Estimated Annual Costs of Campylobacter-Associated Guillain-Barré Syndrome.

By Jean C. Buzby, Tanya Roberts, Food and Consumer Economics Division, Economic

Research Service, U.S. Department of Agriculture, and Ban Mishu Allos, Vanderbilt

University, School of Medicine. Agricultural Economic Report No. 756.

Abstract

Guillain-Barré syndrome (GBS) is an autoimmune reaction that can cause acute neuromuscular paralysis. Of an estimated 2,628 to 9,575 new U.S. cases with GBS annually,

526 to 3,830 are triggered by infection with Campylobacter, the most frequently isolated

cause of foodborne diarrhea. Estimated total annual costs of Campylobacter-associated

GBS of $0.2 to $1.8 billion plus previously estimated costs of campylobacteriosis ($1.3

to $6.2 billion) add to total annual costs from Campylobacter of $1.5 to $8.0 billion

(1995 dollars). Assuming 55-70 percent of costs are attributable to foodborne sources,

costs of campylobacteriosis from food sources ($0.7 to $4.3 billion) and costs of associated GBS ($0.1 to $1.3 billion) combined equal total annual costs of $0.8 to $5.6 billion

from foodborne Campylobacter. Reducing Campylobacter in food could prevent up to

$5.6 billion in costs annually.

Keywords: Campylobacter, cost-of-illness, foodborne pathogens, Guillain-Barré syndrome, lost productivity, medical costs.

Acknowledgments

The authors wish to thank Phaedra Schaeffer of the Centers for Disease Control and

Prevention and Stephen Crutchfield, James MacDonald, and Ann Vandeman of ERS for

providing valuable editorial comments and suggestions. We also wish to thank neurologists David Cornblath, Michael Graves, Carol Lee Koski, Allan Ropper, and others too

numerous to mention here for their comments and suggestions. We thank Tom Steahr,

University of Connecticut, and Ann Vandeman for providing national survey data, and

Charles Helbing, U.S. Health Care Financing Administration, for providing Medicare

data. We owe special thanks to our editor, Dale Simms of ERS.

Washington, DC 20005-4788 July 1997
Contents

Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .iii

Abbreviations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .iv

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1

Guillain-Barré Syndrome . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

The Cost-of-Illness Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

Human Capital (HC) Approach . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

Willingness-to-Pay Approach . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

Landefeld and Seskin Hybrid Approach . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

Costs of Campylobacter-Associated Guillain-Barré Syndrome . . . . . . . . . . . . . . . .7

Assumptions Used in Cost-of-Illness Analysis . . . . . . . . . . . . . . . . . . . . . . . .7

Annual Medical Costs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9

Annual Productivity Losses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12

Total Cost Estimates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14

Sensitivity Analyses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14

Sensitivity Analysis - Value of Adjusted Productivity Losses . . . . . . . . . . . .15

Sensitivity Analysis - Probability of Receiving Mechanical Ventilation . . . . .15

Foodborne Campylobacter-Associated Guillain-Barré Syndrome . . . . . . . . . . . . .16

Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19

Appendix: Guillain-Barré Syndrome . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23

ii USDA/ERS Estimated Annual Costs of Campylobacter-Associated GBS
Summary

Microbial pathogens in food cause between 6.5 million and 33 million cases of human

illness and up to 9,000 deaths each year in the United States. These illnesses and deaths

cost the United States billions of dollars each year in medical costs and lost productivity.

Campylobacter is one of the most common causes of foodborne diarrheal illness in the

United States. Sources of Campylobacter include raw and undercooked poultry, raw

milk, and polluted water. Up to $5.6 billion in human illness costs could be saved each

year in the United States by reducing Campylobacter in food.

Out of an estimated 2,628 to 9,575 patients diagnosed with Guillain Barré syndrome

(GBS) in the United States each year, 526 to 3,830 (20-40 percent) are triggered by

Campylobacter infection. GBS is a disease of the nervous system characterized by a

rapid onset, various degrees of numbness, pain, and progressive weakness or paralysis.

GBS is believed to be an autoimmune reaction that is triggered by factors such as gastrointestinal or respiratory illness. Two percent die from the illness, and up to 65 percent

of patients with GBS report neurological pain. Other potential lingering disabilities

include abnormalities of the nervous system and changes in heart rate, blood pressure,

vision, and body temperature. Most patients are hospitalized and some have relapses.

This report estimates:

• the annual U.S. cost of Campylobacter-associated GBS: $0.2 to $1.8 billion (1995

dollars);

• the annual U.S. cost from Campylobacter infections of $1.5-8.0 billion (total annual costs of Campylobacter-associated GBS plus costs of campylobacteriosis ($1.3-

$6.2 billion)); and

• costs attributable to foodborne sources. Assuming that 55-70 percent of all

Campylobacter infections are attributable to foodborne sources, costs of foodborne

campylobacteriosis ($0.7-$4.3 billion) and associated GBS ($0.1-$1.3 billion) equal

$0.8-$5.6 billion each year.

These costs of foodborne Campylobacter can be used in cost-effectiveness studies or

benefit-cost analyses of programs that prevent Campylobacter contamination of food.

Although there are several different triggering factors for GBS, no single factor appears

to cause a greater proportion of GBS cases than does Campylobacter. Ways to reduce

GBS triggered by other factors such as surgery are less understood. Therefore, societal

efforts to reduce GBS caused by Campylobacter may have higher net returns than

efforts to reduce GBS caused by other triggering factors. 

As with other cost-of-illness (COI) estimates, the COI estimates for Campylobacterassociated GBS understate true values because they do not include such components as

pain and suffering, lost leisure time, the cost of preventive actions, travel costs,

resources spent on research, and lawsuits. The estimates are also conservative in that

they do not reflect the productivity losses of those patients with GBS who returned to

work but had to take a lower paying job because of their illness.

Estimated Annual Costs of Campylobacter-Associated GBS USDA/ERS iii
iv USDA/ERS Estimated Annual Costs of Campylobacter-Associated GBS

Abbreviations

BLS Bureau of Labor Statistics

CDC Centers for Disease Control and Prevention

COI Cost-of-illness

CPI Consumer Price Index

ERS Economic Research Service

GBS Guillain-Barré syndrome

GPO Government Printing Office

HCFA Health Care Finance Administration

ICD-9 International Classification of Diseases Codes—9th edition

ICU Intensive care unit

IVIG Immunoglobulin treatments

LS Landefeld and Seskin

MV Mechanical ventilation

NHDS National Hospital Discharge Survey

PE Plasma exchange

USDA United States Department of Agriculture

VOSL Value of a statistical life

WTP Willingness to pay 
Introduction

Microbial pathogens in food include bacteria, viruses,

parasites, and fungi. These pathogens cause between

6.5 million and 33 million cases of human illness and

up to 9,000 deaths each year in the United States

(Council for Agricultural Science and Technology,

1994). These illnesses and deaths cost the United

States billions of dollars each year in medical costs

and lost productivity (Buzby and Roberts, 1996).

The fundamental economic issues surrounding microbial food safety are asymmetric information and market failure. Because most pathogens are invisible to

the naked eye, consumers generally are unable to

determine the risk of foodborne illness posed by their

food consumption choices (Crutchfield et al., 1997).

Meanwhile, producers are likely (but not necessarily)

to be better informed than consumers about the food

safety risks of the foods they produce. However,

producers have no direct incentive to supply this

information. This asymmetry in food safety information and the lack of producer incentive to supply such

information means that most food safety risks are not

incorporated into market prices and quantities. This

market failure leads to more pathogens in the food

supply, greater risk to human health, and higher levels of illness and mortality related to foodborne

pathogens (Crutchfield et al., 1997).

Incorporating economics into food safety decisions

would help society achieve a target level of food

safety that either maximizes economic benefits or

minimizes costs. The role of economics in microbial

food safety is to define the savings of resources associated with pathogen reduction, and to assess the

costs and benefits of achieving social goals like the

provision of more healthful foods. This requires

information about the baseline costs posed by foodborne illnesses. This study estimates the annual costs

of one complication of a foodborne illness—GuillainBarré syndrome (GBS) that follows some

Campylobacter infections. ERS embarked on this

project because foodborne data indicate

Campylobacter is the most common cause of bacterial foodborne illness in the United States (CDC, 1997)

and because quantifying societal costs of a foodborne

illness entails a cost analysis of both acute and secondary complications. 

Guillain-Barré syndrome is the leading cause of acute

neuromuscular paralysis in the United States now

that polio has been virtually eliminated by vaccination programs (Parry, 1993, p. 10; Mishu et al., 1993,

p. 947). Although paralysis from GBS is generally

reversible to some extent over time, some patients

die prematurely because of the illness while others

are bedridden for life.

Although the cause of GBS is not well defined, many

believe it is an autoimmune reaction triggered by factors such as some gastrointestinal or respiratory illnesses, surgery, and certain vaccinations. In particular, one potential trigger of GBS is infection caused

by Campylobacter, a common foodborne and waterborne pathogen that causes the gastrointestinal 

Estimated Annual Costs of Campylobacter-Associated GBS USDA/ERS 1

Estimated Annual Costs 

of Campylobacter-Associated 

Guillain-Barré Syndrome

Jean C. Buzby

Tanya Roberts

Ban Mishu Allos
illness, campylobacteriosis.1 The Centers for Disease

Control and Prevention (CDC) estimate that roughly

1 in 100 people are diagnosed with symptoms of

Campylobacter infection in the United States each

year (Tauxe, 1992, p. 3). Tauxe (1992) estimated

that of 2.5 million people ill with campylobacteriosis

in the United States each year, 200 to 730 die

because of their illness. Although only a small percentage of campylobacteriosis cases develop GBS,

there appears to be a strong link between

Campylobacter and GBS. An estimated 20 to 40

percent of GBS cases are caused by Campylobacter

infections (Mishu and Blaser, 1993). 

People can get campylobacteriosis by drinking water

or raw milk contaminated with Campylobacter and

by consuming contaminated raw or undercooked

meat (Skirrow and Blaser, 1992). Consuming contaminated poultry is the predominant source of sporadic cases of Campylobacter infections (Tauxe,

1992, p. 12). The intestine of birds and warm-blooded animals is a natural habitat for Campylobacter

(Park et al., 1991, p. 101S) and studies show that

chicken slaughter and processing leads to heavy surface contamination (Park et al., 1991; Skirrow and

Blaser, 1992, p. 6; Sjögren and Kaijser, 1988, p. 3).

Up to 80 percent of poultry at retail are contaminated

with Campylobacter (Skirrow and Blaser, 1992, p.

4), and this contamination appears to peak between

July and October (Tauxe et al., 1988; Harris et al.,

1986, p. 404). To a lesser extent, turkey, raw milk,

cake icing, raw clams, raw hamburger, water, and

contact with pets have been epidemiologically linked

with campylobacteriosis in the United States (Blaser

et al., 1983, p. 163; Stern, 1992, p. 50; Tauxe et al.,

1988; CAST, 1994, p. 11). 

This study estimates the annual cost-of-illness of

GBS caused by all Campylobacter infections and by

foodborne Campylobacter infections in the United

States. Medical costs and the costs of lost productivity provide public health cost estimates of

Campylobacter-associated GBS. These cost-of-illness estimates can be compared against the estimated

annual costs of new procedures that reduce

Campylobacter in the food chain. 

One potential procedure to reduce the incidence of

GBS is a Campylobacter vaccination program for

people. A high proportion of campylobacteriosis

cases are foodborne (estimated at 55-70 percent) and

75 percent of these foodborne cases are attributed to

meat and poultry (Federal Register, July 25, 1996).2

The 1996 U.S. Department of Agriculture’s (USDA)

regulation on Hazard Analysis and Critical Control

Point (HACCP) systems for meat and poultry can

indirectly reduce the annual incidence of GBS by

reducing the load of Campylobacter in meat and

poultry. There are other ways to partially reduce the

likelihood of foodborne Campylobacter infections,

such as thoroughly cooking meat and poultry and

preventing raw meat and poultry juices from commingling with cooked meat and poultry or with other

foods. New or expanded educational programs could

help educate consumers and food handlers about safe

food handling techniques to prevent campylobacteriosis and other foodborne diseases. Therefore, some

portion of the estimated annual costs of GBS in the

United States could be avoided by reducing the incidence of campylobacteriosis.

Other than Campylobacter, triggering factors for

GBS include viral infections, surgery, systemic illness, and vaccinations (Parry, 1993). However, no

single factor appears to cause a greater proportion of

GBS cases than does Campylobacter. Ways to

reduce GBS triggered by other factors such as

surgery are less understood. Therefore, societal

efforts to reduce GBS caused by Campylobacter may

have higher net returns than efforts to reduce GBS

caused by other triggering factors.

For those key data points not supported by strong

consensus, sensitivity analyses were performed to

2 USDA/ERS Estimated Annual Costs of Campylobacter-Associated GBS

2 Roughly 55 to 70 percent of all Campylobacter infections are estimated

to be foodborne. In a Seattle-King County Department of Public Health

surveillance study (1984, p. 153), roughly 55 percent of all

Campylobacter cases were attributed to food origins: drinking raw milk

(5.2 percent) and eating poultry (48.2 percent). Tauxe (1992, p. 15) summarized Deming et al.’s (1987) results of a study of campylobacteriosis

cases in students at a Georgia college, and found that 70 percent were

attributed to eating chicken (30 percent attributed to contact with cats).

Raw chicken could also have cross-contaminated other foods in the

kitchen. 

1 Because infections with C. jejuni and C. coli are clinically indistinguishable and because more than 99 percent of Campylobacter isolates in

the United States are C. jejuni (Tauxe, 1992), the term Campylobacter is

used here to include both C. jejuni and C. coli.
determine the impact on costs of variations in adjusted productivity losses, days on mechanical ventilation (MV),3 and probabilities of patients with

Campylobacter-associated GBS who require MV,

plasma exchange (PE), and intravenous immunoglobulin (IVIG) treatments.4

Estimates of the total annual costs of GBS caused by

all Campylobacter infections and by foodborne

Campylobacter infections can be added to previously

estimated annual costs of campylobacteriosis (Buzby

et al., 1996; Buzby and Roberts, 1996) in the United

States to obtain a more complete accounting of the

economic impact of Campylobacter to Americans.

These estimates are also compared with cost-of-illness estimates for other foodborne pathogens to estimate the relative impact of the pathogens on society. 

Guillain-Barré Syndrome

Each year, there are an estimated 2,628 to 9,575 people who develop GBS in the United States. [See

appendix for details on characterization of disease,

medical care, and estimated cases.] Final outcomes

range considerably. Although most patients with

GBS recover from the paralysis with only minor

residual symptoms, others are permanently bedridden, wheelchair-bound, or beset by fatal complications. Most patients with GBS are hospitalized and

some have relapses. GBS can affect people of all

ages but older patients with GBS are more likely to

have a poor prognosis than are younger patients with

GBS.

The current standard of care for treating patients with

GBS includes plasma exchange and/or intravenous

immunoglobulin treatments. In recent studies,

approximately 20 percent of all patients with GBS

required mechanical ventilation to assist breathing.

Sunderrajan and Davenport (1985) found that the

probability that patients with GBS will be put on

mechanical ventilation increases with age. The average age of those patients with GBS requiring

mechanical ventilation was roughly 47 years and the

average age of those patients with GBS who did not

require ventilation was roughly 30 years. We

assumed these values in the baseline analysis in this

study.

Several participants of the 1995 American Neurology

Association meeting suggested that the overall case

fatality rate for patients with GBS has decreased and

is currently around 2 percent. More seriously ill

patients with GBS who are mechanically ventilated

are more likely to die than those less severely ill. In

Sunderrajan and Davenport’s (1985) sample of 40

patients with GBS, 28 percent of the mechanically

ventilated patients died while there were no deaths

among those not on mechanical ventilation. 

Since the first report of Campylobacter infection

complicated by GBS was published in 1982 (Rhodes

and Tattersfield, 1982), evidence has accumulated

that these infections may be an important trigger of

GBS. Serologic and cultural studies have confirmed

that 20-40 percent of patients with GBS had infection

with C. jejuni in the 1-3 weeks prior to the onset of

neurologic symptoms (Mishu and Blaser, 1993;

Kuroki et al., 1993; Rees et al., 1995). Assuming

that 20 to 40 percent of all patients with GBS have

prior Campylobacter infections, there are an estimated 526 to 3,830 new patients diagnosed with

Campylobacter-associated GBS each year in the

United States.

There is little evidence to suggest that significant person-to-person transmission of Campylobacter takes

place (Tauxe, 1992, p. 11). However, there have

been a few documented cases of pregnant women

with bacteremia that have been associated with

severe fetal infections (Blaser et al., 1983a, p. 165).

This report estimates annual costs for all patients

with GBS who had prior Campylobacter infections,

regardless of the source of Campylobacter infection

(foodborne, waterborne, etc.). The study then estimates the annual costs of GBS caused by foodborne

Campylobacter assuming that 55 to 70 percent of all

Estimated Annual Costs of Campylobacter-Associated GBS USDA/ERS 3

3 Mechanical ventilation is where breathing is regulated by a mechanical

ventilator in an intubated patient. MV may be required in patients with

GBS whose weakness or paralysis is severe.

4 In plasma exchange (PE/plasmapheresis), “blood is removed from the

patient, plasma is separated from blood cells and discarded, and blood

cells are suspended in colloid solution and reinfused” (Thornton and

Griggs, 1994, p. 262). Thornton and Griggs (p. 260) state “it is likely

that plasma exchange acts by removing pathogenic antibodies” and they

offer seven possible explanations of how IVIG, where pooled human IgG

(a plasma protein) is intravenously administered, works. 
Campylobacter infections are foodborne.5 Although

some studies suggest that Campylobacter-associated

GBS is more severe than GBS caused by other factors (Molnar et al., 1982; Rhodes and Tattersfield,

1982; Constant et al., 1983), this distinction is not

made here because of data limitations. 

The Cost-of-Illness Method

The cost-of-illness (COI) method, developed by

Malzberg (1950) and codified by Rice (1966), is a

damage function approach and sums the costs borne

by all individuals afflicted with a given disease.

Most COI studies on foodborne illness estimate the

present value of lifetime medical costs and lost productivity (i.e., forgone income and household production caused by the illness) to obtain partial estimates of annual costs (e.g., Cohen et al., 1978;

Roberts, 1989; Todd, 1989; Buzby et al., 1996). One

could argue, following Harberger’s (1971) argument

confirmed by Willig (1976), that the opportunity cost

of the resources consumed in treating (or preventing)

acute and chronic foodborne illnesses is a reasonable

measure of society’s welfare loss. A more complete

accounting of cost categories would include evaluation of the loss of leisure time, pain and suffering,

industry costs, and public health expenditures by the

government. 

Without other information such as the availability of

treatment options and their effectiveness, cost-of-illness studies cannot tell us whether or not scarce

health-care resources should be allocated to treating

(or preventing) the diseases studied (Drummond,

1992, p. 2). Cost-of-illness estimates can, however,

serve as useful inputs in cost-effectiveness analyses,

cost-benefit analyses, cost-utility analyses, and other

applied research that may in turn be used to prioritize

resource allocation by policymakers.6 For example,

the cost-of-illness estimates for selected foodborne

illnesses (Buzby et al., 1996) were used in the U.S.

Department of Agriculture’s cost-benefit analysis for

its Hazard Analysis and Critical Control Point

(HACCP) rule, which was designed to improve the

safety of meat and poultry (Federal Register, July 25,

1996). Other COI studies have estimated the economic costs of an assortment of diseases including

obesity (Colditz, 1992); dyspepsia and schizophrenia

(Ament and Evers, 1993); and asthma, lung cancer,

and coronary artery disease (Abt Associates Inc.,

1992).7

On the macro level, it is the value of the total societal

burden that should influence the allocation of

resources (Ament and Evers, 1993, p. 31). This

value can be determined by methods such as willingness-to-accept (WTA) and willingness-to-pay (WTP).

“In these methods human life and limb are valued

according to the amount people are willing to spend

to obtain reductions in the probability of death,

injury, or disability (WTP) or, alternatively, the

amount by which they must be compensated in order

to accept an increased risk (WTA)” (Ament and

Evers, 1993, p. 31). 

However, obtaining WTP or WTA for a specific illness or injury may be prohibitively time-consuming

or expensive. WTP methods use a variety of techniques ranging from direct questioning to experimental auctions to determine values for nonmarket goods.

And, even if a WTP estimate for a food-safety hazard

is available, the estimate is not easily applied elsewhere since the hazard may have a different incidence or case fatality rate. For food safety, what is

being valued are reductions in the risk of acute illness, chronic complications, and premature death

associated with foodborne pathogens. The one WTP

application to foodborne disease by Hayes et al.

(1995) found experimental-auction participants willing to pay $0.40 to $1.00 to purchase a safer sandwich.8

Most cost-of-illness estimates account only for medical costs and costs of lost productivity, and therefore, underestimate the true economic burden to society. The scope of COI studies can vary from a spe4 USDA/ERS Estimated Annual Costs of Campylobacter-Associated GBS

7 Jarvinen (1988) provides an annotated bibliography of about 600 costof-illness studies.

8 Bids did not vary with risk levels, suggesting future work is needed to

understand exactly what the bids reflect.

5 Buzby and Roberts (1996) assumed that 55 to 70 percent of

Campylobacter infections were foodborne and estimated that annual

medical costs and productivity losses for campylobacteriosis from food

sources ranged from $0.7 billion to $4.3 billion in 1995 dollars.

6 Hodgson (1994) provides a thorough review of COI estimates in costeffectiveness analysis. Haddix et al. (1996) provides a review of costbenefit analysis, cost-effectiveness analysis, and cost-utility analysis with

an emphasis on the valuation of health outcomes.
cific disease with only one type of cost to several diseases with an exhaustive cost accounting (Hodgson

and Meiners, 1982, p. 437). The COI method is easy

to apply and uses accessible data on personal earnings and medical expenditures (French, 1990, p.

1118). Also, these data are precise enough to allow

for sensitivity analyses of the COI estimates to

changes in medical costs, demographic profiles of

affected individuals, or outcome severities. 

One conceptual difficulty with the COI method is

that it usually requires a proxy monetary value for

productivity losses for injury- or illness-related death

and/or a proxy monetary value for premature retirement. One commonly used proxy is an estimate of

the value of a statistical life (VOSL). Though there

is no universally accepted method to estimate the

VOSL (Cropper and Oates, 1992; Hayes et al., 1995;

Randall, 1993; Smith, 1992; Viscusi, 1992), there are

two conceptual approaches: the human capital (HC)

approach and the willingness-to-pay (WTP) approach

(Landefeld and Seskin, 1982).9 The HC approach

aims to capture forgone earnings whereas the WTP

approach aims to capture the value that people place

on small changes in their probability of survival.

Note that analysts use the term “value of a statistical

life” very loosely, especially in the case of HC estimates, which are crude representations of this controversial and ambiguous value, a value likely to be

only loosely related to income.

Human Capital (HC) Approach

The human capital (HC) approach assumes that the

value of an individual’s life from a societal perspective can be measured by an individual’s future production potential. This production potential can be

approximated by the discounted present value of

future labor earnings forgone due to premature death

or retirement. 

Expected earnings are discounted back to the year of

the incidence (Van Doorslaer and Bouter, 1990, p.

259) and therefore one measurement problem is the

choice of the appropriate discount rate. A frequent

ethical/philosophical objection to the HC approach is

that some demographic groups are valued more highly than others: values are higher for men than for

women and values are higher for young and middleaged adults than for the elderly and children. The

HC approach places little value on reducing risk of

the elderly, because they have low future earnings to

forgo. Similarly, the method typically attaches low

values to risk reduction for children because future

earnings are discounted to present values. Assigning

low values for reducing risks to children and the

elderly seems illogical because people can and do

spend substantial amounts on risk avoidance for

those groups, especially children. Also, in periods of

high unemployment, it is likely that deceased or sick

workers will not only be replaced but at little cost

(Ament and Evers, 1993, p. 32).

Although the HC approach is criticized because it

incompletely measures the value of a statistical life,

it does measure the earnings component of the burden of a disease (e.g., part of the value lost to mortality or morbidity) (Hodgson and Meiners, 1982, p.

438-439). Time lost from work and other productive

activities is a valuable economic resource that is

unavailable for other uses. Although the WTP

approach is more grounded in economic theory, the

HC approach has some theoretical foundation. Given

the assumption that earnings reflect productivity, the

HC approach can be supported by the economic theory of marginal productivity (Hodgson and Meiners,

1982, p. 442). 

Willingness-To-Pay Approach

The WTP approach is conceptually appealing

because it can cover more of the potential costs of an

illness or injury than can the HC approach and

because it has some foundation in Pareto’s theory of

optimality (Hodgson and Meiners, 1982, p. 443).10

While there are several methods that attempt to isoEstimated Annual Costs of Campylobacter-Associated GBS USDA/ERS 5

9 In estimating the societal costs of a particular illness or injury, WTP

estimates can be useful in two ways. First, WTP estimates can be used

as a direct and theoretically preferable replacement for cost-of-illness

estimates if the WTP estimates are available for the specific

illness/injury, incidence rate, and mortality rate of interest. Second, WTP

estimates for reductions in other mortality risks can be used in a cost-ofillness analysis as a proxy monetary value for adjusted productivity losses for those who die prematurely or are unable to ever return to work

because of an illness or injury.

10 A Pareto efficient allocation of resources is where “it is not possible

(through further reallocations) to make one person better off without

making someone else worse off” (Nicholson, 1989, p. 476).
late willingness-to-pay, recent attention in estimating

the value of a statistical life has focused on the wagerisk estimation in labor markets.11 Wage-risk studies

derive the value of risk reduction by statistically estimating the effect of occupational mortality and injury

risks on wages. Typically, employers must offer

workers higher wages to induce them to take a job

with some injury risks, as opposed to a similar job

with no such risks. Conversely, workers accept jobs

with lower wages, given that those jobs offer minimal risks. The “risk premium” is then the increased

wage needed to attract workers to riskier jobs.

However, wage-risk estimates can be biased downwards if real or perceived barriers (e.g., long-term

labor contracts) prevent workers from reacting to

changes in workplace risks or if workers underestimate their true exposure to these risks (French, 1990,

p. 118). 

The typical wage-risk study uses a measure of mortality risk, and measures the effects of a small change

in mortality risk on wages; a typical study might find

that an increase in mortality risk of 1 in 10,000 (one

extra death in a year for every 10,000 workers in the

relevant population) would be associated with a wage

increase of $300. In an industry with 10,000 workers, then, we could expect one additional worker to

die each year on average, and as a result total wage

payments would be $3 million higher ($300 times

10,000 workers). In that case we would say that the

value of a statistical life was estimated to be $3 million, because industry had to pay that amount to

induce workers to take on a risk that would likely

leave one dead. Alternatively, one could say that

workers would, in the aggregate, be willing to pay $3

million through wage reductions in order to purchase

a reduction in risk that prevents one death. 

In practice, WTP estimates face measurement difficulties and are rarely found in cost-of-illness studies

(Hodgson and Meiners, 1982, p. 443; Ament and

Evers, 1993, p. 31). Most cost-of-illness studies are

based on HC estimates (Van Doorslaer and Bouter,

1990, p. 259; Ament and Evers, 1993, p. 31). In

wage-risk studies, the VOSL “is not a universal constant, but reflects the wage-risk tradeoff pertinent to

the preferences of the workers in a particular sample”

(Viscusi, 1993, p. 1930). Viscusi (1993) found that

estimates from wage-risk studies ranged between

$0.6 million and $16.2 million in 1990 dollars due to

differences in methodology and data sets. These

broad ranges complicate resource allocation decisions.

Landefeld and Seskin Hybrid Approach

The Landefeld and Seskin (LS)(1982) approach is a

hybrid of the HC and WTP approaches. LS estimates include more than the forgone earnings found

in HC estimates while capturing considerably less

than what WTP aims to capture (i.e., LS does not

capture reductions in the risk of items such as pain,

suffering, and lost leisure time). The LS approach

generates the present value of expected lifetime

income and housekeeping services at a 3-percent real

rate of return, adjusted for an annual 1-percent

increase in labor productivity, and a risk-aversion

factor of 1.6. Total income in Landefeld and Seskin

(1982, p. 561) includes labor income adjusted

upwards to include nonlabor monetary income

sources such as rents, royalties, interest, and transfer

payments as well as nonlabor nonmonetary factors

such as the value of housekeeping, which is excluded

from the U.S. gross national product. The risk-aversion factor increases the present value of expected

forgone earnings by 60 percent. The risk-aversion

factor is based on the ratio of life insurance premium

payments to life insurance loss payments (Bailey,

1980). In most cases, life insurance premiums represent “household WTP for potential losses associated

with the death of an income-earning household member” (Landefeld and Seskin, 1982, p. 562). 

LS estimates are primarily human capital estimates of

forgone earnings with a few adjustments, and thus

can be considered as “adjusted productivity losses”

rather than “VOSL.” In our baseline analysis, we use

LS estimates to represent productivity losses for

those patients with GBS who die prematurely or who

are no longer able to return to work. The LS formula

for adjusted productivity losses is:

6 USDA/ERS Estimated Annual Costs of Campylobacter-Associated GBS

11 Fisher et al. (1989, p. 89) divide the WTP approach into three categories of studies: (1) contingent market studies, (2) consumer market

studies, and (3) wage-risk [hedonic-wage] studies. Here, we discuss only

wage-risk studies because they are the most applicable to food safety.

T

Adjusted productivity losses = [ S Yt ] α t=0 (1 + r)t
where T = remaining lifetime, t = a particular year,

Yt = after-tax income (labor plus nonlabor) and the

market value of household production, r = household’s opportunity cost of investing in risk-reducing

activities, and α = risk-aversion factor.12 We interpolated the LS estimates between LS’s 4-year age

groups, averaged the LS estimates across gender for

each age category, and updated to 1995 dollars using

the change in usual and average weekly earnings

from the U.S. Bureau of Labor Statistics.

For our baseline analysis, we used LS estimates

because they are more conservative than WTP estimates, and more importantly, they incorporate valuable information on age-specific outcomes. The LS

estimates of adjusted-productivity losses are low

compared with VOSL estimates based on the risk

premium in labor markets, a willingness-to-accept

measure which theory tells us mirrors WTP.13 For

example, Viscusi’s (1993, p. 1930) review of labormarket (wage-risk) studies found that most VOSL

estimates ranged between $3 million and $7 million

in 1990 dollars. After updating to 1995 dollars, LS

estimates ranged from $15,000 to $1,979,000

(depending on the age of the representative individual). This difference is not surprising as the WTP

approach aims to directly capture more than does the

LS approach. This report provides a sensitivity

analysis that shows estimated total costs when the LS

estimates of adjusted-productivity losses are replaced

by the more comprehensive $5-million VOSL estimate. 

Costs of Campylobacter-Associated

Guillain-Barré Syndrome

Prior to the actual cost estimation of Campylobacterassociated GBS, it was necessary to focus the analysis through assumptions. Assumptions were made

where accurate or representative data were lacking

and sensitivity analyses were performed on the most

critical data points that are not supported by consensus.

Assumptions Used in Cost-of-Illness

Analysis 

Table 1 provides the assumptions used in estimating

the annual cost of Campylobacter-associated GBS.

We also assume that people can be infected by

Campylobacter, at most, once a year. This assumption is reasonable because the antibody response to

infection with Campylobacter should provide temporary protection from re-infection. All patients with

GBS are assumed to require hospitalization because

of the difficulty in diagnosing GBS and because of

the typical severity and duration of paralysis associated with this illness. 

For this study, the estimation of the annual cost of

GBS using the cost-of-illness method was complicated by demographic differences in patients with GBS

and by the broad array of possible GBS symptoms,

subsequent medical costs, and final outcomes.

Patients with GBS were categorized into workable

groups for cost estimation. 

We divided the annual number of patients with GBS

into two age/ventilation categories: mechanically

ventilated patients and those not on mechanical ventilation (fig. 1). The first age/ventilation category used

a 30-year-old individual to represent patients with

GBS who were not mechanically ventilated.14 The

second age/ventilation category used a 47-year-old

individual to represent more seriously paralyzed

patients with GBS who were mechanically ventilated

to assist breathing.15 Those who are mechanically

ventilated face more serious complications and prognoses than those who are not. For each age/ventilation category, three outcomes are considered: those

who (1) resume work, (2) cannot return to work, and

(3) die. Those patients who return to work include

Estimated Annual Costs of Campylobacter-Associated GBS USDA/ERS 7

12 Landefeld and Seskin (1982) used a 3-percent discount rate.

13 Willingness-to-accept is particularly apt for valuing risks due to foodborne pathogens. When purchasing food with pathogens, one is tacitly

accepting the pathogens along with the food.

14 Sunderrajan and Davenport (1985) found that the average age of

mechanically ventilated patients with GBS was 47.0 +/- 5.6 years and the

average age of those patients with GBS who did not require ventilation

was 30.1 +/- 4.3 years. 

15 Had we not focused on mechanical ventilation and had we wanted to

select two representative ages, we might have chosen a broader span

between our representative ages. Halls et al. (1988), Moore and James

(1981), and Storey et al. (1989) found bimodal age distributions that suggest a broader age span. Because Sunderrajan and Davenport’s (1985)

average age of ventilated and nonventilated patients are means, they are

more centrally located. For example, although older patients with GBS

are more likely to require mechanical ventilation, a few very young

patients with GBS who are mechanically ventilated can pull the mean

toward the center of a natural age span.
Table 1—Assumptions used to estimate the annual costs of Campylobacter-associated Guillain-Barré 

syndrome in the United States, 19951

Cost category Assumptions

General Assumptions * 55 to 70 percent of Campylobacter infections are foodborne (Deming et al., 1987; Seattle-King County 

Dept. of Public Health, 1984).

* 20 to 40 percent of all patients with GBS were caused by Campylobacter infections.

* 20 percent were mechanically ventilated, 80 percent were not, and all patients required hospitalization.

Medical Costs * Total fees for physician care, laboratory tests, and other medical items were assumed to be equal to hospital 

room costs but were updated to 1995 dollars using different Consumer Price Index (CPI), as appropriate.

A regular hospital room costs $978 per day and associated fees are $962 per day.

An Intensive care unit (ICU) hospital room costs double the cost of a regular room per day (or $1,956) with 

$1,924 in fees/day.

* Plasma exchange (PE) and intravenous immunoglobulin treatments (IVIG) were computed separately.

71 percent of all patients were treated with PE and 37 percent were treated with IVIG.

PE costs $5,500 per patient and IVIG costs $5,700 per patient.

Patients on mechanical ventilation Patients not on mechanical ventilation

* Mean hospital stay; 98.5 days. * Mean hospital stay; 19.1 days.

* 68.4 days in ICU, 30.1 days in regular hospital room. * 6 days in ICU, 13.1 days in regular hospital room.

* Mean duration of mechanical ventilation is 68 days.

Productivity Losses * The value of an hour of time is the same for all patients of any race, gender, or geographical location 

in the United States.

Patients on mechanical ventilation Patients not on mechanical ventilation

* For the 27 percent that cannot work at all and the * For the 19 percent that cannot work at all, estimat10 percent that died, estimated productivity losses for ed productivity losses for a 30 year-old individual 

a 47-year-old individual were used. were used.

* 63 percent resumed work. * 81 percent resumed work.

For those who resumed work:

* The number of days spent recuperating at home is twice the number of days spent in the hospital, adjusted for 

weekends.

* Productivity loss uses the Bureau of Labor Statistics usual weekly earnings for all part-time and full-time wage 

and salary earners (pre-tax, no nonsalary benefits) plus an additional 40 percent to account for nonsalary benefits, divided by 5 work days to get a daily rate, and multiplied by the estimated days lost from work (sum of work 

days hospitalized and work days recuperating at home, adjusted for weekends).

For those who did not go back to work:

* The present value of adjusted productivity losses was computed as the average of male and female values 

given by Landefeld and Seskin (1982) interpolated to the appropriate age (47 or 30) and updated to 1995 values 

using the change in average weekly earnings (BLS).

Other costs2 * Excluded due to lack of reliable measurement.

1 Case estimates were divided into those who were mechanically ventilated and those who were not.

In this table, “patients with GBS” refers to patients with Campylobacter-associated GBS.

2 “Other costs” include physical, psychological, and other social costs.

8 USDA/ERS Estimated Annual Costs of Campylobacter-Associated GBS
patients with GBS who recover completely or find a

less demanding job. 

For the 80 percent of the patients with GBS who

were not mechanically ventilated, we used

Sunderrajan and Davenport’s (1985) probabilities: all

survived, 81 percent returned to work, and 19 percent

did not return to work. Several participants of the

1995 American Neurology Association meeting suggested that we use an overall case fatality rate of 2

percent for patients with GBS. Because all the

patients who died in Sunderrajan and Davenport’s

(1985) study were mechanically ventilated, we

adjusted the outcome probabilities for mechanically

ventilated patients to reflect this lower case fatality

rate.16 In our study, out of the 105 to 766 patients

with Campylobacter-associated GBS on mechanical

ventilation, 11 to 76 die (10 percent) and none of

those not on mechanical ventilation died, for an overall case fatality rate of 2 percent. 

Annual Medical Costs

The annual medical costs of Campylobacter-associated GBS, for each of the two ventilation categories,

are comprised of: (1) IVIG (immunoglobulin treatments), (2) plasma exchange, (3) regular hospital

room, (4) Intensive Care Unit (ICU) hospital room,

(5) regular hospital room fees, and (6) ICU hospital

room fees (table 2).17

Costs varied depending on the number of days spent

in ICU and the number of days spent in a regular

hospital room. Total annual costs for the two types

of hospital rooms and associated fees were calculated

by multiplying the daily cost of each component by

the number of days the component is used and by the

number of patients with GBS receiving that component. The costs of mechanical ventilation were

assumed to be included in the fees associated with an

ICU room. Total costs for IVIG and plasma

exchange were calculated by multiplying the cost per

treatment by the average number of treatments per

Estimated Annual Costs of Campylobacter-Associated GBS USDA/ERS 9

Campylobacter

Cases

Campylobacter

Outcomes

Campylobacter-associated

GBS Ventilation Categories

Campylobacter-associated

GBS Outcome Categories

>2,500,000 Cases

>99% Recover

Most cases

<1% Develop GBS

526 to 3,830 Cases

20% Require ventilation

105 to 766 Cases

80% Do not require

ventilation

421 to 3,064 Cases

63% Resume work

66 to 483 Cases

27% Cannot work at all

28 to 207 Cases

10% Die

11 to 76 Cases

81% Resume work

341 to 2,482 Cases

19% Cannot work at all

0 Cases

80 to 582 Cases

0% Die

16 In the Sunderrajan and Davenport (1985) study, out of the mechanically ventilated patients with GBS, 28 percent died, 50 percent resumed

work, and 22 percent did not return to work. We adjusted these figures

by reducing the case fatality rate for these cases from 28 to 10 percent

and proportionately increasing the other two categories a total of 18 percent to reflect this decreased case fatality rate.

17 Those Campylobacter-associated patients with GBS who died are

assumed to incur the same costs as the surviving patients in their ventilation category. Rehabilitation costs after hospitalization were not included

due to data limitations.

Figure 1

Estimated annual cases and disease outcomes of Campylobacter-associated Guillain-Barré syndrome
patient and by the number of patients with GBS

receiving that treatment. 

IVIG

Thornton and Griggs (1994) estimate that the cost of

intravenous gamma globulin or immunoglobulin is

$5,000 to $12,000 per 2 gm/kg course.18 To obtain

better cost estimates, we surveyed five neurologists

on the medical advisory board of the Guillain-Barré

Syndrome Foundation International (1994) and found

the average cost of one IVIG treatment to be $5,700.

Patients with GBS were found to require an average

of 1.03 treatments, so in this analysis, the estimated

cost of IVIG per GBS patient receiving IVIG is

$5,871 (table 2). Assuming that 37 percent (also

from the informal survey of neurologists) of all

patients with GBS require IVIG, the estimated total

annual cost of IVIG for all patients with GBS ranged

from $1.1 million to $8.4 million a year.

Plasma Exchange

Thornton and Griggs (1994) estimate the cost of plasma exchange (PE) per course of 5 treatments ranges

from $6,000 to $12,000 (p. 263).19 Our survey indicated that the average cost of one course of plasma

exchange is $5,000 and that patients with GBS

require an average of 1.1 courses. Assuming that 71

percent (from the informal survey of neurologists) of

all patients with GBS require plasma exchange, the

estimated cost of plasma exchange for all patients

with GBS ranges from $2.0 million to $15.0 million

a year (table 2).

10 USDA/ERS Estimated Annual Costs of Campylobacter-Associated GBS

Table 2—Estimated annual U.S. medical costs of Campylobacter-associated Guillain-Barré syndrome, by

mechanical ventilation category, 1995

Severity Base rate Treatment Rate per Low # High # Low High

category per item per day patient patients patients costs costs

$ # $ # # $ million

Nonventilated patients

Immunoglobulin 5,700 1 5,871 156 1,134 0.9 6.7

Plasma exchange 5,000 1.1 5,500 299 2,175 1.6 12.0

ICU room 1,956 6 11,736 421 3,064 4.9 36.0

ICU fees 1,924 6 11,544 421 3,064 4.9 35.4

Hospital room 978 13.1 12,812 421 3,064 5.4 39.3

Other medical fees 962 13.1 12,602 421 3,064 5.3 38.6

Sub-total n.a. n.a. n.a. 421 3,064 23.1 167.8

Ventilated patients

Immunoglobulin 5,700 1 5,871 39 283 0.2 1.7

Plasma exchange 5,000 1.1 5,500 75 544 0.4 3.0

ICU room 1,956 68.4 133,790 105 766 14.0 102.5

ICU fees 1,924 68.4 131,602 105 766 13.8 100.8

Hospital room 978 30.1 29,438 105 766 3.1 22.5

Other medical fees 962 30.1 28,956 105 766 3.0 22.2

Sub-total n.a. n.a. n.a. 105 766 34.6 252.7

Total n.a n.a. n.a. 526 3,830 57.7 420.5

n.a. means not applicable. Item means days or treatments, as appropriate. Figures may not total due to rounding. Total fees for physician care,

laboratory tests, and other medical items are assumed to be equal to hospital room costs but are updated with the physician’s consumer price

index (CPI) instead of the hospital CPI. It is assumed that an intensive care unit hospital room costs double the cost of a regular room per day.

19 One course of plasma exchange usually lasts 2 to 3 hours and requires

special equipment typically found only in larger medical centers and hospitals. Not all patients respond to plasma exchange and technical difficulties periodically interrupt treatment (Thornton and Griggs, 1994, p.

263).

18 A 1990 Dutch study (van der Meché et al., 1992) found that intravenous immunoglobulin treatments (IVIG) appear to be at least equally

effective as plasma exchange for patients with GBS after 4 weeks of

treatment. However, this may not be the same in the United States

because the Dutch patients with GBS who were treated with plasma

exchange fared poorly when compared with patients in the United States.
Regular and ICU Hospital Room 

The average length of hospital stay for patients with

GBS varied between studies but was typically longer

for those patients with GBS who required ventilation

(Ropper et al. 1991, p. 264). For the 3,611 nonventilated patients with GBS in Health Care Finance

Administration (HCFA)’s 1992 Medicare data, the

mean length of stay was 15.6 days. For the 371

mechanically ventilated patients with GBS in the

Medicare database, the average length of stay was

36.4 days. Sunderrajan and Davenport (1985, p. 334)

found that nonventilated patients with GBS were hospitalized 19.1 (+/- 4.6) days and ventilated patients

with GBS stayed in the hospital an average of 98.5

(+/- 30.5) days. In the current study, all patients with

Campylobacter-associated GBS were assumed to

require hospitalization and we adopt Sunderrajan and

Davenport’s figures. 

Mechanical ventilation is typically administered in

ICU. Therefore, those patients with Campylobacterassociated GBS who were mechanically ventilated

were assumed to spend the same number of days in

an ICU as they spend on mechanical ventilation (68.4

days), with the remainder (30.1 days) spent in regular

hospital rooms. For those not mechanically ventilated, we assume one-third of the 19.1 days spent in the

hospital were spent in ICU (6 days).

Our estimate of the average daily hospitalization cost

was $978 per patient per day.20 We assumed that the

daily cost of an ICU hospital room is double that of a

regular hospital room (approx. $1,956/day). The

estimated total annual cost of regular hospital rooms

for patients with Campylobacter-associated GBS

ranged from $8.5 million to $61.8 million. ICU hospital rooms were estimated at $18.9 million to $138.5

million. 

Other Medical Fees Associated With Regular and

ICU Hospital Rooms

The above hospital room costs do not include physician fees, pharmacy costs, and medical treatments

such as mechanical ventilation. Charges for those

items associated with a regular hospital room were

assumed to be the same as the regular hospital room

rate, but were updated with the consumer price index

(CPI) for physician services instead of the hospital

room CPI.21 Similarly, the fees for the items associated with the ICU room are the same as the ICU

room rate, but we updated these fees with the physician services CPI. ICU care requires more specialized equipment than does care in a regular hospital

room and therefore fees associated with ICU care are

greater. For example, the cost of mechanical ventilation is assumed to be incorporated in the fees associated with the ICU hospital room because patients

under mechanical ventilation are in ICU.22 Estimated

daily fees associated with a regular hospital room

were $962 and estimated daily fees associated with

an ICU room were $1,924. The estimated total annual cost of fees associated with regular hospital rooms

for patients with Campylobacter-associated GBS

ranges from $8.3 million to $60.8 million; for ICU

fees, $18.7 million to $136.2 million (table 2). 

Overall, the estimated total medical costs for the 526

to 3,830 patients with Campylobacter-associated

GBS ranged from $57.7 million and $420.5 million a

year. The largest costs for ventilated patients with

GBS was for ICU rooms and for nonventilated

patients, regular hospital rooms. 

HCFA Medicare data were used to validate our primary estimates. Of the 3,982 Medicare patients with

GBS in 1992, 371 were on mechanical ventilation

during their hospital stay and 3,611 were not.23

HCFA’s medical charge per patient with GBS who

required mechanical ventilation was (in 1992 dollars)

$103,693; the average per patient with GBS who did

Estimated Annual Costs of Campylobacter-Associated GBS USDA/ERS 11

20 In 1992, the daily hospitalization cost per person in community hospitals was estimated at $820 per patient (American Hospital Association in

Statistical Abstract of the United States 1994, table 182). This estimate

was updated to 1995 dollars using the change in the hospital room CPI

(1992 CPI from the Statistical Abstract of the United States 1994, table

163; and the 1995 hospital room CPI from personal correspondence with

BLS in March 1996).

21 As before, we used the 1992 hospital cost of $820 per day, but we

updated this cost with the physician services CPI (1992 CPI from

Statistical Abstract of the United States 1994, table 163; 1995 CPI from

personal communication with BLS in March 1996).

22 Personnel at a major midwestern hospital estimated that the average

daily cost of mechanical ventilation was $117. We assume that this cost

is indirectly covered by the fees associated with the ICU hospital room.

23 For the Medicare data, whether or not a GBS patient had mechanical

ventilation was determined by the presence of an ICD-9 code for the surgical procedure #967. The number of GBS patients on mechanical ventilation could be an underestimate if other relevant ICD-9 surgical procedure codes should have been included in the analysis. In our analysis, an

estimated 20 percent of patients with GBS required mechanical ventilation, whereas only 9.3 percent of the 3,982 Medicare patients with GBS

required mechanical ventilation.
not require mechanical ventilation was $22,757 (table

3).24 After updating to 1995 dollars, these Medicare

estimates are roughly 38 percent of the average total

medical costs estimated in this analysis for ventilated

patients ($329,860) and 50 percent of the costs for

patients not requiring mechanical ventilation

($54,770). This difference may be due to Medicare

cost limits; the expenditures by other health agencies

may be substantially higher. Also, Medicare patients

are older, on average, than all patients with GBS, and

are more likely to die, which would cap total medical

costs.

Annual Productivity Losses

Annual productivity losses were estimated for each

of the six categories of patients with GBS in this

study (2 ventilation categories times 3 outcome categories)(table 4). For patients who returned to work,

productivity losses per patient were approximated by

multiplying the baseline daily income by the average

number of days of work missed. The value of an

hour of time was assumed to be the same for patients

12 USDA/ERS Estimated Annual Costs of Campylobacter-Associated GBS

24 This translates to $124,809 and $27,391, respectively, in 1995 dollars

after updating with the hospital room CPI (1992 from Statistical Abstract

of the United States 1994, table 163; 1995 CPI from personal communication with BLS in March 1996).

Table 3—Short-stay hospital use by Medicare beneficiaries with diagnosis 357.0, by age 

Per discharge

Age Discharges Charges Payments Days care Charge Payment

------------$1,000------------ -----1992 dollars----

All beneficiaries with GBS

Total 3,982 120,647 49,619 70,057 30,298 12,461

<65 520 13,258 5,345 7,556 25,496 10,279

65-69 978 32,722 13,249 18,107 33,458 13,547

70-74 907 28,392 11,394 17,118 31,303 12,562

75-79 882 28,570 11,797 15,959 32,392 13,375

80-84 450 11,893 5,416 7,551 26,429 12,036

85+ 245 5,812 2,418 3,766 23,721 9,869

All beneficiaries with GBS that required mechanical ventilation

Total 371 38,470 13,741 13,518 103,693 37,037

<65 40 3,965 1,367 1,260 99,125 34,179

65-69 108 11,659 4,178 3,983 107,950 38,682

70-74 94 9,707 3,311 3,729 103,263 35,227

75-79 79 7,962 2,872 2,696 100,790 36,351

80-84 37 3,857 1,575 1,606 104,233 42,572

85+ 13 1,321 438 344 101,604 33,670

All beneficiaries with GBS that did not

require mechanical ventilation

Total 3,611 82,176 35,878 56,439 22,757 9,936

<65 480 9,293 3,978 6,296 19,360 8,287

65-69 970 21,064 9,071 14,124 24,211 10,426

70-74 813 18,685 8,083 13,389 22,983 9,942

75-79 803 20,608 8,925 13,263 25,663 11,114

80-84 413 8,036 3,841 5,945 19,458 9,301

85+ 232 4,491 1,980 3,422 19,357 8,535

Source: Charlie Helbing, Health Care Finance Administration, 1994.

Guillain-Barré syndrome (GBS) as diagnosed with ICD-9 code 357.0

Ventilation requirement was identified for those patients requiring surgical procedure 96.7
of any race, gender, or geographical location in the

United States. The baseline daily income was

derived from the usual weekly earnings by adjusting

for nonsalary benefits, the labor force participation

rate, and weekends. We used the average of “usual

weekly earnings of employed full-time and part-time

wage and salary workers” reported by the U.S.

Bureau of Labor Statistics.25 The 1995 average

weekly earnings were $490 for a worker aged 25-34

and $650 for a worker aged 45-54 (BLS, 1996). To

this, 40 percent of weekly earnings was added as an

estimate of all nonsalary benefits (e.g., health, vacation, and retirement benefits).26 Averaged across

gender, the labor force participation rate was 83.8

percent for those aged 25-34 and 81.4 percent for

those aged 45-54 (U.S. Dept. Commerce, BLS,

1996). These two participation rates were used for

the two representative age groups in this study (30-

and 47-year-old patients with GBS). The usual

weekly earnings were divided by 5 work days to

adjust for weekends. After adjusting for nonsalary

benefits, labor force participation rates, and weekends, the estimated average daily productivity loss

per person is roughly $115 for a worker 30 years of

age. For a 47-year-old worker, the daily loss of productivity is $148.

In addition to work days missed while in the hospital,

this analysis assumed that for every day spent in the

hospital, twice as many days were spent at home

recuperating before the patient could return to work

(if at all). After adjusting for weekends, the average

number of days missed from work was 41 days for a

nonventilated patient with Campylobacter-associated

GBS (19.1 days in hospital times 3 times 5/7 workdays per week) and 211 days for a ventilated patient

with Campylobacter-associated GBS (98.5 days in

hospital times 3 times 5/7). Recovery rates and illness duration are likely to vary widely but there are

few published data on the rate of recovery.

Sunderrajan and Davenport’s (1985) estimate of the

number of days hospitalized was used here because

their study most concisely reported recovery rates for

ventilated and nonventilated patients with GBS. This

study errs on the side of conservatism. Because of

the seriousness of paralysis and the propensity of

patients with GBS to have lingering symptoms, the

Estimated Annual Costs of Campylobacter-Associated GBS USDA/ERS 13

25 To avoid double-counting of income, the Government’s lost tax revenue and transfer payments such as pension or relief payments are usually omitted (Cooper and Rice, 1976). Double-counting would occur if tax

losses were combined with losses in earnings and it would be triplecounting if these taxes were used to pay for the medical care of GBS

patients (Cooper and Rice, 1976).

26 Personal conversation with BLS in Dec. 1995 provided the March

1994 employer costs for employee compensation per hour worked, divided into wage/salary ($12.25) and all nonsalary benefit ($4.85) components. Using these estimates, all nonsalary benefits are roughly 40 percent of wage/salary earnings. Therefore, total compensation is roughly

1.4 times the wage/salary earnings.

Table 4—Estimated annual U.S. productivity losses from Campylobacter-associated Guillain-Barré syndrome, by mechanical ventilation category, 1995

Average Days Pay missed

Severity daily work per Low # High # Low High

category income missed patient patients patients costs costs

$ # $ # # $ million

Nonventilated patients

Resumed work1 115 41 4,707 341 2,482 1.6 11.7

Could not work n.a. n.a. 1,809,959 80 582 144.8 1,053.4

Died n.a. n.a. 1,809,959 0 0 0 0

Ventilated patients

Resumed work1 148 211 31,239 66 483 2.1 15.1

Could not work n.a. n.a. 1,054,788 28 207 29.5 218.3

Died n.a. n.a. 1,054,788 11 76 11.6 80.2

Total n.a. n.a. n.a. 526 3,830 189.6 1,378.7

n.a. means not applicable. Figures may not total due to rounding.

1 Analysis assumes that for each day spent in the hospital, two days are spent at home recuperating before returning to work.
mean duration of illness is probably longer than the

values used here. Kennedy et al. (1978, p. 98) found

that recovery ranged “from 1 to 59 weeks after the

onset.”

Lost productivity for the 341 to 2,482 nonventilated

patients who were able to return to work is estimated

at $1.6 million to $11.7 million per year. For the 66

to 483 ventilated patients, estimated lost productivity

ranges from $2.1 million to $15.1 million. The estimated annual total cost of lost productivity of all

patients with Campylobacter-associated GBS who

were able to return to work ranged from $3.7 million

to $26.8 million.

To obtain the cost of lost productivity for those

patients who died or did not return to work,

Landefeld and Seskin’s (LS)(1982, p. 563) estimates

of the present value of adjusted productivity losses

were used, after averaging across gender for each age

category and updating to 1995 dollars.27

After updating to 1995 dollars, the LS estimate for a

30-year-old (nonventilated) individual is roughly

$1,809,959 and the LS estimate for a 47-year-old

(ventilated) individual is roughly $1,054,788. The

estimated total cost of lost productivity for patients

with Campylobacter-associated GBS who survive

their illness yet do not return to work ranges from

$174.3 million to $1,271.7 million. This includes

$144.8 million to $1,053.4 million for the 80 to 582

nonventilated patients and $29.5 million to $218.3

million for the 28 to 207 ventilated patients.

Following Sunderrajan and Davenport (1985), it is

estimated that none of the nonventilated patients

died, and of the 105 to 766 patients who were on

mechanical ventilation, 11 to 76 died. Using the

1995 LS estimates, the estimated total annual productivity loss for those patients with GBS who died

ranges from $11.6 million to $80.2 million. Across

all six categories of patients with Campylobacterassociated GBS, the estimated total annual productivity losses from Campylobacter-associated GBS in the

United States ranges from $189.6 million to $1,378.7

million.

Total Cost Estimates

On average, the cost of lost productivity was over

three times larger than the medical costs (table 5).

Estimated total annual medical costs from

Campylobacter-associated GBS in the United States

range from $57.7 million to $420.5 million a year

and estimated total annual productivity losses range

from $189.6 million to $1,378.7 million. Medical

costs and productivity losses together equal total

annual costs of $0.25 billion to $1.8 billion per year.

These estimates do not include costs of campylobacteriosis.

Sensitivity Analyses

Some of the estimates used in this study to calculate

medical costs and the costs of lost productivity are

subject to wide variation and controversy. Sensitivity

analyses were performed to handle variations in two

14 USDA/ERS Estimated Annual Costs of Campylobacter-Associated GBS

Table 5—Estimated annual U.S. medical, productivity, and total costs of Campylobacter-associated GuillainBarré syndrome and of foodborne Campylobacter-associated Guillain-Barré syndrome, 1995 

Source Patients Deaths Medical costs Productivity costs Total costs

category Low High Low High Low High

Number ------------------------------------------$ million-----------------------------------

All1 526-3,830 11-76 57.7 420.5 189.6 1,378.7 247.3 1,799.2

55% foodborne 289-2,107 6-42 31.7 231.3 104.3 758.3 136.0 989.6

70% foodborne 368-2,681 8-53 40.3 294.3 132.7 965.1 173.1 1,259.4

1 Includes GBS associated with Campylobacter infections from all sources (e.g., food, water). Figures may not total due to rounding.

27 The BLS data series on usual weekly earnings did not have early

enough data so we used another BLS average weekly earnings series (for

nonsupervisory, nonagricultural positions; BLS, 1996) to update the LS

numbers from 1977 to 1983 dollars. We then updated these 1983 numbers to 1995 dollars.
key estimates: adjusted productivity losses for those

who die or are unable to return to work because of

their illness, and the probability that patients with

Campylobacter-associated GBS receive mechanical

ventilation.28

Sensitivity Analysis - Value of Adjusted

Productivity Losses

The Landefeld and Seskin (1982) estimates used in

this study to represent adjusted productivity losses

are relatively low when compared with other, more

comprehensive valuations. Viscusi (1993) found that

most VOSL estimates ranged between $3 million and

$7 million in 1990 dollars (p. 1942).29 In 1995 dollars, Viscusi’s range becomes $3.6 million to $8.4

million.30 The U.S. Department of Health and

Human Services uses a standard $5 million per statistical life (Williams, 1995). In our sensitivity analysis, we replaced the LS estimates with these three

values in 1995 dollars. This sensitivity analysis was

particularly crucial to obtain defensible cost-of-illness estimates because the costs of lost productivity

from Campylobacter-associated GBS constitute the

bulk of the cost-of-illness estimates. When the baseline LS estimates of adjusted productivity losses are

replaced with VOSL estimates of $3.6, $5.0, and

$8.4 million, estimated costs increase dramatically

(table 6).

Sensitivity Analysis - Probability of

Receiving Mechanical Ventilation

The baseline analysis assumed that 20 percent of all

patients with GBS required mechanical ventilation.

Yet, higher probabilities are likely. After adjusting

for different sample sizes in 12 separate studies, 30

percent of patients with GBS, on average, were put

on a ventilator (app. table 2). The average was even

higher for the four American studies (36.5 percent).

In contrast, the 1992 U.S. Medicare Statistical

Support data revealed that 9.3 percent of the 3,982

patients with GBS required mechanical ventilation

(table 3)(Helbing, 1994). This sensitivity analysis

considered the impacts on costs of a 9-percent and a

37-percent mechanical ventilation rate for patients

with GBS. 

Table 7 provides cost estimates for using both a low

mechanical ventilation requirement rate (9 percent)

and a high mechanical ventilation requirement rate

(37 percent) in the baseline analysis (LS estimates)

and in the scenario where the adjusted productivity

loss per person is set at $5.0 million. The estimated

number of deaths changed along with the new estimated range of ventilated patients for each scenario.

For the low (9 percent) mechanical ventilation rate, 4

Estimated Annual Costs of Campylobacter-Associated GBS USDA/ERS 15

28 To account for uncertainty of the data, three other sensitivity analyses

were also performed: (1) the share treated with IVIG was halved from 37

percent to 18.5 percent, (2) the share treated with plasma exchange was

halved from 71 percent to 35.5 percent, and (3) the average number of

days GBS patients were on mechanical ventilation was reduced from

68.4 days to 41.5 days (adjusted average from five GBS studies). In

these sensitivity analyses, results were altered by less than 2.5 percent.

29 Fisher et al. (1989) found that the most defensible empirical estimates

for a VOSL range from $1.6 million to $8.5 million (in 1986 dollars).

30 Updated using average of the usual weekly earnings of employed

part-time and full-time wage and salary workers (BLS, 1995).

Table 6—Sensitivity analyses under alternate value of a statistical life assumptions

Adjusted productivity Medical costs Productivity costs Total costs

loss used1 Low High Low High Low High

$ million

Baseline 57.7 420.5 189.6 1,378.7 247.3 1,799.2

VOSL = $3.6 mil. 57.7 420.5 432.1 3,140.8 489.8 3,561.3

VOSL = $5.0 mil. 57.7 420.5 598.7 4,351.8 656.4 4,772.3

VOSL = $8.4 mil. 57.7 420.5 1,003.3 7,292.8 1,061.0 7,713.3

1 “Baseline” category uses Landefeld and Seskin’s (1982) estimates of adjusted productivity losses. “VOSL=$3.6 mil.” is when the LS estimate

is replaced by Viscusi’s lower value of a statistical life (VOSL) estimate. “VOSL=$5 mil.” is when the LS estimate is replaced by the Department

of Health and Human Service’s standard VOSL estimate. “VOSL=$8.4 mil.” is when the LS estimate is replaced by Viscusi’s upper VOSL estimate. Viscusi’s estimates have been updated so estimates are in 1995 dollars.
to 34 patients died as compared with 19 to 141 in the

high (37 percent) mechanical ventilation rate. 

Under both productivity loss scenarios, the low rate

reduced total estimated annual medical costs to

between $41.7 million and $304.7 million (table 7).

Estimated productivity losses also changed because

the number of patients with Campylobacter-associated GBS in each outcome category was tied to the

number of patients in the two ventilation categories.

Under the low mechanical ventilation assumption,

estimated productivity losses and total cost

decreased. Estimated total annual costs under the LS

scenario dropped to between $227.1 million and

$1,657.0 million, $584.5 million to $4,269.8 million

under the $5.0 million adjusted productivity loss scenario.

The high mechanical ventilation rate (37 percent)

increased total estimated annual medical costs to

between $82.5 million and $599.6 million.

Estimated productivity losses and total costs

increased with the higher rate of mechanical ventilation. Estimated total costs under the LS/high

mechanical ventilation rate increased to between

$277.5 million and $2,018.3 million, $762.6 million

to $5,546.7 million under the $5.0 million VOSL

scenario.

Foodborne CampylobacterAssociated Guillain-Barré Syndrome

Based on the findings of the Seattle-King County

Department of Public Health (1984) and Deming et

al. (1987), we assumed that 55 percent to 70 percent

of all Campylobacter infections are foodborne. At

55 percent, an estimated 289 to 2,107 cases of GBS

are caused by foodborne Campylobacter infections

each year, including 6 to 42 deaths (table 5).

Estimated annual medical costs range between $31.7

million and $231.3 million and estimated annual productivity losses range from $104.3 million to $758.3

million. Estimated annual total costs range from

$136.0 million to $989.6 million. 

Assuming that 70 percent of all Campylobacter-associated GBS has foodborne origins, an estimated 368

to 2,681 cases (8 to 53 deaths) incur medical costs

between $40.3 million and $294.3 million and productivity losses from $132.7 million to $965.1 million. Estimated total annual costs range from $173.1

million to $1,259.4 million. 

Thus, assuming that 55 percent to 70 percent of all

Campylobacter infections and associated GBS illnesses are from food sources, annual costs of

Campylobacter-associated GBS linked to food is

$136.0 million to $1,259.4 million. These estimates

16 USDA/ERS Estimated Annual Costs of Campylobacter-Associated GBS

Table 7—Sensitivity analyses on the share of patients with Guillain-Barré syndrome that are mechanically

ventilated1

Productivity loss scenario:

Landefeld and Seskin $5 million 

Medical scenario: Type Low High Low High

$ million

Low (9%) mechanical Annual medical cost 41.7 304.7 41.7 304.7

ventilation Annual productivity loss 185.4 1,352.3 542.8 3,965.1

Total annual cost 227.1 1,657.0 584.5 4,269.8

High (37%) mechanical Annual medical cost 82.5 599.6 82.5 599.6

ventilation Annual productivity loss 195.0 1,418.7 680.1 4,947.1

Total annual cost 277.5 2,018.3 762.6 5,546.7

1 For each mechanical ventilation requirement rate scenario, table 7 provides both low and high estimates of the medical costs, costs of lost

productivity, and total costs to reflect the range of patients with GBS in each category. The two paired columns of numbers distinguish between

the two productivity loss scenarios. The first column presents cost estimates using the Landefeld and Seskin (1982) estimates (which varies by

age) of adjusted productivity losses. The second column presents cost estimates when the LS estimates are replaced with a $5.0 million estimate for every individual who cannot return to work or dies prematurely because of their illness, regardless of age.
can be compared against the costs of reducing

Campylobacter in the U.S. food supply. 

Conclusions

Buzby and Roberts (1996) provide cost-of-illness

estimates for seven common foodborne pathogens

(Salmonella, Campylobacter, E. coli O157:H7,

Listeria monocytogenes, Clostridium perfringens,

Staphylococcus aureus, Toxoplasma gondii) in 1995

dollars. They estimate that foodborne

Campylobacter costs society $0.7 billion to $4.3 billion each year in 1995 dollars. This range increases

to $0.8 billion to $5.6 billion when the estimated cost

of GBS caused by Campylobacter-associated infections attributed to food sources is added (table 8). 

When looking at the low cost estimates for these

seven pathogens, Campylobacter is the third most

costly of the pathogens, after Toxoplasma gondii and

Salmonella. When looking at the high cost estimates,

Campylobacter is the most costly of the seven

pathogens. Although comparing estimates between

different cost-of-illness studies should not be analyzed cardinally because of the different assumptions

involved, comparisons can pinpoint those pathogens

that may need extra attention by policymakers and

members of the food industry.

In our primary analysis, which used the LS estimates,

the estimated total annual cost of Campylobacterassociated GBS from all sources ranges between

$247.3 million and $1,799.2 million. LS estimates of

adjusted productivity losses are relatively low compared with the VOSL estimates, so our baseline estimates tend to be conservative. As with other cost-ofillness estimates, the COI estimates for

Campylobacter-associated GBS understate true values because they do not include components such as

pain and suffering, lost leisure time, the cost of preventive actions, travel costs, resources spent on

research, and lawsuits (table 9). The estimates are

also conservative in that they do not reflect the productivity losses of those patients with GBS who

returned to work but had to take a lower paying job

because of their illness.

The portion of the estimated annual human illness

costs of Campylobacter-associated Guillain-Barré

syndrome attributed to preventable foodborne campylobacteriosis cases can be weighed against the costs

of implementing improvements for preventing these

foodborne illness cases to determine net societal benefits. Currently, cost estimates specific to the prevention of Campylobacter alone have not been developed. However, cost estimates of implementing

USDA’s HACCP rule for meat and poultry are available (Federal Register, July 25, 1996). HACCP,

when implemented, will likely reduce contamination

of meat and poultry by many pathogens, including

Campylobacter. Therefore, the estimated human illness costs from Campylobacter-associated GuillainEstimated Annual Costs of Campylobacter-Associated GBS USDA/ERS 17

Table 8—Estimated U.S. costs of foodborne illness from select pathogens

Pathogen Estimated costs 

Low High

$ billion (1995)

Campylobacter jejuni or coli 1

(including related GBS costs) 0.8 5.6

Clostridium perfringens 0.1 0.1

Escherichia coli O157:H7 0.3 0.7

Listeria monocytogenes 2 0.1 0.3

Salmonella (non-typhoid) 0.9 3.5

Staphylococcus aureus 1.2 1.2

Toxoplasma gondii 3 3.2 3.2

Total 6.6 14.6

1 Campylobacteriosis accounts for $0.7-$4.3 billion (Buzby and

Roberts, 1996) and Campylobacter-associated GBS accounts for

$0.1-$1.3 billion (current study), combined the costs are $0.8 to

$5.6 billion.

2 Due to data limitations, this estimate only includes patients who

were hospitalized.

3 Includes congenital cases only. Immunocompromised patients

such as patients with Acquired Immunodeficiency Disease

Syndrome (AIDS) also face high risks from this parasite.

Source: Buzby and Roberts (1996). These estimates used

Landefeld and Seskin’s estimates of adjusted productivity losses.
18 USDA/ERS Estimated Annual Costs of Campylobacter-Associated GBS

Costs to Individuals/Households1

Human Illness Costs:

Medical costs:

Physician visits

Laboratory costs

Hospitalization or nursing home

Drugs and other medications

Ambulance or other travel costs

Income or productivity loss for:

Ill person or person dying

Caregiver for ill person

Other illness costs:

Travel costs to visit ill person

Home modifications

Vocational/physical rehabilitation 

Child care costs

Special educational programs

Institutional care

Lost leisure time

Psychological costs:

Pain and other psychological costs

Risk aversion

Averting behavior costs:

Extra cleaning/cooking time costs

Extra cost of refrigerator, freezer, etc.

Flavor changes from traditional recipes (especially meat, milk, 

egg dishes)

Increased food cost when more expensive but safer foods are 

purchased

Altruism (willingness-to-pay for others to avoid illness)

Industry Costs

Impact of pathogens on animal production costs:

Morbidity and mortality of animals on farms

Reduced growth rate/feed efficiency and increased time to market

Costs of disposal of contaminated animals on farm and at 

slaughterhouse

Increased trimming or reworking at slaughterhouse and processing plant

Illness among workers because of handling contaminated animals

or products

Increased meat product spoilage due to pathogen contamination

Control costs for pathogens at all links in the food chain:2

New farm practices (age segregated housing, sterilized feed, etc.)

Altered animal transport and marketing patterns (animal i.d., 

feeding/watering)

New slaughterhouse procedures (hide wash, knife sterilization, 

carcass sterilizing)

New processing procedures (pathogen tests, contract purchasing 

requirements)

Altered product transport (increased use of time/temperature 

indicators)

New wholesale/retail practices (pathogen tests, employee 

training, procedures)

Risk assessment modelling by industry for all links in the food 

chain

Price incentives for pathogen-reduced product at each link in the 

food chain 

Outbreak costs:

Herd slaughter/product recall

Plant closings and cleanup

Regulatory fines

Product liability suits from consumers and other firms3

Reduced product demand because of outbreak:

Generic animal product - all firms affected

Reduction for specific firm at wholesale or retail level

Increased advertising or consumer assurances following outbreak

Impact of outbreaks on tourism industry

Regulatory and Public Health Sector Costs for Foodborne

Pathogens

Disease surveillance costs to:

Monitor incidence/severity of human disease by foodborne 

pathogens

Monitor pathogen incidence in the food chain

Develop integrated database from farm to table for foodborne 

pathogens

Research to:

Identify new foodborne pathogens for acute and chronic human 

illnesses

Establish high-risk products and production and consumption 

practices

Identify which consumers are at high-risk for which pathogens

Develop cheaper and faster pathogen tests

Risk assessment modelling for all links in the food chain

Outbreak costs:

Costs of investigating outbreak

Testing to contain an outbreak (for example, serum testing and 

administration of IVIG in persons exposed to Hepatitis A)

Costs of cleanup

Legal suits to enforce regulations that may have been violated3

Other considerations:

Distributional effects in different regions, industries, etc.

Equity considerations, such as special concern for children 

1 Willingness-to-pay estimates for reducing risks of foodborne disease is a comprehensive estimate of all these categories (assuming

that the individual has included employer-funded sick leave and medical programs in their estimates). The estimate is comprehensive and

covers reduced risks for everyone—those who will become ill as well

as those who will not.

2 Some industry costs may fall with better pathogen control, such

as reduced product spoilage, possible increases in product shelf-life,

and extended shelf-life permitting shipment to more distant markets

or lowering shipment costs to nearby markets.

3 In adding up costs, care must be taken to assure that product liability costs to firms are not already counted in the estimated pain and

suffering cost to individuals. However, the legal and court expenses

incurred by all parties are social costs.

Table 9—Social costs of foodborne illness
Barré syndrome could be added to the HACCP’s benefits of reducing Campylobacter to get an improved

estimate of the true benefits of USDA’s HACCP rule.

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Appendix:

Guillain-Barré Syndrome

Characterization of the Disease

GBS is believed to be an autoimmune reaction and

has been associated with various prior events including infection, trauma, or immunization (see box).

Although GBS is relatively rare, it is a severe illness.

Ropper et al. (1991, p. 128) state that GBS “is usually a monophasic illness, with a rapid initial onset,

progressive weakness over one to four weeks, and

recovery over subsequent months.” GBS is characterized by inflammation and damage to the myelin,

which is the insulation surrounding the central conducting core or axon of the peripheral nerves (i.e.,

those extending out from the spinal cord). In severe

cases, there can be complete paralysis of the axial,

respiratory, cranial, and peripheral muscles whereby

the patient, though alert, can only communicate by

eye movements (Parry, 1993, p. 12). 

Final GBS outcomes range considerably. Although

most patients with GBS recover with only minor

residual symptoms, others are permanently bedridden, wheelchair-bound, or beset by fatal complications. Other potential lingering disabilities include

abnormalities in the autonomic nerves and changes in

heart rate, blood pressure, vision, and body temperature (GBS Foundation, 1990, p. 7). Most patients

with GBS are hospitalized because of paralysis and

some have relapses. Hughes (1990, p. 173) states

that the prognosis of GBS varies and “up to 13 percent die and a further 20 percent are left significantly

disabled” (e.g., unable to work after a year).

A common cause of death among patients with GBS

is cardiac arrhythmias secondary to autonomic nervous system dysfunction. In 15 separate studies of

Estimated Annual Costs of Campylobacter-Associated GBS USDA/ERS 23

Triggers for Guillain-Barré Syndrome

As with other autoimmune diseases, GBS has several precipitating factors. Triggering factors other than

Campylobacter include viral infections, surgery, systemic

illnesses, and vaccinations (Parry, 1993, p. 116). Some

women get GBS during pregnancy and may be paralyzed

during childbirth. There have been reported outbreaks in

Jordan in 1978 upon exposure to polluted water and in

Finland after a national oral poliovirus vaccination (GBS

Foundation, 1990, p. 5). 

Another outbreak occurred in 1976 and 1977 following

the U.S. Government sponsored mass inoculation using

the A/New Jersey/1976/H1N1 (swine) influenza vaccine.

This National Influenza Immunization Program was discontinued on December 16, 1976 and the Centers for

Disease Control and Prevention (CDC) launched a national surveillance program for those patients with GBS

whose disease onset occurred between October 1, 1976

and January 31, 1977 to determine if there was an association between the vaccination and GBS (Breman and

Hayner, 1984, p. 881). The national surveillance program

relied primarily on reports from neurologists and other

clinicians gathered by State epidemiologists and was supplemented by a CDC hospital discharge study performed

in cooperation with the Michigan Department of Public

Health (Breman and Hayner, 1984, p. 880). The

Michigan study conclusively found that the swine flu vaccination increased the risk of GBS and that the risk was

elevated for only 6 weeks after the immunization

(Breman and Hayner, 1984, p. 886). 

Although the A/New Jersey strain is no longer used, its

connection with the upsurge in patients with GBS raised

the possibility that vaccination is a precipitating factor for

GBS. Roscelli et al.’s (1991) retrospective study of

active duty soldiers vaccinated between 1980 and 1988

found no association between the vaccinations and the

289 army patients diagnosed with GBS (p. 955). Yet,

Roscelli et al. recommend continued surveillance with

future vaccine formulations because the swine flu episode

suggests that the risk from GBS may vary with different

vaccines (p. 955).
case fatality rates associated with GBS, 12.5 percent

of patients is the highest percentage that died (appendix table 1). The simple average of the case fatality

rate over these 15 studies is 5.0 percent, and when

each study is weighted by its sample size, the case

fatality rate becomes 4.9 percent. The adjusted average case fatality rates for the four American studies

is slightly lower (4.7 percent), perhaps reflecting differences in case severity or medical treatment.

Several participants of the 1995 American Neurology

Association meeting suggested that the overall case

fatality rate for patients with GBS has decreased and

is currently around 2 percent. 

Patients with GBS who are mechanically ventilated

are more likely to die than those who do not require

mechanical ventilation (roughly 20-30 percent are

mechanically ventilated). In Sunderrajan and

Davenport’s (1985) sample of 40 patients with GBS,

28 percent of the mechanically ventilated patients

died, with no deaths among those not on mechanical

ventilation.

Up to 65 percent of patients with GBS report neurological pain (Beghi et al., 1985). One patient’s pain

persisted for more than 1 year (Andersson and Sidén,

1982). Muscle cramping, foot drag, and minor sensory abnormalities such as tingling and pain commonly persist in otherwise recovered patients with

GBS.1

The rates of recovery following GBS vary between

studies. This may be due to the subjective definition

of “recovery” or to the lack of followup outcome

data. Parry (1993, p. 89) states that 85 percent of

patients with GBS achieve a “complete functional

recovery” while Ropper et al. (1991, p. 265) state

that 75 percent of patients with GBS recover enough

to return to normal life within 6-12 months.

Functional recovery may not mean a complete recovery but rather a return to participation in normal daily

activities. Neurologic symptoms may linger and prevent a complete recovery. In one study, less than 15

percent had “absolutely no residual symptoms”

(Ropper et al., 1991, p. 265). Potential barriers to

regaining a normal lifestyle and resuming work are

the pain, tingling, muscle aches, and physical exhaus24 USDA/ERS Estimated Annual Costs of Campylobacter-Associated GBS

Appendix table 1—Case fatality rates of Guillain-Barré syndrome patients in recent studies

Death

Study (year) Nationality Patients Deaths rate

- - - - - Number - - - - - Percent

Löffel et al. (1977) Swiss 123 3 2.4

Moore and James (1981) Australian 33 1 3.0

Andersson and Sidén (1982) Swiss 60 4 6.7

Beghi et al. (1985)1 American 48 2 4.2

GBS Study Group (1985) American/Canadian 245 7 2.9

Sunderrajan and Davenport (1985) American 40 5 12.5

Winer et al. (1985) English 71 8 11.3

French Coop. Group (1987) French/Swiss 220 14 6.4

Singh et al. (1987) Indian 24 2 8.3

Halls et al. (1988) Danish 34 0 0.0

Storey et al. (1989) Australian 110 5 4.5

de Jager and Minderhoud (1991) Dutch 63 5 7.9

Koobatian et al. (1991) American 51 4 7.8

van der Meché et al. (1992) Dutch 147 3 2.0

Winner and Evans (1993) English 72 4 5.6

Total 1,368 67 ——2

1 Kennedy et al. (1978) used the same Olmstead County data.

2 After adjusting for sample size, the average death rate in these studies is 4.9 percent and the average for the four U.S. studies is 4.7 percent.

1 Foot drag refers to a condition in which patients require braces or specialized shoes to help keep their toes up while walking to prevent accidental falls.
tion that may follow a certain amount of activity

(GBS Foundation, 1990, p. 26). Excessive exercise

can lead to temporary relapses (GBS Foundation,

1990, p. 26).

The incidence of GBS does not vary according to

race, seasonal variability, or region of the United

States. Although there may appear to be “pockets”

of higher GBS incidence in some parts of the United

States, this is likely due to differences in reporting

systems and varying medical awareness of GBS. 

Most of the studies reviewed for this analysis had

samples with more male patients than females, (e.g.,

Andersson and Sidén, 1982; Beghi et al., 1985;

Kennedy et al., 1978; Koobatian et al., 1991; Löffel

et al., 1977; Singh et al., 1987; Storey et al., 1989;

Rantala et al., 1991). A few studies had more

females than males (e.g., Moore and James, 1981;

Winner and Evans, 1993). This study does not segregate outcome categories for patients with GBS by

gender because the dollar value of one day of lost

productivity due to GBS is assumed to be equal for

both genders.

GBS can affect people of all ages. Patients with

GBS range in age from 9 months to 97 years. It

appears that there is an increasing incidence of GBS

with age (Kennedy et al., 1978; Koobatian et al.,

1991).2 Beghi et al. (1985) found that people over

the age of 60 have higher GBS age-adjusted incidence rates than people under 18 years old (p. 1054).

Other studies showed bimodal or biphasic distributions (e.g., Halls et al., 1988, p. 118; Moore and

James, 1981; Storey et al., 1989). In general, these

studies showed an initial peak of GBS incidence for

people in their twenties, a lower incidence for people

in their thirties and forties, and the largest peak for

people older than 50. Older patients with GBS are

more likely than younger patients to have a poor

prognosis.3

Common Medical Procedures for Treating

Patients with GBS

Between 6.3 and 50 percent of all patients with GBS

are mechanically ventilated to assist breathing during

some portion of their hospital stay (appendix table 2).

After adjusting each of these studies for sample size,

30 percent of patients with Campylobacter-associated

GBS are on mechanical ventilation. In the most

recent studies, approximately 20 percent of all

patients with GBS required mechanical ventilation.

This is the value assumed in the baseline analysis in

this study. The adjusted average percent of mechanically ventilated patients in the four American studies

is higher (36.5 percent). 

Charles Helbing of the Health Care Finance

Administration (HCFA) provided 1992 Medicare

Statistical Support data for short hospital stays by

Medicare beneficiaries (those over 65 years old).

Out of 3,982 Medicare patients with GBS in 1992,

only 9.3 percent required mechanical ventilation.

Sunderrajan and Davenport (1985) found that the

probability that patients with GBS will be put on

mechanical ventilation increases with age, that the

average age of those patients with GBS requiring

mechanical ventilation was 47.0 +/- 5.6 years, and

that the average age of those patients with GBS who

did not require ventilation was 30.1 +/- 4.3 years.

After weighting each study by its proportion of

patients with GBS relative to the total for the five

studies, the adjusted average number of days a

patient with GBS is on a ventilator is 41.5 days (app.

table 3). Older patients with GBS are more likely to

spend more time on mechanical ventilation than

younger patients with GBS. Sunderrajan and

Davenport (1985) found that patients under 46 years

old were on mechanical ventilation for an average of

21.4 days and those older than 46 were on mechanical ventilation for an average of 98.3 days. 

Estimated Annual Costs of Campylobacter-Associated GBS USDA/ERS 25

2 In Northern China, a variant of GBS associated with C. jejuni, Acute

Motor Axonal Neuropathy (AMAN), strikes mostly children and young

adults and damages the nerve fibers themselves instead of the myelin

insulation (GBS Foundation, 1990, p. 4). This variant is believed to be

connected with chicken droppings. 

3 McKhann et al. (1988) assessed the relationship between outcome of

the disease and age as a continuous variable. They found that outcomes

were less favorable with age. Winner and Evans (1993, p. 164) compared clinical features in patients with GBS age 20-59 with those 60 or

older. They found “no significant differences between old and young in:

occurrence or type of preceding illness; site of symptoms at onset; severity of maximal neurological impairment....requirement for artificial ventilation; case fatality rate...”
26 USDA/ERS Estimated Annual Costs of Campylobacter-Associated GBS

Appendix table 2—Probabilities surrounding patients with Guillain-Barré syndrome who were mechanically

ventilated

Percent on

Study (year) Nationality Patients Deaths mechanical 

ventilation

- - - Number - - - Percent

Löffel et al. (1977) Swiss 123 18 14.6

Moore and James (1981) Australian 33 9 27.3

Andersson and Sidén (1982) Swiss 60 10 16.7

Beghi et al. (1985)1 American 48 3 6.3

GBS Study Group (1985) American/Canadian 245 109 44.5

Sunderrajan and Davenport (1985) American 40 18 45.0

French Coop. Group (1987) French/Swiss 220 82 37.3

Halls et al. (1988) Danish 34 5 14.7

Chevrolet and Deléamont (1991) Swiss 10 5 50.0

Koobatian et al. (1991) American 51 10 19.6

Rantala et al. (1991) Finish 27 5 18.5

Winner and Evans (1993) English 72 15 20.8

Total 963 289 ——2

1 This Olmstead County data is updated every few years and was also used by Kennedy et al. (1978).

2 After adjusting for sample size, the average probability of a GBS patient requiring mechanical ventilation in the studies listed above is 30 percent and the average for the four U.S. studies is 36.5 percent.

Appendix table 3—Average number of days patients with Guillain-Barré syndrome were on mechanical

ventilation (MV)

Average

Patients Patients days on

Study (year)1 Nationality in study on MV MV 

- - - - - - - - Number - - - - - - - -

Moore and James (1981) Australian 33 9 63

Andersson and Sidén (1982) Swiss 60 10 30

Sunderrajan and Davenport (1985)2 American 40 18 68.4

Chevrolet and Deléamont (1991) Swiss 10 5 24.9

Winner and Evans (1993) English 72 15 28.6

Total 215 57 ——3

1 We did not include Halls et al. (1988) because the paper had a typographical error. They stated that the duration of mechanical ventilation for

their “five” patients was “10, 19, 19, 19, 64, and 215” days.

2 Sunderrajan and Davenport (1985) found that their non-ventilated patients averaged 19.1 days in hospital.

3 The simple average number of days a GBS patient is on a ventilator is 43 days and after weighting each study by its sample size, the adjusted

average number of days a GBS patient is on a ventilator is 41.5 days.
The current standard of care for treating patients with

GBS includes plasma exchange (plasmapheresis)(PE)

and/or intravenous immunoglobulin (IVIG) treatments.4 Nerve growth hormones may be another

promising treatment for GBS. These hormones are

proteins that are injected directly into nerves and are

currently being tested for other diseases.

Estimates of Cases

The National Center for Health Statistics5 provided

three sources of data regarding the number of GBS

cases occurring in the United States each year: (1)

1990 National Ambulatory Medical Care Survey

data, (2) 1990 National Mortality Follow-back

Survey data, and (3) 1979-93 National Hospital

Discharge Survey data. All three surveys incorporated International Code of Diseases classification system (ICD-9) codes, thus maintaining consistency

across samples.6

The 1990 National Ambulatory Medical Care

(NAMC) survey lists the diagnoses for each patient

made by office-based physicians in randomly chosen

regions or counties in the United States.7 In the

NAMC survey, no outpatients were diagnosed with

GBS using the ICD-9 code for GBS.8 This may

reflect the severity of GBS whereby most patients are

hospitalized. The National Mortality Follow-back

Survey (NMFS) data indicated that 402 patients with

GBS died in 1990 and that 203 of these patients had

GBS listed as the primary illness.

The National Hospital Discharge Survey (NHDS)

provides information on the duration of hospital stays

for 10 percent of all non-Federal short-stay hospitals

in the United States. Up to seven diagnoses are

assigned to each patient, with the first diagnosis representing the primary illness.9 The NHDS annual

average of 9,575 patients with GBS (for 1979-93, as

1 of 7 diagnosed illnesses) suggests an incidence rate

of 3.64 in 100,000 for the same population (appendix

table 4). 

The NHDS incidence rate is high when compared

with rates found in most GBS studies where 1 to 2

cases occur per 100,000 people (e.g., Mishu and

Blaser, 1993; Beghi et al., 1985; Hughes, 1990;

Ropper, 1992). For example, in a 42-year epidemiological and clinical study in Olmstead County,

Minnesota, the mean annual incidence of GBS was

1.7 in 100,000 people (Kennedy et al., 1978).10 We

spoke to several neurologists at the 1995 Annual

Meeting of the American Neurological Association

who told us that an incidence rate for GBS of 1 in

Estimated Annual Costs of Campylobacter-Associated GBS USDA/ERS 27

9 The NHDS estimates of the number of GBS patients are conservative

because they include only those patients diagnosed with GBS, and like

other illnesses, GBS is under-reported (e.g., diagnoses may be classified

as miscellaneous).

10 The Olmstead County data are updated every few years. Kennedy et

al. (1978) is one of many papers that use these data.

Appendix table 4—Estimated number of patients

with Guillain-Barré syndrome who were discharged from U.S. hospitals by year1

Patients

Year with GBS

1979 6,618

1980 8,677

1981 9,185

1982 13,323

1983 9,061

1984 7,061

1985 11,341

1986 9,736

1987 11,805

1988 11,969

1989 6,996

1990 7,706

1991 7,168

1992 7,562

1993 15,417

1 These data include Guillain-Barré syndrome (GBS) caused from

all factors. The average is 9,575 patients with GBS per year.

Source: National Hospital Discharge Survey data, 1979-93.

4 In PE, “blood is removed from the patient, plasma is separated from

blood cells and discarded, and blood cells are suspended in colloid solution and reinfused” (Thornton and Griggs, 1994, p. 262). Thornton and

Griggs (p. 260) state “it is likely that plasma exchange acts by removing

pathogenic antibodies” and they offer seven possible explanations of how

IVIG works, which is less understood. IVIG is where pooled human IgG

(a plasma protein) is intravenously administered. 

5 The National Center for Health Statistics is part of U.S. Department of

Health and Human Services’ Centers for Disease Control and Prevention.

6 The ICD-9 code for GBS is 357.0.

7 The most accepted guidelines for diagnosing GBS are provided by the

ad hoc National Institute of Neurological and Communicative Disorders

and Stroke (NINCDS) committee. 

8 Diagnosis of GBS typically relies on obtaining spinal cord fluid to

detect elevated cerebrospinal fluid protein and on nerve conduction

velocity-electromyography (NCV-EMG) to detect nerve conduction

blocks or slowing.
100,000 people was a reasonable low estimate for

our analysis. This rate translates into 2,628 new

patients with GBS in the United States annually for a

1995 population of roughly 262.8 million people

(U.S. Bureau of the Census, 1995).11 Here, we use a

range of 2,628 to 9,575 patients with GBS per year to

reflect the uncertainty about the true number of

patients with GBS per year (appendix table 5). 

Guillain-Barré Syndrome Attributed to Food

Since the first report of Campylobacter infection

complicated by GBS was published in 1982 (Rhodes

and Tattersfield, 1982), evidence has accumulated

that these infections may be an important trigger of

GBS. Serologic and cultural studies all over the

world have confirmed that 20-40 percent or more of

patients with GBS had infection with C. jejuni in the

1-3 weeks prior to the onset of neurologic symptoms

(Mishu and Blaser, 1993; Kuroki et al., 1993; Rees et

al., 1995). In 50 to 75 percent of all patients with

GBS, onset is preceded 1 to 3 weeks by an acute

infectious illness of the gastrointestinal or respiratory

tract (Mishu and Blaser, 1993, p. 104). Although

respiratory symptoms are reported most frequently,

gastrointestinal symptoms are common and precede

GBS in 10 to 30 percent of cases.

Kuroki et al. (1993) isolated Campylobacter from

stools of patients with GBS and used serological evidence to conclude that 41 percent of patients with

GBS were linked to Campylobacter infection. Not

all patients with GBS in whom Campylobacter is cultured report gastrointestinal symptoms, meaning that

the immune system’s production of antibodies to

Campylobacter has stopped the intestinal infection,

but the antibodies have already triggered GBS.

Asymptomatic Campylobacter infections are not

uncommon; up to 50 percent of persons with cultureproven Campylobacter infections may be asymptomatic (Riordan, 1988). Campylobacter infections

may trigger GBS even in the absence of gastrointestinal symptoms. In Kuroki et al. (1993), 26 percent of

Campylobacter-infected patients with GBS had no

preceding gastrointestinal symptoms.

Campylobacter may be the most common bacterial

foodborne pathogen in the United States. Dairy

products are the most common cause of reported outbreaks of Campylobacter infections, whereas poultry

is the most common source for sporadic

Campylobacter infections. Contaminated water and

all undercooked meats are other common vehicles of

transmission of Campylobacter. The CDC estimate

28 USDA/ERS Estimated Annual Costs of Campylobacter-Associated GBS

Appendix table 5—Estimated annual incidence of Campylobacter infections, Guillain-Barré syndrome

(GBS), and Campylobacter-associated GBS in the United States

Annual incidence

Disease (patients/100,000 pop.) Total patients/year

Campylobacter infection 1,0002 2,627,5501,6

Patients with GBS Low High Low High

All GBS 1.03 3.641,4 2,6281,3 9,5754

GBS associated with Campylobacter infection 0.201,5 1.461,5 5265 3,8305

1 Based on estimated 1995 U.S. population of 262,755,000 people (U.S. Bureau of the Census, 1995).

2 Tauxe, 1992.

3 Low estimate from Mishu and Blaser (1993) and Hughes (1990, p. 101) and from advice from neurologists at the 1995 Annual Meeting of the

American Neurological Association.

4 National Center for Health Statistics’ National Hospital Discharge Survey (NHDS) data, average 1979-1993.

5 Estimated at 20 percent to 40 percent of all patients with GBS. 526 patients is 20 percent of the estimate of 2,628 patients with GBS per year.

3,830 patients is 40 percent of the NHDS estimate of 9,575 patients with GBS per year. Here we consider Campylobacter infections from all

sources, not just foodborne.

6 For every 100,000 people that have Campylobacter infections each year, 20 to 146 develop GBS. This estimate of the number of

Campylobacter infections uses the same procedure as Tauxe (1988) but is applied to a larger population.

11 For this analysis, incidence is defined as the number of new cases that

develop in 1 year per 100,000 people. 
that roughly 1 in 100 people are diagnosed with

symptoms of Campylobacter infections in the United

States each year (Tauxe 1992, p. 3). Tauxe (1988)

estimated that of 2.5 million people ill with campylobacteriosis in the United States each year, 200 to

730 die because of their illness. 

Assuming that 20 to 40 percent of all patients with

GBS are caused by antecedent Campylobacter infections (Mishu and Blaser, 1993), there are an estimated 526 to 3,830 new patients diagnosed with

Campylobacter-associated GBS each year in the

United States.12 The current study focuses on this

range of cases.

The current study estimates annual costs for all

patients with GBS who had antecedent

Campylobacter infections, regardless of the source of

Campylobacter infection (i.e., foodborne, waterborne, etc.). The study then estimates the annual

costs of GBS caused by foodborne Campylobacter,

assuming that 55 to 70 percent of all Campylobacter

infections are foodborne.13 Although some studies

suggest that Campylobacter-associated GBS is more

severe than GBS caused by other factors (Molnar et

al., 1982; Rhodes and Tattersfield, 1982; Constant et

al., 1983), this distinction is not made in this study

because of data limitations.

Estimated Annual Costs of Campylobacter-Associated GBS USDA/ERS 29

12 526 patients with GBS is equal to 20 percent multiplied by the low

estimate of 2,628 patients with GBS per year. 3,830 patients with GBS

is equal to 40 percent multiplied by the NHDS estimate of 9,575 patients

with GBS per year.

13 Buzby and Roberts (1996) assumed 55 to 70 percent of

Campylobacter infections were foodborne and estimated that annual

medical costs and productivity losses for campylobacteriosis from food

sources range from $0.7 billion to $4.3 billion in 1995 dollars.