middle east respiratory syndrome: humans and healthcare facilities

Humans and healthcare facilities

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; citations 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 hotzone

• 1st report of novel CoV– 20th Sept 2012

•Most cases human-to-human • acquired via healthcare setting • weak transmission between humans

• Seroprevalence 0.15% • 2013, 10,009 adults, KSA • highest seroprevalence among shepherds and slaughterhouse

workers

The hotzone is a hot subtropical zone

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Hajj: “The massest of Mass gatherings” -Helen Branswell

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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) for entry • CEACAM5 helps attach

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Hu et al. Virol J .2015 12:221

Ancestors of MERS-CoV

•Bats • focus of first papers • many recent CoVs discovered • likely ancestors do exist among

• “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

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Camel cold • Much contact – mild disease

• 1st case owned camels • juveniles more often virus positive • camel-to-human infection inferred

• Same species in camels & humans

• High level of virus in camel secretions

• No other animal found to host virus • alpaca have antibody

• Camel herds can be 100% seropositive

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Camel virus- human spillover

• 225 genomes

•Camel & human • interspersed throughout tree

• 96.5-100% nt identity

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MERS-CoV: A distinct virus

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“Contact”

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Rare contact

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Persistence

•MERS-CoV is stable on surfaces • more stable than influenza A(H1N1) virus • Aerosol (10min) & hard surfaces)

•MERS-CoV RNA can shed for >1 month • detected from a HCW for 42 days

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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

• 35% -74% (ICU) mortality (median: 12 days onset>death) • SARS-10%

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Treatment

•No antivirals available • enzyme inhibitors • repurposed existing drugs

• Early use of IFN-2b + ribavirin • 8 hours post-inoculation in macaques

• impossible to achieve!

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Treatment

• Passive immunotherapy - clinical effect? • infrequent donors (2%) • titres low/short-lived in convalescent human sera

•Vaccines • a range in the pipeline for humans and animals

• Supportive care

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Spread of MERS-CoV is about humans

•African exports (testing) •Arabian herds (endemic) •Recombination

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MERS: a disease of

human errors?

King Abdulaziz Medical City Riyadh, KSA 2015

• 81/130 cases confirmed (62%); 51 deaths (39%) • 43/130 HCWs (33%; no deaths)

• 21/130 (16%) were asymptomatic

• 96 hospitalized (63 in ICU) • 34 isolated at home

• Four generations of hospital transmission

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King Abdulaziz Medical City Riyadh, KSA 2015

•Camel contact

• Thought to have been driven by: • emergency room overcrowding • uncontrolled patient movement • high visitor traffic

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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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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/cell entry

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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 -

opportunistic?

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27 ICTMM SEPT 2016 1-Choi. Yonsei Med J. 2015 56(5):1174-76

South Korea outbreak, May-Dec 2015

South Korea outbreak fallout

•Quarantine limited to close contacts • casual contacts needed to be included as well

• 4 beds/room

• Family members responsible for some of care • prolonged, close contact

• Patients easily moved between hospitals • Hospitals didn’t share past disease history on patients

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Preventing large healthcare outbreaks • 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 30 ICTMM SEPT 2016

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Control MERS in the hotzone, avoid global spread

Stop hospital outbreaks, MERS cases

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Thankyou