I’d imagine that the haaj gives Epidemioligists quite a few waking nightmares. The combination of huge population movements, close contact between so many people and increased stress (on people and resources) is a bad enough combination of risk factors. Now add in a war and the consequent disruption to health services just over the border in Yemen, and a known local reservoir of MERS-CoV, which could mutate into a more communicable or more deadly (or both) form at any time, then you’ve got a recipe for a few sleepless nights for anyone in Epidemiology or Public Health.
