The World Health Organization defines mass gatherings (MGs) as “events attended by a sufficient number of people to strain the planning and response resources of a community, state or nation” [1]. MGs carry potential health risks to the local population and to the global community [2-4]. Such gatherings pose a significant public health threat to the host country and the attendees’ countries of origin [2,3,5-8]. The nature of MGs can be political rallies, social events, religious activities, sporting events, and others [5]. Organizers of most MGs, especially those of a longer duration such as the Hajj, Olympics, or the Kumbh Melas in India, offer basic health services to the attendees [9,10]. Individuals attending the MGs and the host population are at risk of communicable disease infections, injuries, and exacerbations of noncommunicable diseases (NCDs). MGs have been associated with high rates of morbidity and mortality from NCDs, accidents, and terrorist attacks [11].

During the Hajj MG, high rates of morbidity and mortality from NCDs, such as cardiovascular diseases, diabetes mellitus (DM), and asthma were reported [2,3,12-14,15-17]. Attendees traveling to the event from outside the country may be exposed to a different environment in addition to altering their daily routine and diets [18,19]. Walking long distances, changes in daily activities, and poor adherence to diet and medications could negatively impact NCD control, particularly hypertension (HT), DM, and ischemic heart diseases (IHDs) [18]. The incidence of severe acute cardiovascular events is more than doubled during MGs for people exposed to intense stress [2,20,21].

In Iraq, religious MGs occur throughout the year, mainly in Karbala, Najaf, and Baghdad. Arbaeenia is the largest religious MG and convenes in Karbala annually [5]. During Arbaeenia, Shi’a Muslims commemorate the 40 days following the day of the martyrdom of Hussein bin Ali, the grandson of the Prophet Muhammad, at the Battle of Karbala in 61 AH (680 CE) [5].

More than 10 million people, mainly from Iraq, visit Imam Hussein’s shrine in Karbala. Attendees walk hundreds of kilometers for many days to reach Karbala. These visitors are exposed to risks that could affect their health including intense physical activity and poor adherence to diet regimes and medications. The Arbaeenia MG follows the Islamic lunar calendar, and the date moves forward by 10 to 11 days every year, therefore presenting health risks associated with seasonal variation [5,22].

The public health impact of religious MGs in Iraq has rarely been studied [5]. This study aimed to describe NCD emergencies during the Arbaeenia MG and to assess predisposing factors for NCD emergencies.

The study was conducted from November 27 to December 16, 2014, in 3 Iraqi governorates: Karbala, Najaf, and Babel, located to the south of Baghdad, with a population of over a million each. We implemented the study in two phases, the pre-event phase that covered the first 7 days of the survey and the event phase covering 13 days, during their journey to the event. The pre-event phase serves as a baseline for NCD emergencies and admissions; the event phase captures the burden of NCDs during the MG.

Data on all patients attended for NCD diagnoses at emergency rooms (ERs) or admitted to 1 of the 7 hospitals selected for the study were collected. The selected hospitals included the 4 main Ministry of Health (MOH) hospitals located at the center of selected governorates and 3 small hospitals located along the road to Karbala. A total of 3 of the selected hospitals (Al-Seder, Al-Hakeem, and Al-Haideria) were located in Najaf, 3 in Babel (Hashmia, Al-Qasim, and Merjan), and 1 in Karbala (Al-Hussein Hospital).

NCD emergencies include the following 6 groups: HT or hypotension; DM: hypoglycemia, ketoacidosis, and hyperosmolar syndrome; IHD: angina pectoris, myocardial infarction (MI), arrhythmias; cerebrovascular accident (CVA): ischemic and hemorrhagic accidents; chronic obstructive pulmonary disease (COPD): asthma and other intermittent, persistent COPDs; and cardiogenic pulmonary edema (PE): heart failure owing to IHDs.

Data on the pre-event phase were collected by a team of 6 Field Epidemiology Training Program graduates and current officers led by the principal investigator. Data were abstracted from available registers and logbooks of the 7 selected hospitals in the pre-event phase. During the event phase, data were collected daily (24 hours) by direct interview with patients or accompanying relatives and treating physicians using a questionnaire, which was filled by trained health personnel.

The information collected included age, sex, residence, provisional diagnosis obtained from treating physicians, and potential predisposing factors that might have led to development of the NCD emergency, which included intense physical activity, poor adherence to dietary regimen, poor adherence to medications, exposure to noxious gases or fumes, and history of recent respiratory infection (RI).

Epi Info developed by US Center of Diseases Control and Prevention, Atlanta, Georgia and SPSS acquired by IBM were used for data entry and analysis. We estimated the daily average number of patients with NCDs attending the ER by study phase and tested the differences between the daily average patients in the pre-event and event study phase by demographics and by hospitals or departments. We used a t test to test statistical differences at P<.05. We estimated the risk ratio (RR) and 95% CIs of predisposing factors for NCD emergencies.

Official approval was obtained from the Iraqi MOH before implementation of the study. Confidentiality of data throughout the study was assured, and access to data was limited to research team members.

This is the first study to describe NCD emergencies during MG events in Iraq. The most common emergencies attended in the hospitals during the event were HT, IHD, asthma, and diabetes (hyperglycemia). The load of the NCD emergencies during the MG event increased 4-fold, and the daily average cases also doubled compared with the pre-event. This indicates the immense burden of NCD emergencies to hospitals during MG events and the need for adequate planning of services by the government of Iraq. This is beyond the MOH capacity and domain and needs the participation of other ministries and governmental agencies.

The daily average for NCD emergencies increased 2-fold in IHD and asthma and almost 3-fold in severe HT and diabetes (hyperglycemia) during the event. These findings are consistent with other studies conducted in the region during religious MG events [5,13,14,23]. Severe HT and diabetes (hyperglycemia) are likely to be sensitive to changes in physical activity, diet and medications, which are disrupted during the MG.

The study shows that intensive physical activity leads to IHD emergency but is inversely correlated with severe HT and diabetic-hyperglycemia emergencies during the MG event. Regular exercise controls HT and diabetic hyperglycemia and improves IHD, but sudden physical activities in individuals with cardiovascular diseases might precipitate heart attack [17]. Poor adherence to diet and medications for hypertensive, diabetics, and asthmatic patients predispose to ER attendance for treatment in the MG event. Similarly, exposure to noxious gases or fumes, which is obvious in Iraq MG, and history of recent RI lead to ER attendance for asthma treatment. Individuals with NCDs should be accompanied by caring relatives, in addition to receiving regular checkups at mobile clinics to avoid medical emergencies and premature deaths.

The risk for medical emergencies and hospital admissions during MG are often related to the size of the masses, climatic conditions, demographics, services availability, prior planning, and behaviors of the attendees. The purpose of the MG studied was religious, where masses march orderly, but the lack of prior planning for service needs, harsh climatic conditions, long distance walk, lack of adequate services, and overcrowding may have contributed to medical emergencies observed in the study. Setting up temporary resting places, mobile clinics, and maintaining sufficient supply of health care staff could minimize the need for ER medical services and hospitalizations, which could be addressed through proper planning and implementation.

Most of the NCD emergencies were handled in the ER departments and few were admitted to the hospitals, which is similar to a study conducted in Iraq during the Ashuraa religious MG [5]. The majority of the NCD cases were aged younger than 50 years and more likely to be healthy, which may have contributed to low hospitalizations.

The study has some limitations. The increased load during the event phase was solely related to patients with NCD emergencies attending ER departments. Some NCD emergency cases may have been missed because of the chaotic conditions at the ER departments during the MG. Some patients attended in ER may have also been admitted to the hospitals after the data were collected, affecting the percent of admissions. As this study was confined to the hospitals, NCD emergency cases treated in mobile clinics were not counted; thus, the increase of cases in the event could be higher than the numbers reported. The study was limited to 7 hospitals, and the load of NCD emergencies attended in other hospitals may result in different estimates of the effect of MG on NCD emergencies.

In conclusion, with the pilgrims approaching their destination to Karbala city during Arbaeenia MG, the hospitals on the roads leading to the city experienced an increased load of patients because of different NCD emergencies. Although the MOH is more concerned with outbreaks of communicable diseases during MGs, NCDs should be seriously considered in the MGs planning. The hospitals should be fully equipped with the necessary supplies and trained health workers. Furthermore, health education for pilgrims is mandatory, particularly on the factors that can exacerbate their diseases.