The Lancet Infectious Disease
Jan 2012  Volume 12  Number 1  p1 – 88
http://www.thelancet.com/journals/laninf/issue/current

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Mass gatherings medicine
Ziad A Memish, Gwen Stephens, Adullah Al Rabeeah

Preview
Between the eighth and 12th days of Dhu al-Hajjah, the 12th month of the Islamic calendar, Saudi Arabia welcomed 3 million people to Mecca for the annual Hajj pilgrimage. As Hajj ended in mid-November, the country had many reasons to be grateful. Risk of injury and death during the pilgrimage has fallen since 2007, with redesigned venues and modern crowd-control strategies. Medical treatment for injuries, infections, and various chronic diseases will have been provided to thousands. Despite intense crowding and the diversity of ethnic groups and nationalities in attendance, around 2 million visitors from more than 183 countries will return home, having participated in this singularly rigorous and peaceful event.

Series
Emergence of medicine for mass gatherings: lessons from the Hajj
Ziad A Memish, Gwen M Stephens, Robert Steffen, Qanta A Ahmed

Summary
Although definitions of mass gatherings (MG) vary greatly, they consist of large numbers of people attending an event at a specific site for a finite time. Examples of MGs include World Youth Day, the summer and winter Olympics, rock concerts, and political rallies. Some of the largest MGs are spiritual in nature. Among all MGs, the public health issues, associated with the Hajj (an annual pilgrimage to Mecca, Saudi Arabia) is clearly the best reported—probably because of its international or even intercontinental implications in terms of the spread of infectious disease. Hajj routinely attracts 2·5 million Muslims for worship. WHO’s global health initiatives have converged with Saudi Arabia’s efforts to ensure the wellbeing of pilgrims, contain infectious diseases, and reinforce global health security through the management of the Hajj. Both initiatives emphasise the importance of MG health policies guided by sound evidence and based on experience and the timeliness of calls for a new academic science-based specialty of MG medicine.

Global perspectives for prevention of infectious diseases associated with mass gatherings
Ibrahim Abubakar, Philippe Gautret, Gary W Brunette, Lucille Blumberg, David Johnson, Gilles Poumerol, Ziad A Memish, Maurizio Barbeschi, Ali S Khan

Summary
We assess risks of communicable diseases that are associated with mass gatherings (MGs), outline approaches to risk assessment and mitigation, and draw attention to some key challenges encountered by organisers and participants. Crowding and lack of sanitation at MGs can lead to the emergence of infectious diseases, and rapid population movement can spread them across the world. Many infections pose huge challenges to planners of MGs; however, these events also provide an opportunity to engage in public health action that will benefit host communities and the countries from which participants originate.