The Origin and Evolution of SARS

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The Origin and Evolution of SARS
Yi Guan

• Dept. of Microbiology, Faculty of Medicine,
• The University of Hong Kong
• The First Affiliated Hospital,
• Guangzhou Med. College
• Shenzhen C.D.C. Guangdong Province

NIAID, Grant A195357 SARS FUNDS, Univ. of Hong
Kong
HKU, HK SAR, P.R. China Sept 30, 2003
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Hypothetical Birthplace of SARS
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Guangdong Province
Hong Kong
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Guangdong Province
Hong Kong
The First SARS case was recognized on Nov. 16,
2002
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Guangdong Province
Hong Kong
On Dec 17, 2002, SARS case was observed in the
second city. 11 cases were recorded, 8 of them
are medical staff
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Guangdong Province
Hong Kong
The first SARS case in Zhongshan was reported on
Dec. 26, 2002. Total 28 cases were clinically
recognized. 13 of them are medical staff who had
direct contact history with SARS patients.
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Investigation Conclusion 1. Outbreak of atypical
pneumonia (unidentified infectious agent, most
likely viral infection) 2. Infectious Disease,
with family and hospital clustered (incubation
about 4 days, 1-11days) 3. Documented Diagnosis
definition, Treatment and Prevention
principles 4. Suggest to set up case report
system Jan. 21, 2003
Zhong-Shan outbreak
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Guangdong Province
Hong Kong
The first community SARS case in Guangzhou was
reported on Jan.31, 2003.
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The First Super-Infectious case--- gt100 cases

• Visited Zhongshan and got onset there
• Jan 31, 03 admitted to The 2nd Affiliate
  Hospital at the afternoon,
• lt24 hours, gt 30 medical staffs infected
• Feb 1, 03 - Feb 8, 03 transferred into The 3rd
  Affiliated Hospital,
• within those 8 days, 26 medical staffs got
  infected.
• Feb 8, 03 transferred into Guangzhou Infectious
  Disease Hospital.
• Family members and relatives of the patient also
  got infected (19).

HKU, HK SAR, P.R. China Sept 30, 2003
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Nov 16, 02 - Feb 9, 03 305 SARS cases reported,
5 people were killed by the disease in Guangdong
No. of case
Outbreak time
City
Jan. 31, 2003 Dec. 26, 2002 Nov. 16,
2002 Nil Dec. 17, 2002 Nil
226 28 19 15 11 6 305
Guangzhou Zhongshan Foshan Jiangmen Heyuen Sh
enzhen Total
HKU, HK SAR, P.R. China Sept 30, 2003
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No. of reported cases of Guangdong
Peak time of outbreak is on Feb. 9, 50
cases/day Feb. 12, 03 30 new cases Feb. 19,
03 5 new cases
HKU, HK SAR, P.R. China Sept 30, 2003
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HKU started to initiate the investigation
in Guangdong as early as on Feb 11, 03. One Big
Question Whether H5N1 bird flu get into humans,
like 1997 incident? On Feb 12, 03, we got 18
patients samples On Feb 18, 03, we got 22
patients samples
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Preliminary results

• The major efforts were focused on to
• isolate H5N1 influenza virus
• We did isolate H5N1 influenza virus from Hong
  Kong family, and one from Guangzhou atypical
  pneumonia case
• We failed to isolate coronavirus earlier, but do
  benefit to the coming investigation in HK, i.e.
  our response system started to run before the
  case got into HK (setting up a lab in Guangzhou)

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Isolation of coronavirus by FrHK4 cell cultures
GZ43
GZ50
GZ60
Doctor
Clerk
Nurse
16
A
C
B
D
17
HKU39849
TOR2
HKU-66078
86
Urbani
SIN2677
CUHK-Su10
66
HKU-65806
HKU-36871
99
BJ01
CUHK-W1
GZ50
GZ01
GZ60
60
94
GZ43
0.0005
18
B
A
C
D
C
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Serological test for pair sera from patients with
SARS
Total
Sample number
Titer increase
2nd sera
1st sera
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21, 22, 23, 24, 26, 27, 28, 30, 31, 34, V
gt 4 folds

-
4
4, 18, 32, III
gt 4 folds


4
1, I, II, IV
lt 4 folds


19
Total
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Questions?????
Where the SARS-Cov came from, Or how it was
derived from?
What we know, what we dont know and,
what studies are needed.
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Observation

• Several observations support the hypothesis of a
  wild animal reservoir
• cases began independently in at least 5 different
  municipalities
• early cases more likely to report living near
  agricultural market
• 39 (9/23) of early cases were food handlers with
  likely animals contact

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Himalayan palm civet (Paguma larvata)
Hog-badger (Arctonyx collaris)
Beaver (Castor fiber)
Chinese Ferret-Badger (Melogale moschata)
Raccoon-dog (Nyctereutes procyonoides)
Chinese muntjac (Muntiacus reevesi)
Chinese Hare (Lepus sinensis)
Domestic cat (Felis catus)
Eight species of wild and domestic animals were
sampled in a live-animal market of Shenzhen on
May 7, 03
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Methods
Human
Animals
Sampling (nasal, rectal swabs, blood)

Blood
RT-PCR diagnostic test Virus isolation and
identification
Neutralizing antibody detection
Sequencing viral genome
Western Blot Assay
Sequence comparison Phylogenetic analysis
HKU, HK SAR, P.R. China Sept 30, 2003
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Himalayan palm civet
Raccoon-dog
Six civets sampled, 4 out of them were PCR
positive and 4 viruses were isolated
One animal was PCR positive and 1 virus was
isolated
HKU, HK SAR, P.R. China Sept 30, 2003
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EM Photo of SCoV-like viruses
HKU, HK SAR, P.R. China Sept 30, 2003
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Genome difference between animal and human
SARS-Cov
Deletion of human virus
HKU, HK SAR, P.R. China Sept 30, 2003
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HKU, HK SAR, P.R. China Sept 30, 2003
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Phylogenetic analysis of S gene of human and
animal SARS viruses
SZ1
Animal
SZ13
MHV
SZ16
SZ3
GZ50
CUHK-W1
HKU36871
HKU39848
HKU66078
Human
HKU65806
Urbani
Tor2
GZ01
GZ60
GZ43
100 nucleotide
HKU, HK SAR, P.R. China Sept 30, 2003
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Detection of antibodies against recombinant
nucleocapsid protein of SCoV in animal sera by
Western Blot Assay
HKU, HK SAR, P.R. China Sept 30, 2003
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Antibody detection from people working at the
market
HKU, HK SAR, P.R. China Sept 30, 2003
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Summary
1. SCoV-like viruses are prevalent in
different types of wild animals in the retail
market. 2. These animals together mankind
forming a new ecosystem. 3. SARS is zoonosis.
HKU, HK SAR, P.R. China Sept 30, 2003
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Need for further animal research

• To control SARS we must understand the natural
  history of the virus
• Field and laboratory studies are needed to
  determine the possible range of animal
  reservoirs, if there are amplification hosts and
  how the virus spills over to humans
• Control strategies must focus on human and animal
  populations to be effective

HKU, HK SAR, P.R. China Sept 30, 2003
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Acknowledgements
1. NIAID, Grant A195357 2. Ministry of Health,
China Government 3. Guangdong Government 4.
Guangdong CDC 5. The First Affiliated Hospital,
Guangzhou Medical College 6. Department of
Health, Shenzhen Government 7. Shenzhen CDC 8.
Department of Microbiology, HKU
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