The Hajj, the pilgrimage to Mecca by millions of Muslims from around the world, is one of the largest gatherings of man on the face of the earth. This annual event took place just last month with relatively little fanfare from the news media, which is, from an epidemiological standpoint, a very good thing. Every year, public health officials wring their hands at the thought of possible outbreaks caused by the global pathogen du jour capitalizing upon the convergence of millions of worshipers in the Saudi Arabian desert. SARS stole the headlines in 2009, Middle Eastern Respiratory Virus or MERS had it last year, and Ebola seemed a likely contender for this calendar year.
The Ministry of Health in Saudi Arabia is acutely aware of the risks inherent to such a huge convention of human bodies, with one Deputy Minister noting that “no other mass gathering can compare, either in scale or in regularity” (1). The mass migration of millions of people from over 180 countries and their congregation in one tiny locale for two weeks would seem to be the beacon call to human pathogens. But is the wariness with which we often approach an event like the Hajj well-founded? Are microbes actually being transmitted among pilgrims? A recent article based on work conducted last year by a team of French and Saudi health officials suggests that this indeed is the case.