severe acute respiratory syndrome (sars)
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Severe Acute Respiratory Syndrome (SARS). A A Model for Preparedness for Emerging Diseases Finding and Filling Gaps. What is the status of “Big Gaps”. Clinical manifestations of full blown SARS Diagnosis and therapy Clinical spectrum Characteristics of transmission & transmitters - PowerPoint PPT PresentationTRANSCRIPT
Severe Acute Respiratory Syndrome (SARS)
AA Model for Preparedness for Emerging Diseases
Finding and
Filling Gaps
What is the status of “Big Gaps”• Clinical manifestations of full blown SARS• Diagnosis and therapy • Clinical spectrum• Characteristics of transmission & transmitters• Seasonality and potential geographic range• Causative agent? Any important co-factors? • Protective factors—do children provide clues?• Where did the causative agent come from?• Is there a persistent reservoir?• How about those time lags—
– Recognizing and publicizing new syndrome– Public health prevention measures
“Big Gap” Status• Clinical manifestations of full blown SARS• Diagnosis and therapy • Clinical spectrum• Characteristics of transmission & transmitters• Seasonality and potential geographic range• Causative agent? Any important co-factors? • Protective factors—do children provide clues?• Where did the causative agent come from?• Is there a persistent reservoir?• How about those time lags—
– Recognizing and publicizing new syndrome– Public health prevention measures
“Big Gap” Status• Clinical manifestations of full blown SARS• Diagnosis and therapy • Clinical spectrum• Characteristics of transmission & transmitters• Seasonality and potential geographic range• What causes it? Any important co-factors? • Protective factors—do children provide clues?• Where did the causative agent come from?• Is there a persistent reservoir?• How about those time lags—
– Recognizing and publicizing new syndrome– Public health prevention measures
Chain of TransmissionPt “ZF”
0
5
10
15
20
25
Family HCW-Hosp 1 HCW-Hosp 2Tertiary HCW-Hosp 1 Index Case
12 3*
* *
* 1st, 2nd, and 3rd hospitalizations
China (and its neighbors)
HK-Dhaka
Flights to Bangkok
BKK-DAC
“Big Gap” Status• Clinical manifestations of full blown SARS• Diagnosis and therapy • Clinical spectrum• Characteristics of transmission & transmitters• Seasonality and potential geographic range• What causes it? Any important co-factors? • Protective factors—do children provide clues?• Where did the causative agent come from?• Is there a persistent reservoir?• How about those time lags—
– Recognizing and publicizing new syndrome– Public health prevention measures
Transmission PatternGuangdong-first 1000 cases
through February
• 28% in health care workers
• 20% in family members
• 52% unknown contacts
• 5% of cases were food preparers (compared with 1% of those with typical pneumonias over the previous two years)
Food Handlers as the Original Sentinels?
Nearly 35% of the cases recognized before Feb 1, 2003 were among food handlers—many lived near “wet markets”
Ample exposure to secretions, blood, urine and feces of domesticated/bred and wild animals in Guangdong Province
Animal Market, Guangzhou
Finding the SourceLearning from By-gone Epidemics
• Legionnaires’ disease– The bacteria are everywhere, but only one source is
usually responsible for an epidemic– Can you tell me how to clean the cooling tower?
• Schistosomiasis in Malawi• E. coli 0157 outbreaks: from hamburgers to
water parks• Message: Let epidemiology guide the animal
coronavirus surveys and confirm with molecular epi/genetic studies
Epi Studies• Begin with case-control study of first 50-100 known cases in
Guangdong– Focus on
• Pets• Visits to animal markets• Animals purchased or used
– Detail interaction with animal
• Food ingested– How cooked/served/eaten
• Nested study with case food preparers and food preparer controls– Specific behaviors/functions
• Include serologic data on cases/controls• Get isolates or sequences from as many early cases as possible• Consider similar work in cases without known contacts
“Big Gap” Status• Clinical manifestations of full blown SARS• Diagnosis and therapy • Clinical spectrum• Characteristics of transmission & transmitters• Seasonality and potential geographic range• What causes it? Any important co-factors? • Protective factors—do children provide clues?• Where did the causative agent come from?• Is there a persistent reservoir?• How about those time lags—
– Recognizing and publicizing new syndrome– Public health prevention measures
Epidemics of Emerging or Known Diseases Early Recognition and Response
What is Required?• Surveillance Systems
– Hospital-based • focused on disease or known syndrome• Enough information to recognize novel clinical or
epidemiologic pattern – unusual combination of signs/symptoms– occupational clustering (may consider surveillance in sentinel
populations—i.e. health care workers
– Behavior-based• Vinegar sales would have been a clue• Antimicrobial drug sales
– Physician-based via education/networks/hotlines
Epidemics of Emerging or Known Diseases Early Recognition and Response
Surveillance Characteristics• System should be easy to participate in• Individual reporting should be electronic• Analysis should have automated capacity with built-in
pattern recognition and also flexibility for operator manipulation
• Trained personnel need to maintain and use it• Pre-established thresholds for anomalies/prepared to
respond• Teams trained, ready, and available to investigate• International support/trust• Prepared for communication/education
VietnamSingapore
Toronto
63 cases205 cases
142 cases
Global Spread of a Novel Pathogen
Hong Kong1500 cases
Guangdong1500 cases
Big Lesson from SARSPolitical Will Required to Support, Enhance
and Utilize Public Health Infrastructure• Need for quick, transparent steps to declare presence of
lethal pathogen with borders• Intensify surveillance and report results• Use contact tracing, quarantine, and border control
measures when needed• Apply stringent infection control measures in health care
settings when indicated• Provide public with timely information
• Magnitude• Known risks• How one can protect himself/herself and family
• International public health enforcement??
Keep Some Perspective
• 5,000 cases in China—population 1.3 billion• 8,000 cases globally• Not easy to get SARS• Not the greatest health problem faced, but a
test for our preparedness to respond to public health crises
• We can use this experience to improve ourselves
May the Lord grant me a sword and no need to use it. --Czech Proverb
Politics and Public Health