Middle East Respiratory Syndrome Coronavirus (MERS-CoV) is a novel coronavirus that was first identified in Saudi Arabia in 2012. Coronaviruses are enveloped viruses with positive-sense RNA genomes that derive their name from the crown-like appearance of viral spike proteins on their surface. MERS-CoV is classified within the Betacoronavirus genus and is closely related to bat coronaviruses. Camels are believed to be the primary animal reservoir, with limited human-to-human transmission occurring, mainly in healthcare settings. Clinical presentation ranges from asymptomatic to severe pneumonia and multi-organ failure. There is currently no vaccine available for MERS-CoV.

1. Middle East Respiratory Syndrome
Coronavirus (MERS-CoV)

2. Coronaviruses
 Corona viruses are species in the genera
of virus belonging to the subfamily Coronavirinae in
the family Coronaviridae.
 Corona viruses are enveloped viruses with a positive-
sense RNA genome and with a nucleo-capsid of
helical symmetry.

3.  The name "coronavirus" is derived from the
Latin corona, meaning crown or halo.
 Coronaviruses derive their name from the fact that
under electron microscopic examination, each virion
is surrounded by a "corona," or halo. This is due to
the presence of viral spike peplomers emanating
from envelope.

5. .Genome organization
 The genome consists of seven genes.
 The first 22 kb contains the replicase gene,
which is organized into two overlapping open
reading frames, ORFs 1a and 1b.
 These ORFs are translated into the pp1a and
the pp1ab replicase polyproteins.
 The protein domains of the replicase polyprotein
are nonstructural protein numbers (nsp1 to 16)
 PLP1 and PLP2, papain-like proteases; X,
domain encoding predicted adenosine
diphosphate-ribose 1"-phosphatase activity
(ADRP); 3CLpro, 3C-like protease; RdRp,
RNA-dependent RNA polymerase; Hel,
helicase; ExoN, putative exonuclease; XendoU,
putative poly(U)-specific endoribonuclease; 2′-
O-MT, methyltransferase.
 Genes 2 to 7 are translated to structural proteins
S, E, M, N

6. Alpha Co-V:
– Human examples: HCoV-220E, HCoV-NL63
– Pig, dog, and cat CoVs
Beta Co-V:
– HCoV-OC43, HCoV-HKU1, HCoV-SARS
– MHV, rat, pig and cow CoVs
– MERS-CoV
Gamma Co-V:
– Chicken and turkey CoVs
Delta Co-V:
– Bird CoVs
Classification

7. Listing of human coronaviruses
 Human coronavirus 229E
 Human coronavirus OC43
 SARS-CoV
 Human Coronavirus NL63 (HCoV-NL63, New Haven
coronavirus)
 Human coronavirus HKU1
 Middle East respiratory syndrome coronavirus (MERS-
CoV), previously known as Novel coronavirus 2012 and
HCoV-EMC.

8. IDENTIFICATION OF A NOVEL
CORONAVIRUS AS A CAUSE OF SEVERE
RESPIRATORY DISEASE
 During summer of 2012, in Jeddah, Saudi Arabia, a unknown
coronavirus (CoV) isolated from sputum of a patient with acute
pneumonia and renal failure . The isolate was provisionally called
human coronavirus Erasmus Medical Center (EMC) .
 Shortly thereafter, in September 2012, the same type of virus,
named human coronavirus England 1, recovered from a patient
with severe respiratory illness who had been transferred from the
Gulf region of the Middle East to London, United Kingdom
(GenBank accession no.KC164505.2).
 The onset of the new disease was traced back to an even earlier
time point. In April 2012, a cluster of pneumonia cases in health
care workers had occurred in an intensive care unit of a hospital
in Zarqa, Jordan . Two persons died, both of whom were
confirmed to have been infected with the novel coronavirus
through a retrospective analysis of stored samples.

9.  60 year old Saudi man
 Presented on 13th June, 2012 with 7d h/o fever, cough, expectoration
and recent shortness of breath.
 Pt presented with acute pneumonia and later renal failure.
 Pt’s sputum inoculated on Vero and LLC-MK2 cells for viral culture
showed cytopathic effects.
 All known respiratory tract pathogens yielded negative results.
 Pancoronavirus RT-PCR showed that PCR fragments corresponded
to a conserved region of ORF1b of the replicase gene of a
coronavirus.
 Phylogenetic analysis showed that this novel virus together with the
bat coronaviruses HKU4 and HKU5 belonged to subgroup 2c of the
lineage Betacoronavirus, indicating the emergence of a novel
coronavirus.
 Pt developed ARDS and died on June 24th.
First Reported MERS-Coronavirus Case

10. CASE1: CHESTRADIOGRAPHS
On Admission
2 Days later
Multiple patchy
opacities in
middle and lower
lung fields
Opacities more
confluent and
dense

11.  Full-length genome sequences determined for three independent virus
isolates from Saudi Arabia (GenBank accession no. JX869059.2),
Jordan (GenBank accession no. KC776174.1), and the United Kingdom
(GenBank accession no.KC164505.2) revealed more than 99%
sequence identity (∼100 nucleotide variations in a 30.1-kb genome),
indicating that these viruses diverged from a common ancestor very
recently.
 This new corona virus is now known as Middle East respiratory
syndrome corona virus (MERS-CoV). It was named by the Corona virus
Study Group of the International Committee on Taxonomy of Viruses in
May 2013.

12. Phylogeny
 Within the subfamily Coronavirinae , the novel virus
is a representative of a new, yet-to-be-established
species in lineage C of the genus Betacoronavirus,
which currently includes the species Tylonycteris bat
coronavirus HKU4 and Pipistrellus bat coronavirus
HKU5 .
 more than 90% sequence identity

13. Phylogenetic relationships among members of the subfamily Coronavirinae and taxonomic
position of MERS-CoV.
De Groot R J et al. J. Virol. 2013;87:7790-7792

14. Epidemilogy
 As of 11 June 2014, 699 laboratory-confirmed cases
of human infection with MERS-CoV have been
reported to WHO, including at least 209 deaths
(30 % mortality).
 Most MERS-CoV cases have been reported in
adults (median age approximately 47 years, male
predominance 63.5% of cases reporting are male)
although children and adults of all ages have been
infected (range 9 months to 94 years).
 Most hospitalized MERS-CoV patients have had
chronic co-morbidities

15.  The epidemiological data available suggest that the
infection is primarily zoonotic in nature, with limited
human-to-human transmission.
 Bats appear to be the natural host, it is proposed that a
single variant from a spectrum of related betacoronaviruses
in bats successfully crossed over to and rapidly established
itself in an intermediate animal host species (at least in the
Middle East), with subsequent incidental spillover into the
human population.
 Such spillover events would be facilitated through frequent
intermediate host-human interactions and perhaps through
viral adaptations acquired during the initial species jump.
 At present there is no evidence for sustained community
transmission, the concern is that the virus may take the next
step and adapt to efficient human-to-human transmission.

16. What is the source of the MERS virus—
bats, camels, domestic animals?
 Strains of MERS‐CoV that match human strains have
been isolated from camels in Egypt, Qatar, and Saudi
Arabia.
 These and other studies have found MERS‐CoV
antibodies in camels across Africa and the Middle East.
Human and camel genetic sequence data demonstrate
a close link between the virus found in camels and that
found in people.
 It is possible that other reservoirs exist. However,
other animals, including goats, cows, sheep, water
buffalo, swine, and wild birds, have been tested for
antibodies to MERS‐CoV, but so far none have been
found in these animals.
 These studies indicate that camels are a likely source
of infection in humans.

17.  All the cases have been linked to
countries in and near the Arabian
Peninsula, including Saudi Arabia,
UAE, Qatar, Oman, Jordan,
Kuwait, Yemen, and Lebanon.
 To date, the affected countries in
the Middle East include Iran,
Jordan, Kuwait, Lebanon,
Oman,Qatar, Saudi Arabia (KSA),
United Arab Emirates (UAE) and
Yemen;
 Africa: Algeria, Egypt and
Tunisia;
 Europe: France, Germany, Greece,
Italy, the Netherlands and the
United Kingdom
 Asia: Malaysia and Philippines
 North America: the United States
of America (USA).
 Most affected individuals having
recently travelled to the Arabian
Peninsula.

18.  All cases have had some connection (whether
direct or indirect) with the Middle East.
 In France, Italy, Tunisia and the United Kingdom,
limited local transmission has occurred in people
who had not been to the Middle East but who had
been in close contact with laboratory-confirmed or
probable cases.

20. Time trend

21. Route of transmission
 Droplet and direct contact probably is suspected
as the most likely route.
 A considerable proportion of MERS-CoV cases
have been part of clusters in which limited non-
sustained human-to-human transmission has
occurred.
 Human-to-human transmission has occurred in
health care settings, among close family contacts,
and in the work place.

22.  Close contact is defined as:
a)Being within approx 6 feet (2 meters) within the room or
care area for a prolonged period of time (e.g., healthcare
personnel, household members) while not wearing
recommended personal protective equipment (i.e., gowns,
gloves, respirator, eye protection)
b)Having direct contact with infectious secretions (e.g., being
coughed on) while not wearing recommended personal
protective equipment

23. People at Increased Risk for MERS
 Recent Travellers from the Arabian Peninsula
 Close Contacts of an Ill Traveller from the Arabian
Peninsula
 People with Exposure to Camels as MERS-CoV has
been found in some camels, and some MERS
patients have reported contact with camels.

24. Site of infection
 Primarily infect the upper respiratory and gastrointestinal
tract of mammals and birds.
 Dipeptidyl peptidase 4 (DPP4 , CD26), which is present on the
surfaces of human nonciliated bronchial epithelial cells, receptor
for MERS-CoV.
 In a cell line susceptibility study, MERS-CoV infected several
human cell lines, including lower (but not upper) respiratory,
kidney, intestinal, and liver cells, as well as histiocytes.
 The range of tissue tropism in vitro was broader than that for any
other known human coronavirus.
 MERS-CoV can also infect nonhuman primate, porcine, bat, and
rabbit cell lines .

25. Clinical manifestation
 Incubation period is 2-14 days.
 A wide clinical spectrum of MERS-CoV infection has
been reported ranging from asymptomatic infection to
acute upper respiratory illness, and rapidly progressive
pneumonitis, respiratory failure, septic shock and
multi-organ failure resulting in death.

26. CONTn..
 Most people confirmed to have MERS-CoV infection
have had severe acute respiratory illness with
symptoms of:
 fever
 cough
 shortness of breath
 Some people also had gastrointestinal symptoms
including diarrhea and nausea/vomiting
 For many people with MERS, more severe
complications followed, such as ARDS, pneumonia ,
kidney failure, multiorgan failure. About 30% of
people with MERS died. Most of the people who died
had an underlying medical condition.

27. WHO categories
 Patient Under Investigation
 Confirmed Case
 Probable Case
 Contact Under Investigation of a Confirmed Case of
MERS

28. “Patient under investigation” (PUI)
Persons who meet the following criteria should be reported and evaluated for
MERS-CoV infection:
 Fever AND pneumonia or ARDS AND:
 A history of travel from countries in or near the Arabian Peninsulawithin 14
days before symptom onset, OR
 Close contact with a symptomatic traveller who developed fever and ARDS
within 14 days after traveling from countries in or near the Arabian
Peninsula OR
 A member of a cluster of patients with severe acute respiratory illness (e.g.,
fever and pneumonia requiring hospitalization) of unknown etiology in which
MERS-CoV is being evaluated, in consultation with state and local health
departments.

29.  Fever AND symptoms of respiratory illness (
e.g. cough, shortness of breath) AND being in
a healthcare facility (as a patient, worker, or
visitor) within 14 days before symptom onset
in a country or territory in or near the Arabian
Peninsula in which recent healthcare-
associated cases of MERS identified.

30. Contact Under Investigation of a Confirmed
Case of MERS
 As part of investigation of confirmed cases, in
consultation with a state or local health department, a
person with fever or symptoms of respiratory illness
within 14 days following close contact with a confirmed
case of MERS while the case was ill should be evaluated
for MERS-CoV infection.

31. Probable Case
 A probable case is a PUI with absent or
inconclusive laboratory results for MERS-CoV
infection and who is a close contact of a laboratory-
confirmed MERS-CoV case.
 Examples of laboratory results that may be
considered inconclusive include a positive test on a
single PCR target, a positive test with an assay that
has limited performance data available

32. Confirmed Case
 A confirmed case is a person with laboratory
confirmation of MERS-CoV infection.
 Confirmatory laboratory testing requires a positive
PCR on at least two specific genomic targets or a
single positive target with sequencing on a second.

33. Laboratory diagnosis
 MERS-CoV virus detected with higher viral load
and longer duration in lower respiratory tract
compared to URT
 Also detected in feces, serum, and urine.
 Limited data available on duration of respiratory
and extrapulmonary MERS-CoV shedding.
 To confirm clearance of the virus, respiratory
samples should continue to be collected until two
consecutive negative results.
 The frequency of specimen collection will depend
on local circumstances but should be at least every
2‐4 days.

34. Specimen Type and Priority
To increase the likelihood of detecting infection, it
is recommended to collect specimens from
different sites – for example a nasopharyngeal
swab and a lower respiratory tract specimen such
as sputum, bronchoalveolar lavage, bronchial
wash, or tracheal aspirate.

35.  Specimens should be collected at different times after
symptom onset, if possible.
 lower respiratory tract, serum, and stool specimens,
priority for collection and PCR testing.
 For short periods (≤ 72 hours), most specimens should
be held at 2-8°C , for delays exceeding 72 hrs, freeze
specimens at -70°C as soon as possible after collection.

36. Real time RTPCR
 Targets for rRTPCR upstream of the E protein gene (upE), open reading frame 1b
(ORF 1b) and open reading frame 1a (ORF 1a)
 The assay for the upE target is considered highly sensitive and recommended for
screening, ORF 1a assay considered of equal sensitivity. The ORF 1b assay is
considered less sensitive than the ORF 1a assay.
 US CDC has developed rRTPCR assays targeting nucleocapsid (N) protein gene,
which can complement upE and ORF 1a assays for screening and confirmation
 To date, these rRT‐PCR assays have shown no cross‐reactivity with other respiratory
viruses including human coronaviruses
 Two target sites on the MERS‐CoV genome suitable for sequencing to aid
confirmation have been identified. These are in the RNA‐dependent RNA
polymerase (RdRp) and (N) genes

37. Algorithm for testing

38. Serology
 US CDC recommends two‐stage approach
 Screening test using a recombinant nucleocapsid
(N) protein‐based indirect ELISA followed by a
confirmatory test using a whole‐virus indirect
fluorescent antibody (IFA) test or neutralization test.

39. Serology in relation to defining a
MERS‐CoV
• Where a patient has evidence of seroconversion in at
least one screening assay and confirmation by a
neutralization assay in samples taken at least 14 days
apart, can be considered a confirmed case, regardless
of the results of PCR assays.
• When a symptomatic patient has a positive result for at
least one screening assay plus a positive result for a
neutralization assay in a single specimen this would
indicate a probable case

40. Serological surveys
• Usually only a single specimen is available from
each person in the survey.
• Positive result for at least one screening assay plus
a positive result for a neutralization assay would
indicate a past infection

41. Virus isolation
 The virus was propagated by
using African green monkey
and rhesus macaque kidney
epithelial cells (Vero and
LLC-MK2 cell lines)
 CPE- Syncytia formation
 Virus isolated first by Dr Ali
Moh Zaki (erasmus medical
centre netherland)

42. Treatment
 No antivirals recommended
 Treatment is supportive
 No vaccines developed

43. Agents proposed:
 Convalescent plasma
 Interfron-α and interferon-γ
 Protease Inhibitors
 Intravenous Immunoglobulin
 Cyclosporin A
 Ribavirin
 Corticosteroids
 Interferon plus ribavirin

44. Possible dosages and schedule of therapeutic agents for
MERS-CoV Infection

45. MERS-CoV Vaccine candidate
 Novavax on June 6, 2013 announced that it had
successfully produced a vaccine candidate
 The vaccine candidate was made using nanoparticle
vaccine technology, is based on the major surface
spike (S) protein.
 Recombinant modified vaccinia virus Ankara (MVA)
expressing full-length MERS-CoV spike (S) protein
(MVA-MERS-S)
 Vaccinated mice produced high levels of serum
antibodies neutralizing MERS-CoV.

46. PREVENTION
 Do not consume raw or undercooked animal
products, including milk and meat.
 Until more is understood about MERS, people with
diabetes, renal failure, chronic lung disease, and
immunocompromised persons are considered to be
at high risk of severe disease from MERS‐CoV
infection.
 Therefore, these people should avoid contact with
camels, raw camel milk or camel urine, or eating
meat that has not been properly cooked.

47. MERS Vs SARS
 Although the clinical syndromes of MERS
resembled those described in severe SARS, MERS
often had renal failure and multiorgan dysfunction
 Higher mortality (around 30% vs 10%)
 MERS-CoV has a much broader tissue tropism
than SARS-CoV

48. MERS Vs SARS cont..
 MERS-CoV can establish a productive infection in
MDMs unlike the abortive infection of SARS-CoV in
MDMs
 Efficient viral replication in these cells implicates
that the virus can overcome the host defenses and is
highly virulent. They act as viral reservoirs and
vehicles for further replication and dissemination

49. MERS Vs SARS cont..
 Both viruses were unable to significantly stimulate the
expression of antiviral cytokines (IFN-α] and IFN-β)
 MERS-CoV induced higher expression levels of
interleukin 12, IFN-γ, and chemokines than SARS-CoV.
 The expression of MHC class I and costimulatory
molecules were significantly higher in MERS-CoV–
infected MDMs than in SARS-CoV–infected cells.
 This might lead to large number of immune cells
infiltrating lower respiratory tract, causing severe
inflammation and tissue damage
IP-10 and MCP-1, suppress proliferation of human
myeloid progenitor cells , were highly induced upon
MERS-CoV infection. The induction of these
chemokines aggravate lymphopenia in patients with
MERS

50. Infection Prevention and Control Recommendations
for Hospitalized Patients with (MERS-CoV)
These recommendations are based upon available
information (as of June 10, 2013) and the following
considerations:
 Suspected high rate of morbidity and mortality
among infected patients
 Evidence of limited human-to-human transmission
 Poorly characterized clinical signs and symptoms
 Unknown modes of transmission of MERS-CoV
 Lack of a vaccine and chemoprophylaxis

51. Component Recommendation(s) Comments
Patient
placement
•Airborne Infection
Isolation Room (AIIR)
•If an AIIR is not available, the patient
should be transferred as soon as is
feasible to a facility where an AIIR is
available.
•Pending transfer, place a facemask on
the patient and isolate him/her in a
single-patient room with the door closed.
•The patient should not be placed in any
room where room exhaust is recirculated
without high-efficiency particulate air
(HEPA) filtration.

52. Component Recommendation(s) Comments
•Once in an AIIR, the patient’s
facemask may be removed; the
facemask should remain on if the
patient is not in an AIIR.
•When outside of the AIIR, patients
should wear a facemask to contain
secretions
•Limit transport and movement of the
patient outside of the AIIR to
medically-essential purposes.
•Implement staffing policies to
minimize the number of personnel that
must enter the room.

53. Component Recommendation(s) Comments
Personal Protective
Equipment (PPE) for
Healthcare personnel
(HCP)
•Gloves
•Gowns
•Eye protection (goggles or face
shield)
•Respiratory protection that is
at least as protective as a fit-
tested NIOSH-certified
disposable N95 filtering
facepiece respirator.
• If a respirator is
unavailable, a facemask
should be worn. In this
situation respirators
should be made available
as quickly as possible.
•Recommended PPE should
be worn by HCP upon entry
into patient rooms or care
areas.
•Upon exit from the patient
room or care area, PPE
should be removed and
either
• Discarded, or
• For re-useable PPE,
cleaned and
disinfected
according to the
manufacturer’s
reprocessing
instructions

54. Component Recommendation(s) Comments
Environmental
Infection Control
•Follow standard procedures, per
hospital policy and
manufacturers’ instructions, for
cleaning and/or disinfection of:
• Environmental surfaces
and equipment
• Textiles and laundry
• Food utensils and
dishware
Hand Hygiene HCP should perform hand hygiene frequently, including before
and after all patient contact, contact with potentially infectious material, and
before putting on and upon removal of PPE, including gloves.
Duration of Infection Control Precautions
At this time, information is lacking to definitively determine a
recommended duration for keeping patients in isolation precautions.
Duration of precautions should be determined on a case-by-case basis, in
conjunction with local, state, and federal health authorities.

55. Travellers guidelines
• CDC does not recommend that most travellers
change their plans because of MERS.
• However, the Saudi Arabia Ministry of Health
has made special recommendations for
travelers to Hajj and Umrah.

56. Because of the risk of MERS, Saudi Arabia recommends that the
following groups should postpone their plans for Hajj and Umrah
this year:
 People over 65 years old
 Children under 12 years old
 Pregnant women
 People with chronic diseases (such as heart disease, kidney
disease, diabetes, or respiratory disease)
 People with weakened immune systems
 People with cancer or terminal illnesses

57. References
 Middle East Respiratory Syndrome Coronavirus Spike Protein Delivered by
Modified Vaccinia Virus Ankara Efficiently Induces Virus-Neutralizing
Antibodies. J. Virol. November 2013 vol. 87no. 21 11950-11954
 Clinical features and viral diagnosis of two cases of infection with Middle
East Respiratory Syndrome coronavirus: a report of nosocomial
transmission. Lancet (2013).
 Therapeutic Options for Middle East Respiratory Syndrome
Coronavirus (MERS-CoV) – possible lessons from a systematic
review of SARS-CoV therapy. International Journal of Infectious Diseases
17 (2013) e792–e798.
 http://www.cdc.gov.in/merscoronavirus
 www.who.int/coronavirus/mers
 www.cdc.gov/sars
 Evidence for Camel-to-Human Transmission of MERS Coronavirus. N Engl
J Med 2014; 370:2499-2505