Background: Arbaeen is one of the world’ s largest religious gatherings. It is held in Karbala, Iraq, and can pose many significant challenges to the health of pilgrims and the host population as well as the health system of Iraq. Objectives: The present study was conducted to reflect an overview of the health-related challenges associated with the Arbaeen ceremonies. Methods: This qualitative study was conducted from October 6 (ten days before Arbaeen ceremonies) to October 16, 2019, in Najaf, Karbala, and the route pilgrims walk in Iraq. Semi-structured and in-depth interviews were conducted with disaster and emergency specialists, health experts, nurses, general physicians, and specialist doctors. Twelve experts and six pilgrims were interviewed. Thematic analysis was used to analyze the data. Results: The findings were categorized into three main groups: treatment issues, public health, and infrastructure. The main complaints pilgrims had were bone and joint pain, muscle spasms, headache, toothache, pharyngitis, rhinorrhea, and common cold, purulent throat, and gastrointestinal symptoms. The main problems of those with chronic conditions included having forgotten to take medications or running out of medications. Food and water safety and sanitary conditions were inappropriate. Iraq’ s health system was not prepared to fulfill the health needs of the people at such a gathering. Conclusion: Arbaeen ceremonies impose a heavy burden on Iraq’ s healthcare system and cause numerous health challenges. Moreover, Iraq’ s healthcare system does not have the capacity or readiness to meet the challenges of this event; international aid from the countries whose citizens attend the event are needed. Although the Iranian Red Crescent cooperated extensively, the collaboration must be more coordinated and broadened.

The Arbaeen Pilgrimage is one of the largest religious gatherings in the world, which is held on the 40th day of the martyrdom of Imam Hussein, the third Imam of Shia. According to the definition of the World Health Organization (WHO), mass gathering refers to a structured or spontaneous event held with the participation of at least 25, 000 people at a specific site for a certain duration and purpose (1). More than 20 million people from all around the world marchtowardsImamHussein’ s shrine in Karbala within 10 to 20 days. The pilgrims walk hundreds of kilometers for a few days to reach Karbala. Religious organizations and the general public are the main providers of water, food, shelter, residence, and treatment facilities for pilgrims. ...

Dear Editor-in-Chief: A mass gathering (MG) is defined by World Health Organization (WHO) as "any occasion, either organized or spontaneous, that attracts sufficient numbers of people to strain the planning and response resources of the community, city or nation hosting the event" (1). Hajj pilgrimage is one of the fundamental pillars of Islam which must be performed by those Muslims with adequate means and health once in their lifetime (2). Hajj as a mass gathering of pilgrims around the world can amplify the transmission of epidemic prone diseases at the Hajj place and the countries which departed pilgrims as well. This letter was aimed to highlight (i) the rationale for implementing syndromic surveillance in the era of public health issues of Hajj pilgrimage and (ii) challenges faced to Iranian health system.