GENEVA - As the fight for knowledge unfolds behind lab doors, global health experts are crossing their fingers that hajj season passes safely as they struggle with the enigmatic, deadly SARS-like virus.
This is really a new phenomenon that we're dealing with, Keiji Fukuda, WHO assistant director general for health security, told the International Conference on Prevention and Infection Control in Geneva, Agence France Presse (AFP) reported on Saturday, June 29.
We don't know what the potential is yet, based on the information we have, for sustained human-to-human transmission.
We don't know what the full geographic extent of this virus is right now.
First recorded in Saudi Arabia in 2012, the deadly virus known as Middle East Respiratory Syndrome (MERS) has been striking hardest in the kingdom.
The SARS-like virus can be lethal by causing respiratory problems, pneumonia, and kidney failure.
The first recorded MERS death was in June 2012 in Saudi Arabia. Yet, the count has ticked up steadily taking it to 77, the bulk of them in the kingdom.
Forty MERS patients have died to date, an extremely high rate of 52%, compared to 9% of the 8,273 recorded patients with SARS, which was centered on Asia.
With millions of Muslims turning to Makkah and Madinah to perform hajj every year, fears were maximizing about providing the virus a perfect opportunity to spread across the world.
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.
"We need to get the facts clear and get the appropriate advice to all your countries where your pilgrims want to go to Makkah, UN World Health Organisation (WHO) head Margaret Chan sounded the alarm to ministers at the agency's annual congress in May.
It is something quite urgent," she said.
Muslims from around the world pour into Makkah every year to perform hajj, one of the five pillars of Islam.
Hajj consists of several ceremonies, which are meant to symbolize the essential concepts of the Islamic faith, and to commemorate the trials of Prophet Abraham and his family.
Every able-bodied adult Muslim who can financially afford the trip must perform hajj at least once in a lifetime.
Proved to be transmitted between humans, MERS, unlike its cousin SARS virus, which sparked a scare a decade ago, does not seem very contagious.
It's really a balance between too much precaution and no precaution, leading virologist Laurent Kaiser of the Geneva University Hospitals told AFP.
At this time, we have to be worried, we have to be careful.
While MERS centres on Saudi Arabia, there have been laboratory-confirmed cases originating in Jordan, Qatar and the United Arab Emirates.
Britain, France, Germany, Italy and Tunisia have had cases who were either sent there for care or who fell ill after returning from the Middle East.
So far, the virus has been found in nations with health services capable of tracing and tackling such diseases.
But the hajj draws a broad spectrum of Muslims, including from poor countries which struggle to cope even with commonplace diseases.
"We don't know if the disease is there right now. They don't have surveillance," Saudi Arabia's deputy health minister, Ziad Memish, told AFP on the sidelines of the Geneva conference.
Managing two hajj seasons with previous viral episodes in the past decade; SARS in 2003 and H1N1 influenza in 2009, health experts praised Saudi authorities for beefing up vigilance for infectious diseases.
The authorities success in `Umrah season has reflected high expectations for similar success in hajj.
"I think it's comforting that as of today, 4 and a half million people have performed the `umrah in Makkah and nothing has happened," Memish, who is also a medical professor and runs a WHO-accredited research center on the medicine of mass gatherings, said.
"But of course we're making all the arrangements and all the planning to do active surveillance, to be able to intervene."