reviewing mers hospital outbreaks
TRANSCRIPT
Reviewing
MERS Hospital Outbreaks
Macao Association of Health Policy
Dr. Tong Ka Io
2015.10
Internet photos
Internet photo
Time Place Hospitals Cases HCW% CFR
2012.03-04 Jordan, Zarqa 1~2 9 (+2) 67% 22%
2013.04-05 KSA, Al-Hasa 4 23 (+11) 9% 65%
2014.03-04 KSA, Tabuk 1 10 70% ?
2014.03-06 KSA, Jeddah 14 ~200 31% 37%
2014.04 KSA, Riyadh 1 15 ? ?
2014.04-05 UAE, Al-Ain >1 28 70% ?
2014.09-11 KSA, Taif & Riyadh >3 27 ? ?
2015.04-06 KSA, Hofuf 13 44 14% 45%
2015.05-07 ROK, Seoul & others 16 186 21% 20%
Major Hospital-Associated MERS Outbreaks Ever Reported
HCW = Health care workers CFR = Case fatality rate
Time Place Hospitals Cases HCW% CFR
2012.03-04 Jordan, Zarqa 1~2 9 (+2) 67% 22%
2013.04-05 KSA, Al-Hasa 4 23 (+11) 9% 65%
2014.03-04 KSA, Tabuk 1 10 70% ?
2014.03-06 KSA, Jeddah 14 ~200 31% 37%
2014.04 KSA, Riyadh 1 15 ? ?
2014.04-05 UAE, Al-Ain >1 28 70% ?
2014.09-11 KSA, Taif & Riyadh >3 27 ? ?
2015.04-06 KSA, Hofuf 13 44 14% 45%
2015.05-07 ROK, Seoul & others 16 186 21% 20%
Major Hospital-Associated MERS Outbreaks Ever Reported
HCW = Health care workers CFR = Case fatality rate
Outline
2012.03-04, Zarqa, Jordan
2013.04-05, Al-Hasa, KSA
2014.03-06, Jeddah, KSA
2015.05-07, Republic of Korea
Critical lessons
Implications for prevention
2012.03-04, Zarqa, Jordan
ECDC Epidemiological Updates
Internet map
Zarqa, Jordan Internet photo
The outbreak
2012.04.19, Jordan MOH reported an outbreak of
pneumonia in the Zarqa Public Hospital’s CCU-ICU.
7 nurses, 1 doctor and 1 brother of a nurse were among
the 13 suspect cases.
2012.04.20, ICU closed after death of 1 nurse.
The outbreak
2012.04.19, Jordan MOH reported an outbreak of
pneumonia in the Zarqa Public Hospital’s CCU-ICU.
7 nurses, 1 doctor and 1 brother of a nurse were among
the 13 suspect cases.
2012.04.20, ICU closed after death of 1 nurse.
2012.09, MERS-CoV first identified in a patient from Saudi
Arabia.
The outbreak
2012.04.19, Jordan MOH reported an outbreak of
pneumonia in the Zarqa Public Hospital’s CCU-ICU.
7 nurses, 1 doctor and 1 brother of a nurse were among
the 13 suspect cases.
2012.04.20, ICU closed after death of 1 nurse.
2012.09, MERS-CoV first identified in a patient from Saudi
Arabia.
2012.11, testing of stored samples from 2 died patients of
Jordan cluster confirmed MERS-CoV infection.
2014, 7 more cases were retrospectively confirmed by
serologic tests
Hijawi B, Abdallat M, Sayaydeh A, et al. Novel coronavirus infections in Jordan, April 2012: epidemiological findings from a
retrospective investigation. East Mediterr Health J 2013; 19 (Suppl 1):S12-S18.
Hijawi B, Abdallat M, Sayaydeh A, et al. Novel coronavirus infections in Jordan, April 2012: epidemiological findings from a
retrospective investigation. East Mediterr Health J 2013; 19 (Suppl 1):S12-S18.
303
9
3
2
1
12
11
6
4
?
Estimated by author of this presentation
Al-Abdallat MM, Payne DC, Alqasrawi S, et al. Hospital-associated outbreak of Middle East respiratory syndrome
coronavirus: a serologic, epidemiologic, and clinical description. Clin Infect Dis 2014; 59:1225-1233.
Magnitude
Confirmed cases: 9
Probable cases: 2
Hijawi B, Abdallat M, Sayaydeh A, et al. Novel coronavirus infections in Jordan, April 2012: epidemiological findings from a
retrospective investigation. East Mediterr Health J 2013; 19 (Suppl 1):S12-S18.
Al-Abdallat MM, Payne DC, Alqasrawi S, et al. Hospital-associated outbreak of Middle East respiratory syndrome
coronavirus: a serologic, epidemiologic, and clinical description. Clin Infect Dis 2014; 59:1225-1233.
Case pattern
Sex: male 67% (6/9)
Age: 40y (25-60y)
Underlying illness: 44% (4/9), atrial septal defect,
hypertension, pregnancy
Manifestations: among 8 hospitalized cases,
cough 88%, fever 75%, dyspnea 63%, wheezing
25%; pneumonia 88%
Hijawi B, Abdallat M, Sayaydeh A, et al. Novel coronavirus infections in Jordan, April 2012: epidemiological findings from a
retrospective investigation. East Mediterr Health J 2013; 19 (Suppl 1):S12-S18.
Al-Abdallat MM, Payne DC, Alqasrawi S, et al. Hospital-associated outbreak of Middle East respiratory syndrome
coronavirus: a serologic, epidemiologic, and clinical description. Clin Infect Dis 2014; 59:1225-1233.
Impact
ICU admission: 44% (4/9)
Mechanical ventilation: 22% (2/9)
Death: 22% (2/9)
Hijawi B, Abdallat M, Sayaydeh A, et al. Novel coronavirus infections in Jordan, April 2012: epidemiological findings from a
retrospective investigation. East Mediterr Health J 2013; 19 (Suppl 1):S12-S18.
Al-Abdallat MM, Payne DC, Alqasrawi S, et al. Hospital-associated outbreak of Middle East respiratory syndrome
coronavirus: a serologic, epidemiologic, and clinical description. Clin Infect Dis 2014; 59:1225-1233.
Interpersonal characteristics
Links: animal 0%, travel 0%, HCW 67%,
patient 11%, relative 22%
Transmissibility: non-spreader [67%],
spreader [33%], super-spreader [0%]
Generations: [3~4], primary case
unknown [ ] = estimated by author of this presentation
Hijawi B, Abdallat M, Sayaydeh A, et al. Novel coronavirus infections in Jordan, April 2012: epidemiological findings from a
retrospective investigation. East Mediterr Health J 2013; 19 (Suppl 1):S12-S18.
Al-Abdallat MM, Payne DC, Alqasrawi S, et al. Hospital-associated outbreak of Middle East respiratory syndrome
coronavirus: a serologic, epidemiologic, and clinical description. Clin Infect Dis 2014; 59:1225-1233.
Temporal characteristics
First – last onset: 03.21(?)-04.26(?)
Incubation period: ≦10d
Serial interval: [10-17d]
[ ] = estimated by author of this presentation
Hijawi B, Abdallat M, Sayaydeh A, et al. Novel coronavirus infections in Jordan, April 2012: epidemiological findings from a
retrospective investigation. East Mediterr Health J 2013; 19 (Suppl 1):S12-S18.
Al-Abdallat MM, Payne DC, Alqasrawi S, et al. Hospital-associated outbreak of Middle East respiratory syndrome
coronavirus: a serologic, epidemiologic, and clinical description. Clin Infect Dis 2014; 59:1225-1233.
Spatial characteristics
Sites of transmission
Zarqa Hospital (public, 300 beds) CCU-ICU
“there were no physical barriers between CCU and ICU beds,
spaced approximately 3 meters. Isolation or negative-pressure
rooms were not present and infection control compliance issues
were reported during the outbreak.”
Distance of transmission
Same open unit
Hijawi B, Abdallat M, Sayaydeh A, et al. Novel coronavirus infections in Jordan, April 2012: epidemiological findings from a
retrospective investigation. East Mediterr Health J 2013; 19 (Suppl 1):S12-S18.
Al-Abdallat MM, Payne DC, Alqasrawi S, et al. Hospital-associated outbreak of Middle East respiratory syndrome
coronavirus: a serologic, epidemiologic, and clinical description. Clin Infect Dis 2014; 59:1225-1233.
2013.04-05, Al-Hasa, KSA
ECDC Epidemiological Updates
Internet map
Al-Hasa, KSA Internet photo
The outbreak
2013.04.01-05.23, a total of 23 cases of MERS-
CoV infection were reported in the governorate
of Al-Hasa, eastern province of Saudi Arabia
Assiri A, McGeer A, Perl TM, et al. Hospital outbreak of Middle East respiratory syndrome coronavirus. N Engl J Med 2013;
369:407-416.
Assiri A, McGeer A, Perl TM, et al. Hospital outbreak of Middle East respiratory syndrome coronavirus. N Engl J Med 2013; 369:407-416.
Assiri A, McGeer A, Perl TM, et al. Hospital outbreak of Middle East respiratory syndrome coronavirus. N Engl J Med 2013; 369:407-416.
Cotten, M et al. Transmission and evolution of the Middle East respiratory syndrome coronavirus in Saudi Arabia: a
descriptive genomic study. The Lancet , 2013 Volume 382, Issue 9909 , 1993 – 2002.
Magnitude
Confirmed cases: 23
Probable cases: 11
Assiri A, McGeer A, Perl TM, et al. Hospital outbreak of Middle East respiratory syndrome coronavirus. N Engl J Med 2013;
369:407-416.
Case pattern
Sex: male 74% (17/23)
Age: 56y (24-94y)
Underlying illness: Diabetes Mellitus 74%, end-
stage renal disease 52%, lung disease 43%,
cardiac disease 39%, obesity 24%
Manifestations: cough 87%, fever 87%, dyspnea
48%, gastrointestinal symptoms 35%;
pneumonia 70%
Assiri A, McGeer A, Perl TM, et al. Hospital outbreak of Middle East respiratory syndrome coronavirus. N Engl J Med 2013;
369:407-416.
Impact
ICU admission: 78% (18/23)
Mechanical ventilation: 78% (18/23)
Death: 65% (15/23)
Assiri A, McGeer A, Perl TM, et al. Hospital outbreak of Middle East respiratory syndrome coronavirus. N Engl J Med 2013;
369:407-416.
Interpersonal characteristics
Links: animal ?%, travel ?%, HCW 9%,
patient 78%, relative 13%
Transmissibility: non-spreader [61%],
spreader [39%], super-spreader [0%]
Generations: [4~5], more than one
primary cases unknown
[ ] = estimated by author of this presentation
Assiri A, McGeer A, Perl TM, et al. Hospital outbreak of Middle East respiratory syndrome coronavirus. N Engl J Med 2013;
369:407-416.
Temporal characteristics
First – last onset: 04.08-05.12
Incubation period: 5.2d (1.9-14.7d)
Serial interval: 7.6d (2.5-23.1d)
Assiri A, McGeer A, Perl TM, et al. Hospital outbreak of Middle East respiratory syndrome coronavirus. N Engl J Med 2013;
369:407-416.
Spatial characteristics
Sites of transmission
Hospital A (general, 150 beds) dialysis unit (open unit
with 16 beds spaced 1.3-1.5m apart), ICU (two open 6-
bed bays), Ward
Hospital B (general) ward; Hospital C (general) dialysis;
Hospital D (regional referral) ICU, ward
Distance of transmission
Same ward, up to 3 rooms separated
Assiri A, McGeer A, Perl TM, et al. Hospital outbreak of Middle East respiratory syndrome coronavirus. N Engl J Med 2013;
369:407-416.
2014.03-06, Jeddah, KSA
WHO Disease Outbreak News
Situation in the Middle East
2014 spring, an exponential increase of MERS
cases occurred in Kingdom of Saudi Arabia –
concentrated in health care facilities of Riyadh
and Jeddah – and United Arab Emirates.
Jeddah, KSA: ~200 cases, 14 hospitals, one
phylogenetic clade
Riyadh, KSA: ~200 cases, multiple hospital outbreaks,
at least 6 different clades
Tabuk, KSA: 10 cases, one hospital
Al Ain, UAE: 28 cases, one hospital
Drosten C, Muth D, Corman VM, et al. An observational, laboratory-based study of outbreaks of Middle East respiratory
syndrome corona virus in Jeddah and Riyadh, Kingdom of Saudi Arabia, 2014. Clin Infect Dis 2015; 60:369-377.
WHO Disease Outbreak News
Internet map
Riyadh, KSA Internet photo
Saad M, Omrani AS, Baig K, et al. Clinical aspects and outcomes of 70 patients with Middle East respiratory syndrome
coronavirus infection: a single-center experience in Saudi Arabia. Int J Infect Dis 2014; 29:301-306.
(Riyadh)
Tabuk, KSA Internet photo
Al Ain, UAE Internet photo
Jeddah, KSA Internet photo
Magnitude
Confirmed cases (2014.01-06)
Jeddah, KSA: ~200, one phylogenetic clade
Drosten C, Muth D, Corman VM, et al. An observational, laboratory-based study of outbreaks of Middle East respiratory
syndrome corona virus in Jeddah and Riyadh, Kingdom of Saudi Arabia, 2014. Clin Infect Dis 2015; 60:369-377.
WHO Disease Outbreak News
Case pattern
Sex: male 68%
Age: 45y (interquartile 30-59y)
Underlying illness: ?
Manifestations: asymptomatic or mild 25%
Oboho IK, Tomczyk SM, Al-Asmari AM, et al. 2014 MERS-CoV outbreak in Jeddah: a link to healthcare facilities. N Engl J
Med 2015; 372:846-854.
Impact
ICU admission: 37%
Mechanical ventilation: ?
Death: 37%
Oboho IK, Tomczyk SM, Al-Asmari AM, et al. 2014 MERS-CoV outbreak in Jeddah: a link to healthcare facilities. N Engl J
Med 2015; 372:846-854.
Interpersonal characteristics
Links: animal ?%, travel ?%, HCW 31%,
exposure to a health care facility 88%
Transmissibility: non-spreader ?%,
spreader ?%, super-spreader >0%
Generations: ?
Oboho IK, Tomczyk SM, Al-Asmari AM, et al. 2014 MERS-CoV outbreak in Jeddah: a link to healthcare facilities. N Engl J
Med 2015; 372:846-854.
Temporal characteristics
First – last onset: Mar-Jun
Incubation period: ?
Serial interval: ?
Oboho IK, Tomczyk SM, Al-Asmari AM, et al. 2014 MERS-CoV outbreak in Jeddah: a link to healthcare facilities. N Engl J
Med 2015; 372:846-854.
Spatial characteristics
Sites of transmission
King Fahd Hospital: largest communal hospital; “bad
management, crowding and lax hygiene”
Other 13 Hospitals
Sites of super-spreading
Hospitals ?
Distance of transmission
?
Drosten C, Muth D, Corman VM, et al. An observational, laboratory-based study of outbreaks of Middle East respiratory
syndrome corona virus in Jeddah and Riyadh, Kingdom of Saudi Arabia, 2014. Clin Infect Dis 2015; 60:369-377.
Al-Tawfiq JA, Perl TM. Middle East respiratory syndrome coronavirus in healthcare settings. Curr Opin Infect Dis. 2015
Aug;28(4):392-6.
2015.05-07, Republic of Korea
WHO Disease Outbreak News
Situation in the Middle East
2015.01.01-07.21, KSA reported 222 MERS cases
Riyadh, KSA: 88 cases
Hofuf, KSA: 46 cases, mainly from an outbreak
involving 13 hospitals
WHO Disease Outbreak News
ECDC Epidemiological Updates
ECDC Epidemiological Updates
Internet photo Hofuf, KSA
ECDC Epidemiological Updates
ECDC Epidemiological Updates
Seoul, ROK Internet photo
The outbreak
2015.05.20, ROK reported the first imported case
of MERS of the country. The case further led to
the largest transmission cluster of the disease
worldwide.
Internet image
ECDC Epidemiological Updates
Closure of ER of Samsung Medical Center Internet photo
WHO Disease Outbreak News
Magnitude
Confirmed cases: 185+1 ex to China
Probable cases: ?
WHO Disease Outbreak News
Case pattern
Sex: male 60%
Age: 55y (16-87y)
Underlying illness: asthma, COPD, TB,
cardiovascular disease, diabetes mellitus, renal
disease, pregnancy, ……
Manifestations: ?
Cowling BJ, Park M, Fang VJ, Wu P, Leung GM, Wu JT. Preliminary epidemiological assessment of MERS-CoV outbreak in
South Korea, May to June 2015. Euro Surveill. 2015;20(25):pii=21163.
WHO Disease Outbreak News
Impact
ICU admission: ?%
Mechanical ventilation: ?%
Death: 20%
WHO Disease Outbreak News
Interpersonal characteristics
Links: animal 0%, travel 0.5%, HCW 21%,
patient 44%, relative 35%
Transmissibility: of the first 166 cases non-
spreader [87%], spreader [11%], super-
spreader 2%
Generations: [4~5]
[ ] = estimated by author of this presentation
Cowling BJ, Park M, Fang VJ, Wu P, Leung GM, Wu JT. Preliminary epidemiological assessment of MERS-CoV outbreak in
South Korea, May to June 2015. Euro Surveill. 2015;20(25):pii=21163.
WHO and ROK-MOH
Inpatients 44%
Relatives 35%
Nurses 8%
Doctors 4%
Caregivers 4%
Radiographers 1%
Ambulance workers 1%
Security guards 1% Transfer staff 1% Computing personnel 1%
HCWs 21%
Interpersonal distribution of 186 MERS cases of ROK
WHO and ROK-MOH
Taiwan DOH-CDC
Cowling BJ, Park M, Fang VJ,
Wu P, Leung GM, Wu JT.
Preliminary epidemiological
assessment of MERS-CoV
outbreak in South Korea, May
to June 2015. Euro Surveill.
2015;20(25):pii=21163.
Super-spreader
Case 1
M, 68y
Underlying illness: ???
Travel to Bahrain, UAE, KSA, Qatar
Onset: 05.11
Diagnosis: 05.20
Outcome: recovered
Secondary cases: ≧30
8 of them caused further transmission
Cowling BJ, Park M, Fang VJ, Wu P, Leung GM, Wu JT.
Preliminary epidemiological assessment of MERS-CoV
outbreak in South Korea, May to June 2015. Euro Surveill.
2015;20(25):pii=21163.
Super-spreader
Case 14
M, 35y
Underlying illness: TB
Same ward with case 1
Onset: 05.20
Diagnosis: 05.30
Outcome: recovered
Secondary cases: ≧81
8 of them caused further transmission
Cowling BJ, Park M, Fang VJ, Wu P, Leung GM, Wu JT.
Preliminary epidemiological assessment of MERS-CoV
outbreak in South Korea, May to June 2015. Euro Surveill.
2015;20(25):pii=21163.
Super-spreader
Case 16
M, 40y
Underlying illness: ???
Same ward with case 1
Onset: 05.20
Diagnosis: 05.31
Outcome: recovered
Secondary cases: ≧23
1 of them caused further transmission
Cowling BJ, Park M, Fang VJ, Wu P, Leung GM, Wu JT.
Preliminary epidemiological assessment of MERS-CoV
outbreak in South Korea, May to June 2015. Euro Surveill.
2015;20(25):pii=21163.
Temporal characteristics
First – last onset: 05.11-07.02
Incubation period: 6.3d
Serial interval: 12.6d
Cowling BJ, Park M, Fang VJ, Wu P, Leung GM, Wu JT. Preliminary epidemiological assessment of MERS-CoV outbreak in
South Korea, May to June 2015. Euro Surveill. 2015;20(25):pii=21163.
Spatial characteristics
Sites of transmission
16 Hospitals – ER, inpatient and outpatient
departments
Sites of super-spreading
4 Hospitals – ER, inpatient and outpatient
Distance of transmission
Same room, same ward, different floors of the same
hospital
WHO and ROK-MOH
City Hospital Units No of Cases
Seoul Samsung Medical Center 90
Gyeonggi Pyeongtaek St. Mary’s Hospital 37
Daejeon Daechung Hospital Inpatient 14
Daejeon Konyang University Hospital Inpatient, Staff cafeteria 11
Gyeonggi Hallym University Medical Center 6
Seoul Kyung Hee University Healthcare System ER 5
Seoul Konkuk University Hospital ER, Inpatient 4
Gyeonggi Pyeongtaek Goodmorning Hospital 4
Seoul Asan Medical Center ER 1
Seoul Yeouido St. Mary’s Hospital ER 1
Seoul 365 Yeol Lin Hospital Outpatient 1
Seoul Song Tae-eui Internal Medicine Clinic Outpatient 1
Busan Good Gang-An Hospital Inpatient 1
Gyeonggi Yangji Seoul Samsung Clinic Outpatient 1
Chungnam Seoul Clinic Outpatient 1
Chungnam Asan Chungmu Hospital Inpatient 1
WHO and ROK-MOH
Samsung Medical Center Internet photo
Pyeongtaek St. Mary’s Hospital Internet photo
Daechung Hospital Internet photo
Konyang University Hospital Internet photo
Factors leading to the outbreak
MERS-CoV was unexpected
and unfamiliar to most
physicians in ROK;
Sub-optimal prevention and
control measures in some
hospitals, related in part to
overcrowding;
The custom of “doctor-
shopping”, as well as visits
to hospitalized patients by
many friends and family
members.
(WHO)
Internet image
Typical conditions within hospitals in ROK Internet photo
Typical conditions within hospitals in ROK Internet photo
Factors related to super-spreading events
Case 1
Least knowledge of doctors
about MERS, incomplete
information from patient about
his travel
Patient had pneumonia, kept
coughing and wheezing
Patient was admitted to a
restructured room which had
no exhaust system
Hospitals were overcrowded
with patients, family members,
caregivers and visitors
Case 14
Doctors diagnosed patient as
pneumonia and failed to detect
his connection with case 1
Patient had TB, persistently
coughing and wheezing, did
not put on a mask
ER was overcrowded (200
seats in 800 square feet)
Patient waited in ER for 48
hours and sometimes loitered
outside
Critical lessons
Critical lessons
1. Animal sources
2. Primary cases
3. Interhuman transmission
4. Health care settings
5. Super-spreading events
Outbreak 1 Outbreak 2 Outbreak 3 Outbreak 4
Time Mar-Apr, 2012 Apr-May, 2013 Mar-Jun, 2014 May-Jul, 2015
Space Zarqa, Jordan Al-Hasa, KSA Jeddah, KSA
ROK,
imported from
Middle East
Animal contact none unknown unknown none
Animal sources
1. Animal sources undoubtedly exist, but the species, route
of transmission and transmissibility largely remain
unknown.
2. All outbreaks occurred in / linked to the Middle East
(natural epidemic focus), but the precise geographical
limits remain uncertain.
3. Animal-to-human transmissions occurred frequently and
dispersed in vast areas of the Middle East.
4. Apparent seasonality (March to June) was noted. This may
be coincident with calving of camels in the Middle East.
5. No effect of zoonotic risk management evidenced since
2012.
WHO Disease Outbreak News
http://virologydownunder.blogspo
t.com/2015_01_01_archive.html
Outbreak 1 Outbreak 2 Outbreak 3 Outbreak 4
Time Mar-Apr, 2012 Apr-May, 2013 Mar-Jun, 2014 May-Jul, 2015
Space Zarqa, Jordan Al-Hasa, KSA Jeddah, KSA
ROK,
imported from
Middle East
Animal contact none unknown unknown none
Primary case unknown unknown unknown 68y male
Onset to diagnosis unknown unknown unknown 9 days
Primary cases
1. All outbreaks were caused by delay in recognition of
one or more primary cases.
2. Primary cases linked to animal sources or the natural
epidemic focus.
3. Primary cases are more likely to be male with older
age, underlying medical conditions, severe clinical
manifestations and fatal outcome.
4. Primary cases may remain unknown after all.
5. Unknown if there are more identifiable
characteristics of primary cases.
The WHO MERS-CoV Research Group. State of knowledge and data gaps of Middle East respiratory syndrome coronavirus (MERSCoV) in
humans. PLoS Curr 2013 Nov 12;5.
Outbreak 1 Outbreak 2 Outbreak 3 Outbreak 4
Time Mar-Apr, 2012 Apr-May, 2013 Mar-Jun, 2014 May-Jul, 2015
Space Zarqa, Jordan Al-Hasa, KSA Jeddah, KSA
ROK,
imported from
Middle East
Animal contact none unknown unknown none
Primary case unknown unknown unknown 68y male
Onset to diagnosis unknown unknown unknown 9 days
Size of outbreak 9+2 23+11 ~200 186
Generations 3~4 4~5 ? 4~5
Non-spreaders 67% 61% ?% 87%
Super-spreaders 0, 0% 0, 0% ?, ?% 3, 2%
Interhuman transmission
1. All MERS human outbreaks were not self-sustained,
suggesting a Basic Reproduction Number (R0 ) < 1.
2. Human-to-human transmissions occurred only in
households and health care settings.
3. Great difference in transmissibility – majority of
patients were “non-spreaders”, while a few turned
out to be “super-spreaders”.
4. Normalized infection control practices are well
sufficient to promptly stop further transmission.
Cauchemez S, Van Kerkhove MD, Riley S, Donnelly CA, Fraser C, Ferguson NM. Transmission scenarios for Middle East Respiratory
Syndrome Coronavirus (MERSCoV) and how to tell them apart . Euro Surveill. 2013;18(24):pii=20503.
Outbreak 1 Outbreak 2 Outbreak 3 Outbreak 4
Time Mar-Apr, 2012 Apr-May, 2013 Mar-Jun, 2014 May-Jul, 2015
Space Zarqa, Jordan Al-Hasa, KSA Jeddah, KSA
ROK,
imported from
Middle East
Animal contact none unknown unknown none
Primary case unknown unknown unknown 68y male
Onset to diagnosis unknown unknown unknown 9 days
Size of outbreak 9+2 23+11 ~200 186
Generations 3~4 4~5 ? 4~5
Non-spreaders 67% 61% ?% 87%
Super-spreaders 0, 0% 0, 0% ?, ?% 3, 2%
Hospitals 1~2 4 14 16
Units CCU-ICU Dialysis unit,
ICU, wards ?
ER, inpatient,
outpatient
HCW 67% 9% 31% 21%
Health care settings
1. All major MERS outbreaks were amplified in health
care settings.
2. Outbreaks occurred in wards and outpatient
departments of large hospitals, among which ER,
ICU, and dialysis unit seemed more protruding.
3. Common characteristics of the outbreak settings
included overcrowding, substandard ventilation, lax
infection control practices, and accumulation of
vulnerable individuals.
4. Normalized infection control practices are well
sufficient to promptly stop further transmission.
http://virologydownunder.blogspot.com/2014/05/pressure-testing.html
Outbreak 1 Outbreak 2 Outbreak 3 Outbreak 4
Time Mar-Apr, 2012 Apr-May, 2013 Mar-Jun, 2014 May-Jul, 2015
Space Zarqa, Jordan Al-Hasa, KSA Jeddah, KSA
ROK,
imported from
Middle East
Animal contact none unknown unknown none
Primary case unknown unknown unknown 68y male
Onset to diagnosis unknown unknown unknown 9 days
Size of outbreak 9+2 23+11 ~200 186
Generations 3~4 4~5 ? 4~5
Non-spreaders 67% 61% ?% 87%
Super-spreaders 0, 0% 0, 0% ?, ?% 3, 2%
Hospitals 1~2 4 14 16
Units CCU-ICU Dialysis unit,
ICU, wards ?
ER, inpatient,
outpatient
HCW 67% 9% 31% 21%
http://endtimeheadlines.org/2015/06/mers-starts-to-spread-more-widely-in-korea/
Super-spreading events
1. Super-spreading events multiplied the size, temporal
and spatial extension, threat and impact of MERS
outbreaks.
2. The prerequisite of super-spreading event is a high
risk patient who sheds virus extensively (super-
spreader).
3. High risk environment (overcrowding and/or sub-
standard ventilation) and high risk activities (aerosol
generating procedures and/or lax infection control
practices) are conditioning factors for super-
spreading events.
Factors for super-spreading events
High risk activities
High risk environment
High risk patients
Implications for prevention
Core strategy
Control of sources of infection
1. Control of animal sources
2. Risk management of health care settings
3. Risk management of high risk activities
4. Early identification of primary / index cases
5. Prevention of super-spreading events
Control of animal sources
1. Further scientific studies to verify the species,
route of transmission, transmissibility, and
geographic limits of natural epidemic focus
2. Zoonotic biosecurity practices
3. Animal vaccination
4. Environment modifications
Risk management of health care
settings
1. Risk assessment of health care units and
identification of high risk settings (ER, ICU,
dialysis unit, etc.)
2. Secure optimal ventilation for high risk settings
3. Install sufficient airborne infection isolation (AII)
rooms according to the need of health care
facilities
4. Eliminate overcrowding of high risk settings
5. Stringent control regime for patients with
respiratory infection to enter high risk settings
Internet photo
Emergency Room, CSJ Central Hospital, Macao
Internet photo Hemodialysis Centre, Kiang Wu Hospital, Macao
Risk management of high risk
activities
1. Aerosol generating procedures: stringent
selection of subjects, airborne precautions,
airborne infection isolation facilities
2. Infection control practices: clear policy, training
and renewing, guidance and reminders, mutual
and hierarchical supervision, audits
3. Patient behaviors: education and supervision
4. Visit and company: defined based on risk
Early identification of primary / index
cases
1. Critical knowledge for front-line health care
professionals
Existence of natural epidemic focus
The index case may not have contact with animal or human
patient, or travel history
Even in lack of known epidemiological links, unusual /
unexplained clinical picture, clustering and/or involvement
of health care workers are hints for testing
Sensitivity of test is low for upper respiratory samples, thus
negative results do not exclude the diagnosis
2. Relevant information and education, on the disease
and the situation, for the general public
Prevention of super-spreading events
In addition to the 4 basic aforementioned strategies,
some specific efforts may target the “potential
super-spreaders”
Further scientific studies to verify the identifiable
characteristics of super-spreaders: age, underlying
conditions, immunodeficiency, symptoms, etc.
Identify patient groups and minimize their nosocomial
exposure to acute respiratory infection patients by
stringent control of entry and separation in health care
settings
Routine and close monitoring of these patients for signs of
nosocomial respiratory infection, and prompt control
Conclusion
Control of sources of infection
1. Control of animal sources
2. Risk management of health care settings
3. Risk management of high risk activities
4. Early identification of primary / index cases
5. Prevention of super-spreading events
中東呼吸綜合徵(MERS) 醫院暴發綜述
澳門衛生政策學會
湯家耀醫生
2015.10