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Gain insights into the Severe Acute Respiratory Syndrome (SARS) outbreak, including symptoms, quarantine effectiveness, control measures in various countries, communication challenges, and lessons for future epidemic modeling.
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Modeling Lessons Learned from the SARS Outbreak Paul A. Dreyer Jr., Ph.D. Associate Mathematician RAND
Outline • Brief Introduction to SARS • Lessons Learned • Quarantines • Differing Control Measures • Communication • Hoaxes • Conclusions
Introduction to Severe Acute Respiratory Syndrome (SARS) • Symptoms • Initially, high fever and chills, body aches • After 2-7 days, dry coughing (along with possible oxygen depletion of blood) • Incubation period up to 14 days • Fatality rate about 10 percent (as of 4/25) • Treatment • CDC recommends treatment for pneumonia • Still working on vaccine, determining vectors (transmission by ‘close contact’) • SARS coronavirus identified, sequenced
Lessons Learned: Quarantines • Quarantines seem to be effective, provided people actually quarantine themselves • Individual refusals to quarantine in Toronto • Concerns about stigmatization lead to concealment of illness • Lack of notification to quarantine • Taiwan: Personal attendants for inpatient care may have spread disease
“Ideal” Quarantine Method Contact w/SARS Infected Person Healthy Person Symptoms? Notification Of Possible Contact No Yes Treatment and Notification Yes Symptoms? Quarantine Until Contact + 10 Days No
“Realistic” Quarantine Issues Contact w/SARS Infected Person Healthy Person Symptoms? Notification Of Possible Contact No Yes Problems: - Misdiagnosis - Non-reporting Treatment and Notification Yes Symptoms? Quarantine Until Contact + 10 Days No
“Realistic” Quarantine Issues Contact w/SARS Infected Person Problem: 100% coverage of all contacts difficult Healthy Person Symptoms? Notification Of Possible Contact No Yes Treatment and Notification Yes Symptoms? Quarantine Until Contact + 10 Days No
“Realistic” Quarantine Issues Contact w/SARS Infected Person Healthy Person Symptoms? Notification Of Possible Contact No Yes Treatment and Notification Problem: Refusal To Quarantine Yes Symptoms? Quarantine Until Contact + 10 Days No
Lessons Learned: Differing Control Measures • United States • No limitations on travel (travel advisories by CDC) • CDC activated its Emergency Operations Center • CDC recommends isolation of SARS-infected individuals • Basic infection control procedures at hospitals • CDC distributing health alert cards to passengers • returning from travel in infected regions
Lessons Learned: Differing Control Measures • Canada • Hospital and school closings • Checks at airport of incoming passengers • Quarantines of health care workers
Lessons Learned: Differing Control Measures • Singapore • $10k fines and jail for breaking quarantine • Illegal to mislead officials about travel history • Health Ministry can: • Quarantine any building • Destroy any materials suspected to be • sources of infection
Lessons Learned: Differing Control Measures • Taiwan • 10 day quarantines of all incoming passengers • from SARS-infected areas (+ masks on flights) • Widespread education of healthcare workers • Full protective clothing for healthcare workers • (including disposable 2nd layer of clothing) • Active surveillance of exposed healthcare workers • and contacts of patients (+ quarantines)
Lessons Learned: Differing Control Measures • Control measures vary from minor (US) to highly restrictive (Taiwan, Singapore, China) • Differing control measures should be reflected in any modeling of global epidemics
Lessons Learned: Communication • Communication methods are imperfect • Not everyone receives notifications • Not everyone believes the notifications • However, new methods are developing • Hong Kong hoax • 6 million SMS messages sent to cell phones • Location-based SARS updates via cell phone • Real-time updated websites of SARS information • SARS helpline also used for case detection
Lessons Learned: Hoaxes • Hong Kong hoaxes • Los Angeles airplane scare • Hoaxes (or misinformation) cause: • misallocation of resources • increased fear/confusion in populace • possible health risks (smallpox)
Conclusions • Epidemiological models should: • Incorporate realistic quarantine models • Acknowledge differing (and possibly conflicting) control systems across nations • Consider imperfect information gathering as well as new communication methods