SARS Timeline

Nov 16 ‘02 Feb 11 ‘03 Feb 28 March 11 March 12 March 19 March 27 April 5 April 9 April 14 April 17 April 28

First cases Hong Kong WHO Sequence

retrospectively and Vietnam issues of suspected

Recognized, report out- travel agent, a

Guangdong, breaks in advisories coronavirus,

China hospital established

workers China

Acute coverup India

respiratory WHO admitted;

reported in issues SARS SARSGuangdong global made top

by China alert priority Vietnam

MOH contain-

Reported First ing virus

First in U.S. and SARS in (WHO)

SARS Europe Africa

case –

Vietnam

Case Distribution of SARS Worldwide

ERSI, May 2003

ERSI, May 2003

Hotel MHong Kong

Guangdong Province,

China A

A

H,JA

H,J

Hong Kong SAR

95 HCW

>100 close contacts

United States

1 HCW

I, L,M

I,L,M

K Ireland

0 HCWK

Singapore

34 HCW37 close contacts

C,D,E

C,D,E

B

B

Vietnam

37 HCW

21 close contacts

F,G

Canada

18 HCWF,G

11 close contacts

Effect of Travel and Missed Cases on the SARS EpidemicSpread from Hotel M, Hong Kong

SARS Hotspots (as of May 28, 2003)

# Probable Cases # Deaths

China 5322 321Hong Kong 1728 269Taiwan 596 76Singapore 206 31Canada 148 26United States 65 0Vietnam 63 5Philippines 12 2Other Countries 62 4

Total 8202 734

0

50

100

150

200

250

4,22

4,24

4,26

4,28

4,30

5,02

5,04

5,06

5,08

5,10

Number of SARS Cases Reported over Time (China)

Symptoms of SARS

• Cough• High fever• Severe pneumonia• Difficult to distinguish from other

respiratory diseases in early stages

1.6

7.2

29.2

18.7

21.5

18.016.1 16.5

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

0- 10- 20- 30- 40- 50- 60- 70-

（ 1/1,000,000）

Incidence Difference across Different Age Groups (China)

CDC, 2003

0.0 0.0 0.93.0

5.0

10.0

17.6

28.026.3

0.0

5.0

10.0

15.0

20.0

25.0

30.0

0- 10- 20- 30- 40- 50- 60- 70- 80-

Fatality Rates of Different Age Groups

CDC, 2003

                                                         

                                                                                                                                 

Etiology

SARS DiagnosticsKey Messages

• SARS diagnostic assays are sensitive and specific, but may not provide definitive diagnosis early in the illness

• Changes in the quantity, type, and timing of specimens collected may improve detection of SARS-CoV infection

• Rapid and accurate diagnosis of other respiratory pathogens associated with SARS-like illness may help rule out SARS-CoV infection and calm public fears

• Interpretation of test results must take into consideration possibility of false positives and negatives; a clear strategy to minimize such possibilities and to confirm test results are essential

CDC, 2003

Peiris: personal communication

Prevention of SARS

                                             

Definitions of Quarantine Isolation

• Separation and restricted movement of ill persons with contagious disease

• Often in a hospital setting• Primarily individual level, may be populations

Quarantine• Separation and restricted movement of well persons

presumed exposed to contagion• Often at home, may be designated residential facility• Applied at the individual or community level

May be voluntary or mandatory

CDC, 2003

A collective action for the common good predicated on aiding individuals infected or exposed to infectious agents while protecting others from the dangers of inadvertent exposure

Public good Civil liberties

Modern Quarantine

Meeting needs of individuals infected and exposed is paramount

CDC, 2003

Key Issues to Consider

• Surveillance• Clinical evaluation • Infection control measures• Patient isolation• Engineering controls• Exposure evaluation• Staffing needs and personnel policies• Access controls• Supplies and equipment• Communication

CDC, 2003

SARS Mysteries

Origin of SARS – animal reservoirs?

Is coronavirus the etiologic agent?

• Cases without antibody

• Non-cases with antibody

SARS Mysteries (continued)

What proportion of exposed persons

develop clinical disease and death?

• Proportion of exposed, infected and asymptomatic

Are there asymptomatic carriers?

• Reports of cases without known source of exposure

SARS Mysteries (continued)

What causes “super shedders”?• Host characteristics; e.g., age

• Agent characteristics – “virulent strain”

Is pathology caused by the virus or the

response to the virus?

• AIDS patients appear to be resistant to SARS

SARS Mysteries (continued)

Will SARS reappear in the fall?

• SARS is transmitted through the respiratory route. These diseases, like influenza, tend to have a season cycle with resurgence in the late fall, winter and early spring

Will SARS Re-emerge?

Potential sources of re-emergence

• Animal reservoir

• Humans with persistent infection

• Unrecognized transmission in humans

• Laboratory exposure

SARS most likely to recur outside U.S.

• Well-established global surveillance is important to recognition of first case