TORONTO – With rapidly climbing patient numbers and cases popping up in the U.S. and elsewhere, the MERS virus is getting a lot of attention lately. If you’re trying to catch up to this relatively new disease threat, you probably have some questions.
Here are some answers:
Q: What is MERS?
A: MERS is the short name for Middle East respiratory syndrome. The disease is caused by the MERS coronavirus – MERS-CoV – a relatively newly recognized animal virus that has been sporadically infecting people in several countries in the Middle East.
Q: I have heard it described as a cousin of SARS. What does that mean?
A: The viruses responsible for both SARS and MERS are coronaviruses. The family gets its name from the crown-like spikes on their surfaces. There are lots of coronaviruses; different ones infect different animal species. But before MERS CoV was discovered only five were known to infect people. Some cause common colds while MERS and SARS cause severe disease in some of the people who contract them.
Q: How long has the virus been around and where does it come from?
A: The first known MERS infections occurred in April 2012 in Jordan, but there could have been earlier cases that were missed. The Jordan cases were diagnosed after the fact; the first time scientists spotted the infection in real time was when a man from Saudi Arabia got sick and died in a Jidda hospital in June 2012.
The virus may have originated in Egyptian tomb bats, but it definitely infects camels, which seem to be a source of human infections. The virus isn’t new in camels; there is evidence camels in Saudi Arabia were infected as far back as 1992.
Q: How are people contracting a camel virus?
A: That’s not currently known. Camels play an integral role in Middle Eastern life. They are ridden, used as beasts of burden, raced, kept as pets, slaughtered as religious sacrifices or for meat, and milked. Unpasteurized camel milk and cheeses made from it are popular, and some people drink camel urine because it is believed to have medicinal qualities. The Saudi government recently urged people not to drink unpasteurized camel milk and the World Health Organization urged people with health conditions like diabetes not to eat raw camel meat or drink camel urine or unpasteurized camel milk. But it isn’t yet clear if those products are triggering infections.
Q: Is MERS spreading from person to person?
A: The virus is transmitting person to person, but in a limited way. Secondary cases are sometimes seen in households – one person gets sick and infects one or two more. But with few exceptions, those second generation cases don’t seem to transmit to a third generation.
There is, however, quite a bit of spread within hospital settings. Most of the spike in cases this spring is due to hospital outbreaks in the U.A.E. and Saudi Arabia. Hospitals are a great place for viruses to spread; they are crowded with people in poor health who are more vulnerable to picking up an infection. And procedures like inserting a tube down the throat of a MERS case so that the person can be put on a breathing machine can lead to infection of the health-care personnel if the staff isn’t properly protected.
Q: It’s been found in places other than the Middle East, hasn’t it?
A: At this point all known cases trace back to the Middle East, to Saudi Arabia, the U.A.E., Qatar, Jordan, Oman, Kuwait, Yemen and Lebanon. But a few sick individuals from some of the affected countries have gone to Western Europe for care. And some travellers and religious pilgrims have taken the disease to other parts of the globe.
Countries that have had imported cases are: Britain, Germany, France, Germany, France, Italy, Greece, Tunisia, Egypt, Malaysia, the Philippines and the United States. In France and Tunisia, the imported case infected one or two people locally. In Britain, it’s thought there were three generations of spread before transmission stopped. Jordan has had both imported and locally acquired cases.
Q: Will it come to Canada? Will it cause a pandemic?
A: Finding sporadic cases in travellers in Canada would not be unexpected, given the patterns of international travel. The United States has already had two imported MERS cases. Canadian health officials have been on the lookout for MERS infection in returning residents and incoming travellers since MERS was first identified. The goal is to find cases quickly and isolate them to shut down the possibility of local spread.
It is impossible to say at this point what the future holds for the MERS virus. Science cannot currently predict if the virus will adapt to spread more easily among people.
Q: How do doctors treat MERS patients? Are there drugs or a preventative vaccine?
A: There are no drugs to specifically treat MERS. Patients are given what’s called supportive care, things like additional oxygen and antibiotics if they develop a secondary bacterial infection. If their condition becomes severe, patients are put on ventilators, machines which breathe for them.
There is no vaccine for MERS. Several biotech companies are working on candidate vaccines and have issued hopeful press releases about their progress. But a candidate vaccine is only a prototype. It would require extensive safety and efficacy testing which would take years and cost hundreds of millions of dollars. A camel vaccine may be easier to bring to market, if one can be made.