But the so-called Emergency Committee, which was struck by the WHO to advise Director General Dr. Margaret Chan, said it believes the ongoing situation is serious and requires close monitoring. It asked the WHO not to disband the committee and to allow it to reconvene as new evidence on the disease emerges.
A senior WHO official suggested the outside advisers felt declaring MERS a global emergency at this point could have undermined the weight of the instrument — a public health emergency of international concern, or PHEIC — which is established under the International Health Regulations.
"I think that one of the issues which the emergency committee members discussed in a sense was that declarations and events have to be proportional to each other. Otherwise you begin to lose credibility," said Dr. Keiji Fukuda, assistant director general for health security and the environment.
"In general, this is a quite heavy declaration. Basically it sends a signal that this is something which needs the highest level (of political) attention," Fukuda said of the IHR tool.
"You want to make these declarations when they are proportional to the event. You don't want to just simply make such a declaration without realizing the weight of what you're asking countries to do."
The WHO said Chan accepted the Emergency Committee's recommendation. And Fukuda expressed a sense of comfort with the decision.
"I think that the emergency committee did a really good job in landing where I think many of us assess the situation to be. In essence, again, they are not saying this is unimportant. They are not saying, 'Let's just now move on to other things.'
"I think they're sending out a pretty balanced message," he said.
The 15 experts from around the world included specialists in laboratory sciences, public health and hospital infection control. For Wednesday's meeting, a risk communications expert was also on the call to advise the committee.
Panel members include Dr. Theresa Tam, head of the health security infrastructure branch of the Public Health Agency of Canada, Maria Zambon, director of Public Health England's Reference Microbiology Services, and Dr. Ziad Memish, Saudi Arabia's deputy health minister.
Saudi Arabia has reported the most cases of the new disease and in fact revealed two more on Wednesday. Those new infections — a man who had contact with a previous MERS patient and a health-care worker — both likely involved person-to-person spread of the virus. In both cases the infections were mild and did not require hospitalization, the health ministry statement said.
The new cases bring the global total of confirmed cases to 84, with 45 deaths. All infections have occurred in or link back to four countries on the Arabian Peninsula — Saudi Arabia, Jordan, Qatar and the United Arab Emirates — though cases have been exported to Britain, France, Germany, Italy and Tunisia via tourists or infected people who travelled to European hospitals for care.
Fukuda said the WHO will probably ask the Emergency Committee to take another look at the MERS situation in the fall, although it could call the committee back into session sooner if events demand it.
The committee also gave the WHO recommendations on things that should be improved to strengthen the global capacity to deal with the MERS situation, including surveillance for the diseases, laboratory capacity to test for it, systems to trace people who have been in contact with known cases, and research to find the source of the virus. Despite the fact that the virus was first discovered in June 2012, where it lives in nature remains a mystery.
Fukuda said work is already underway on the issue the committee highlighted.
For instance, he said the WHO hopes to soon post travel guidance for individuals and countries.
He said the WHO is not considering asking people not to travel to affected countries at this point. But it has received many requests from countries for advice on how to handle the fact that Muslims from around the world are travelling or will be travelling in coming months to Saudi Arabia to take part in two massive pilgrimages.
One is Umrah, which can be done at any time of the year, but is popularly done during Ramadan, the current month of the Muslim calendar. The second is the Hajj, which draws upwards of three million pilgrims to Saudi Arabia from around the world. This year the Hajj takes place in early October.