United States General Accounting Office

GAO Report to the Honorable Tom Harkin,

Ranking Minority Member, Committee

on Agriculture, Nutrition, and Forestry,

U.S. Senate

April 1999 FOOD SAFETY

The Agricultural Use of

Antibiotics and Its

Implications for

Human Health

GAO/RCED-99-74

GAO United States

General Accounting Office

Washington, D.C. 20548

Resources, Community, and

Economic Development Division

B-281942 

April 28, 1999

The Honorable Tom Harkin

Ranking Minority Member, Committee on

Agriculture, Nutrition, and Forestry

United States Senate

Infectious diseases are the third leading cause of death in the United

States, behind heart disease and cancer, and antibiotics are often

necessary in their treatment. Antibiotic resistance, which occurs when

antibiotics that had been used effectively to treat infections are no longer

able to kill bacteria growth, is a serious human health problem. The

factors that contribute to antibiotic resistance include the nature of

disease-producing bacteria (pathogens), environmental pressures, and the

use of antibiotics in human medicine as well as in agriculture.

As you have requested, this report explores antibiotic-resistance issues

that may stem from the use of antibiotics in agriculture. Specifically, this

report examines (1) how antibiotics are used in agriculture and the

implications of that use for human health, (2) the federal roles and

responsibilities for overseeing the use of antibiotics in agriculture, and

(3) the issues surrounding the debate over whether to further regulate or

restrict the use of antibiotics in agriculture.

To conduct this work, we reviewed scientific and medical studies, reports,

and other literature and spoke with experts in government, academia, and

private industry. We performed our review from May 1998 through

April 1999 in accordance with generally accepted government auditing

standards. Further details of our scope and methodology are discussed in

appendix I.

Results in Brief Antibiotics are used in agriculture to treat and prevent diseases in animals

and in food plants and as a feed additive to improve the growth rate in

animals. Research has linked the use of antibiotics in agriculture to the

emergence of antibiotic-resistant strains of disease-causing bacteria. These

bacteria, which are known to cause illness or disease in humans, include

Salmonella, Campylobacter, and Escherichia coli, commonly known as E.

coli. Although the ill effects of these foodborne pathogens are generally

mild to moderate, each year several thousand persons have severe illness

resulting in hundreds of deaths. However, there are no current

comprehensive estimates of the extent to which antibiotic-resistant strains

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have resulted in illnesses and deaths. Researchers believe these organisms

acquire resistance to antibiotics while in an animal; the resistant strain is

then passed to humans through food or through direct contact with

animals or animal waste. In addition to this direct transfer of

antibiotic-resistant organisms, some research indicates that the use of

antibiotics in food animals may reduce the effectiveness of related

antibiotics when used to treat humans. While research has linked the use

of antibiotics in agriculture to the emergence of antibiotic-resistant

foodborne pathogens, agricultural use is only one of several factors that

contributes to antibiotic resistance in humans for pathogens that are not

foodborne.

Several federal agencies have responsibilities regarding the use of

antibiotics in agriculture. Approving antibiotics and setting allowable

levels for antibiotic residues in food products is determined by the

Department of Health and Human Services’ Food and Drug Administration

for animals and the Environmental Protection Agency for food plants.

Testing for antibiotic levels in foods is performed by the Food Safety and

Inspection Service for meat and poultry and by the Food and Drug

Administration for eggs, milk, and food plants. Monitoring the

development of resistance to antibiotics in humans, including resistance

stemming from agricultural sources, is conducted under a program run

jointly by the U.S. Department of Agriculture, the Food and Drug

Administration, and the Department of Health and Human Services’

Centers for Disease Control and Prevention.

The debate over whether to further regulate or restrict the use of

antibiotics in animals and plants centers around the risk their use may

pose to human health relative to their benefits to agriculture. This concern

has prompted several European countries to ban the use in animal feed of

four antibiotics that are considered very important in treating humans.

Representatives of beef, pork, and poultry producers and pharmaceutical

manufacturers assert that antibiotics play an important role in providing

an abundant and affordable food supply. In their view, agricultural use is

only one potential contributor to antibiotic resistance in humans and the

research does not warrant restricting antibiotic use in agriculture. This

debate exists within the federal government as well. The U.S. Department

of Agriculture believes that more research is needed before decisions are

made regarding the further regulation or restriction of antibiotic use in

food animals. The Department of Health and Human Services, on the other

hand, believes that based on the scientific evidence, steps are needed

now—not at some time in the future—to decrease such use. However, the

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Food and Drug Administration’s recently proposed framework for

evaluating the safety of antibiotics for use in food-producing animals does

not include specific time frames for reevaluating currently approved

antibiotics. The proposed framework targets new antibiotics and new uses

of currently approved antibiotics. The framework will apply to the current

uses of antibiotics only to the extent resources allow. We are

recommending that the departments of Agriculture and Health and Human

Services work together to develop and implement a plan with specific

goals, time frames, and resources needed for determining the safe use of

antibiotics in agriculture.

Background Many infectious diseases—including pneumonia, tuberculosis, and

common childhood ear infections—are caused by bacteria that have

developed resistance to one or more previously effective antibiotics.

Resistance may occur when the introduction of an antibiotic imposes

“selective pressure” on an organism that has mutated by random genetic

change. The antibiotic will not be able to kill the resistant strain of the

organism. If susceptible bacteria are killed, remaining resistant bacteria

may then become the dominant strain. For example, for nearly 40 years

after penicillin was introduced, it was used successfully to treat

pneumonia; today, penicillin-resistant strains of pneumonia are dominant

in many countries. Also, disease-causing bacteria—or pathogens—may

develop resistance spontaneously. For further information about the

development of antibiotic resistance and the public health burden

associated with resistant bacteria, see Antimicrobial Resistance: Data to

Assess Public Health Threat From Resistant Bacteria Are Limited

(GAO/HEHS/NSIAD/RCED-99-132, Apr. 28, 1999).1

Experts Believe the

Use of Antibiotics in

Agriculture Is Linked

to the Emergence of

Antibiotic Resistance

Antibiotics are used in both food-producing animals and on food plants to

treat specific diseases afflicting specific animals and plants and to prevent

the spread of diseases that are known to occur in particular herds, flocks,

and crops under certain conditions. Antibiotics are also used in food

animals to enhance their growth rate and feed efficiency—that is,

increasing the amount of feed that is absorbed by the animal. Antibiotics

used on animals may be obtained over-the-counter in feed stores and are

included in commercially available animal feed. Antibiotics may also be

dispensed under a veterinarian’s prescription. For larger animals (such as

cattle), antibiotics may be administered by injection or mixed with water;

for smaller animals (such as poultry), they are generally mixed with feed

1

An antimicrobial is a substance used to treat a bacterial, fungal, or viral infection.

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or water. As a pesticide for disease treatment and prevention, antibiotics

are generally sprayed onto plants. However, data are not available on the

quantities of specific antibiotics used in agriculture and the purposes for

which they are used. Appendix II presents information on the major

classes of antibiotics, provides examples of specific antibiotics within

each class, and indicates the antibiotics within that class have been

approved for use on animals, plants, and/or humans.

Research Has Linked

Three Diseases With

Antibiotic-Resistant Strains

Affecting Humans to the

Use of Antibiotics in

Animals

Experts, including those in the Department of Health and Human Service’s

(HHS) Food and Drug Administration (FDA), and Centers for Disease

Control and Prevention (CDC), believe that resistant strains of three

specific organisms that cause illness or disease in humans—Salmonella,

Campylobacter, and E. coli—are linked to the use of antibiotics in

animals. Salmonella and Campylobacter infections generally cause

intestinal distress and do not require medical treatment.

However, each year several thousand persons have severe illnesses

resulting in hundreds of deaths. Young children, the elderly, and patients

whose immune systems are compromised are especially at risk. Severe

cases of Salmonella have been associated with infections in the blood and

the lining of the brain and other deep body tissue. According to CDC, each

year an estimated 8,000 to 18,000 hospitalizations, 2,400 bloodstream

infections, and 500 deaths are associated with Salmonella infections. One

in 1,000 Campylobacter infections result in Guillain-Barré Syndrome, a

disease that can cause paralysis. Most E. coli strains are relatively

harmless in humans, but one strain causes a potentially serious illness in

children and individuals with weakened immune systems. However, there

are no current comprehensive estimates of the extent to which

antibiotic-resistant strains of Salmonella, Campylobacter and E. coli have

resulted in severe illnesses or deaths in humans. According to scientists at

CDC, resistant strains of these organisms acquire resistance to antibiotics

while in the animal. The resistant strain of the disease is then transferred

to humans through food or through contact with animals or animal waste.

A more detailed discussion of these organisms and their development of

antibiotic resistance is presented in appendix II.

In addition to the direct foodborne transfer of antibiotic resistance from

these three specific organisms, some research suggests that the use of

antibiotics in food animals may reduce the effectiveness of related

antibiotics used to treat humans. This concern is often raised about

antibiotics administered in low doses over a continuous period, such as

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those used in agriculture to promote animal growth. The research most

often cited with this issue was conducted in Denmark during the early

1990s and concerns the closely related antibiotics avoparcin and

vancomycin. Scientists there reported linking the use of avoparcin in

animals to the emergence of vancomycin-resistant enterococci—generally

known as VRE—in humans. VRE is an organism generally contracted in a

hospital setting that causes serious, and in some cases untreatable,

infections in humans.

In the United States, avoparcin has never been approved for use in

agriculture or human medicine, and vancomycin has never been approved

for use in agriculture. However, according to FDA officials, FDA discovered

an instance in which avoparcin was used illegally in the United States in

the production of veal and possibly other meat products. FDA pursued

regulatory enforcement, and, according to officials, the individual

responsible was convicted of a crime.

Vancomycin is an extremely important drug in the treatment of

antibiotic-resistant bacterial infections in humans, many of which are

serious and life-threatening and cannot be treated by any other currently

approved antibiotic. According to CDC, the excessive use of vancomycin in

human medicine is a primary cause for the rapid rise of VRE in the United

States. Studies estimate that doctors inappropriately prescribe

vancomycin in treating illnesses in humans 30 to 80 percent of the time.

While research is available on the emergence of antibiotic-resistant strains

of foodborne pathogens, such as Salmonella, Campylobacter, and E. coli,

for nonfoodborne human pathogens (such as VRE), agricultural use is only

one factor that contributes to the problem of antibiotic resistance in

humans. Only a few studies, primarily in Europe, have examined

agriculture’s contribution—relative to the contributions of other factors,

such as the inappropriate prescribing of antibiotics in human

medicine—to the development of resistance in nonfoodborne human

pathogens. Appendix I identifies several studies, reports, and scientific

articles by, among others, the National Research Council, World Health

Organization, Institutes of Medicine, Office of Technology Assessment,

and British House of Lords, that discuss and assess the research on these

issues.

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Several Agencies

Have Responsibilities

Regarding the Use of

Antibiotics in

Agriculture

Several federal agencies have roles involving the use of antibiotics in

agriculture and a multiagency program—the National Antimicrobial

Resistance Monitoring System-Enteric Bacteria—tracks the development

of antibiotic-resistant strains of Salmonella and Campylobacter (see table

1).

Table 1: Federal Agencies’ Roles Related to the Use of Antibiotics in Agriculture

Federal agencies

Approval for

agriculture use

Testing for residual

levels

Monitoring resistance

development

Related monitoring

programs

U.S. Department of Agriculture

Agricultural Research

Service X

Animal and Plant Health

Inspection Service X X

Food Safety and Inspection

Service X X

Department of Health and Human Services

Centers for Disease Control

and Prevention X X

Food and Drug

Administration X X

Environmental Protection Agency

Office of Pesticide Programs X

Two agencies are responsible for approving the use of antibiotics by the

agriculture industry. FDA approves all antibiotics used for food-producing

animals; the Environmental Protection Agency (EPA) approves antibiotics

used as pesticides on produce and plants. FDA has approved many

antibiotics for use on food-producing animals; EPA has approved two

antibiotics for use on plants. FDA and EPA each establish maximum

allowable residue levels (tolerances) for the antibiotics they approve and

have regulatory authority to withdraw approvals, although withdrawing

approval can be a lengthy and difficult process.

The U.S. Department of Agriculture’s (USDA) Food Safety and Inspection

Service (FSIS) operates a program to ensure that antibiotic residues in food

products are within established limits. FSIS’ National Residue Program

tests meat and poultry products for antibiotic residues. These tests are

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performed on the carcasses of slaughtered animals and on samples

collected at ports of entry throughout the United States.2

The National Antimicrobial Resistance Monitoring System’s-Enteric

Bacteria program is the only federal program specifically focused on

testing for antimicrobial resistance related to agriculture. The program

was created in 1996 as a joint effort by FDA, CDC, and USDA. Initially,

Salmonella was selected as the sentinel organism for tracking antibiotic

resistance. Samples for this program are collected from humans in clinical

settings and from animals in clinical and nonclinical settings. The samples

are tested for susceptibility to 17 antibiotics. These antibiotics were

selected because they are either commonly used in animal and/or human

medicine or because they are very important to human medicine. CDC tests

the samples collected from humans, and USDA tests the samples collected

from animals. In 1997, the program was expanded to include testing of

Campylobacter samples. The head of veterinary testing for this program

told us that its scope has been relatively limited, however, because the

resources devoted to it have been limited.

Two other federal programs collect information related to disease-causing

organisms and antibiotic use, but neither is focused on antibiotic

resistance. USDA’s Animal and Plant Health Inspection Service operates the

National Animal Health Monitoring System. Through this program, the

agency conducts studies on animal health that include information about

antibiotic use—the reasons producers use antibiotics, the way antibiotics

are administered to the animals, and the size of producers’ operations. The

studies do not collect information about the quantities of antibiotics used.

However, the program has contributed samples for the National

Antimicrobial Resistance Monitoring System-Enteric Bacteria program.

CDC operates the Foodborne Disease Active Surveillance Network—also

known as FoodNet. This is a surveillance system designed to allow more

accurate and precise estimates and interpretation of the prevalence of

foodborne diseases over time.

2

FSIS is planning to eventually include the testing of egg products in the National Residue Program.

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Debate Is Ongoing

Over the Potential

Risk to Human Health

From the Agricultural

Use of Antibiotics

The debate over whether to further regulate or restrict the use of

antibiotics in agriculture centers around the risk their use may pose to

human health relative to their benefits to agriculture. Much of this debate

concerns the uncertainty about whether and to what extent antibiotic

resistance in humans may be acquired from the continued application of

low doses of certain antibiotics in animal feeds. We first questioned the

health implications of using antibiotics in animal feeds in 1977.3

 We noted

that the safety and effectiveness of the practice had not been established

and that the possibility existed that antibiotic-resistant bacteria may

develop and be transferred from animals to humans. Among other things,

we recommended that FDA determine the safety of antibiotics used in

animal feeds on the basis of available data and withdraw approval of any

not shown to be safe.

According to the Director of FDA’s Center for Veterinary Medicine, in 1978,

FDA proposed withdrawing approval of penicillin and tetracycline for other

than disease treatment in animals. In response to concerns over the

absence of definitive data to confirm that those antibiotics presented a

hazard to human health, FDA contracted with the National Academy of

Sciences to review the available data. According to a June 1980 report by a

House appropriations subcommittee, the Academy’s review found that

“the postulated hazards to human health...were neither proven nor

disproven.” The Academy recommended that additional research be

conducted to fill data gaps. The subcommittee report asked FDA to delay

implementing its proposal pending the final results of the additional

research and evidentiary hearings.

The World Health Organization, the United Nations’ group responsible for

monitoring global health, sponsored two recent conferences to examine

the research on antibiotic resistance and agriculture. The first conference,

in October 1997, addressed the medical impacts of the use of

antimicrobials in food-producing animals. At the conclusion of this

conference, scientists advocated (1) a more thorough assessment of the

risks, (2) increased monitoring to detect the emergence of resistance, and

(3) terminating the use of antibiotics for growth promotion in animals if

they are also used in human medicine or are known to potentially become

cross-resistant to antibiotics used in human medicine. Scientists attending

the second conference in June 1998 recommended more research on the

emergence of resistance to, and prudent practices for using, the class of

antibiotics known as quinolones in animals.

3

Need to Establish Safety and Effectiveness of Antibiotics Used in Animal Feeds (GAO/HRD-77-81,

June 27, 1977).

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Other Countries Believe

Potential Human Health

Risks Warrant Limiting

Antibiotic Use in

Agriculture

On the basis of their assessment of the potential risks, several countries

have acted to reduce the agricultural use of antibiotics. The United

Kingdom banned the use of penicillin and tetracycline for growth

promotion in the early 1970s; other European countries followed suit

shortly thereafter. Sweden banned the use of all antibiotics for growth

promotion in 1986, and Denmark banned the use of one antibiotic in

animal feed in 1998.4

 Canada’s health department has called for a

voluntary reduction in the amount of antibiotics used in agriculture. In

December 1998, health ministers for the European Union voted to ban four

antibiotics that were widely used to promote animal growth. They

announced that they were taking this action as a precaution to minimize

the risk of the development of resistant bacteria and to preserve the

efficacy of certain antibiotics used in human medicine.5

 The ban is

scheduled to become effective for the 15 members of the European Union

on July 1, 1999.

Associations Representing

Agriculture and

Pharmaceutical Industries

and Veterinarians Believe

Restricting Antibiotics Is

Not Warranted

In the United States, associations representing beef, pork, and poultry

producers and pharmaceutical manufacturers have stated that restricting

the use of antibiotics in agriculture is not warranted and is not supported

by science. In their view, the use of antibiotics in agriculture is only one

potential contributor to antibiotic resistance in humans and the extent of

agriculture’s contribution has not been determined. They also believe that

the research does not warrant restricting the use of antibiotics in

agriculture. These associations believe that antibiotics are vital to

agricultural industries and contend that most producers are already using

antibiotics prudently.

The Animal Health Institute, a trade association representing

manufacturers of animal health products, including pharmaceuticals, has

announced a plan that calls for (1) assessing the benefits and risks to

humans from treating animals with antibiotics, (2) developing guidelines

for prudently using antibiotics in farm animals, and (3) supporting

improved surveillance and monitoring of the use of antibiotics.

Associations representing beef, pork, and dairy producers are also

advising their members on antibiotic use. The National Cattlemen’s Beef

Association has advised its members to “strive to limit the need for

4

Denmark’s ban on virginiamycin went into effect in January 1998.

5

The European Union, which is comprised of Austria, Belgium, Denmark, Finland, France, Germany,

Greece, Ireland, Italy, Luxembourg, the Netherlands, Portugal, Spain, Sweden, and the United

Kingdom, has proposed a ban on bacitracin zinc, spiramycin, virginiamycin, and tylosin phosphate.

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[antibiotic] use through sound husbandry and preventative practices.”

Both the National Milk Producers Federation and the National Pork

Producers Council have developed 10-point Quality Assurance programs

that advise members how to properly use antibiotics during production.

The National Broiler Council told us that poultry producers use antibiotics

prudently. Officials from Tyson, the nation’s largest poultry producer, told

us that the company stopped using antibiotics to promote animal growth

more than 2 years ago and has been experimenting with alternative poultry

production practices.

The American Veterinary Medical Association has been working with its

members to develop a set of principles aimed at safeguarding public health

and educating veterinarians on the potential risks posed by antibiotic use

in agriculture. The proposed principles include (1) emphasizing

appropriate animal husbandry and hygiene, routine health examinations,

and vaccinations in preference to antibiotics; (2) considering therapeutic

alternatives prior to using antibiotics; (3) avoiding, in initial therapy, those

antibiotics that are considered important in treating infections in humans,

and (4) avoiding the inappropriate use of antibiotics, such as for viral

infections without bacterial complications.

Federal Efforts to Identify

and Address Potential

Risks

USDA, CDC, and FDA agree that antibiotics are critical in treating diseases in

animals as well as humans. As we noted earlier, under the National

Antimicrobial Resistance Monitoring System-Enteric Bacteria program,

these agencies have been active in monitoring the emergence of

antibiotic-resistant Salmonella since 1996 and resistant Campylobacter

since 1997. They shared their concerns with us about the potential impact

on human health from using antibiotics in agriculture. CDC and FDA agree

that the agricultural use of antibiotics is a significant source of antibiotic

resistance among foodborne pathogens. They also agree that the extent to

which the agricultural use of antibiotics contributes to resistance in

other—nonfoodborne—pathogens that cause diseases in humans is not

precisely known, although evidence is increasing that these uses can be an

important contributing factor.

USDA’s activities have been limited to the testing and monitoring that the

Food Safety and Inspection Service, the Animal and Plant Health

Inspection Service, and the Agricultural Research Service do under the

National Antimicrobial Resistance Monitoring System-Enteric Bacteria

program. With regard to the debate over whether to further regulate or

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restrict the use of antibiotics in agriculture, USDA believes that, before any

decisions are made, more research is needed to determine how animals

acquire resistant strains of Salmonella, Campylobacter, and E. coli. USDA

also believes that research is needed to determine the extent to which

environmental sources contribute to the development of resistance in

these pathogens. In addition, according to USDA officials, the potential

health risks to humans from using antibiotics to promote animal growth

need to be weighed against the economic benefits to the consumers of this

use.

CDC’s experts have advocated several measures to reduce the use of

antibiotics in agriculture. CDC researchers believe that some antibiotics

should not be used in animal feed to promote growth. These researchers

told us that, in treating diseases, veterinarians need to ensure that they are

prescribing the appropriate doses of antibiotics. To prevent the spread of

disease, alternatives to antibiotics—such as improved hygiene and

sanitation, feed safety, and “direct-fed microbials”—good or harmless

bacteria that can be used to outcompete harmful or bad bacteria—should

be used when appropriate. With regard to promoting growth in animals,

CDC supports restricting the use of antibiotics because CDC believes such

use results in antibiotic resistance that is transmitted to humans through

the food supply and may limit treatment options in ill persons. CDC has

specifically suggested that FDA reconsider its approval of penicillin and

tetracycline for promoting growth in animals, as well as its approval of

fluoroquinolones for disease treatment and prevention in poultry.

According to CDC, fluoroquinolones are vital antibiotics for the treatment

of serious Salmonella and Campylobacter infections in humans.

According to FDA officials, the development of fluoroquinolone-resistant

strains of Salmonella and Campylobacter highlights the need to better

address the potential development of bacterial resistance as part of the

safety determination prior to approving new antibiotics for use in

food-producing animals. FDA has publicly stated that the current regulatory

structure is inadequate to properly evaluate the human health impact of

antibiotic resistance from the use of antibiotics in food-producing animals.

To address these concerns, in November 1998 FDA’s Center for Veterinary

Medicine published Proposed Framework for Evaluating and Assuring the

Human Safety of the Microbial Effects of Antimicrobial New Animal Drugs

Intended for Use in Food- Producing Animals. This framework is intended

to provide a mechanism for evaluating and ensuring the human safety of

antibiotics and other antimicrobials used in food animals, including those

used for growth promotion.

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The proposed framework includes components for assessing antibiotics

on the basis of (1) the importance of the antibiotic to human medicine,

(2) preapproval data showing a safe level of resistance transfer, (3) the

establishment of thresholds for monitoring safe resistance levels, (4) the

effect of proposed uses on human pathogen load, and (5) post approval

studies and monitoring. The Animal Health Institute objects to the

post-approval monitoring requirements of FDA’s proposed framework,

saying that it would be cost-prohibitive and that it is not justified from a

public health standpoint.

HHS noted that the framework sets out a conceptual risk-based process, the

goal of which is to ensure that the antibiotics that are significant in human

treatment are not lost because of the use of antimicrobials in animals

while also providing for the safe use of antimicrobials in animals. The

proposed framework includes a footnote indicating that the agency

anticipates that the framework will be used, as resources allow, to review

existing approved uses of antibiotics on food-producing animals. Although

FDA officials told us that they intend to use the framework for evaluating

the safety of all antibiotics currently approved, the framework does not

specify a specific strategy and time frame for this reevaluation. In

January 1999, FDA convened a public meeting to discuss and obtain

comments on the proposed framework. FDA is in the process of revising

the framework in response to the meeting and the written comments it has

received.

Finally, although FDA officials told us in July 1998 that they shared CDC’s

concerns about fluoroquinolone resistance, FDA has not initiated an action

to withdraw its earlier approval for the use of fluoroquinolones on poultry.

In addition, FDA approved fluoroquinolones for use on beef cattle in

August 1998.

Conclusions Although research has linked the use of antibiotics in agriculture to

antibiotic-resistant strains of specific foodborne pathogens that affect

humans, agricultural use is only one factor in the emergence of antibiotic

resistance in nonfoodborne pathogens. Debate exists over whether the

role of agricultural use in the overall burden of antibiotic-resistant

infections of humans warrants further regulation or restriction. CDC

believes the potential human health risks call for action to restrict

antibiotics for growth promotion in animals. We first raised concerns in

1977 about the potential human health risks of this practice. Today, more

than two decades later, federal agencies have not reached agreement on

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the safe use of antibiotics in agriculture. In developing a federal response,

both human health concerns and the impact on the agriculture industry

are factors to consider.

Recommendation to

the Secretaries of

Agriculture and

Health and Human

Services

In light of the emergence of antibiotic resistance in humans, questions

about the extent that the agricultural use of antibiotics contributes to the

human health burden, and the debate over whether further regulation or

restriction of use in agriculture is needed, we recommend that the

Secretaries of Agriculture and of Health and Human Services develop and

implement a plan that contains specific goals, time frames, and resources

needed to evaluate the risks and benefits of the existing and future use of

antibiotics in agriculture, including identifying and filling critical data gaps

and research needs.

Agency Comments We provided copies of a draft of this report to USDA, HHS, and EPA for their

review and comment. To obtain USDA’s comments, we met with officials in

the Food Safety and Inspection Service; the Animal and Plant Health

Inspection Service; and the Agricultural Research Service, including the

Associate Deputy Administrator for Animal Production, Product Value and

Safety. HHS provided written comments, which appear with our response

in appendix IV. EPA had no formal comments on the draft report. The

agencies also provided technical comments that we incorporated

throughout the report as appropriate.

USDA generally found the draft report to be an accurate presentation of the

facts and agreed with the recommendation but believed the draft

overstated the extent to which antibiotic use in agriculture may be linked

to the emergence of antibiotic resistance in humans. USDA acknowledged

that the use of antimicrobials can lead to the development of resistance

but does not believe that there is consensus among experts that research

has linked the use of antibiotics in agriculture to the emergence of

resistant strains of Salmonella, Campylobacter, and E. coli in humans.

USDA also commented that more research is needed before decisions are

made to further regulate or restrict the use of antibiotics in agriculture. We

have incorporated USDA’s positions into the report.

HHS, on the other hand, believed the draft report did not fully recognize

what HHS believes is the current state of knowledge—the increasing body

of evidence pointing to the connection between the agricultural use of

antibiotics and resistant foodborne illnesses, and the potential adverse

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human health consequences of antibiotic use in agriculture. Noting that

preventive action is needed now, the Department stated, “steps need to be

taken to decrease the use in agriculture of antibiotics that contribute to

the development of resistant strains of human pathogens.” It also pointed

out that the public health community is concerned not only with the

growth promotion uses of antibiotics in agriculture but also with uses to

treat and prevent disease, which “can be significant contributors to the

pool of resistant microorganisms that enter the food chain” and often

involve “critical drugs of last resort in treating a variety of human

infections.” While the Department believes no further research is needed

to prove the link for foodborne pathogens, it does believes more research

would be beneficial in assessing agricultural practices that can reduce

antimicrobial use, identifying the types of use that are high or low risk, and

better understanding the potential risks of resistance transfer from animal

organisms other than typical foodborne pathogens.

With regard to our recommendation, HHS pointed out that under the Food

and Drug Administration’s proposed framework, applicants would have to

conduct tests to determine the potential for inducing resistance for new

animal drugs. It also stated that the framework would allow the Food and

Drug Administration to withdraw already marketed antibiotics. While we

agree that the framework is an important step, especially for developing

data on antibiotic use, it does not include specific goals and time frames.

Moreover, the proposal states that currently approved antibiotics and their

uses will be assessed only to the extent resources allow. Without a specific

plan, goals, time frames, and the identification of needed resources for

such assessments, human health concerns that were raised more than two

decades ago may remain unanswered. Finally, the disparity between USDA’s

and the HHS’ views further highlights the need for the departments to work

together to ensure that both human health concerns and the impact on the

agriculture industry are considered. We have incorporated HHS’ comments

into the report as appropriate.

As arranged with your office, unless you publicly announce its contents

earlier, we plan no further distribution of this report until 14 days from the

date of this letter. At that time, we will send copies of this report to the

Honorable Richard Lugar, Chairman, Senate Committee on Agriculture,

Nutrition, and Forestry; the Honorable Larry Combest, Chairman, and the

Honorable Charles Stenholm, Ranking Minority Member, House

Committee on Agriculture; the Honorable James Jefford, Chairman, and

the Honorable Edward M. Kennedy, Ranking Minority Member, Senate

Page 14 GAO/RCED-99-74 Food Safety
B-281942 

Committee on Health, Education, Labor, and Pensions; and the Honorable

Tom Bliley, Chairman, and the Honorable John Dingell, Ranking Minority

Member, House Committee on Commerce. We will also send copies to the

Honorable Dan Glickman, Secretary of Agriculture; the Honorable Donna

Shalala, Secretary of Health and Human Services; the Honorable Carol

Browner, Administrator, Environmental Protection Agency; the Honorable

Jane Henney, M.D., Commissioner, Food and Drug Administration; the

Honorable Jeffrey P. Koplan, M.D., Director, Centers for Disease Control

and Prevention; the Honorable Jacob J. Lew, Director, Office of

Management and Budget; and other interested parties. We will also make

copies available to other on request.

If you any questions about this report, please contact me at (202) 512-5138.

Major contributors to the report are listed appendix V.

Lawrence J. Dyckman

 Director, Food and Agriculture Issues

Page 15 GAO/RCED-99-74 Food Safety
Contents

Letter 1

Appendix I 

Objectives, Scope,

and Methodology

18

Appendix II 

Approved Uses of

Selected Classes of

Antibiotics in the

United States

20

Appendix III 

Antibiotic-Resistant

Strains Have Emerged

in Three Food-Related

Organisms That Cause

Diseases in Humans

23

Appendix IV 

Comments From the

Department of Health

and Human Services

25

GAO’s Comments 30

Appendix V 

Major Contributors to

This Report

33

Tables Table 1: Federal Agencies’ Roles Related to the Use of

Antibiotics in Agriculture

6

Table II.1: Major Classes of Antibiotics, Examples in Each Class,

and Approval for Use on Animals, Plants, and/or Humans

20

Page 16 GAO/RCED-99-74 Food Safety
Contents

Abbreviations

APHIS Animal and Plant Health Inspection Service

ARS Agricultural Research Service

CDC Centers for Disease Control and Prevention

EPA Environmental Protection Agency

FDA Food and Drug Administration

FSIS Food Safety and Inspection Service

HHS Department of Health and Human Services

VRE vancomycin-resistant enterococci

USDA Department of Agriculture

Page 17 GAO/RCED-99-74 Food Safety
Appendix I 

Objectives, Scope, and Methodology

This report examines (1) how antibiotics are used in agriculture and the

implications of that use for human health; (2) federal roles and

responsibilities for overseeing the use of antibiotics in agriculture; and

(3) issues surrounding the debate over whether to further regulate or

restrict the use of antibiotics in agriculture.

To determine how antibiotics are used in agriculture, we spoke with

officials from the Center for Veterinary Medicine in the Food and Drug

Administration (FDA); the Office of Pesticide Programs in the

Environmental Protection Agency (EPA); and the Agricultural Research

Service (ARS), Animal and Plant Health Inspection Service (APHIS) and

Food Safety and Inspection Service (FSIS) in the U.S. Department of

Agriculture (USDA). We also met with officials representing specific

agricultural industries, including the National Pork Producers Council, the

National Milk Producers Federation, the National Broiler Council, and the

National Cattlemen’s Beef Association. In addition, we spoke with officials

from the American Feed Industry Association, the American Veterinary

Medical Association, and the Animal Health Institute. From these

meetings, we also identified the classes of antibiotics with examples of

specific antibiotics approved for agriculture and the agricultural use for

which they are approved. For comparison, we used the Physicians’ Desk

Reference to identify classes of antibiotics and examples of antibiotics

used on humans.

To determine the implications for human health of the agricultural use of

antibiotics, we reviewed the relevant research findings of studies, reports,

and other scientific and medical literature, including, among others, “The

Use of Drugs in Food Animals: Benefits and Risk;” National Research

Council, July 9, 1998; “The Medical Impact of the Use of Antimicrobials in

Food Animals,” World Health Organization, October 1997; Workshop

Report, “Orphans and Incentives: Developing Technologies to Address

Emerging Infections,” Institute of Medicine, 1997; Workshop Report,

“Antimicrobial Resistance: Issues and Options,” Institute of Medicine,1998;

Impacts of Antibiotic-Resistant Bacteria,” U.S. Congress, Office of

Technology Assessment (OTA-H-629; Washington, D.C., U..S. Government

Printing Office, September 1995); “Joint Committee on the Use of

Antibiotics in Animal Husbandry and Veterinary Medicine,” November

1969 (Swann Report); the British House of Lords, Select Committee on

Science and Technology Seventh Report; “Emergence of

Multidrug-Resistant Salmonella Enterica Serotype Typhimurium DT-104

Infections in the United States,” The New England Journal of Medicine

(May 1998); “Technology Crisis and the Future of Agribusiness: Antibiotic

Page 18 GAO/RCED-99-74 Food Safety
Appendix I 

Objectives, Scope, and Methodology

Resistance in Humans and Animals,” Harvard Business School, July 1997;

“Can We Use Less Antibiotics?” Swedish Ministry of Agriculture, Food,

and Fisheries, 1997; “Protecting the Crown Jewels of Medicine, A strategic

plan to preserve the effectiveness of antibiotics.” Center for Science in the

Public Interest, 1998. We met with officials and scientists from the Centers

for Disease Control and Prevention (CDC), FDA and USDA and other experts,

both in and out of government, to obtain their expert opinions of the

studies and research that has been done on the subject.

To determine federal roles and responsibilities for overseeing the use of

antibiotics in agriculture, we spoke with officials and collected data from

FDA, EPA, CDC, and USDA’s Agricultural Research Service, Animal and Plant

Health Inspection Service, and Food Safety and Inspection Service. We

also reviewed applicable laws and regulations for these agencies.

To determine the issues surrounding the debate over whether to further

regulate or restrict the use of antibiotics in agriculture, we reviewed and

analyzed reports and documents published by, among others, the Institute

of Medicine, the National Research Council, the Office of Technology

Assessment, CDC, FDA, USDA, EPA, agricultural industry associations, the

New England Journal of Medicine, and the World Health Organization. We

discussed the issues with officials from the National Institutes of Health,

CDC, FDA, USDA, EPA, and the World Health Organization, and from

associations representing agricultural associations, veterinarians, and

pharmaceutical manufacturers.

We performed our review from May 1998 through April 1999 in accordance

with generally accepted government auditing standards.

Page 19 GAO/RCED-99-74 Food Safety
Appendix II 

Approved Uses of Selected Classes of

Antibiotics in the United States

Table II.1 lists major classes of antibiotics, provides examples of specific

antibiotics within each class, and indicates whether any antibiotics within

the class have been approved for use on animals, plants, and/or humans.

Based on information in the Physicians’ Desk Reference, this classification

of antibiotics is grouped according to specific characteristics, such as

similarities in chemical composition or in the way they kill or inhibit

bacterial organisms. (The Physicians’ Desk Reference provides the latest

available information on more than 2,500 specific pharmaceutical

products. Each entry provides an exact copy of the product’s

FDA-approved labeling.) While the table shows that many classes of

antibiotics approved for use in agriculture are also approved for use in

human medicine, it is important to note that the antibiotics cited as

examples may or may not be the antibiotic approved for a particular use.

For example, only two antibiotics have been approved for use on food

plants: streptomycin, which is an antibiotic in the class of

aminoglycosides, and oxytetracycline, an antibiotic in the class of

tetracyclines.

Table II.1: Major Classes of Antibiotics, Examples in Each Class, and Approval for Use on Animals, Plants, and/or Humans

Animals

Plants

Agriculture

Humans Antibiotic classes

(selected examples) Species

Disease

treatment

Disease

prevention

Growth

promotion

Aminoglycosides

(gentamicin, neomycin,

streptomycin)

beef cattle,

goats, poultry,a

sheep, swine,

certain plants

• • • •

Beta-Lactams

— penicillins 

(amoxocillin, ampicillin)

beef cattle,

dairy cows,

fowl,b poultry,

sheep, swine

• • • •

—Cephalosporins

1st generation

(cefadroxil)

•

—Cephalosporins

2nd generation

(cefuroxime)

•

—Cephalosporins

3rd generation

(ceftiofur)

beef cattle,

dairy cows,

poultry, sheep,

swine

• • •

Chloramphenicol •

Florfenicol beef cattle •

(continued)

Page 20 GAO/RCED-99-74 Food Safety
Appendix II 

Approved Uses of Selected Classes of

Antibiotics in the United States

Animals

Plants

Agriculture

Humans Antibiotic classes

(selected examples) Species

Disease

treatment

Disease

prevention

Growth

promotion

Cycloserines

(cycloserine)

•

Glycopeptides

(vancomycin)

•

Ionophores

(monensin, salinomycin,

semduramicin, lasalocid)

beef cattle,

fowl, goats,

poultry, rabbits,

sheep

• •

Lincosamides

(lincomycin)

poultry, swine • • •

Macrolides

(erythromycin, tilmicosin,

tylosin)

beef cattle,

poultry, swine

• • • •

Monobactams

(aztreonam)

•

Polypeptides (bacitracin) fowl, poultry,

swine

• • • •

Quinolones

Fluoroquinolones

(sarafloxacin,

enrofloxacin)

beef cattle,

poultry

• • •

Streptogramins

(virginiamycin)

beef cattle,

poultry, swine

• • •

Sulfonamides

(sulfadimethoxine,

sulfamethazine,

sulfisoxazole)

beef cattle,

dairy cows,

fowl, poultry,

swine, catfish,

trout, salmon

• • •

Tetracyclines

(chlortetracycline,

oxytetracycline,

tetracycline)

Beef cattle,

dairy cows,

fowl, honey

bees, poultry,

sheep, swine,

catfish, trout,

salmon, lobster,

certain plants

• • • • •

Other antibiotics

Bambermycin beef cattle,

poultry, swine

• •

Carbadox swine • • •

Novobiocin fowl, poultry • • •

Spectinomycin poultry, swine • •

(Table notes on next page)

Page 21 GAO/RCED-99-74 Food Safety
Appendix II 

Approved Uses of Selected Classes of

Antibiotics in the United States

aPoultry includes at least one of the following birds: broiler chickens, laying hens, and turkeys.

bFowl includes at least one of the following birds: ducks, pheasants, and quail.

Source: GAO

Page 22 GAO/RCED-99-74 Food Safety
Appendix III 

Antibiotic-Resistant Strains Have Emerged

in Three Food-Related Organisms That

Cause Diseases in Humans

Federal experts believe that research has linked the use of antibiotics in

agriculture to the emergence of antibiotic-resistant strains of three

disease-causing organisms. These organisms, which are known to cause

illness or disease in humans, are Salmonella, Campylobacter, and

Escherichia coli, commonly known as E. coli.

Salmonella Salmonella is an organism commonly found in poultry, eggs, beef, and

other foods of animal origin. According to public health officials, an

estimated 800,000 to 4 million cases of Salmonella infections occur each

year in the United States. Salmonella typically causes intestinal distress

and does not require medical treatment. However, severe cases of

Salmonella have been associated with reactive arthritis, as well as with

infections in the blood, in the meningeal linings of the brain, and in other

deep body tissues. Persons experiencing severe symptoms often seek

medical treatment. According to CDC, each year an estimated 8,000 to

18,000 hospitalizations, 2,400 bloodstream infections, and 500 deaths are

associated with Salmonella infections. Also, according to CDC, 40 percent

of people with a Salmonella infection who seek medical attention are

treated with antibiotics.

One particularly serious strain of Salmonella—Salmonella DT-104—is

known to be resistant to several antibiotics. CDC estimates that between

68,000 and 340,000 cases of Salmonella DT-104 occur annually in the

United States. About 95 percent of Salmonella DT-104 strains are resistant

to five antimicrobials—ampicillin, chloramphenicol, streptomycin,

sulfonamides, and tetracycline. Human illness from Salmonella DT-104

was first recognized in the United Kingdom in the mid-1980s. In 1993,

veterinarians in England began to treat poultry with fluoroquinolones, an

important class of antibiotics for treating diseases in humans. By 1996,

United Kingdom scientists reported that 14 percent of the Salmonella

DT-104 strains had a decreased susceptibility to fluoroquinolones.

Scientists are very concerned about the development of

fluoroquinolone-resistant Salmonella, because fluoroquinolones are the

drugs of choice to treat Salmonella infections in adults. Although

fluoroquinolone-resistant Salmonella infections are currently rare in the

United States, there has been a trend of decreasing susceptibility to

fluoroquinolones since they were first approved for agricultural use in

1995.

Page 23 GAO/RCED-99-74 Food Safety
Appendix III 

Antibiotic-Resistant Strains Have Emerged

in Three Food-Related Organisms That

Cause Diseases in Humans

Campylobacter Campylobacter is also an organism commonly found in poultry and other

food of animal origin, including pork and beef. According to public health

officials, 2 million to 4 million people suffer Campylobacter infections

annually. Campylobacter infections generally cause intestinal distress and

do not require medical treatment. However, one in every 1,000 reported

cases of Campylobacter results in Guillain-Barré Syndrome, a disease

associated with paralysis. The first case of domestically acquired

fluoroquinolone-resistant Campylobacter in humans in the United States

were identified in 1996, shortly after FDA approved fluoroquinolones for

use in poultry. World Health Organization scientists concluded that prior

to the use of fluoroquinolones in animals, there had been no reports of

fluoroquinolone-resistant Campylobacter infections in humans who had

no previous exposure to this class of antibiotics. CDC scientists believe this

provides evidence that antibiotic-resistant strains of Campylobacter are

transmitted directly from animals to humans.

E. Coli Although many strains of E. coli are carried normally in the intestines of

humans and animals, some strains cause foodborne illnesses. One

strain—E. coli O157:H7—causes potentially serious illness, particularly for

children and individuals with weakened immune systems. Each year in the

United States, an estimated 50 to 100 people die from E. coli 0157:H7

infections. Although antibiotics are not the recommended treatment for E.

coli O157:H7 infections, antibiotics are often given because of the

symptoms displayed in the patient and because some doctors believe

antibiotics will help. Antibiotic-resistant strains of E. coli O157:H7 have

been identified in animals, food, and humans, and the emergence of

antibiotic resistance in E. coli O157:H7 is of concern to scientists because

laboratory studies have demonstrated that organisms may exchange

genes, including the gene that allows an organism to resist an antibiotic.

Page 24 GAO/RCED-99-74 Food Safety
Appendix IV 

Comments From the Department of Health

and Human Services

Note: GAO comments

supplementing those in the

report text appear at the

end of this appendix.

Page 25 GAO/RCED-99-74 Food Safety
Appendix IV 

Comments From the Department of Health

and Human Services

See comment 1.

See comment 2.

See comment 3.

See comment 4.

Page 26 GAO/RCED-99-74 Food Safety
Appendix IV 

Comments From the Department of Health

and Human Services

See comment 5.

See comment 6.

See comment 7.

See comment 8.

See comment 9.

See comment 10.

Page 27 GAO/RCED-99-74 Food Safety
Appendix IV 

Comments From the Department of Health

and Human Services

See comment 11.

Page 28 GAO/RCED-99-74 Food Safety
Appendix IV 

Comments From the Department of Health

and Human Services

Page 29 GAO/RCED-99-74 Food Safety
Appendix IV 

Comments From the Department of Health

and Human Services

GAO’s Comments 1. We recognize the complexity of antimicrobial resistance and have

reviewed the considerable body of research on the human health

implications of the agricultural use of antibiotics. However, this report is

not intended to be a complete technical assessment of the public health

issues surrounding the agricultural use of antibiotics. Rather, it provides

information on agricultural use and the implications of that use for human

health, federal roles and responsibilities regarding the use of antibiotics in

agriculture, and the issues surrounding the debate over whether to further

regulate or restrict agricultural use. With regard to this debate, we present

the many divergent, sometimes conflicting, viewpoints. For a more

technical discussion of this complex public health issue, with citations to

several specific research papers, see Antimicrobial Resistance: Data to

Assess Public Health Threat From Resistant Bacteria Are Limited

(GAO/HEHS/NSIAD/RCED-99-132, Apr. 28, 1999).

2. The report acknowledges that the factors that contribute to antibiotic

resistance include the nature of pathogens, environmental pressures, and

the use of antibiotics in human medicine and in agriculture. The report

also discusses three antibiotic-resistant foodborne infections linked to the

use of antibiotics in food-producing animals.

3. It was not our intent to suggest that a major scientific study should be

undertaken to quantify agriculture’s contribution to the resistance

problem relative to other factors. However, the report does recognize that

there is not consensus on agriculture’s role. Indeed, the U.S. Department

of Agriculture (USDA) does not believe there is consensus among experts

that research has linked the use of antibiotics in agriculture to the

emergence of resistant strains of Salmonella, Campylobacter, and E. coli

in humans. We revised the report to clarify the Department of Health and

Human Services’ (HHS) positions that research has established that the use

of antimicrobials in agriculture contributes to resistant foodborne

pathogens and that there is a pressing need to promote the more prudent

use of antibiotics in each setting.

4. HHS notes that growth promotants deserve careful scrutiny but that a

simple ban on growth promotants would not address all uses of antibiotics

in agriculture. HHS states that the Food and Drug Administration’s (FDA)

proposal: Proposed Framework for Evaluating and Assuring the Human

Safety of the Microbial Effects of Antimicrobial New Animal Drugs

Intended for Use in Food-Producing Animals will address all uses of

antibiotics in agriculture. While the framework is an important step

forward, it does not include specific goals and time frames for such

Page 30 GAO/RCED-99-74 Food Safety
Appendix IV 

Comments From the Department of Health

and Human Services

assessments to help ensure that needed evaluations occur in a timely

manner. Moreover, the framework will be applied to currently approved

antibiotics—including currently used growth promotants—only to the

extent resources allow. We revised the report to clarify HHS’ position on

the issue of antibiotic use in food-producing animals and to more fully

describe FDA’s proposal.

5. The report text discusses the National Antimicrobial Resistance

Monitoring System-Enteric Bacteria program, and appendix II discusses

the emergence of multidrug-resistant strains of foodborne diseases.

6. HHS notes that the draft report did not mention that the lack of detailed

animal drug use information is a barrier to advancing scientific discussion

on the adverse human health consequences of antibiotic use in agriculture.

HHS states that the implementation of FDA’s framework would obtain these

data. We have revised the report to acknowledge that data are not

available on the quantities of specific antibiotics used in agriculture and

the purposes for which they are used. Our recommendation directs HHS

and USDA to identify data gaps as part of a plan for evaluating the risks and

benefits of existing and future uses of antibiotics in agriculture. As stated

previously, however, we do not agree that the implementation of FDA’s

framework would obtain these data in a timely fashion for new antibiotic

uses or, necessarily, at any time for existing uses.

7. As our report states, only a few studies, primarily conducted in Europe,

have examined agriculture’s contribution to the development of resistance

in nonfoodborne human pathogens. We believe our report presents a

balanced perspective with respect to the positions of industry,

researchers, and federal agencies. However, in recognition of the different

perspectives on the issue, we modified the recommendation to focus on

the debate over the need to further regulate or restrict the agricultural use

of antibiotics.

8. While our report does not discuss in detail the transfer of resistance

from nonpathogenic organisms to human pathogens, which, as HHS points

out, is a difficult and unresolved issue, it does discuss the development of

resistance from other than direct pathogen transfer and the fact that

laboratory studies have demonstrated that organisms can exchange genes,

including the gene that allows resistance.

9. We revised the report to include the data on the extent to which

Salmonella and Campylobacter pose a threat to humans.

Page 31 GAO/RCED-99-74 Food Safety
Appendix IV 

Comments From the Department of Health

and Human Services

10. HHS also pointed out that the public health community is concerned not

only with growth promotion uses of antibiotics in agriculture but also with

disease treatment and prevention uses, which “can be significant

contributors to the pool of resistant microorganisms that enter the food

chain” and often involve “critical drugs of last resort in treating a variety

of human infections.” It was not our intent to suggest otherwise. Our

report discusses several antibiotics that are importance to human

medicine that have been approved for use on animals, including

fluoroquinolones, which FDA has recently approved for disease treatment

on poultry and cattle. We included this comment in the Agency Comments

section of the report.

11. Finally, with regard to our recommendation, HHS pointed out that under

FDA’s proposed framework, applicants would have to conduct tests to

determine new animal drugs’ potential for inducing resistance. HHS also

stated that the framework would allow FDA to withdraw already marketed

antibiotics. As we noted earlier, the FDA framework is an important step,

especially for developing data on antibiotic use; however, the proposal

states that currently approved antibiotics and their uses will be assessed

only to the extent resources allow. Moreover, without a specific plan,

goals, time frames, and the identification of needed resources for such

assessments, human health concerns that were raised more than two

decades ago may remain unanswered.

Page 32 GAO/RCED-99-74 Food Safety
Appendix V 

Major Contributors to This Report

Robert E. Robertson, Associate Director

Erin Lansburgh, Assistant Director

Stuart Ryba, Evaluator-in-Charge

Natalie Herzog

Jerry Seigler

Shannon Bondi

(150090) Page 33 GAO/RCED-99-74 Food Safety
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