The Monetary Burden of Cystic Echinococcosis in Iran
Majid Fasihi Harandi1,2*, Christine M. Budke3, Sima Rostami2
1Research Center for Modeling in Health, Kerman University of Medical Sciences, Kerman, Iran, 2Department of Parasitology, School of Medicine, Kerman University of
Medical Sciences, Kerman, Iran, 3Department of Veterinary Integrative Biosciences, College of Veterinary and Biomedical Sciences, Texas A&M University, College Station,
Texas, United States of America
Cystic echinococcosis (CE) is a globally distributed parasitic infection of humans and livestock. The disease is of significant
medical and economic importance in many developing countries, including Iran. However, the socioeconomic impact of the
disease, in most endemic countries, is not fully understood. The purpose of the present study was to determine the
monetary burden of CE in Iran. Epidemiological data, including prevalence and incidence of CE in humans and animals, were
obtained from regional hospitals, the scientific literature, and official government reports. Economic data relating to human
and animal disease, including cost of treatment, productivity losses, and livestock production losses were obtained from
official national and international datasets. Monte Carlo simulation methods were used to represent uncertainty in input
parameters. Mean number of surgical CE cases per year for 2000–2009 was estimated at 1,295. The number of asymptomatic
individuals living in the country was estimated at 635,232 (95% Credible Interval, CI 149,466–1,120,998). The overall annual
cost of CE in Iran was estimated at US$232.3 million (95% CI US$103.1–397.8 million), including both direct and indirect
costs. The cost associated with human CE was estimated at US$93.39 million (95% CI US$6.1–222.7 million) and the annual
cost associated with CE in livestock was estimated at US$132 million (95% CI US$61.8–246.5 million). The cost per surgical
human case was estimated at US$1,539. CE has a considerable economic impact on Iran, with the cost of the disease
approximated at 0.03% of the country’s gross domestic product. Establishment of a CE surveillance system and
implementation of a control program are necessary to reduce the economic burden of CE on the country. Cost-benefit
analysis of different control programs is recommended, incorporating present knowledge of the economic losses due to CE
Citation: Fasihi Harandi M, Budke CM, Rostami S (2012) The Monetary Burden of Cystic Echinococcosis in Iran. PLoS Negl Trop Dis 6(11): e1915. doi:10.1371/
Editor: Paul Torgerson, University of Zurich, Switzerland
Received January 15, 2012; Accepted October 5, 2012; Published November 29, 2012
Copyright: ? 2012 Fasihi Harandi et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits
unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Funding: Funding was provided by Vice-Chancellor for Education and the Research Center for Modeling in Health, Kerman University of Medical Sciences,
Kerman, Iran under a small grant scheme, grant No. 90-167. The funder had no role in study design, data collection and analysis, decision to publish, or
preparation of the manuscript.
Competing Interests: The authors have declared that no competing interests exist.
* E-mail: email@example.com
Cystic echinococcosis (CE), a chronic disease caused by the
larval form of the tapeworm Echinococcus granulosus, is one of the
most important helminth-associated zoonoses globally [1,2]. The
parasite’s domestic life cycle involves livestock and dogs as the
primary intermediate and definitive hosts, respectively. Canids
harboring adult E. granulosus worms excrete eggs into the
environment, where intermediate hosts become infected through
ingestion of the eggs. Humans can also act as aberrant
intermediate hosts if they ingest infective parasite eggs either
through contaminated food or directly from an infected canid. A
cystic larval form (metacestode) gradually develops, most com-
monly in the liver or lungs. However, other organs can also be
affected. Clinical signs typically develop as a result of this space-
occupying lesion exerting pressure on surrounding tissues.
Rupture of the cyst and spillage of the contents may cause
anaphylactic shock and secondary CE. In many parts of the world,
including Iran, surgery remains the treatment of choice for most
individuals suffering from CE .
Cystic echinococcosis is a cosmopolitan zoonosis, with highly
endemic areas especially prevalent in regions of South America,
North Africa, China, and the Middle East . Iran is an important
endemic focus of CE where several species of intermediate host are
commonly infected with E. granulosus . High infection preva-
lences, with different strains of E. granulosus, have been reported in
various domestic livestock including sheep (5.1%–74.4%), goats
(2%–20%), cattle (3.5%–38.3%), buffalo (11.9%–70%), and
camels (25.7%–59.3%) [4,5,6]. Between 5% and 45% of dogs is
reported to be infected with E.granulosus in different provinces of
Iran (reviewed in ). Human CE cases are also regularly reported
from medical centers in different parts of the country and the
incidence of CE is estimated 1.18-3 per 100,000 populations in
different regions .
Recently, the World Health Organization (WHO) included CE
in a subgroup of selected Neglected Tropical Diseases (NTDs) to
be addressed within its 2008–2015 strategic plan for control of
NTDs [8,9]. The WHO recommends that the impact of zoonotic
infections be assessed before implementation of any control
measure [10,11]. Costs associated with CE have been shown to
have a great impact on affected individuals, their families, and the
community as a whole [12,13]. Monetary losses due to CE have
been estimated for Uruguay , Wales , Jordan , Tunisia
, Turkey , Spain , Peru  and for a highly endemic
area of the Tibetan plateau [21,22]. In addition, the non-monetary
burden of CE has been assessed for a highly endemic region of
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China and globally utilizing the disability adjusted life year
Although CE is assumed to be a significant public health and
economic problem in Iran, the extent of its socioeconomic impact
is not fully understood. Economic losses due to CE in ruminants
have been previously estimated in three provinces of Iran
(Khuzestan, North Khorasan, and Ardabil) [24,25,26]. However,
these studies were not concerned with human CE and used
potentially biased methods to estimate livestock-related losses.
Accurate assessment of the disease burden is crucial to raise
awareness of decision-makers and to prioritize use of limited
resources to provide timely preventive measures [27,28]. The
purpose of the present study is to estimate the monetary burden of
CE in Iran using existing country-level data on human and animal
Materials and Methods
Human epidemiological data
Population data for Iran for 2010 were extrapolated from the
2006 population census, with 71.8% of the population living in
urban areas . Due to a lack of surveillance data, the number of
CE patients, by age and gender, that underwent surgery between
2000 and 2009 in 34 referral hospitals in seven of the country’s
most populous provinces (representing 51.4% of the total
population) was collected to determine average annual surgical
incidence. In total, 5,993 CE surgeries were identified over this 10-
year period. For the remaining 23 provinces, data from individual
scientific reports were used when available [30,31,32,33]. For
those provinces with no data, information from neighboring
provinces with similar socioeconomic status was applied. Based on
these sources, an annual number of 1,295 CE surgeries was
calculated. All CE recurrences with re-operations were regarded as
new surgical cases. Approximately 80% of surgical CE cases in
Iran are treated in public hospitals, with the remaining 20%
treated in private hospitals. Only surgical cases of CE were
included in this study due to a lack of data on cases that seek
treatment, but that are treated medically. In order to estimate the
number of undiagnosed or asymptomatic cases of CE in Iran, data
on ultrasound prevalence of CE (1.2% and 0.2%) were used
(Table 1) [34,35]. Lengths of hospital stay and mortality rates were
based on available literature (Table 1).
Livestock epidemiological data
The livestock species primarily involved in the domestic cycle of
CE in Iran are sheep, goats, cattle, buffalo, and camels. Data for
livestock populations and annual numbers of slaughtered animals
were obtained from official government reports (Table 2) .
The low percentage of the total sheep and goat population
slaughtered annually (12.8% and 8.5%, respectively) may reflect
the practice of slaughtering outside of abattoirs. To account for
home slaughtering, losses were also evaluated assuming that
slaughter rates are twice what are reported at the abattoirs,
assuming a mean of 1.25 offspring per ewe/doe per year. Milk,
wool, and hide/skin production values were based on either
Statistical Center of Iran (SCI) reports or United Nation’s Food
and Agriculture Organization (FAO) FAOSTAT data [29,36].
Livestock prevalence data were obtained from abattoir-based
studies available from the literature. Only studies where a
researcher confirmed the presence of CE cysts were included
because abattoir-reported cases are not considered reliable in Iran.
Prevalence data obtained from 3 or more studies were combined
for cattle, sheep, and goats using a meta-analysis for proportions in
R statistical data analysis software, ver. 2.12.0 (META package
version 1.6-1; by Guido Schwarzer) (Table 2) . Due to the
limited available data for buffalos, a meta-analysis could not be
performed for this species. Therefore, the mean prevalence from
two studies on CE in buffalo in Iran (12.4% and 11.9%) was used
Human economic data
Costs associated with direct and indirect losses associated with
human surgical CE were assessed. Direct costs included cost of
surgery, hospital accommodation, diagnostic imaging, clinical
laboratory and histopathology testing, and drug costs in both
public and private hospitals. The Puncture Aspiration Injection
Re-aspiration (PAIR) technique, which is widely used in other
parts of the world, is rarely used in Iran. Therefore, the procedure
was not costed in this study. Unit costs of services were obtained
from official tariffs established by the Iranian Ministry of Health
and Medical Education . Service costs were calculated by
multiplying the unit cost of an individual parameter by its
frequency in the course of disease. Expert attending surgeons from
Afzalipour Medical Center in Kerman, Iran were asked to
estimate the frequency of common CE-associated procedures and
services when these data were not available elsewhere.
Indirect costs associated with human CE included lost wages
due to work absenteeism during hospitalization and recovery, due
to time off to stay with a child with CE, and due to CE-related
mortality. Income data for urban and rural populations were
obtained from official reports of the CBI. Gender specific wage
data were not available for Iran or its neighboring countries.
Therefore, based on studies conducted in other regions, it was
assumed that women earn approximately 0.70 times as much as
men . Breakdown of wages by age was also not available for
Iran. Therefore, it was assumed that this breakdown would also be
similar to the findings from other studies . Unemployment
figures were based on SCI data. Productivity for females who do
not work outside of the home was assumed to be equivalent to
30% of the daily income of an officially employed female of the
same age group .
Cystic echinococcosis (CE), caused by the tapeworm
Echinococcus granulosus, is a zoonotic infection that occurs
worldwide. The adult parasite resides in the small
intestines of dogs and the cyst form can develop in the
liver and lungs of both humans and livestock. CE causes
medical, veterinary, and economic losses in endemic areas.
However, data on the economic consequences of CE are
lacking. The present study estimated the monetary burden
of CE in Iran. We used epidemiological and economic
information to estimate direct and indirect costs of human
and livestock CE in the country. Costs associated with
human CE included the costs of surgery and hospital
services in addition to lost wages due to work absenteeism
during hospitalization and recovery. Costs associated with
CE in livestock included losses due to condemnation of
livers and lungs during carcass inspections, decreased
carcass weight, reproductive losses, and reductions in milk
and other animal products. We estimated the overall
annual cost of CE in Iran at US$232.25 million, with the cost
of the disease estimated to be approximately 0.03% of the
country’s gross domestic product. Implementation of a
control program is necessary to reduce the economic
burden of CE on Iran.
Burden of Echinococcosis in Iran
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A 100% loss of daily wages or productivity was assumed for CE
surgical patients for the period of hospitalization. However, no
losses were evaluated for unemployed patients since government
unemployment benefits, which are received by all members of
society whether they work in the public or private sector, were
assumed to remain unchanged during the treatment period. Since
unemployment benefit coverage is most likely not complete, the
cost estimation is probably underestimated, especially in rural
populations. For CE patients under the age of 18 years, a 30%
wage loss for a man 30–39 years of age was applied for the period
of hospitalization. This was based on the assumption that a parent
would need to devote a proportion of his or her time to caring for
the child [17,19]. It was assumed that premature mortality causes
an annual income loss of between 1 and 364 days in any given
year. Therefore, a uniform distribution was defined for the
number of lost days due to CE-related deaths. In asymptomatic
individuals, lost wages were calculated in terms of annual
monetary income and a productivity loss of 0–5% for one year
Livestock economic data
Direct and indirect costs due to CE-associated losses in livestock
species were evaluated. Direct costs associated with CE in livestock
are due to the condemnation of livers and lungs during carcass
inspections in abattoirs. A uniform distribution was applied to liver
and lungs losses based on market prices across Iran (Table 3). It
Table 1. Human epidemiological parameters associated with CE in Iran.
CategoryValueUnit DistributionRange Reference
Population (2010)74,733,230 IndividualsFixed- 
Average income per day-urban23.48US$
Average income per day-rural14.09US$
Annual surgical incidence of CE 1.27 Per 100,000Uniform 0.80–1.73 See Methods
Hepatic cysts 55.5 PercentFixed- See Methods
Pulmonary cysts30.9PercentFixed- [25,31,33,51,52]*
Hepatic and pulmonary involvement4.1 PercentFixed- See Methods
Other organs9.5 PercentFixed- See Methods
Undiagnosed cases of CE0.85 PercentUniform 0.2–1.5[34,35]
Length of hospital stay11.4Days Uniform7–15.8 [53,54,55]
Mortality among surgical cases2.5PercentUniform1–5 [56,57,58]
No of absentee days for recovery 18DaysUniform8–28[53,54]
Age and sex distribution"
"Based on surgical incidence.
Burden of Echinococcosis in Iran
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was assumed that the entire liver and/or lungs of infected cattle,
sheep, goats, and buffalo would be condemned. The cost of
infected camel livers, but not lungs, was included in the estimate
because camel lungs are not traditionally consumed in Iran.
Indirect losses due to decreased carcass weight, reduction in
milk production, decreased wool production, decreased hide/skin
value, and reproductive losses were estimated. Values of livestock
parameters used to estimate economic losses associated with CE
were assumed to be similar to those used in previous assessments of
livestock-associated CE losses [16,17,19,21]. Based on these
values, a 2.5% decrease in milk production, 15% reduction in
wool quality, 5.5% reduction in fecundity, 10% decrease in hide/
skin production, and 6.25% reduction in carcass weight were
utilized for this study. Farmers’ investment was not taken into
account in the presented cost estimates due to lack of data on this
topic available from Iran or other countries in this region.
Uncertainty and sensitivity analysis
Data were compiled in Excel spreadsheets (Microsoft Corp,
Redmond, WA). The risk analysis and simulation software
@RISK (Palisade corp., Ithaca, NY, ver. 4.5) for Excel was used
to estimate monetary costs attributed to CE infection in humans
and livestock. Output variables were defined according to
parameters involved in the estimation of direct and indirect costs
associated with CE in humans and livestock intermediate hosts
(Table 4). Distributions were assigned based on the most likely
range for each variable. Median and 2.5 and 97.5 percentiles (95%
credible intervals, CIs) were calculated for each output variable.
Table 2. Epidemiological parameters and annual livestock production values for Iran.
CategoryValue (CI) UnitDistributionReference
*No of slaughtered animals/year6,446,354AnimalsFixed 
Prevalence of CE at abattoir23.5 (8–39)PercentNormal [5,26,59,60,61,62,63,64,65]
Meat production390,000Tonne Fixed 
Skin/hide production64,800 Tonne Fixed 
Wool production 52,455Tonne Fixed
Population 22,333,547Animals Fixed
*No of slaughtered animals/year1,912,640 AnimalsFixed 
Prevalence of CE at abattoir 8 (5–11)Percent Normal [5,26,59,60,61,62,63,64,65]
Meat production 106,000TonneFixed
Milk production270,157 Tonne Fixed
Skin/hide production18,875 Tonne Fixed
Wool production 2,905 Tonne Fixed
No of slaughtered animals/year 1,432,270AnimalsFixed 
Prevalence of CE at abattoir20 (13–27) PercentNormal[5,26,59,60,61,62,63,64,65]
Meat production360,000 TonneFixed
Milk production5,965,728TonneFixed 
Hide/leather production 47,700TonneFixed 
No of slaughtered animals/year30,926AnimalsFixed
Prevalence of CE at abattoir 12.5PercentFixed[5,26]
Milk production245,000Tonne Fixed
Hide/leather production 2,048TonneFixed 
Population151,932 AnimalsFixed 
No of slaughtered animals/year 45,127AnimalsFixed 
Prevalence of CE at abattoir32 (15–49)PercentNormal[66,67,68,69,70,71]
Meat production1,680 TonneFixed
*Assuming government-reported slaughter rates for sheep and goats.
Burden of Echinococcosis in Iran
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Monte Carlo simulation using a Latin Hypercube approach with
10,000 iterations was performed to model parameter uncertainty.
A sensitivity analysis was conducted using stepwise linear
regression of the estimated costs against the input parameter
values to assess the impact of each input parameter on the overall
cost estimate. A separate sensitivity analysis was run excluding
losses related to asymptomatic/non-healthcare seeking human CE
Human CE costs
Table 4 contains estimates of the annual direct and indirect
costs associated with CE in humans in Iran. The cost of surgical
treatment for a case of hepatic or pulmonary CE in a public
hospital was estimated at US$1,027 (95% CI US$676–1,379) and
US$851 (95% CI US$528–1,173), respectively. The corresponding
values for surgical treatment of CE in a private hospital were
estimated at US$1,911 (95% CI US$1,431–2,387) for hepatic and
US$2,458 (95% CI US$1,976–2,939) for pulmonary involvement.
The overall annual cost of CE in Iran was estimated at US$232.25
million (95% CI US$103.11–397.84 million). The cost associated
with human CE was estimated at US$93.39 million (95% CI
US$6.11–222.72 million), of which US$1.09 million (95% CI
US$820,000–1.44 million) and US$92.34 million (95% CI
US$5.01–221.55 million) were attributed to direct and indirect
Human CE contributed to more than 40% of the total annual
cost of CE in Iran. This was mainly due to the impact of human
productivity losses in the asymptomatic/non-healthcare seeking
population. This figure decreased to 1.1% of the total estimated
cost when productivity losses in the asymptomatic/non-healthcare
seeking population were excluded. Direct costs of human CE were
estimated at 1.2% of the total cost of human disease. However,
direct costs accounted for three quarters of the economic losses in
surgical CE cases.
Livestock associated CE costs
Assuming government slaughter values, the median annual
cost associated with CE in livestock was estimated at US$132.0
million (95% CI US$61.8–246.5 million), of which US$23.5
million (95% CI US$12.7–36.5 million) was direct and US$108.4
million (95% CI US$45.0–216.9 million) was indirect cost.
Sheep and cattle CE were responsible for 48% and 42% of the
total economic losses due to livestock CE in Iran, respectively.
Direct costs associated with CE in livestock accounted for 10.1%
of the overall cost of the disease. Indirect costs associated with
CE in livestock were primarily due to losses in fecundity and milk
reduction. Indirect costs due to CE in livestock intermediate
hosts comprised more than 80% of the total livestock-associated
costs of CE and approximately 47% of the overall cost of CE in
Iran. Costs associated with sheep and goat CE, assuming the
practice of home slaughtering, are found in Table 5.
The impact of uncertain parameters on the total monetary
burden of CE in Iran and the corresponding regression coefficient
values are shown in Figure 1. Productivity losses in asymptomatic
individuals, CE prevalence in sheep, and fecundity losses in sheep
and cattle had the largest impact on overall cost of the disease
(Figure 1a). When productivity losses in asymptomatic/non-
healthcare seeking individuals were excluded, fecundity losses
and CE prevalence in sheep and cattle had the largest overall
impact (Figure 1b).
Estimating the economic impact of a zoonotic disease is a way
of quantifying the significance of the disease in both human and
livestock populations. In addition, this type of analysis helps
decision-makers prioritize resources for disease control and
prevention. The aim of the present study was to estimate the
economic impacts of CE in Iran. Findings indicated that CE
costs Iran more than US$230 million per year. This is a
considerable burden as this equates to about 0.03% of the
country’s Gross Domestic Product (GDP). A value of 0.03% of
the country’s GDP is in line with the findings of other studies
where this value ranged from 0.003% to 0.04% of GDP
The overall cost of CE in Iran was estimated to be higher than
the CE-associated monetary losses for other countries, including
Jordan (US$ 3.9 million), Uruguay (US$ 9.0 million), Tunisia (US$
14.7 million), Turkey (US$ 89 million- livestock losses only), and
Table 3. Value of livestock parameters (per Kg) used to
estimate the monetary burden of CE in Iran.
CategoryValue (US$) Distribution RangeReference
Live animal 2.86Uniform2.46–3.26[29,36]
Lung 10.12Uniform 8.67–11.56
Hide/skin 1.64Fixed- 
Wool0.59 Fixed- 
Live animal 2.78Uniform2.40–3.16 [29,36]
Lung10.12 Uniform 8.67–11.56 
Live animal 2.54Uniform2.26–2.81[29,36]
Live animal2.54 Uniform2.26–2.81[29,36]
Live animal 1.21Fixed- 
N Assumed to be similar to that of cattle.
Burden of Echinococcosis in Iran
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Spain (US$ 200 million) [14,15,16,18,19]. This is partly the result
of larger human and livestock populations in Iran compared to the
other studied countries (Table 6). Iran is the third most populous
and second largest country in the Middle East and has the fourth
largest sheep population in the world . However, direct
comparison of economic losses associated with CE from different
countries is difficult since past studies have used a variety of
methodologies to arrive at cost estimates.
In previous studies on ruminant echinococcosis economic losses
due to CE have been estimated using conventional calculation
methods. Livestock CE-related
US$459,660 in the city of Ahwaz , at US$421,826 in nine
districts of North Khorasan province  and at US$51,900 in
Ardabil province .
Based on the results of this study, the monetary burden of CE in
Iran is substantial, especially when indirect costs due to
Table 4. Annual direct and indirect costs associated with CE in humans and livestock in Iran.
CategoryMedian cost (US $) 95% CI
Costs of hepatic CE593,485 410,640–818,157
Costs of pulmonary CE261,800189,390–340,775
Costs of CE in liver and lung75,420 53,198–100,919
Costs of CE in other organs 101,45670,080–139,730
Direct costs of CE 1,097,950 855,548–1,381,656
Indirect costs of CE1
Indirect costs of CE"
Total costs of human CE1
Total costs of human CE"
Direct costs of CE12,524,9604,047,542–22,354,430
Indirect costs of CE59,036,660 4,047,542–22,354,430
Total costs of sheep CE71,551,620 16,585,770–152,227,400
Direct costs of CE1,074,601 608,845–1,610,484
Indirect costs of CE6,031,210 1,271,019–12,306,230
Total costs of goat CE7,105,811 2,235,714–13,586,770
Direct costs of CE9,992,2406,412,567–13,777,960
Indirect costs of CE47,920,830 18,608,570–84,215,220
Total costs of cattle CE57,913,070 27,012,570–96,117,080
Direct costs of CE131,108 114,636–148,589
Indirect costs of CE787,311 314,762–1,273,489
Total costs of buffalo CE918,418 445,066–1,403,014
Direct costs of CE13,433 6,201–20,886
Indirect costs of CE 586,974 175,347–1,140,535
Total costs of camel CE600,406184,034–1,158,064
Direct costs 23,726,34014,323,200–34,387,130
Indirect costs114,363,000 51,049,920–196,475,100
Total costs of animal CE 138,089,30069,524,500–226,669,800
Direct costs of CE in human and animals 24,824,29015,425,180–35,444,500
Indirect costs of CE in human and animals1
Indirect costs of CE in human and animals"
TOTAL MONETORY COSTS OF CE IN IRAN1
TOTAL MONETORY COSTS OF CE IN IRAN"
*Assuming government-reported slaughter rates for sheep and goats.
1Excluding asymptomatic/non-healthcare seeking human population.
"Including asymptomatic/non-healthcare seeking human population.
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productivity losses in the asymptomatic/non-healthcare seeking
population were taken into consideration. Productivity losses for
asymptomatic/non-healthcare seeking individuals added about
US$ 100 million to the overall cost estimate of CE in the country.
This estimate was based on the two community-based ultrasound
studies that have been carried out in Iran. However, this was not
optimal since both of the studies were conducted in rural/nomadic
populations. Nevertheless CE cases are increasingly reported from
urban regions. The number of CE cases from rural and urban
areas was shown not be significantly different in Iran. Several
studies have shown that CE is equally prevalent in rural and urban
regions, especially due to the increased recreational/camping
activities of the urban population and large migrations of people
from rural to the urban/peri-urban regions of the country during
last three decades [31,39]. This same phenomenon has been
documented in other countries, including Serbia , Croatia
 and Libya . Like other NTDs prevalent in less developed
countries, it appears that CE is being urbanized and can no longer
be considered solely as a rural disease [43,44].
The ratio of community ultrasound prevalence to the annual
surgical incidence of CE was 669.3, which is higher than the ratio
of 45.4 found in Florida, Uruguay , the ratio of 22 to 344 for
Turkey [46,47], and the ratio of 241 for Morocco . However,
the value is comparable with the ratio of 405 to 1,889 determined
for Libya [47,48]. While this may mean that the number of
asymptomatic/non-healthcare seeking individuals in Iran was
overestimated, it also could indicate that health-seeking behavior
of Iranians is different from that of people in other countries.
Compared to Uruguayans, Turks, and Moroccans, Iranians may
have either less access to health care or do not seek health care
services provided in the country due to different health-seeking
behaviors. Differences in the pathogenicity of E. granulosus
genotypes/strains may also explain this dissimilarity since it is
generally believed that genotypes of E. granulosus can differ in
infectivity and/or clinical severity . By applying the ratios for
Turkey (334) and Uruguay (45.4) to the incidence rate of surgical
cases in Iran, the prevalence of asymptomatic/non-healthcare
seeking cases of CE would be 0.23% and 0.06%, respectively
compared to the estimated 0.85% used in this study.
A limitation of this study was how to assess productivity losses
for those individuals who were not formally employed. Based on
limited available data, a 30% productivity loss was assumed for
women who are not officially employed outside of the home. This
value was chosen because a sick homemaker indirectly affects the
entire family’s productivity and increases living costs of the family.
Indirect costs of CE in humans and livestock accounted for more
than 80% of overall monetary losses in this study, which is in
agreement with the results of other studies in endemic areas
[14,15,16,17,18,19,21]. Indirect costs reflect economic effects of
the disease that are often not taken into consideration by
agriculture and health officials. Indirect costs associated with
human CE treatment were probably underestimated in this study.
Additional indirect costs may include expenses associated with
travel from a rural area to the city, or from one urban area to
another urban area to seek appropriate health care, as well as
expenses due to an accompanying spouse or other member of the
family. Additional studies are needed in order to provide better
evidences of the true impact of indirect losses due to CE in both
humans and livestock intermediate hosts.
Availability of high quality epidemiological and economic data
is crucial for improving the accuracy of the estimation. Lack of
age-stratified CE prevalence data for livestock was another
limitation of the present study. However, abattoir-based CE
prevalence data tends to be underestimated due to the fact that, in
Iran, animals that are slaughtered in abattoirs tend to be young
and, therefore, have a lower chance of being infected compared to
older animals. Another important issue is the unexpectedly low
proportion of the sheep and goat population reported to be
slaughtered each year (12.8% and 8.5%, respectively). These
figures reflect animals that are slaughtered in registered abattoirs,
which is almost definitely an underestimation. Many people,
especially those living in rural/suburban areas, practice home
slaughter. In addition, a number of unregulated abattoirs also exist
within the country. However, the extent of slaughtering outside
official channels is not fully understood and needs to be
investigated. To account for the practice of home slaughter, a
second scenario was considered assuming that 25% and 17% of
sheep and goat populations are slaughtered every year, respec-
tively. As expected, this second scenario resulted in both increased
direct and indirect costs for these species (Table 5). However, the
overall effect of the second scenario on the total monetary cost of
human and animal CE was relatively small (i.e., a 7.7% increase
from US$236.7 million to US$254.9 million). Regarding the high
proportion of camel population reported to be slaughtered each
Table 5. Estimated monetary losses associated with CE in Iran based on two scenarios for home slaughtering.
ScenariosDirect costs, US$ (95% CI) Indirect costs, US$ (95% CI)
Direct and indirect costs, US$
Government reported values
assuming that 12.8% of sheep
and 8.5% of goats are
Goat 1,074,601 (608,845–1,610,484) 6,031,210 (1,271,019–12,306,230)7,105,811 (2,235,714–13,586,770)
Total 13,589,560 (5,037,907–
Adjusting for home slaughtering
assuming that 25% of sheep
and 17% of goats are
Goat2,149,359 (1,225,908–3,259,446)6,400,930 (1,580,594–12,635,600)8,550,289 (3,359,383–15,273,460)
Burden of Echinococcosis in Iran
PLOS Neglected Tropical Diseases | www.plosntds.org7November 2012 | Volume 6 | Issue 11 | e1915
Figure 1. Regression coefficients of parameters associated with the total cost of CE in Iran.
Burden of Echinococcosis in Iran
PLOS Neglected Tropical Diseases | www.plosntds.org8 November 2012 | Volume 6 | Issue 11 | e1915
year (29.7%) that seems very high for such a long-lived animal, we
retrieved camel data from official sources (Statistical Center of
Iran). Underestimation of the total population of camels is quite
probable because of the very traditional nature of camel farming
in the country and illegal import of camels across the eastern
Findings of the present study indicate that CE imposes a
substantial economic impact on Iran. Reduction of human and
livestock infection through implementation of CE control
programs is necessary to reduce the economic burden of CE on
the country. Cost-benefit analysis of different control programs is
now possible in light of present knowledge on the economic losses
associated with CE in Iran. However, because comparing
monetary costs in different countries with different socioeconomic
statuses is often not optimal, a complementary analysis of the non-
monetary burden of CE is recommended to compare CE burden
in different geographical regions. In addition, evaluation of the
non-monetary burden of the disease and measurement of cost per
DALY averted by the control campaigns is recommended.
Therefore, a paper evaluating CE-associated DALYs in Iran is
currently in preparation. This is the first study to evaluate
monetary losses due to human and livestock CE in Iran. However,
additional research is needed to improve CE monetary burden
estimates and to develop uniform methodologies for assessment
Conceived and designed the experiments: MFH CMB SR. Performed the
experiments: MFH CMB SR. Analyzed the data: MFH CMB. Contributed
reagents/materials/analysis tools: MFH CMB. Wrote the paper: MFH
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