Middle East Respiratory Syndrome Coronavirus (MERS-CoV)

NOTE: Information on MERS-CoV has been retained for historical purposes only. For current information, refer to the WHO website: http://www.who.int/emergencies/mers-cov/en/.

About MERS-CoV [ref: WHO]

In September 2012, a new coronavirus was isolated from a patient in Saudi Arabia [ref ProMed]. Since then, there have been a limited number of human cases identified, clustered mainly in the Arabian Peninsula. This particular strain of coronavirus has not been previously identified in humans. There is very limited information on transmission, severity and clinical impact with only a small number of cases reported thus far. The emergence of this new coronavirus is globally recognized as an important and major challenge for all of the countries which have been affected as well as the rest of the world.

The greatest global concern is about the potential for this new virus to spread. This is partly because the virus has already caused severe disease in multiple countries, although in small numbers. Different clusters seen in multiple countries increasingly support the hypothesis that when there is close contact this novel coronavirus can transmit from person-to-person. This pattern of person-to- person transmission has remained limited to some small clusters and, so far, there is no evidence that this virus has the capacity to sustain generalized transmission in communities. Persons with underlying medical conditions may have increased susceptibility to infection. The incubation period may exceed 10 days in some patients.

Staff working in health care must increase their levels of surveillance about this new infection. There are also some questions that urgently need to be answered including how are people are getting infected, and what are the main risk factors for either infection or development of severe disease. The answers to these questions hold the keys to preventing infection.

Epidemiology of MERS-CoV

[Ref: WHO] Updated 21 March 2016
NOTE: Cases are classified according to country where infection was acquired

Country	Cases	Deaths
Saudi Arabia	1,374	575
South Korea	186	36
United Arab Emirates (UAE)	81	9
Jordan	32	10
Qatar	15	6
Oman	9	3
Iran	6	2
Kuwait	4	2
Tunisia	2	0
United Kingdom	2	1
Yemen	1	1
France	1	0
Lebanon	1	0
TOTAL	1,714	645

Since April 2012, there have been 1,714 cases of human infection with MERS-CoV. Several countries in the Middle East have reported cases, including Egypt, Iran, Jordan, Kuwait, Lebanon, Oman, Qatar, Saudi Arabia, the United Arab Emirates (UAE) and Yemen. Cases have also been reported by other countries: Algeria, Bangladesh, France, Germany, Greece, Italy, Malaysia, Thailand, the United Kingdom and South Korea. All of the cases outside of the Middle East have had a direct or indirect connection to the Middle East, with the exception of a cluster in South Korea. Six hundred and forty-five (645) of the 1,714 cases have died (case fatality rate 38%).

In South Korea, the first case was identified on May 20, 2015 with links to the Middle East. This has resulted in the largest outbreak reported outside the Kingdom of Saudi Arabia. Tertiary cases have been reported (i.e., cases with no direct exposure to the index case).

In Tunisia, France and the United Kingdom, there has been limited local transmission among close contacts who had not been to the Middle East but had been in contact with a traveler recently returned from the Middle East. Most clusters reported to date have occurred among family contacts or in a health care setting. Human-to-human transmission occurred in at least some of these clusters, however, the exact mode of transmission is still unknown.

Infection in health care workers accounts for 242 cases (14%).

So far, the source of the virus remains unknown but the pattern of transmission points towards an animal reservoir (e.g., camel) in the Middle East, from which humans sporadically become infected through zoonotic transmission. There is evidence of a seasonal transmission pattern (March-April onwards). Human-to-human transmission between close contacts and in hospital settings has occurred, but there is no evidence of sustained transmission among humans.Â Secondary cases appear to have a milder disease than that of primary cases.

For more information and current updates:

Surveillance for MERS-CoV Infection

[Ref: PHAC, WHO]

The Public Health Agency of Canada requests that probable and confirmed cases be reported within 24 hours of being classified as such.

For more information on MERS-CoV surveillance:

National Interim Surveillance Case Definition - Middle East respiratory syndrome coronavirus (MERS-CoV) (PHAC 23 September 2013)
Revised interim case definition (WHO 3 July 2013)
Interim surveillance recommendations for human infection with Middle East respiratory syndrome coronavirus (WHO 27 Jun 2013)

Symptoms of MERS-CoV Infection

All of the laboratory confirmed cases have had respiratory disease as part of the illness, and most have had severe acute respiratory disease requiring hospitalization. Reported clinical features include acute respiratory distress syndrome (ARDS), renal failure requiring hemodialysis, consumptive coagulopathy, and pericarditis. Many patients have also had gastrointestinal symptoms including diarrhea during the course of their illness. One patient, who was immunocompromised, presented with fever, diarrhea and abdominal pain, but had no respiratory symptoms initially; pneumonia was identified incidentally on a radiograph.

The National Institutes of Health has found that a combination of two antiviral drugs, ribavirin and interferon-alpha 2b, can inhibit replication of the virus in cell cultures [Falzarano et al. Inhibition of novel human coronavirus-EMC replication by a combination of interferon-alpha2b and ribavirin. Scientific Reports 2013, doi: 10.1038/srep01686].

Interim guidance document on clinical management of severe acute respiratory infections when novel coronavirus is suspected: what to do and what not to do (WHO 11 Feb 2013)

Infection Prevention and Control

[ref: PHAC]

Prior to any patient interaction, all healthcare workers (HCWs) have a responsibility to assess the infectious risk posed to themselves and to other patients, visitors, and HCWs. This risk assessment is based on professional judgment about the clinical situation and up-to-date information on how the specific healthcare organization has designed and implemented engineering and administrative controls, along with the availability and use of personal protective equipment (PPE).

Recommendations for infection prevention and control measures for patients presenting with suspected or confirmed infection or co-infection with MERS-CoV in acute care settings include:

1. Routine Practices: For all patients, at all times, in all healthcare settings including when performing a point-of-care risk assessment, and adherence to respiratory hygiene and hand hygiene.

2. Contact and Droplet Precautions (should be implemented empirically):

Wear gloves and a long-sleeved gown upon entering the patient's room, cubicle or designated bedspace.
Wear facial protection (surgical or procedure mask and eye protection, or face shield, or mask with visor attachment) when within two metres of a patient suspected or confirmed to have MERS-CoV infection.

3. Airborne Precautions: When performing aerosol-generating medical procedures (AGMPs). A respirator and face/eye protection should be used by all HCWs present in a room where an AGMP is being performed on a patient suspected or confirmed to have MERS-CoV infection. Whenever possible, AGMPs should be performed in an airborne infection isolation room.

It should be noted that, in Ontario, Airborne Precautions (including respirator and airborne infection isolation room) are recommended. This is also the recommendation from the Centers for Disease Control (CDC) in the U.S.

As information becomes available, these recommendations will be re-evaluated and updated as needed. For more information on Infection Prevention and Control:

Laboratory Information and Speciment Collection

Specimens to be collected for diagnosis of MERS-CoV include: nasopharyngeal swab*, urine, stool (if diarrhea is present), blood (for serology), blood (for PCR, collected in EDTA). If a bronchoalveolar lavage (BAL) has been done, a portion should be sent for MERS-CoV testing. [ref: PIDAC]

* There is increasing evidence to suggest that nasopharyngeal swabs are less sensitive for detecting infection with MERS-CoV than specimens taken from the lower respiratory tract (e.g., sputum, endotracheal aspirate, bronchoalveolar lavage). [ref: WHO]

Laboratories should have a mechanism for notification and prompt delivery of specimens from suspected patients to public health/reference laboratories. A safety protocol should be in place for laboratory staff who will be handling specimens from suspected cases of MERS-CoV.

Biosafety Guidance for Specimens (PHAC 21 Oct 2013)
Laboratory testing for novel coronavirus - Interim recommendations (WHO 21 Dec 2012)
Novel coronavirus: interim recommendations for laboratory biorisk management (WHO 19 Feb 2013)
Revised testing algorithms, assay protocols and reagent availability (WHO)
Tools for Preparedness: Triage, Screening and Patient Management of Middle East Respiratory Syndrome Coronavirus (MERS-CoV) Infections in Acute Care Settings (PIDAC July 2015)

Travel Advice

Updated 10 June 2015

Since September 2012, the following countries in the Middle East have reported cases of MERS-CoV: Bahrain, Iran, Jordan, Kuwait, Lebanon, Oman, Qatar, Saudi Arabia, United Arab Emirates and Yemen. Based on the current available evidence, the public health risk posed by MERS-CoV to Canadians remains low. Those travelling to the above countries are advised to practice travel precautions as outlined in the following recommendations: