Via The Star, excerpt from a long informative article :
" Virologists are casting a worried eye on this year's Islamic hajj pilgrimage to Saudi Arabia as they struggle with the enigmatic, deadly virus known as MERS which is striking hardest in the kingdom.
Little is known about the new pathogen, beyond the fact that it can be lethal by causing respiratory problems, pneumonia and kidney failure. It can be transmitted between humans, but unlike its cousin, the SARS virus, which sparked a scare a decade ago, it does not seem very contagious.
Even so, for any respiratory virus the mass gathering of the hajj provides a perfect opportunity to first spread at the two holiest Muslim shrines in the cities of Mecca and Medina, and then travel around the globe at jet speed as pilgrims return home.
The 2012 hajj drew 3.1 million people - and this year's event likewise occurs in October, as the northern hemisphere slides into the season for coughs and sneezes.
UN World Health Organisation (WHO) head Margaret Chan sounded the alarm to ministers at the agency's annual congress in May.
"We need to get the facts clear and get the appropriate advice to all your countries where your pilgrims want to go to Mecca. It is something quite urgent," she said.
Experts point first and foremost to figuring out the basics of the Middle East Respiratory Syndrome (MERS) coronavirus.
Is it transmitted by contact - if a patient contaminates his home or workplace with droplets containing virus? Or is it done by breathing in virus from coughs and sneezes? What is the best treatment for it? What about a vaccine? Are there risks of viral mutation? And is there an animal host which acts as a reservoir for the virus?"