MERS 101: If you’ve missed it until now, there’s a new disease afoot

MERS CoV (Crystal Eye Studio / Shutterstock)

TORONTO – It may have been tugging at your attention, popping up in newspaper articles or online news reports you’ve seen out of the corner of your eye. But with so much other news to pay attention to, you may not have turned your focus to a little bug called MERS.

If so, you’re not alone. The virus’s recent North American debut – in two sick travellers who have arrived in the United States over the past couple of weeks – seems to have turned up the heat under a long simmering story that has garnered modest attention until now.

So if you are catching up on this MERS situation, here are some things you ought to know:

MERS is shorthand for Middle East respiratory syndrome, the disease caused by the Middle East respiratory syndrome coronavirus, or MERS-CoV. If you think the term coronavirus sounds familiar, you’re right. The virus that caused the 2003 SARS outbreak was also a coronavirus.

So far 18 countries have reported cases, though the vast majority of infections have occurred in Saudi Arabia. Several neighbouring countries have also had locally acquired cases: Qatar, Jordan, the United Arab Emirates, Kuwait, Oman, Yemen and Lebanon (confirmation from the World Health Organization is pending).

Cases have also been detected in 10 other countries in the form of infected travellers: Britain, Germany, France, Italy, Greece, Tunisia, Egypt, the Philippines, Malaysia and the United States. In a few cases, the person who imported the disease spread it to one or two others locally, but to date no country outside the Middle East has experienced an ongoing outbreak.

Close to 600 cases have been reported by national governments and roughly 175 of those infections have been fatal. The WHO’s official count – which always lags behind the countries’s reports – is 536 cases and 145 deaths.

The virus also infects camels – specifically the one-humped dromedaries – which are believed to be the source of the human infections. But how people are contracting a camel virus remains unclear, especially as a number of cases report no contact with the beasts.

Recently the WHO and Saudi authorities urged people to avoid unpasteurized camel milk and cheeses made from it, and to only eat well-cooked camel meat. The WHO also advised people who are likely to become severely ill if they contract MERS – people with diabetes and other chronic diseases – not to drink camel urine. Some in the Middle East believe camel urine has medicinal qualities.

Public health experts and scientists who specialize in infectious diseases have been watching this situation closely since September 2012, when the world first learned of the existence of the new virus. They do that whenever an animal virus starts infecting people, but the fact that this one is from the same family as the SARS virus definitely increased the concern.

Until recently, however, the outbreak was both slow moving and far away. Cases initially were infrequent, sometimes with months between findings. So perhaps not a high priority in Canada.

And MERS may never be for people living in Glace Bay, N.S. or Kelowna, B.C. or Saskatoon. Scientists can (and some do) offer opinions –  “It’s about to take off!” “It’s never going to take off!” – but the reality is, those are hunches. Science currently cannot determine what this virus or any new virus will do.

“The truth is that none of us are arrogant enough to presume we can predict the future on emerging infections,” explains Dr. Martin Cetron, director of the division of global migration and quarantine at the U.S. Centres for Disease Control and Prevention in Atlanta.

“We need to maintain a healthy degree of humility and respect for the evolution and evolutionary potential of viruses and pathogens.”

There’s a mantra in public health: Hope for the best and prepare for the worst. And that’s exactly what organizations like the Public Health Agency of Canada, the CDC and the WHO have been doing when it comes to MERS.

The Public Health Agency, which was established in response to the SARS crisis, has been helping the provinces and territories prepare for and stay alert to the possible arrival in Canada of people infected with bird flu, MERS, even Ebola. That work paid off in January, when Alberta detected an H5N1 bird flu infection in a woman from Red Deer who had recently returned from several weeks in China.

That case confirmed another public health maxim: “Infectious diseases know no borders.” People travel, and germs hitch rides with them. So in the interconnected modern world, no one has the luxury of saying of something like MERS: “That’s their problem.”

Cetron says his team at CDC has plotted out the full spectrum of possibilities regarding what this virus might do.

As they see it, the MERS virus could remain largely a virus that jumps occasionally from animals to people. Or it could become more SARS-like, spreading more efficiently from person to person and triggering outbreaks in hospitals and in household settings. Or it could adapt more fully to people and acquire the ability to spread as easily among us as something like flu.

“And from our perspective, we will try to plan and prepare for all of those scenarios.”

If the reaction to what still seems to be small numbers of cases appears overblown, keep this in mind: MERS doesn’t need to get to the worst point on Cetron’s spectrum to cause a whole lot of trouble.

Consider SARS. It wasn’t clear in the frantic early days of the outbreak, but SARS virus wasn’t highly contagious. It spread mostly among people who were in close proximity to one another. Once public health officials figured out how it was spreading they were able to fairly quickly snuff out transmission by isolating sick people, quarantining their contacts and ensuring hospital workers were protected against infection.

At the end of the outbreak, SARS infected about 8,500 people, killing about 916 of them. Compared to the annual toll of malaria or tuberculosis, those numbers are small potatoes.

But the SARS outbreak was an enormously disruptive event globally. It is estimated to have cost billions of dollars. Tourism dried up in affected locations. Toronto, the site of Canada’s outbreak, watched international conferences cancel, hotels empty and film crews decamp for other cities.

But that was only part of the cost of SARS. The measures needed to stop its spread in hospitals were draconian. Non-urgent surgeries were postponed, meaning people waiting for hip replacements and the like had even longer waits. Hospitals were closed to visitors, which meant gravely ill and dying patients were left without the comforting presence of loved ones.

The economic, social and psychological toll of SARS far exceeded the measly case counts. That is a major lesson from SARS.

“It doesn’t have to be … the doomsday scenario before there’s significant impact,” Cetron says.

“And with a disease like MERS or SARS where there’s not direct treatment and not a vaccine for prevention, the entire public health effort is all about containment.”

An outbreak doesn’t even have to be as big as SARS to make major trouble and cost serious money. The first MERS case discovered in the United States _ in Indiana _ illustrates that well. Public health staff had to trace the man’s movements and get in touch with people who had been in contact with him _ passengers on two international flights and on a bus from Chicago to Indiana.

“We’re talking about hundreds of person hours. Maybe actually thousands of person hours. And that’s only one small piece” of the response, Cetron says. “So yes, it’s a big deal.”

“Even when you don’t have second generation or third generation cases, you have a huge public health effort and response in terms of people and time and resources and equipment and impact on worker deferral from hospitals and workplaces.”

“It cascades in a big way.”

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