Infectious disease experts have been worriedly watching a new disease for more than a year and a half now, but it’s a fair bet that most people still haven’t twigged to the existence of the world’s latest infectious threat: MERS.
That may be changing, with new infections popping up recently in Malaysia, Greece, the Philippines, and Egypt. And late last week, the United States became the 16th country to detect a case of MERS, in an American health care worker who has been living and working in Riyadh, Saudi Arabia.
The acronym is short for Middle East respiratory syndrome. The disease is caused by a cousin of SARS, the coronavirus that killed roughly 900 people and crippled hospital systems in China, Hong Kong, Vietnam, and Canada in 2003, knocking billions of dollars out of the world’s economy in the process. Canada’s outbreak occurred in Toronto, where I live; I covered SARS from its alarming beginning through its exhausting end. The information coming out of Saudi Arabia is limited, and it’s hard to be sure from a distance, but there appear to be many similarities between how the MERS outbreak is playing out in Saudi hospitals and what happened in Toronto during SARS. We are lucky that to this point MERS doesn’t seem to spread as easily as SARS did, though SARS didn’t spread particularly well either, and it still caused major trouble.
As the name suggests, this new disease has been mostly found in the Middle East, in countries such as Qatar, the United Arab Emirates, Jordan, and most especially Saudi Arabia, which has reported 431 cases and 117 deaths, about 80 percent of known infections. All cases to date link back to seven countries in the Middle East.
But one of the curious things about this new disease is that although cases appear to be concentrated in mainly a handful of countries, the virus itself is much more widespread. Evidence of the MERS coronavirus has been found over a wide swath of territory in dromedary camels, the beasts strongly suspected of passing this virus to people. Camels showing signs of previous infection with the virus have been found as far afield as Spain’s Canary Islands, off the northeastern coast of Africa; Tunisia; Ethiopia; Nigeria; and Kenya.
SARS exploded into the human population, seeding itself in hospitals in several parts of the world before it even had a name. But MERS has been doing a slow burn. The new virus was first identified in June 2012 by an Egyptian doctor working in Saudi Arabia and scientists in a Dutch laboratory he turned to for help. But it was only brought to the world’s attention a few months later, in September 2012, when a gravely ill man from Qatar checked into a London hospital. The virus had ravaged the Qatari man’s lungs; he never recovered, dying after nine months in the hospital.
The early deaths—following devastating illness—spooked public health officials and scientists observing the evolving situation. “Don’t become infected with this virus,” a public health officer familiar with one of the first cases told me more than a year ago. “It is not kind to humans.”
Most of the earliest patients succumbed to their infections, but in the past year some mild and even symptom-free cases have been detected. Still, at this point nearly 30 percent of people who have been diagnosed with MERS did not survive. That’s a staggering percentage for any disease, especially a respiratory one that seems to spread via the mechanisms colds and flu viruses use—though fortunately not as efficiently as those human-adapted viruses spread. SARS, by comparison, killed about 11 percent of those infected.
The recent milder cases support the hunch experts have long held—that the true ratio of fatal cases is lower because until now doctors in the main have only ordered MERS testing on people seriously ill with pneumonia. In fact the ratio has been dropping, from more than 50 percent early on to 28.5 percent, an estimate issued this week by the European Centre for Disease Prevention and Control. Epidemiologically, MERS is probably like an iceberg, with the severe cases making up the visible tip. But as none of the affected countries have been testing broadly to see how many people have been infected, it’s impossible at this point to even guess at how much lower the real death rate might be.
It’s one of many unanswered questions about MERS. Another—and currently more pressing—is what is behind the extraordinary surge of cases over the past five weeks? The cumulative global case count more than doubled last month. Saudi Arabia alone has reported upward of 250 cases since the beginning of April; prior to that, only 207 cases had ever been reported globally.
Some potential explanations for the sharp rise are a seasonal upswing, some outbreaks in Saudi and UAE hospitals where human-to-human spread has been taking place, and an increase in the number of people coming forward for testing. There has also been a spate of exported cases. A Malaysian man in Saudi Arabia on a religious pilgrimage contracted the virus and died after returning home. A man from Greece who lives in Jeddah, Saudi Arabia, flew to Athens after getting sick and was diagnosed there. Jordan and Egypt have recently detected cases in people from Saudi Arabia who sought care in their countries. And a health care professional who works in a Riyadh hospital flew to Chicago via London with the virus in his lungs. From Chicago he boarded a bus for Indiana, where he eventually sought medical treatment.
To date it seems the man, who is recovering, did not infect anyone on his travels or while being treated at Community Hospital in Munster, Indiana. But state public health officials with help from the Centers for Disease Control and Prevention in Atlanta faced the substantial task of tracing people who were in contact with the unidentified man during his travels, checking to see if they are experiencing symptoms. Meanwhile, around 50 hospital workers who had dealings with the man were placed in home isolation, to make sure that if they are coming down with MERS, they don’t infect anyone else. This response will have cost serious money—and all because one man picked up a virus in Saudi Arabia.
More of these kinds of situations are going to happen, the World Health Organization warned recently in a revised risk assessment of MERS. Dr. Kamran Khan, an infectious disease specialist at the University of Toronto who studies global spread of disease through airplane travel, worries about the possibilities, given the legions of foreign workers in the region and the millions of Muslim pilgrims from around the world who flock to the holy cities of Mecca and Medina every year. The numbers of the latter, by the way, will be increasing in coming weeks as Ramadan, the Muslim month of fasting, approaches. Ramadan begins this year at the end of June.
“Just from the standpoint of probabilities, the longer this persists, the likelihood of it showing up in other regions of the globe and causing some of that disruption—that health, that economic disruption—is going to increase,” says Khan.
Experts would dearly like to see the virus contained, driven out of the human population and back into nature. But doing that isn’t going to be easy. For one thing, while camels are clearly a major part of the MERS story, no one is yet certain they are the only source of the virus for humans. Nor does anyone know how camels are infecting people. Is transmission occurring through the drinking of unpasteurized camel milk or consumption of cheese made from it? Or is it the drinking of camel urine, a practice some in the Middle East exercise because they believe the fluid has medicinal qualities? The eating of camel meat? And how about all the people diagnosed with MERS who say they had no contact with camels—how did they become infected?
Camels are enormously important and beloved in the Middle East, where they are beasts of burden, sources of sustenance, and even pets. And that means options used in the past to contain the spillover of animal viruses into people could not be considered here. Starting in 1997, Hong Kong slaughtered all chickens in the city to stop the first human outbreak of H5N1 bird flu. During the SARS outbreak, China culled civet cats, the raccoon-like creatures implicated in the spread to humans of SARS. But no one would countenance the mass killing of camels—and nor should they, says Peter Ben Embarek, a WHO food safety scientist working on the MERS file.
“Culling camels will not solve the problem,” Ben Embarek says, noting replacements brought from Africa would probably carry or catch the virus, too. “That will not make such a solution either practical or feasible or wise, or make sense in any way. So no, that would not be an option.”
Getting people of the region to put some distance between themselves and their camels won’t be an easy sell, either. “Changing behaviors is always extremely difficult,” Ben Embarek says. “It’s really critical that we understand and identify the exact set of conditions that are exposing people to the virus, so we target the most critical behavior or practices to change them.”
In the meantime, with no drug therapy for MERS and no vaccine—and don’t expect one any time soon—MERS is a situation health authorities are watching closely. The hope is new infections will start to drop off after the spring, which may be MERS high season. The fear is the virus will get better at spreading person to person and take its nasty act on the road. The reality is there is no way to predict what MERS has in store. Stay tuned.