SSimulatingimulating SARS …SARS …Small-World Epidemiological Modeling andSmall-World Epidemiological Modeling and

Public Health Policy AssessmentsPublic Health Policy Assessments

Ji-Lung Hsieh (Ji-Lung Hsieh ( 謝吉隆謝吉隆 ))Department of Computer Science, National Chiao Tung UniversityDepartment of Computer Science, National Chiao Tung University

Chung-Yuan Huang (Chung-Yuan Huang ( 黃崇源黃崇源 ))Department of Computer Science and Information Engineering, Chang Gung UniversityDepartment of Computer Science and Information Engineering, Chang Gung University

Chuen-Tsai Sun (Chuen-Tsai Sun ( 孫春在孫春在 ))Department of Computer Science, National Chiao Tung UniversityDepartment of Computer Science, National Chiao Tung University

Yi-Ming Arthur Chen (Yi-Ming Arthur Chen ( 陳宜民陳宜民 ))Institute of Public Health, National Yang-Ming UniversityInstitute of Public Health, National Yang-Ming University

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When 2002-2003 SARS outbreak beganWhen 2002-2003 SARS outbreak began

Confirm viral structure.Confirm viral structure.

Develop vaccines and antidotes.Develop vaccines and antidotes.

Establish faster inspection methodsEstablish faster inspection methods..

Revise public health policies and prevention Revise public health policies and prevention strategies.strategies.

Taking Body Temperature Mask Wearing for General Public

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Public Health PoliciesPublic Health Policies

Balancing the social costs and resource expenditures required Balancing the social costs and resource expenditures required for controlling epidemic outbreaksfor controlling epidemic outbreaks

Mask Policy—General Public vs. Healthcare WorkersTaking Body TemperatureA/B Class Home QuarantinesReducing Public Contact, Controlling Hospital AccessVaccines, Antidotes, …

Improper implementation & inappropriate timing Improper implementation & inappropriate timing Secondary impacts as disease concealmentSocial discrimination against SARS patients and health care workersPanic buying of masks (ex. N95 mask).

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A Suitable Epidemic Simulation PlatformA Suitable Epidemic Simulation Platform

Simulating epidemic transmission dynamics and Simulating epidemic transmission dynamics and associated associated public health policiespublic health policies;;Assisting with understanding the Assisting with understanding the propertiesproperties and and efficaciesefficacies of various public health policies; of various public health policies;Constructing an Constructing an effectiveeffective, , low-costlow-cost, and , and executableexecutable suite of epidemic prevention strategies;suite of epidemic prevention strategies;Reducing the Reducing the difficultiesdifficulties and and costscosts associated with associated with learning epidemiological issues.learning epidemiological issues.

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Epidemic SimulationsEpidemic Simulations

Factors that influence the epidemic transmission dynamicsFactors that influence the epidemic transmission dynamicsEpidemiological Progress

• Incubation, Infectious, Recovered, and Immune Days, …

Individual Diversity• Super-spreader, Inoculator, Immune, Weak Individual…

Social Networks• Interpersonal Relationships and Simple Daily Contact• High Local Clustering and Small-World Phenomena

Mobile Individual Problems• Short- and Long-Distance Movement• Daily visits to fixed and/or multiple locations

Public Health Policies and Strategies

Factors of Individual Diversity

EpidemiologicalFactors

Factors of Social Networks

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Cellular Automata with Social Mirror Identity ModelCellular Automata with Social Mirror Identity Model

Epidemic Disease

Agent Population

Mirror Identity Concept

Social Contact Network

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Simulation FrameworkSimulation Framework

EpidemicDisease

Data fromWHO, CDC,

and individualnational health

authorities

Time points ofimported cases and

public health policies

Interaction rules;population, network, and

epidemic parameters

CASMIM

Input

Initialize

Output

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CASMIM Simulation SystemCASMIM Simulation System

CASMIM

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Statistical Analyses for Simulating SARSStatistical Analyses for Simulating SARS

Reliability TestReliability TestChi-square test

Validity TestValidity TestCorrelation coefficient (CC) [-1, 1]Coefficient of efficiency (CE) [0, 1]Mean square error (MSE) [0, ]Mean absolute error (MAE) [0, ]

1

2 2

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( ) ( )

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t tt

n n

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X X Y YCC

X X Y Y

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( )

n

t ttn

tt

X YCE

X X

2

1

1( ) [0, ]

n

t tt

MSE Y Xn

1

1( ) [0, ]

n

t tt

MAE Y Xn

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Singapore SARS OutbreakSingapore SARS Outbreak

4/28 taking body temperature at

transportation gates

3/24 stop visits to hospital & home

quarantine

3/27 stop class of junior and

elementary school

3/30 restriction on air passenger

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Taipei SARS OutbreakTaipei SARS Outbreak

6/1 taking body temperature

3/26 wearing mask by healthcare workers

3/28 home quarantine

3/30 wearing mask by general public

4/10 taking passenger temperature at airport

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Toronto SARS outbreakToronto SARS outbreak

3/26 Stop visits to hospital &

Home quarantine

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Taking Body TemperatureTaking Body Temperature

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Wearing Masks for General PublicWearing Masks for General Public

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Wearing Masks for Health WorkersWearing Masks for Health Workers

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Assessing Public Health SuitesAssessing Public Health Suites

3/24 Executing public health suites

Conclusions (cont.)Conclusions (cont.)

A novel and complete small-world epidemic modelA novel and complete small-world epidemic modelSimulating epidemic transmission dynamics and associated public health policies;Assisting with understanding the properties and efficacies of various public health policies;Constructing an effective, low-cost, and executable suite of epidemic prevention strategies.Reducing the difficulties and costs associated with learning epidemiological concepts.