1. 4 years on, what do we know?
Ian M. Mackay, PhD
Public and Environmental Health – Virology
Forensic & Scientific Services | Health Support Queensland
Department of Health
& Associate Professor, The University of Queensland
Ian.Mackay@health.qld.gov.au
Opinions expressed here are my own; references available upon request
Middle East respiratory
syndrome (MERS)

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Middle East respiratory syndrome coronavirus
(MERS-CoV)

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Kingdom of Saudi Arabia (KSA) is the hot zone
•1st
report of novel CoV– 20th
Sept 2012
•Most cases are from human-to-human transmission
• respiratory disease caused by a respiratory virus
• weak & sporadic transmission between humans
• acquired mostly from humans in healthcare settings
•Seroprevalence: 0.15%
• 2013, 15 of 10,009 adults, KSA
• highest seroprevalence among shepherds and slaughterhouse
workers
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4. The hot zone is hot & subtropical
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5. Hajj: “The massest of Mass gatherings”
-Helen Branswell
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6. The MERS coronavirus (MERS-CoV)
•Enveloped, 30,000nt (+) RNA virus
•4 structural ( ), 16 NS proteins; recombination
•Little sign of adapting to humans so far
•Single serotype
•Uses dipeptidyl peptidase 4 (DPP4; LRT>URT) for entry
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7. Hu et al. Virol J .2015 12:221
Ancestors of MERS-CoV
•Bats
• focus of first papers
• many recent CoVs discovered
• likely ancestor found
•Conspecific virus
• Neoromicia (Pipistrellus)
capensis
• South Africa
• “NeoCoV”
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MERS-CoV in bats
•1 rtPCR amplicon
• 1 sample
• 1 bat
• 1 species (Taphozous perforatus)
• 1,003 samples Oct 2012 / April 2013
• not convincing

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Why camels?
•Important animals – much contact
• Arabian peninsula
•Mild camel disease – common cold
• 1st
MERS case did own camels
• juvenile camels more often virus positive
• high level of virus in camel secretions
• Camel herds can be 100% seropositive
• Camel-to-human infection reported
•No other animal found to host virus
• alpaca with antibody
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Camel virus > human spillover
•Same virus in camels & humans
•225 genomes
• 3 genetic groupings
•Camel & human variants
• interspersed
• 96.5-100% nt identity

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MERS-CoV: A distinct virus

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“Contact?”

14. Example of rare contact
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15. More likely forms of contact
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16. Persistence
•MERS-CoV is stable on surfaces
• more stable than influenza A(H1N1) virus in aerosol (10min) &
on hard surfaces
•MERS-CoV RNA can shed for >1 month
• detected from a HCW for 42 days
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17. The disease, MERS
•Incubation period 2-16 days (median 4/5 days)
•Comorbidity (e.g. 87%) & cough (e.g. 100%) common
• asymptomatic
• acute URT illness incl. fever, headache, myalgia
• progressive pneumonitis, respiratory failure, septic shock,
multi-organ failure
•20% -74% (ICU) mortality (median: 12 days onset>death)
• SARS-10%
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18. Treatment
•No antivirals available
•Passive immunotherapy (antibody) - clinical effect?
• infrequent donors (2%)
• antibody titres low/short-lived in convalescent human sera
•Vaccines
• a range in the pipeline for humans and animals
•Supportive care
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MERS in humans is about humans with MERS
?

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MERS: cases driven
by habits and errors?
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21. South Korea outbreak, May-Dec 2015
•186 cases, 38 fatalities (20%), 4 waves of infection
•Biggest outbreak outside KSA
• >16,000 people quarantined
•No sustained h2h transmission
• no community outbreaks
•1/186 case travelled to China
•7.4 day incubation period (6.2 > 7.7 > 7.9 by generation)
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22. South Korea outbreak, May-Dec 2015
•1 patient responsible for 81 cases
• visited 4 hospitals
• coughed in the open
• walked through ER to public toilet
•Receptor binding domain mutant in 13/14 variants
• reduced receptor affinity
• not every virus mutates according to a Hollywood script
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23. South Korea outbreak, May-Dec 2015
•Lower proportion fatal
•20% compared to 41% in KSA
• due to the mutation?
• lower % underlying comorbidities in general community
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24. South Korea outbreak washup
•Quarantine was initially limited
• casual contacts needed to be included as well as close contacts
•4 beds/room – cases initially not isolated
• overcrowding
•Family members were responsible for some hospital care
• prolonged, close contact
•Patients easily moved between hospitals
• hospitals didn’t share past disease history on patients
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25. South Korea outbreak, May-Dec 2015
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1-Choi. Yonsei Med J. 2015 56(5):1174-76

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27. Issues to address large healthcare
outbreaks of MERS
•Identify symptomatic patients early; test & re-test
•Strong contact tracing, monitoring and quarantine
•Strong infection, prevention and control measures
• PPE – selection, use, donning/doffing, disposal
• distance between beds
• be aware of aerosol generating procedures
• cleaning & disinfection
• treat / manage patients in isolation
•Communicate with public to build/maintain trust
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Cases are rare but travel is not
•Control MERS in the hotzone, avoid global spread
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29. Stop hospital outbreaks, reduce MERS cases
•Humans create circumstances for super-spreading events
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Thankyou