[Mass gatherings: a systematic review of the literature on large events]

We reviewed the literature on mass gatherings published worldwide to determine event types and topics or epidemiologic aspects covered. Articles using the term mass gatherings indexed in the Scopus database between 2000 and 2015 were reviewed. Of the 518 returned, we selected 96 with relevant information. The main event types studied were related to sports (46%), music (25%) or religious/social content (23%), and the most commonly studied locations were the United States (n=21), the Kingdom of Saudi Arabia (n=17), Australia (n=11), and the United Kingdom (n=10). The four most often studied events were the Hajj (n=17), the Olympic games (n=13), World Youth Day (n=8), and the FIFA World Cup (n=6). The main topics studied were models of health care (n=55), health care evaluation by means of rates of patients presenting for care or transferred to hospitals (n=21), respiratory pathogens (n=18), syndromic surveillance (n=10), and the global spread of diseases (n=10). Mass gatherings are an emerging area of study addressed by various medical specialties that have focused on studying the health care models used at such events. Emergency medicine is particularly involved with this research topic.