as possible to protect the public health, even when all of the factual details are not clearly elucidated. But while the Agency can help to point the way, it is the industry, who will make the real difference, making safe food safer or recalling adulterated product. Today, in the wake of intentional acts of contamination, we must be prepared, better than ever, to respond, to move as quickly and confidently as possible, to protect the public….. which includes all of us and ours. It’s really our public health imperative.
For Further Information:
FSIS Congressional and Public Affairs Staff
Phone: (202) 720-3897
Fax: (202) 720-5704