The Hajj begins

The Kingdom of Saudi Arabia showing the major sites of MERS-CoV
infections and the site of Mecca.

Al Riyadh reports that on Saturday and Sunday 13th the 1,379,000 international pilgrims (94% arriving by air) moved into Mina Valley from the holy city of Mecca (Makkah) located in the Mecca province, the most populated province of the Kingdom of Saudi Arabia (over 5.8 million people). The number includes 752,424 males (55%).

The Hajj starts at sunset (Mahgrib) on Sunday, but many have begun on the Saturday evening.

Pilgrims perform “Tawaf Al-Qudoom” at Mecca (initial round of circumambulation [the act of moving around a sacred object, in this case the cuboidal Kaaba at Mecca]) then move to Mina prior to midday. They sleep there and then move to Arafat after morning prayers. Temperatures were expected to reach 37-41° C yesterday and throughout the week.

Given a 14-day incubation period (most lengthy estimate), if the MERS-CoV is going to show up any differently among hajis this year than it did as a result of last year's Hajj (you may have noticed that no pandemic ensued), we should see those cases having presented with symptoms by 
Sunday the 27th. If we really want to get a feel for how easily transmissible this virus is, then this is the opportunity to observe and test.

Of course, this is an artificial date, given pilgrims have been assembling and mingling for some time during the lead-up to Sunday evening, but I'm using that date as the outer limit for appearance of symptomatic cases using a timepoint in which many people definitely congregated together in large numbers.

We may also see a rise in cases appearing outside the KSA as retuning pilgrims picking up infection just before they depart, become symptomatic on home soil. Or we may not.

Thanks to FluTrackers for posting this link.