Pilgrims and MERS-CoV: what's the risk?

The risk of Middle East Respiratory Syndrome Coronavirus spreading globally is worrying, given the annual mass gathering of the Hajj and the year-long influx of pilgrims undertaking the Umrah. Based on the incidence in Saudi Arabia since June 2012, the most likely scenario given recent pilgrim numbers is estimated to be one case per Hajj, and three Umrah pilgrims per year, but which could plausibly reach seven and ten pilgrims respectively. In addition to the 2015 Hajj, national surveillance systems should be on the alert for the low but long-lasting risk of infected pilgrims returning from the Umrah throughout the year.