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Oversight of Egg Safety

Statement of

Morris E. Potter, D.V.M.
Food Safety Initiatives
Center for Food Safety and Applied Nutrition
Food and Drug Administration
Department of Health and Human Services


the Subcommittee on Oversight of Government Management, Restructuring, and the District of Columbia
Senate Committee on Governmental Affairs

July 1, 1999


Mr. Chairman, Members of the Committee, I am Morris E. Potter, D.V.M., Director of Food Safety Initiatives, Center for Food Safety and Applied Nutrition (CFSAN), Food and Drug Administration (FDA), Department of Health and Human Services (HHS). I am pleased to be here this morning, along with my colleague, Margaret Glavin, Associate Administrator, Food Safety and Inspection Service (FSIS), U.S. Department of Agriculture (USDA) to testify on the Federal role in the oversight of egg safety and the related General Accounting Office's (GAO) report. I am accompanied by Dr. Terry Troxell, Director of FDA’s Office of Plant and Dairy Foods and Beverages, and Dr. David Swerdlow, a medical epidemiologist from the Centers for Disease Control and Prevention (CDC).

Mr. Chairman, my testimony will address the coordination of Federal and State agencies with shared food safety responsibilities. This will include a general discussion of how eggs are regulated, with specific emphasis on FDA’s role. Ms. Glavin’s testimony will describe USDA’s role in more detail. I also will describe the risks associated with Salmonella Enteritidis (SE) in eggs, and the Administration’s accomplishments along the farm-to-table continuum to address the risks. Our goal is to have the best food safety system and we look forward to working with the Committee to that end.

HHS, USDA, and the States have a long history of working together to understand and initiate actions to reduce the risk of Salmonella in eggs. In the 1980s, SE was identified as a growing public health problem, and was linked to contaminated whole shell eggs in 1986. FDA, CDC, USDA's Animal and Plant Health Inspection Service (APHIS), and Agriculture Marketing Service (AMS) immediately responded by working together and with colleagues in State government, universities, and the egg industry to conduct research on SE and eggs and to put in place mechanisms to share new information on prevention and control as that information developed. Contrary to GAO testimony, our coordinated approach has led to many important achievements that are highlighted throughout this testimony.

Recent nationwide surveillance data show a decrease in cases of SE infection, particularly in the Northeast where egg quality assurance program efforts have been the most intense, and active surveillance in FoodNet sites demonstrates a 44 percent decline in SE infection rates between 1996 and 1998 in those areas of the country covered by this surveillance system. Although we are heartened by this progress, the rate of decline is too slow and the remaining public health burden of egg-associated SE infections requires the agencies to do more to address the problem.

Both FDA and FSIS announced initiatives this week that are major steps forward in the egg safety effort. FDA just sent to the Federal Register a proposed rule that would require refrigeration of shell eggs at retail and labeling to instruct consumers on safe handling of eggs. FSIS also has just announced a directive that will implement its refrigeration requirements for storage and transport of eggs.


As you know, the Federal authority to regulate eggs for safety is shared by FDA and FSIS. FDA has jurisdiction over the safety of foods generally, including shell eggs, under the Federal Food, Drug, and Cosmetic Act. FDA also has authority to prevent the spread of communicable diseases under the Public Health Service Act. This authority includes regulating foods when foods may act as a vector of disease, as eggs do for SE.

USDA has responsibility for implementing the Egg Products Inspection Act (EPIA), which it carries out through programs in FSIS and AMS. FSIS has primary responsibility for the inspection of processed egg products to prevent the distribution into commerce of adulterated or misbranded egg products, while AMS conducts a surveillance program to ensure proper disposition of restricted shell eggs. APHIS administers programs for animal health, including an SE control program for flocks that supply hens to laying flocks, and is conducting a study to survey the current practices in the laying industry, and estimate the prevalence of SE in layer flocks. FDA has primary responsibility for the parts of the continuum that involve the production and processing of shell eggs.

In addition, the States play a key role, as they may have their own laws governing eggs, as long as they are consistent with Federal laws. Generally, State laws and regulations focus on how eggs are packed and shipped for sale within their borders, and how eggs are handled by retail stores and food service establishments. FDA and USDA, with help from the States, strive to provide a coherent and comprehensive system to eliminate or reduce the risk of SE contaminated eggs and egg products in each link of the farm-to- table chain.

In May 1992, FDA and USDA signed a Memorandum of Understanding (MOU) to improve coordination of control efforts for egg production flocks, breeder flocks, pullet grow-out facilities, eggs during storage and transportation, labeling, research, consumer education, and retail and manufacturing establishments. In addition, in August 1996, FDA and AMS signed a second MOU establishing more formal methods of sharing inspection information regarding egg safety. While the jurisdiction may be divided, FDA and USDA efforts in exercising jurisdiction have been cooperative and coordinated.


Until the mid-1980s, intact eggs rarely were the source of Salmonella infections. Since 1985, however, the number of egg-associated salmonellosis outbreaks and sporadic infections has increased. Shell eggs are the predominant source of SE infection in the United States for which a food vehicle is identified. Before I discuss each step of the farm-to-table continuum, let me describe the bacterium and the human illness it causes.


Salmonella of various serotypes are commonly found in the digestive tracts of animals, and frequently contaminate our environment. Human illnesses are usually associated with ingesting food contaminated with Salmonella, although transmission also may occur person-to-person by the fecal-oral route, when personal hygiene is poor, and by the animal-to-man route.

The disease salmonellosis is an intestinal infection with Salmonella, and is characterized by diarrhea, fever, abdominal cramps, headache, nausea, and vomiting. Symptoms of salmonellosis usually begin within 6 to 72 hours after consuming contaminated food, last for 4 to 7 days, and resolve without antibiotic treatment for most people who do not have underlying health problems. The infection can spread to the bloodstream and other areas of the body, however, leading to severe and fatal illness. Invasive, life-threatening disease is more likely in children, the elderly, and persons with weakened immune systems. In general, the greater the numbers of microorganisms ingested, the greater the likelihood of disease; however, the infectious dose (i.e., the number of microorganisms required to cause disease) can be very low. The likelihood of disease is also affected by the virulence of the microorganism and the susceptibility of the host. About 2 percent of those who recover from salmonellosis may later develop recurring joint pains and arthritis.

SE in Eggs

Until recently, Salmonella contamination of shell eggs was thought to occur most commonly by trans-shell penetration of bacteria present in the egg's environment. Our current experience with SE, however, has shown that an egg's contents can become contaminated with SE before the egg is laid. Though the mechanism is still not completely understood, SE infects the ovaries and oviducts of some egg laying hens, permitting transovarian contamination of the interior of the egg while the egg is still inside the hen. In general, only a small number of hens in an infected flock shed SE at any given time, and even infected hens lay many uncontaminated eggs. While the percentage of eggs that are contaminated is small, the number of contaminated eggs is large; it has been estimated that of the 47 billion eggs consumed annually as shell eggs, 2.3 million are SE-positive, exposing a large number of people to the risk of illness.


Salmonellosis is a notifiable disease, i.e., physicians and medical laboratories are required to report identified infections to their local health department. The reports are forwarded to the State health department, which summarizes the information and sends it to CDC. This is the nationwide, passive reporting system for all serotypes of Salmonella. While the numbers of another common serotype, Typhimurium, have remained relatively stable, SE infections increased more than 8-fold from 1976 to 1995. Initially, the increases in the United States largely occurred in the Northeast. Later, the increase spread throughout the country. The numbers of SE infections decreased in 1996 and 1997, especially in the Northeast where control efforts began first and have been the most intense. This demonstrates that committed application of good management and strong science during production and concerted efforts to improve egg handling during food preparation and service, especially institutional food service, will bring the numbers down.

The number of Salmonella infections reported to CDC underestimates the true number of infections that occur, however, and this progress should not make us complacent. Most persons infected with Salmonella do not seek medical care, many doctors do not order stool cultures, and some laboratories do not report Salmonella isolations to their health department. It has been estimated that only one in 39 Salmonella infections are reported to CDC; multiplying the 7,924 cases of SE that were reported to CDC in 1997 by 39, it can be estimated that up to 310,000 infections may have actually occurred. Clearly, we must do more to bring this public health problem under adequate control.

In addition to the routine passive surveillance for infections with all serotypes of Salmonella, CDC also maintains special surveillance of outbreaks of infections with SE. In 1985, when this outbreak surveillance began, States reported 26 SE outbreaks (i.e., occurrences of 2 or more cases of a disease related in time and place) to CDC. Nationwide, the numbers of reports peaked in 1990. The numbers of outbreaks increased first in the Northeast in the late 1980s and early 1990s, but have decreased dramatically in the late 1990s. This progress was partially offset by increasing numbers of outbreaks in the West during the early 1990s. From 1985 through 1998, there have been a total of 794 SE outbreaks reported to CDC involving 28,644 illnesses, 2839 hospitalizations, and 79 deaths. Many of these SE outbreaks were attributed to food served in commercial establishments, such as restaurants, hospitals, nursing homes, schools, and prisons, and most (more than 75 percent) were associated with food that contained undercooked eggs. Although most deaths that have occurred during SE outbreaks in recent years have occurred among the elderly in hospitals and nursing homes, salmonellosis can be fatal to an otherwise healthy person if a sufficient dose is ingested, and proper treatment is not administered.

In 1995, FDA, CDC, and FSIS began a collaborative project, The Foodborne Diseases Active Surveillance Network (FoodNet), to collect more precise information on the incidence of foodborne disease in the United States. This information collection included a Salmonella case-control study in 1997 that provided additional information on SE infections. FoodNet recently reported a 44 percent decrease in the infection rate for SE (2.5 to 1.4 per 100,000 U.S. population) from 1996 to 1998 in the areas of the country under surveillance. This decrease is substantial, and we are studying the data to understand the reasons for this decrease to help us refine our control efforts. Implementing egg quality assurance programs that include microbiological testing and egg diversion (i.e., sending eggs from infected flocks to pasteurizing plants), and improved refrigeration of eggs during transport, retail, and home use are likely to have contributed to this reported decrease. Part of the reported decrease also may be explained by a decline in the presence of Salmonella isolated from poultry and meat products because of recently implemented Hazard Analysis and Critical Control Point (HACCP) programs.

In sum, these three data sources on SE indicate that the public health problem is very large, yet we are encouraged that our combined efforts to control SE contamination of eggs and to prevent egg-associated illness have had substantial public health impact. The magnitude of the remaining problem, however, is simply unacceptable.


Farm-to-table oversight of egg safety involves risk management in five areas: production, processing and packing, transportation, retail, and consumption. I will describe each area, the risks posed, and actions taken by HHS, USDA, or States. These steps in the food production chain and the challenges each poses were described in detail in a joint FDA and FSIS, Advanced Notice of Proposed Rulemaking (ANPR), "Salmonella Enteritidis in Eggs", published in the Federal Register, May 19, 1998. The ANPR sought to identify farm-to-table actions that will decrease the food safety risk associated with shell eggs. Comments were solicited on a variety of issues, including egg quality assurance programs, the potential for HACCP on the farm, and preventive controls during packing and processing. The agencies want to explore all reasonable alternatives and gather data on the public health benefits and costs of various regulatory and non-regulatory approaches before proposing a comprehensive food safety system for shell eggs. Comments from this ANPR are being evaluated by both agencies now, and will guide our decisions on the parameters of the comprehensive strategic plan we will propose this fall.

In addition, FSIS and FDA conducted a comprehensive risk assessment of SE, completed in June 1998, to identify possible strategies for enhancing the safety of shell eggs, and this will help focus attention on those factors most likely to have the greatest impact on egg safety.


The egg production step in the farm-to-table continuum is an important area for prevention. We have learned a great deal about control of SE during production by research activities during the past decade, including programs like the Pennsylvania Egg Quality Program. The Pennsylvania program began as a pilot in 1992, and demonstrated key risk factors for the introduction and persistence of SE in the production environment.

A number of other States have since developed egg quality assurance programs. FDA has entered into partnership agreements with some to coordinate activities and facilitate tracebacks. Our current goal is a nationwide program of preventive controls during production. Aspects of egg quality assurance programs that have shown the most promise for minimizing risk of SE-infected laying hens include:

  • purchasing replacement hens certified to be free of SE,
  • environmental testing for SE,
  • adequate assurance of rodent and pest control,
  • biosecurity procedures,
  • cleaning and disinfection of production houses between flocks, and
  • Salmonella-free feed.

Controlling SE during production is crucial in mitigating the risk of SE in eggs, and will be part of our comprehensive strategy. Research in this area is being conducted by both FDA and the Agriculture Research Service (ARS) to uncover all important sources of the SE problem, and to develop ways to maintain SE-free laying hens. Our ability to now move forward on a comprehensive program for improving the safety of eggs is a direct result of the investments in research during the past several years.

An important omission in the GAO report was discussion of Federal research efforts, which have been underway since contamination of eggs with SE was identified, as a public health problem. This research has been critical to our better understanding of SE and efforts to develop science-based control schemes from farm-to-table.

For example, work done by ARS on transovarian infections of laying hens and factors that influence the frequency of SE contamination of eggs has been important in understanding the transmission of SE and the development of effective quality assurance programs. Progress has been impressive, but additional data are needed to solve this complex food safety problem. Thus, Federal agencies continue to aggressively identify, initiate, and support research needed to develop even more effective means for controlling this disease-causing microorganism. Examples of FDA research underway include studying the effects of stress on the immune system of poultry and subsequent contamination of shell eggs with SE, which will assess the effects on the immune system of potential factors such as competing organisms, crowding, temperature, air quality, and lighting. FDA also is studying the pathogen transmission capacities of various insects found in the production environment.

As additional data gaps in our understanding of the dynamics of SE during production are filled so we can be certain that our control strategies will be both effective and efficient, we will initiate performance-based control programs, possibly including on-farm HACCP for eggs. While we are moving controls into place to prevent SE contamination of eggs, we also must react to episodes of contamination and the illness that results from it. In 1995, FDA assumed responsibility for investigating shell egg outbreaks, tracing back egg-associated SE illnesses to particular producers/flocks, sampling, diverting eggs, and collecting flock data to help track the presence of SE. Prior to 1995, APHIS conducted the traceback program. FDA and ARS continue to conduct research to improve the range of prevention and control options available to government and industry.

Processing and Packaging

Processing and packaging are steps in the farm-to-table continuum that involve the washing, grading, and packing of eggs for transport to distributors, retailers, or manufacturers of food products. The principal aspect of SE control during this phase is temperature control to prevent growth of SE already contaminating the internal contents of some eggs. The field and laboratory research focus in this area has been on the effects of rapid or delayed cooling, temperature fluctuations, temperatures that will prevent growth of SE, and technologies that achieve the desired time/temperature conditions. The agencies are aware of ongoing research discussed in the GAO report on methods of rapid cooling. The overall impact on egg safety, costs, and potential problems of the methods being developed in North Carolina and California will be reviewed jointly by FDA and FSIS.


Transportation of shell eggs is the next stage in the farm-to-table continuum. Temperature control is the focus of prevention efforts during transportation. Research has shown that internal egg temperatures of 45º F or lower are unlikely to promote SE growth, should SE be present in the egg. Therefore, on August 27, 1998, FSIS published a final rule implementing amendments to the EPIA, requiring that

  • shell eggs packed for consumer use be stored and transported under ambient temperature not to exceed 45ºF,
  • the packed shell eggs be labeled to state refrigeration is required, and
  • any shell eggs imported into the United States packed for consumer use include a certification that the eggs, at all times after packing, have been stored and transported at an ambient temperature of no greater than 45º F.

FSIS consulted with FDA during development of this final rule. The President just announced an FSIS Directive to implement this final rule.


FDA and FSIS work with the States to encourage uniformity among the State laws affecting food safety in retail and food service establishments. The principle mechanism for this is the Food Code, a model code published by FDA intended for adoption by State and local authorities to use in regulating retail food and food service establishments. At present, 14 states have adopted the Food Code, and adoption is pending in 22 others.

FDA's Food Code requires in retail and food service establishments:

  • Refrigeration of potentially hazardous foods, including shell eggs,
  • Proper cooking of shell eggs, and
  • Substitution of pasteurized eggs for raw eggs in the preparation of foods such as Caesar salad, egg nog, ice cream, Hollandaise or béarnaise sauce, and for pooled eggs that are served to highly susceptible populations.

The Food Code also contains specific guidance on egg safety for foodservice workers who prepare eggs and egg-containing dishes for highly susceptible persons, including nursing home residents. In addition, FDA is directing special guidance to elementary schools and day care centers and, through them, to parents of young children. FDA also is finalizing plans for a safe egg handling educational campaign for foodservice workers, health educators, and inspectors.

FDA also has been working on a proposed rule to address refrigeration and labeling of eggs that is consistent with the requirements of the FSIS rule. The FDA proposed rule, "Food Labeling: Safe Handling Statements: Labeling of Shell Eggs; Shell Eggs: Refrigeration of Shell Eggs Held for Retail Distribution" was just placed on public display at the office of the Federal Register. This proposal directly responds to and corrects problems outlined by GAO. It proposes requirements that all shell eggs be stored and displayed at a temperature of 45º F or less, and would cover shell eggs sold both interstate and intrastate. It also proposes safe handling statements on labels of cartons of shell eggs that have not been treated to destroy Salmonella. The statement would read, "Safe Handling Instructions: Eggs may contain harmful bacteria known to cause serious illness, especially in children, the elderly, and persons with weakened immune systems. For your protection, keep eggs refrigerated, cook eggs until yolks are firm, and cook foods containing eggs thoroughly before eating." This label, once finalized will replace the label requirements included in the FSIS rule. FDA is aware that refrigeration and labeling solve only parts of the problem. The agencies view this regulation as one step in a comprehensive action plan.


During final preparation of eggs and egg-containing dishes in our homes, we can protect ourselves by following simple food safety rules, including proper refrigeration and thorough cooking. The primary tool the agencies have for helping consumers reduce their own risk of foodborne disease is education on safe food handling, and our proposed labeling requirements will be an important adjunct to our other efforts to inform the public. HHS, FSIS, and the Department of Education are partners with consumer groups and industry in a consumer education campaign begun in 1997 as part of the President's Food Safety Initiative. This campaign builds on our previous efforts. The Fight BAC! Campaign covers all aspects of food safety, including information that pertains to safe handling of eggs. September is National Food Safety Month, and this year’s theme, "cook thoroughly," will contain special emphasis on eggs.

The agencies have coordinated other efforts to enhance egg safety during food preparation. The rulemakings on labeling, discussed above, provide consumers with an immediate reminder of how to safely handle eggs. Both FDA and FSIS publish electronically and in print various educational materials to enhance consumer knowledge on the safety of eggs and egg products. Additionally, both FDA and FSIS have taken extra measures to reduce the risk to vulnerable populations, such as the immune compromised or elderly. FDA and FSIS developed fact sheets on egg safety for the food service industry and consumers, to raise consumer awareness of safe handling practices. These fact sheets will be sent to food service directors serving populations who are especially at-risk for illness such as day care center and nursing home food service directors. Egg safety information also will be distributed to consumers through our national and regional offices and through the news media. Special mailings will be sent as well to media outlets and organizations who serve at-risk populations encouraging the inclusion of information on egg safety and encouraging the use of pasteurization in their publications and newsletters.


The President’s Council on Food Safety will create within 120 days a farm-to-table approach for addressing SE and eggs. The information from recent research, the joint FSIS/FDA 1998 Salmonella Enteritidis Risk Assessment, and the comments we received on the joint ANPR of May 19, 1998 referenced above, will be used by the task force to help finalize its recommended strategic plan for a comprehensive system to assure the safety of eggs and egg products. Strategic planning will be a coordinated interagency effort, and will feature a strong element of public input similar to the process used in our development of good practices guidance for fresh produce.


As you know, managing the risks of SE contamination in eggs in each step of the process from farm to table is a complex and challenging task. Since the time that CDC first identified the growing public health problem of SE infections and their association with eggs, HHS and USDA have worked diligently with their state partners, the food industry, and consumers to understand and control SE, and to encourage or require adoption of specific efforts to prevent contamination of eggs and illness among consumers. The decreasing numbers of infections and outbreaks encourages us. We recognize, however, that more progress must be made because the magnitude of the remaining public health problem is too great. SE and its association with eggs has been hard to understand and has revealed its secrets slowly, and the way toward its control has been less straightforward than we had hoped.

While much has been done to address these challenges, more is needed. We will conceive and construct a disease prevention and control strategy that will pull together all of the separate actions - whether HHS and USDA, or state-based - needed to provide for a more comprehensive, coordinated government approach. It is our expectation that the strategic plan we will release by the end of October 1999 will provide that approach.

Mr. Chairman, in response to the question posed by the title of this hearing, "Egg Safety: Are There Cracks in the Federal Food Safety System?" we feel that while there clearly are complex lines of jurisdiction over eggs between FDA, FSIS, and AMS, those lines are not "cracks," but seams. We are committed to smoothing out those seams and providing the country with a seamless coordinated national farm-to-table policy.

I would be happy to answer any questions.