WHO debates MERS: Is it an international public health emergency?

Has the mushrooming outbreak of the new MERS coronavirus reached the point where it's an international public health emergency?

That's the question a panel of outside experts will reconsider today as the World Health Organization's so-called emergency committee on the MERS virus convenes for the fifth time. Dr. Theresa Tam, head of the Public Health Agency of Canada's Health Security Infrastructure Branch, is vice-chair of the committee.

Each previous time the group has expressed concerns about the Middle East respiratory syndrome coronavirus, a cousin of the SARS virus that has been causing sporadic and often severe or fatal illnesses in several countries on the Arabian Peninsula for the past two years.

But each previous time the group said the outbreak did not meet the definition of a public health emergency of international concern as set out in the International Health Regulations, legally binding rules that are designed to protect the world from disease threats that can cross borders.

"Two years out, we still have a poor understanding about basic facts about the virus and its transmission dynamics. It's really kind of unheard of," says Dr. Amesh Adalja, an infectious diseases expert at the University of Pittsburgh Medical Center.

The emergency committee last pondered the question in December, which MERS virus activity actually appeared to have slowed.

That's not the case now. The cumulative global case count, which only crossed the 200 mark in late March, is fast approaching 600 now. Of those cases, more than 150 have died. (The WHO's count lags behind the tally announced by governments; the global health agency said Saturday it had been informed of 536 cases and 145 deaths.)

Preben Aavitsland, Norway's former state epidemiologist and one of the drafters of the International Health Regulations, believes the emergency committee will advise Director General Margaret Chan to declare MERS a global emergency or PHEIC (pronounced "fake") in the jargon of the WHO.

In Aavitsland's eyes, the declaration should have come long ago. Under the International Health Regulations, a public health emergency of international concern is a disease event that poses a health risk to other states because of the potential for cross-border spread and is one that requires a co-ordinated international response.

"Already from the start it was clear that this was a disease that could be exported. And just now we got a new example from Florida," says Aavitsland, referring to Monday's announcement that the United States had detected its second case of MERS, in a health-care professional who travelled from Jidda, Saudi Arabia to Orlando, Fla., on May 1 via London, Boston and Atlanta.

Ten days ago, the U.S. announced its first case, a health-care professional living and working in Saudi Arabia who had travelled to Indiana. In recent weeks Malaysia, the Philippines, Greece, Egypt and Jordan have diagnosed MERS in people who were infected abroad. In the case of Jordan, which has also had locally acquired cases, a MERS patient from Saudi Arabia infected three health-care professionals who treated him. Two of them have since died.

An electron microscope image, made available by the National Institute of Allergy and Infectious Diseases - Rocky Mountain Laboratories, shows novel coronavirus particles, also known as the MERS virus, colourized in yellow. (Associated Press)

Aavitsland says in his view, the WHO has too infrequently used the public health emergency tool, a fact which makes it harder to unsheathe now.

"That's the problem. It's become such an extraordinary thing to do, to declare a PHEIC, that the general public will be frightened just by hearing that they are doing it," he says.

The WHO has only declared a public health emergency twice since the International Health Regulations came into effect in 2005. The first time was the 2009 H1N1 flu pandemic. The second came last week, when the embattled polio eradication effort was declared a public health emergency.

The emergency committee only advises; if it recommends that MERS be declared an emergency, the WHO's director general still has to decide if she will follow the advice. But it seems unlikely Chan, who set up the committee, would reject its advice.

Aavitsland says if a public health emergency is invoked for MERS, it would give the WHO more leverage with which to deal with the situation. That leverage could be used to press Saudi Arabia and other MERS affected countries to be more transparent about their outbreaks and to do more to bring the virus under control.

No start 5 months later

Saudi Arabia in particular has been seen as dragging its heels on key studies that the WHO and the scientific community have been pressing it to do for more than a year. Because it has had the greatest number of cases, it is best positioned to conduct research that could determine definitively what the source of the virus is — it's thought to be camels — and how people are becoming infected.

One of the recommendations of the December emergency committee meeting was that these studies should be undertaken. Five months later they haven't been started. And there has been no public commitment from Saudi Arabia to undertake the work.

But declaring a public health emergency could also afford affected countries protection from sanctions some nations may be considering imposing in a bid to stop importation of MERS cases, Aavitsland says.

"By declaring a PHEIC, WHO could give a temporary recommendation … that countries should not institute travel restrictions and they should not start with border screening which is a notoriously wasteful measure," he explains.

The WHO has already made it clear it does not believe countries should put in place unilateral travel restrictions. But Aavitsland says that when issued under the auspices of an IHR public health emergency, such recommendations carry more weight and place an onus on countries that ignore them to explain their actions.

Pattern hasn't changed

While the spate of recent exported MERS cases may raise the pressure on the emergency committee, many MERS watchers don't share Aavitsland's view on what the outcome of their meeting will be.

Dr. Amesh Adalja, an infectious diseases expert at the University of Pittsburgh Medical Center, says he agrees an argument could have been made for calling MERS an emergency right from the start. But given that it was not, he doesn't see the rationale for changing that position now.

"The pattern of cases hasn't changed," he says, echoing a point the WHO itself made in a MERS status update posted on its website on Saturday.

"I think substantially it's still the same story. Although there's been a rapid rise in cases, I don't think anything demonstrably has changed with the virus or the pattern of transmission."

That said Adalja can see the appeal of invoking public health emergency status, if it would help speed the studies that are badly needed.

Faster with SARS

"Two years out we still have a poor understanding about basic facts about the virus and its transmission dynamics. It's really kind of unheard of," Adalja says.

"People talked about information problems with SARS but we had information much faster with SARS, even though at that point there was a lot of criticism over the way China handled that …. You could make that argument that if you declared a PHEIC you could create more impetus for them to actually answer these questions."

Saudi officials are likely to balk at any such move. In a short report published online over the weekend in the International Journal of Infectious Diseases, several leading Saudi scientists said a recent review of the MERS situation leads to the conclusion that the virus does not have pandemic potential "or even local epidemic potential." The lead author was Dr. Ziad Memish, the country's deputy minister of health. Memish is a member of the emergency committee.

Infectious diseases epidemiologist Marc Lipsitch, a professor at Harvard University, says the claim MERS doesn't have pandemic potential should have come with provisos. While Lipsitch thinks it is likely MERS currently doesn't spread well enough to transmit person to person in an ongoing fashion, he says that could change if the virus's genetic makeup mutated or it was introduced into a health-care setting where it couldn't be controlled.