Should we worry about Saudi Arabia's lethal MERS virus? WHO expert answers

The World Health Organization will disclose on Thursday the results of a rare, closed-door emergency expert panel on a new lethal coronavirus, called Middle East Respiratory Syndrome, or MERS.

The disease has killed 42 people out of 79 reported cases in the last two years and precious little is known about MERS, which in some ways is similar to Severe Acute Respiratory Syndrome, or SARS, a coronavirus that killed about 8,400 people a decade ago.

A recent peer-reviewed study published in Lancet journal concluded MERS “does not yet have pandemic potential,” while cautiously noting, "The situation is still evolving.”

Recently, WHO Director-General Dr. Margaret Chan called MERS her "greatest concern." 

It’s unclear how the coronavirus is transmitted, though close contact is a strong possibility. And so far it has not spread in a sustained manner. The great fear is that the disease, which emerged in Saudi Arabia and has killed 38 people there, could be highly contagious in large communities. 

At a press conference last week, Dr. Keiji Fukuda, WHO assistant director general for health security, said current and upcoming pilgrimages made by millions to Saudi Arabia's city of Mecca were something to worry about.  

"There are already a lot of people coming into Saudi Arabia and going out of Saudi Arabia," Fukuda said. "And in terms of are we worried? Yes, I think we’re always worried in a globalized world that infection can travel quickly from one country to another."  

The Saudi Ministry of Hajj has asked some pilgrims to postpone travel for the official reason of construction on Makkah’s Grand Mosque. However, there is also a concern that millions of people mingling about could present a serious health risk.

The Kingdom has installed medical surveillance systems on its borders to help prevent the spread of the disease, and reduced the number of travel visas issued. It's possible WHO's emergency talks could suggest travel restrictions or make other recommendations.

To put MERS in perspective and to understand what's happening and what could happen next, GlobalPost spoke with Dr. Anthony Mounts, WHO's technical lead on the coronavirus.

This interview was edited for clarity. 

MERS was reported in early 2012, and the infection rate has stayed consistent since then, so why has WHO convened this emergency committee now? The first and last time WHO formed the committee was in 2009 during the H1N1 pandemic.

H1N1 was clearly a major worldwide global event and we needed the emergency committee. But the committee, which meets and makes recommendations on possible action, is not only for major events. It’s not exclusively for pandemics.

How likely is MERS to become what WHO calls a "public health emergency of international concern," or PHEIC?

The International Health Regulations, or IHR, defines a PHEIC as an extraordinary event that “constitutes a public health risk to other states through the international spread of disease.” So is MERS an international risk, and is more coordination between nations required? That’s why the emergency committee was called. They’re considering the data.

MERS is similar to the SARS outbreak in 2003 and in some ways different — it’s not exactly an analogous disease or situation — but what have we learned from our experiences ten years ago that could prove helpful now in terms of organization, outbreak control and treatment?

The similarities are based on two points: MERS and SARS are in the same family of viruses and generally have the same clinical disease pattern: They cause severe respiratory disease. Beyond that it’s a question of transmissibility: Is MERS as transmissible as SARS? We still have to answer that.

In terms of lessons learned, SARS was a successful international collaboration that resulted in a containment of an emergent disease. We learned a lot about how to collaborate for a major response, epidemiological things that had never been done on such a large scale before.

SARS also helped people think about reporting requirements and early disease detection. The IHR is not just a list of rules and regulations. It’s also a mechanism for sharing data. There are now password-protected websites — it's an international focal point — where we can share confidential information to prepare for and anticipate what might happen.

There is no MERS vaccine, and the virus appears to infect groups, likely by personal contact, which creates small clusters of infection in communities. With this in mind, what can people do to avoid infection?

There are not a lot of specifics we can recommend without knowing exactly how MERS is contracted or where it comes from. But that said, we can still help protect people.

For example, with influenza, we don’t know absolutely if it is spread through droplets or hand contact. But there are always the usual stay-healthy recommendations: Wash your hands, don’t expose other people if you are sick, don’t eat undercooked food, drink safe water, don’t be around sick animals, and avoid crowds if possible.

What’s the likelihood of a MERS pandemic during current and upcoming mass pilgrimages? Millions of people will likely travel to Saudi Arabia, and then they will go back to their countries and families.

A pandemic is probably not related to the mass movement of people. It’s really the transmissibility of the virus. If the virus is not very contagious, then perhaps people infect family members back home, as we’ve seen with MERS in the UK and France. But you will only get small, little clusters.

When will we know how transmissible MERS is?

That’s the million dollar question. There has been one recent publication that tried to estimate the transmissibility of the virus based on observations in Saudi Arabia. [Editor's note: That study, cited above and found here, suggested MERS "does not yet have pandemic potential." However, much more research and surveillance is still needed.]

What signs would cause the emergency committee to recommend travel restrictions? If such actions were taken, what would that look like?

That’s the primary question the emergency committee is meant to address. You need to consider the virus' origin, how easily it spreads, what proportion of people infected are severely affected — there’s a whole epidemiological pattern that must be studied. That’s essentially why we have the emergency committee. They look at it from every angle, and there's no simple answer that if X happens then we have to do Y. It’s a very complex question with a wide variety of data.

There are people traveling to Saudi Arabia for deeply religious reasons, and then here’s this outside entity that could suggest they postpone. Has that been an issue in the past? Is there historical precedent for this kind of situation?

I don’t think there’s a precedent, at least not that I can think of. And the religious aspect of it does heighten the complexity. There is a religious obligation to go to Hajj for a lot of people, so that’s something everyone will have to consider.

Related Stories