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Incidence of first ever stroke during Hajj
ceremony
Mahmoud Reza Azarpazhooh
1†
, Reza Bavarsad Shahripour
2,3†
, Moira K Kapral
4
, Naghmeh Mokhber
5
, Ali Shoeibi
1
,
Mohammad Taghi Farzadfard
1
, Mohammad Reza Rafati
6
, Amanda G Thrift
7
, Negar Morovatdar
8
,
Seyed Aidin Sajedi
3
and Amir Azarpazhooh
4,9,10*†
Abstract
Background: The Hajj Ceremony, the largest annual gathering in the world, is the most important life event for
any Muslim. This study was designed to evaluate the incidence of stroke among Iranian pilgrims during the Hajj
ceremony.
Methods: We ascertained all cases of stroke occurring in a population of 92,974 Iranian pilgrims between
November 27, 2007 and January 12, 2008. Incidence and risk factors of the first ever stroke in Hajj pilgrims were
compared, within the same time frame, to those of the Mashhad residents, the second largest city in Iran. Data for
the latter group were extracted from the Mashhad Stroke Incidence Study (MSIS) database.
Results: During the study period, 17 first-ever strokes occurred in the Hajj pilgrims and 40 first-ever stroke strokes
occurred in the MSIS group. Overall, the adjusted incidence rate of first ever stroke in the Hajj cohort was lower
than that of the MSIS population (9 vs. 16 per 100,000). For age- and gender-specific subgroups, the Hajj stroke
crude rates were in general similar to or lower than the general population of Mashhad, Iran, with the exception
of women aged 35 to 44 years and aged >75 years who were at greater risk of having first-ever stroke than the
non-pilgrims of the same age.
Conclusion: The first ever stroke rate among Iranian Hajj pilgrims was lower than that of the general population
in Mashhad, Iran, except for females 35–44 or more than 75 years old. The number of events occurring during the
Hajj suggests that Islamic countries should consider designing preventive and screening programs for pilgrims.
Keywords: Acute stroke, Hajj, Incidence
Background
The Hajj Ceremony, the largest annual gathering in the
world, is the most important life event for any Muslim.
For the majority of the pilgrims, this is a long-desired jour-
ney that may only happen once in their lifetime. Hence, it
can be mentally stressful. Annually, millions of Muslims
from various countries gather in the holy cities of Mecca
and Medina in the Kingdom of Saudi Arabia to perform
their religious rituals. Pilgrims are often in close contact,
and are at increased risk of viral infections, particularly
upper respiratory tract infections [1-5].
Despite the importance of Hajj, there are scant data
on the incidence of important diseases such as vascular
conditions that occur during the pilgrimage. Quantifying
rates of cardiovascular disease during Hajj is important
for Islamic countries [6-9]. If the stroke rate is high dur-
ing Hajj, the Kingdom of Saudi Arabia may need to re-
evaluate its health system infrastructure and hospitals
for stroke treatment. Moreover, Islamic countries may
need to develop vascular preventive and screening pro-
grams for pilgrims. In addition, because of high reported
rates of infection and psychological stress, the Hajj pil-
grimage brings a unique opportunity to evaluate such
risk factors on the occurrence of stroke [6].
* Correspondence: amir.azarpazhooh@utoronto.ca
†
Equal contributors
4
Institute of Health Policy, Management and Evaluation, Faculty of Medicine,
University of Toronto, Ontario, Canada
9
Discipline of Dental Public Health, Faculty of Dentistry, University of Toronto,
Room 515-C, 124 Edward St, Toronto, ON M5G 1G6, Canada
Full list of author information is available at the end of the article
© 2013 Azarpazhooh et al.; licensee BioMed Central Ltd. This is an open access article distributed under the terms of the
Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use,
distribution, and reproduction in any medium, provided the original work is properly cited.
Azarpazhooh et al. BMC Neurology 2013, 13:193
http://www.biomedcentral.com/1471-2377/13/193
Objective
The objectives of this study were: 1) to determine the inci-
dence of first-ever stroke among Iranian pilgrims during
the Hajj ceremony, and 2) to compare the stroke incidence
rate to a proxy estimate of Iran’snationalstrokerate.
Methods
Study design and source of data
The study was approved by the Ethics Committee of the
Hajj and Pilgrimage Organization of Iran and Mashhad
University of Medical Sciences (protocol No. 2195390).
The study participants were 92,974 Iranian pilgrims who
attended the Hajj ceremony between November 27,
2007 and January 12, 2008. These pilgrims were from
different socioeconomic backgrounds and different rural
and urban areas. According to the guidelines of the Hajj
and Pilgrimage Organization of Iran, candidates with
severe dementia, uncontrollable cancer, severe disabling
stroke and recent (less than 3 months) myocardial in-
farction are not eligible to participate in the pilgrimage.
After the initial eligibility screening, pilgrims were gath-
ered as 605 groups (caravans, each including 100–200
pilgrims) and were evaluated before, during, and after
the Hajj ceremony. Before and during the trip, a General
Practitioner (GP) was assigned to each caravan.
Before the trip, the GPs received extensive training
in the medical protocol of the Hajj and Pilgrimage
Organization of Iran. They were responsible for register-
ing past medical conditions, including the history of pre-
vious stroke, and evaluating the health status eligibility
of the pilgrims in their assigned caravans. This informa-
tion was recorded in the patient health chart kept by the
GP of each caravan. During the Hajj pilgrimage, the GPs
were the first point of contact for the pilgrims in case of
medical concerns. The GPs then referred cases with
neurological findings to the two permanent hospitals of
the Iran Red Crescent Society in the Holy cities of
Mecca and Medina, under the care of the study neurolo-
gist (MRA). When imaging was required, the cases were
referred to the local Saudi's Hospitals. All patients were
provided with free access to hospital care and laboratory
tests. After the Hajj ceremony, all Iranian pilgrims were
fully covered by a private healthcare company for any
follow up visits, admission and treatment of diseases
related to the Hajj period. The health data of the
pilgrims, including their demographic characteristics,
past medical history, medical events during and after the
Hajj ceremony, decisions taken by GPs and subsequent
referrals, cause of admission and outcome were regis-
tered in the central data bank of the Hajj and Pilgrimage
Organization of Iran. We received the de-identified data-
set and ascertained all cases of first ever-stroke in Hajj
pilgrims through the retrospective evaluation of pilgrims’
medical records. We also ascertained stroke events in
non-pilgrims from the Mashhad Stroke Incidence Study
(MSIS), our recently published population-based pro-
spective cohort study [10]. The MSIS registered all strokes
occurring in a population of 450,229 residents of the City
of Mashhad (the second largest city in Iran) were regis-
tered during a 12-month period (2006–2007) [10].
Variables and outcome measures
The primary outcome in this study was the incidence
of stroke, defined according to the World Health
Organization as rapidly developing signs of focal or glo-
bal disturbance of cerebral function, lasting for more
than 24 hours (unless interrupted by surgery or death)
with no apparent cause other than a vascular origin
[11,12]. The First-Ever Stroke was defined as a stroke
occurring for the first time during a patient’s lifetime
[12]. Previous stroke was determined using all available
information including hospital records, neuroimaging
results and/or self- or family-reported data. Neuroimag-
ing was used to classify cases with definite strokes into
ischemic stroke, intra-cerebral haemorrhage, or sub-
arachnoid haemorrhage. As per the most recent consen-
sus definition the American Heart Association/American
Stroke Association (AHA/ASA), we included cerebral
venous thrombosis (CVT) as stroke only if patients had
infarction or hemorrhage in localized area of brain be-
cause of thrombosis of a cerebral venous structure [12].
An “undetermined stroke”was defined as a stroke in
which a patient had not undergone CT scanning within
28 days of the onset of symptoms and an autopsy had
not been performed [12].
A“possible stroke”was considered as any acute epi-
sode of neurological disturbance that was suggestive of
stroke but there was insufficient information to establish
whether or not the symptoms and duration (<24 hours
or > 24 hours) fully met the World Health Organization
definition of the definite stroke [13]. A “CT only”stroke
was defined when the patient had no clinical signs
and symptoms of stroke, but neuroimaging identified
changes compatible with stroke [13]. “Possible”and
“CT only”strokes were excluded from the study. We
also excluded CVT cases for whom the symptoms or
signs were caused by reversible edema without infarction
or hemorrhage [12].
The following risk factors were assessed for those
patients diagnosed with first-ever stroke: gender, age,
stressful periods (i.e., mentally or emotionally disruptive
or upsetting situations such as getting lost, losing
money, missing ritual rules, etc.), current smoking
status, and past history of hypertension, diabetes, hyper-
lipidaemia, transient ischemic attack, ischemic heart
disease, and atrial fibrillation. For our second objective,
we regarded the Hajj pilgrims as the exposed group and
compared them to the non-exposed population, derived
Azarpazhooh et al. BMC Neurology 2013, 13:193 Page 2 of 7
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from the data source of the MSIS stroke incidence study,
in the manner of a historical cohort. From the MSIS
database, the first-ever stroke cases during the exact
period of the Hajj ceremony were extracted.
Statistical analysis
The first-ever stroke crude incidence rates were calcu-
lated using the total of Iranian Hajj pilgrims and the
MSIS subjects (above age of 15, in the same time frame),
respectively as the denominator for the Hajj group and
the MSIS group. To calculate standardized incidence
rates, we used direct method of adjustment with SEGI
world population and IRAN 2006 standard population.
We calculated the adjusted incidence rates for each
population and by gender. Due to the different popula-
tion pyramids of Hajj pilgrims and Mashhad residents,
the crude incidence rates were compared only for strati-
fied age and gender groups between two cohorts. The
95% confidence intervals (CI) were calculated for ad-
justed rates on the assumption of a normal distribution
for counts greater than 100 and a Poisson distribution
for counts less than 100. The incidence rates were re-
ported as number of cases per 100,000 population per
month. Proportions were compared by the Chi-square
test or Fisher's exact test when appropriate. Students
T-test was used to compare continuous variables. All
statistical tests were undertaken using SPSS v13.0 soft-
ware. The significance was set at P < 0.05 (two-sided).
Results
Descriptive results
The age distribution of the Hajj pilgrims and the MSIS
population is presented in Figure 1. While 55% of the
MSIS population was less than 35 years of age, the ma-
jority of the pilgrims (75%) were between the ages of 35
and 64 years. During the study period, GPs referred 19
cases suspected of having stroke. A final diagnosis of
first-ever stroke by the study neurologist was made for
17 of these cases (5 men and 12 women). No case was
suspected of “possible”or “CT only”strokes. Thirteen
patients had ischemic stroke (including two cases with
cerebral vein thrombosis); two had intra-cerebral haem-
orrhage; and the other two had undetermined stroke.
CT or MRI of the brain was performed in 15 cases.
Within the same time period, 40 cases (23 men and 17
women) with a final diagnosis of first-ever stroke were
registered in the MSIS database. These included 29 cases
of ischemic stroke, 10 cases of haemorrhagic stroke and
one case of undetermined stroke. The baseline charac-
teristics and risk factors of first-ever stroke patients were
similar between the two groups (Table 1).
First-ever stroke incidence
Table 1 summarizes the age- and gender- specific crude
incidence rates as well as the SEGI- and IRAN 2006-
adjusted rates of first-ever stroke in the two cohorts. For
the age- and gender- specific crude incidence rates, we
noted a lower first-ever stroke rates in the Hajj group
for all strata, except for women aged 35 to 44, 75 to 84
and greater than 85 years. In these subgroups, stroke
rates were significantly higher in the Hajj than in the
MSIS cohort. Overall, the SEGI-adjusted incidence rate
in the Hajj cohort was lower than that of the MSIS
population (7; 95% CI: 4–11 vs. 13; 95% CI: 9–17 per
100,000 per month; P = 0.03). This pattern was similar
for males (4; 95% CI:0.5-7 vs.14; 95% CI: 8–20, per
100,000 per month ; P = 0.02). However, the adjusted
incidence rate of first-ever stroke in the Hajj female
population was not statistically different from the MSIS
population (13; 95% CI: 6–21 vs. 11; 95% CI:6–17 per
100,000 per month; P = 0.07). The IRAN 2006-adjusted
rates followed a pattern similar to those of the SEGI-
adjusted rates.
Figure 1 Distribution of Hajj and MSIS cohorts by age groups.
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Discussion
We investigated the incidence of stroke among Iranian
pilgrims during the 2007 Hajj ceremony, and found that
the overall incidence was lower as compared to what
was seen in the general population of Mashhad, Iran.
This pattern is likely attributable to the pre-pilgrimage
medical screening performed by the Hajj and Pilgrimage
Organization of Iran. The screening program for the
Table 1 Age- and gender -specific Incidence Rates (per 100,000 Population per month) and adjusted incidence rates
for First-Ever Stroke in Hajj (2007) compared with the data from MSIS within the same period
Age (years) Hajj subjects MSIS subjects P value
No. Population at risk Incidence rate (95% CI) No. Population at risk Incidence rate (95% CI)
Both genders
15–24 0 514 –0 112588 ––
25–34 0 4110 –2 83131 2 (0–5) –
35–44 2 19397 10 (4–16) 1 57743 2 (0–5) 0.021
‡
45–54 3 29973 10 (4–16) 5 40596 12 (5–20) 0.67
†
55–64 3 21584 14 (7–21) 5 20096 25 (15–36) 0.07
†
65–74 5 12568 40 (28–52) 11 13103 84 (66–102) 0.001
†
75–84 3 4033 74 (57–91) 13 5944 219 (190–248) 0.001
†
>85 1 739 135 (112–158) 3 1147 262 (230–294) 0.001
†
Total 17 92974 18 (10–26) 40 334348 12 (5–19)
Standardized to SEGI* 7(4–11) 13 (9–17) 0.03
Standardized to IRAN ^ 7(5–9) 12 (8–15) 0.04
Males
15–24 0 234 –0 55458 ––
25–34 0 1303 –1 42266 2 (0–5) –
35–44 0 8102 –0 29202 ––
45–54 2 14646 14 (7–21) 3 20681 15 (7–23) 0.85
†
55–64 2 10704 19 (10–28) 2 10146 20 (11–29) 0.87
†
65–74 0 7140 –5 6820 73 (56–90) –
75–84 1 2710 37 (25–49) 10 3109 322 (287–357) 0.001
†
>85 0 547 –2 556 360 (323–397) –
Totals 5 45419 11 (4–18) 23 168238 14 (7–21)
Standardized to SEGI* 4 (0.5–7) 14 (8–20) 0.02
Standardized to IRAN ^ 4 (0.5–8) 17 (10–24) 0.01
Females
15–24 0 280 –0 57130 ––
25–34 0 2807 –1 40865 2 (0–5) –
35–44 2 11295 18 (10–26) 1 28541 4 (0–8) 0.003
†
45–54 1 15327 7 (2–12) 2 19915 10 (4–16) 0.46
†
55–64 1 10880 9 (3–15) 3 9950 30 (19–41) 0.001
†
65–74 5 5428 92 (73–111) 6 6283 95 (76–114) 0.82
†
75–84 2 1323 151 (127–175) 3 2835 106 (86–126) 0.005
†
>85 1 192 521 (476–566) 1 591 169 (144–194) 0.001
†
Total females 12 47555 25 (15–35) 17 166110 10 (4–16)
Standardized to SEGI* 13 (6–21) 11 (6–17) 0.07
Standardized to IRAN^ 15 (6–23) 12 (7–18) 0.08
MSIS: Mashhad Stroke Incidence Study [11].
†
Chi-square test; ‡Fisher exact test; N/A: Not applicable.
*adjusted by age and sex to the world (SEGI) population.
^adjusted by age and sex to the Iran population.
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Hajj is simple, comprising evaluation of blood pressure,
diabetes and other vascular risk factors. In suspected
cases of vascular disorders, electrocardiography is per-
formed with referral for cardiology or neurology consult-
ation. Candidates with severe dementia, uncontrollable
cancer, severe disabling stroke and recent (less than
3 months) myocardial infarction are excluded from
participation in the Hajj ceremony. Therefore, it can be
argued that such enhanced screening system may have
reduced to some degree the stroke risk factors by select-
ing individuals devoid of severe and life-threatening
disease. The finding implies a research hypothesis
whether population-based screening programs would re-
duce stroke in communities. This simple screening could
be tested in the general population with the aim of treat-
ing these risk factors to prevent vascular events. It is also
possible that the pilgrims with the knowledge of having
the upcoming trip would be more conscious about their
health status. In other words, people participating in the
Hajj are healthier than the general population, similar to
what is observed in the healthy migrant effect [14].
Previous small-scale studies reported that 20-35% of
hospital admissions during Hajj were related to old age
and occurred in patients with associated cardiovascular
conditions [15-18]. To the best of our knowledge no
study has thus far assessed the incidence of stroke
among the Hajj participants. In this present study, we
found that stroke risk in Hajj pilgrims was increased
relative to the general population of Mashhad, Iran in
some subgroups of women, including those aged 33 to
44 years and those aged over 75 years. We have previ-
ously reported a greater risk of CVT in Hajj pilgrim
females [18-38]. Young Muslim women often take oral
contraceptives in the short term during religious cere-
monies to avoid menstruation. This is because menstru-
ation would cancel the sacred state of Ihram, into which a
Muslim must enter in order to perform the religious
rituals. In this present study, we had two cases with CVT
who fell in the stroke criteria of the AHA/ASA [12]. It is
possible that the use of oral contraceptives during the Hajj
contributed to the increased risk of stroke in women aged
35 to 44 years compared to the general population of
Mashhad, Iran. It needs to be noted that some epidemio-
logical studies of stroke did not include CVT. Ischemic
stroke and CVT are important types of stroke and comply
with the clinical definition of stroke. In 2013 Updated Def-
inition of Stroke for the 21st Century, the American Heart
Association/American Stroke Association included CVT
with specific criteria (infarction or hemorrhage in brain
because of thrombosis of a cerebral venous structure) as
stroke [9]. Therefore, we included these two cases that fell
under these specific criteria.
In addition, pilgrims are subjected to high rates of
physical and mental stress as well as infection, in
particular upper respiratory tract infections) [19]. Previ-
ous studies have suggested that recent bacterial or viral
infections, particularly in the preceding week, are a risk
factor for stroke [19-21]. Some studies have also shown
an association between respiratory tract infection epi-
demics and death due to cardiovascular disorders [19],
and reductions in cardiovascular mortality and stroke after
influenza vaccination [22-24] and control of epidemic
respiratory diseases [25-27]. While such infections, inflam-
matory processes and psychological stress may be predis-
posing risk factors for stroke and cardiovascular disease,
their exact role remains unclear [28-33].
Within the Hajj pilgrims, an increased risk of first-ever
stroke was noted in females aged over 65 years com-
pared to their male counterparts. The reasons for this
are uncertain, and may include baseline differences in
stroke risk factors or comorbid conditions. Other poten-
tial explanations include gender differences in the neuro-
biological responses to psychological stress. It has been
shown that brain locations activated in response to psy-
chological stress, the subsequent systemic responses and
the duration of the effect of the stress are different
in men and women [22,34,35]. That said, the existing
literature regarding psychological distress and risk of
stroke is scant, and presents varied findings [22-36].
This study has some limitations. Any occurrence of
stroke would have health planning implications; how-
ever, in order to have a comparable group with the MSIS
subjects, we evaluated only first ever strokes rather than
all strokes. Although the pre-pilgrimage medical screen-
ing may have resulted in overall lower first-ever stroke
rates in Iranian pilgrims, it may have imposed an un-
avoidable selection bias, once comparing the Hajj
pilgrims with the general population of Mashhad, Iran.
The latter group comprises those with diverse socio-
economical status and underlying factors that may affect
their health. Mashhad is the second populous metropol-
itan of Iran and a religious centre that attracts many mi-
grants from all parts of the country. The MSIS has been
so far the only comprehensive population-based study of
stroke in Iran. Although the result of this study cannot
readily be generalized to the whole country, other un-
published local data suggest comparable cerebrovascular
risk profile in other cities, similar to what was found in
the MSIS. This gives us some confidence that Mashhad
can be regarded as representative of the urban population
of Iran and the MSIS results can provide a good proxy of
the national incidence of urban population, but not the
rural population. It should also be noted that the baseline
information and risk profile were only available from the
Hajj pilgrims with first-ever stroke, not all the pilgrims.
Therefore, the comparison between demographic and pre-
morbid risk factors of all Hajj pilgrims and the general
population of Mashhad, Iran was not possible. In addition,
Azarpazhooh et al. BMC Neurology 2013, 13:193 Page 5 of 7
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we were unable to evaluate the processes and outcomes of
care for Hajj pilgrims with stroke.
Despite these limitations, this study was strengthened
by the fact that we accessed the medical information of
more than 90,000 Iranian pilgrims who were closely
monitored during the Hajj ceremony. To the best of our
knowledge, this is the first stroke epidemiological study
among Hajj pilgrims, gathering at the largest annual
event in the world. Islam has 1.6 billion followers in the
world, comprising over 23% of the world population
[39]. Due to the religious rules, attending in Hajj cere-
mony, at least for once, is an aim for Muslims. Iran is
one of the 22 Member States of the WHO Eastern
Mediterranean Region (EMRO). These Member States,
with a population of nearly 583 million people, are pre-
dominantly Muslims [40]. Therefore, the findings of this
study may be considered of value for the EMRO coun-
tries in preparation for the Hajj ceremony, a very large
population.
Conclusions
In conclusion we found that the first ever stroke rate
among Iranian Hajj pilgrims was lower than that of the
general population in Mashhad, Iran, except for females
35–44 or more than 75 years old. Although the results
cannot be generalized to pilgrims from other countries,
they highlight the importance of preventive and screen-
ing programs aimed to reduce vascular risk factors,
stress, and respiratory infections, and the need for the
Kingdom of Saudi Arabia to evaluate the infrastructure
of its healthcare system and hospitals to ensure that ap-
propriate medical care including acute stroke treatment
is available during the Hajj.
Competing interests
The authors declare that they have no competing interests.
Authors’contributions
MRA has made substantial contributions to the study conception, design,
and implementation. He revised the manuscript critically for important
intellectual content. RBS participated in the study design and has been
involved in drafting and revising the manuscript critically for important
intellectual content. MKK and AGT helped in revising the manuscript critically
for important intellectual content according to its result. NM and MRR
helped to design and coordinate the study. AS and MTF participated in the
study design and data collection. SAS and NMD performed the statistical
analysis and has been involved in drafting the manuscript. AA has made
substantial contributions to conception and design, helped to plan for
statistical analysis, and has been involved in drafting the manuscript and
revising it critically for important intellectual content. All authors read and
approved the final manuscript.
Acknowledgement
This study was supported by Iranian Red Crescent Society and Hajj and
Pilgrimage Organization of Iran.
Author details
1
Department of Neurology, Ghaem Hospital, Mashhad University of Medical
Sciences, Mashhad, Iran.
2
Comprehensive Stroke Center, University of
Alabama Hospital, Birmingham, AL, USA.
3
Department of Neurology,
Golestan Hospital, Ahvaz University of Medical Sciences, Ahwaz, Iran.
4
Institute of Health Policy, Management and Evaluation, Faculty of Medicine,
University of Toronto, Ontario, Canada.
5
Department of Neuropsychology,
Ibn-e-Sina Hospital, Mashhad University of Medical Science, Mashhad, Iran.
6
Department of Internal Medicine, Red Crescent Society, Tehran, Iran.
7
Department of Medicine, Southern Clinical School, Monash University,
Melbourne, and National Stroke Research Institute, Florey Neuroscience
Institutes, Heidelberg Heights, Victoria, Australia.
8
Health System Research
Committee, Treatment Affairs of vice chancellery, Mashhad University of
Medical Sciences, Mashhad, Iran.
9
Discipline of Dental Public Health, Faculty
of Dentistry, University of Toronto, Room 515-C, 124 Edward St, Toronto, ON
M5G 1G6, Canada.
10
Toronto Health Economics and Technology Assessment
Collaborative, University of Toronto, Toronto, Canada.
Received: 18 November 2012 Accepted: 27 November 2013
Published: 5 December 2013
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doi:10.1186/1471-2377-13-193
Cite this article as: Azarpazhooh et al.:Incidence of first ever stroke
during Hajj ceremony. BMC Neurology 2013 13:193.
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