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Epidemic and Endemic Outbreak Simulator:
       A Global Stochastic Cellular Automata Approach

                           Presented by: Hector Cuesta-Arvizu
                                Advisor: Armin R. Mikler




                 Center for Computational Epidemiology and Response Analysis
                                  University of North Texas


                                     October 24, 2011
Hector Cuesta-Arvizu (CeCERA)   Epidemic and Endemic Outbreak Simulator   October 24, 2011   1 / 16
Outline


      Introduction (why this is important?).

      Infectious Disease Model SEIR.

      Infectious Disease Model SEIRS.

      Cellular Automata (...the computational part).

      Global Stochastic Contact Model.

      Outbreak Simulator.

      Vaccination Strategies.

      Conclusions.


 Hector Cuesta-Arvizu (CeCERA)   Epidemic and Endemic Outbreak Simulator   October 24, 2011   2 / 16
Introduction


Why is this important?



      The epidemiologist use Models to study the spread of an Infectious
      disease outbreak.

      These Models include, Mathematical, Statistical and Computational
      approaches.

      Simulating these models is the way that epidemiologist can observe
      di?erent outbreak outcomes.

      With the simulation we can try di?erent interventions strategies that
      a?ects the prevalence of an Epidemic or Endemic outbreak.




 Hector Cuesta-Arvizu (CeCERA)   Epidemic and Endemic Outbreak Simulator   October 24, 2011   3 / 16
Infectious Disease Models


Infectious Disease Models

SEIR Susceptible-Exposed-Infected-Recovered
    The SEIR models the shift of individuals¡¯ status between four states:
    susceptible (S), exposed (E), infected (I), and recovered (R). Each of
    those variables represents the number of people in those groups.




 Hector Cuesta-Arvizu (CeCERA)        Epidemic and Endemic Outbreak Simulator   October 24, 2011   4 / 16
Infectious Disease Models


Infectious Disease Models


SEIRS Susceptible-Exposed-Infected-Recovered-Susceptible
    The SEIRS di?ers from the SEIR model by letting recovered
    individuals lose their resistance over time.




 Hector Cuesta-Arvizu (CeCERA)        Epidemic and Endemic Outbreak Simulator   October 24, 2011   5 / 16
Cellular Automata


Cellular Automata

What is a Cellular Automata?
   Discrete model studied in computability theory and mathematics for a
   non-linear problems.
   Facts:
             It consist of an in?nite, regular grid of cells, each in one of a ?nite
             number of states.
             The grid can be any ?nite number of dimensions.
             Each cell is a particular individual o group.




 Hector Cuesta-Arvizu (CeCERA)   Epidemic and Endemic Outbreak Simulator   October 24, 2011   6 / 16
Cellular Automata


Cellular Automata
Neighbourhood
    The Neighbourhood is a selection of cells relative to some speci?ed
    cell and does not change.
      Each cell has the same rules for updating based on the values in this
      neighbourhood.
      Each time the rules are applied to the whole grid a new generation is
      produced.




Local an Global Neighborhoods, Von Newmnan and Moore Neighborhood
 Hector Cuesta-Arvizu (CeCERA)   Epidemic and Endemic Outbreak Simulator   October 24, 2011   7 / 16
Model


Model
The Global Stochastic Contact Model
    The goal of this model is to describe the dynamics of an infectious
    disease in a close population.
      The model is a human-human Global Interaction model.
      Its main purpose is the realization of contacts among individuals,
      facilitating analysis of the spread of diseases




        The cayley graph represent the global interaction between cells
                                (individuals).
 Hector Cuesta-Arvizu (CeCERA)   Epidemic and Endemic Outbreak Simulator   October 24, 2011   8 / 16
Model


Model


The global contact interaction
    Contacts per Time Step:
                                                        CR?N
                                               C=         2
      Total of Contacts in the Event:
                        Ctot = ¦²t¦Ð CR?N where te = (1, 2, 3, ..., n)
                                t=1 2
      C = Number of interactions per each Time Step.
      CR = Contact Rate.
      N = Number of individual in the population.
      t¦Ð = Number of Time Steps.
      Ctot = Total Number of interactions in the event


 Hector Cuesta-Arvizu (CeCERA)   Epidemic and Endemic Outbreak Simulator   October 24, 2011   9 / 16
Outbreak Simulator


Outbreak Simulator


Technological choices for the Simulator
    The main contribution of this work is to present a software system
    that incorporates a global stochastic cellular automata model.
    Technological Choice:
             C# .NET (as a programming language)
             WindowsForms and MonoDesktop (to create graphic interface and grid
             animations during simulations)
      Modules:
             The speci?cation module.
             The simulation module.
             The visualization module.




 Hector Cuesta-Arvizu (CeCERA)   Epidemic and Endemic Outbreak Simulator   October 24, 2011   10 / 16
Outbreak Simulator


Outbreak Simulator
Speci?cation and simulation modules




 Hector Cuesta-Arvizu (CeCERA)   Epidemic and Endemic Outbreak Simulator   October 24, 2011   11 / 16
Outbreak Simulator


Outbreak Simulator

Visualization module
    In ?gure A we can observe the SEIR Epidemic Curve and in ?gure B
    we can observe the SEIRS Endemic Curve.




                                                                           (A)




                                                                           (B)
 Hector Cuesta-Arvizu (CeCERA)   Epidemic and Endemic Outbreak Simulator         October 24, 2011   12 / 16
Intervention Strategies


Vaccination Strategies

Vaccination Strategies




                                                      Figure A.- Vaccination in SEIR Model




                                                     Figure B.- Vaccination in SEIRS Model

 Hector Cuesta-Arvizu (CeCERA)      Epidemic and Endemic Outbreak Simulator   October 24, 2011   13 / 16
Intervention Strategies


Vaccination Strategies

Vaccination Strategies
    Scheduling Vaccination
      Infected Population-Trigger Vaccination




                        Figure C.- Plot of Vaccination Strategies

 Hector Cuesta-Arvizu (CeCERA)      Epidemic and Endemic Outbreak Simulator   October 24, 2011   14 / 16
Conclusions


Conclusions and Future Work




Conclusions and Future Work
    Simulation help to understand spread of diseases.
      Also we can observe di?erent outcomes from intervention strategies.
      Future Work:
             Try di?erent kinds of contact models.
             Integrate Seasonality.




 Hector Cuesta-Arvizu (CeCERA)   Epidemic and Endemic Outbreak Simulator   October 24, 2011   15 / 16
Conclusions


Questions??




Questions ???




 Hector Cuesta-Arvizu (CeCERA)   Epidemic and Endemic Outbreak Simulator   October 24, 2011   16 / 16

More Related Content

Outbreak Simulator First Presentation

  • 1. Epidemic and Endemic Outbreak Simulator: A Global Stochastic Cellular Automata Approach Presented by: Hector Cuesta-Arvizu Advisor: Armin R. Mikler Center for Computational Epidemiology and Response Analysis University of North Texas October 24, 2011 Hector Cuesta-Arvizu (CeCERA) Epidemic and Endemic Outbreak Simulator October 24, 2011 1 / 16
  • 2. Outline Introduction (why this is important?). Infectious Disease Model SEIR. Infectious Disease Model SEIRS. Cellular Automata (...the computational part). Global Stochastic Contact Model. Outbreak Simulator. Vaccination Strategies. Conclusions. Hector Cuesta-Arvizu (CeCERA) Epidemic and Endemic Outbreak Simulator October 24, 2011 2 / 16
  • 3. Introduction Why is this important? The epidemiologist use Models to study the spread of an Infectious disease outbreak. These Models include, Mathematical, Statistical and Computational approaches. Simulating these models is the way that epidemiologist can observe di?erent outbreak outcomes. With the simulation we can try di?erent interventions strategies that a?ects the prevalence of an Epidemic or Endemic outbreak. Hector Cuesta-Arvizu (CeCERA) Epidemic and Endemic Outbreak Simulator October 24, 2011 3 / 16
  • 4. Infectious Disease Models Infectious Disease Models SEIR Susceptible-Exposed-Infected-Recovered The SEIR models the shift of individuals¡¯ status between four states: susceptible (S), exposed (E), infected (I), and recovered (R). Each of those variables represents the number of people in those groups. Hector Cuesta-Arvizu (CeCERA) Epidemic and Endemic Outbreak Simulator October 24, 2011 4 / 16
  • 5. Infectious Disease Models Infectious Disease Models SEIRS Susceptible-Exposed-Infected-Recovered-Susceptible The SEIRS di?ers from the SEIR model by letting recovered individuals lose their resistance over time. Hector Cuesta-Arvizu (CeCERA) Epidemic and Endemic Outbreak Simulator October 24, 2011 5 / 16
  • 6. Cellular Automata Cellular Automata What is a Cellular Automata? Discrete model studied in computability theory and mathematics for a non-linear problems. Facts: It consist of an in?nite, regular grid of cells, each in one of a ?nite number of states. The grid can be any ?nite number of dimensions. Each cell is a particular individual o group. Hector Cuesta-Arvizu (CeCERA) Epidemic and Endemic Outbreak Simulator October 24, 2011 6 / 16
  • 7. Cellular Automata Cellular Automata Neighbourhood The Neighbourhood is a selection of cells relative to some speci?ed cell and does not change. Each cell has the same rules for updating based on the values in this neighbourhood. Each time the rules are applied to the whole grid a new generation is produced. Local an Global Neighborhoods, Von Newmnan and Moore Neighborhood Hector Cuesta-Arvizu (CeCERA) Epidemic and Endemic Outbreak Simulator October 24, 2011 7 / 16
  • 8. Model Model The Global Stochastic Contact Model The goal of this model is to describe the dynamics of an infectious disease in a close population. The model is a human-human Global Interaction model. Its main purpose is the realization of contacts among individuals, facilitating analysis of the spread of diseases The cayley graph represent the global interaction between cells (individuals). Hector Cuesta-Arvizu (CeCERA) Epidemic and Endemic Outbreak Simulator October 24, 2011 8 / 16
  • 9. Model Model The global contact interaction Contacts per Time Step: CR?N C= 2 Total of Contacts in the Event: Ctot = ¦²t¦Ð CR?N where te = (1, 2, 3, ..., n) t=1 2 C = Number of interactions per each Time Step. CR = Contact Rate. N = Number of individual in the population. t¦Ð = Number of Time Steps. Ctot = Total Number of interactions in the event Hector Cuesta-Arvizu (CeCERA) Epidemic and Endemic Outbreak Simulator October 24, 2011 9 / 16
  • 10. Outbreak Simulator Outbreak Simulator Technological choices for the Simulator The main contribution of this work is to present a software system that incorporates a global stochastic cellular automata model. Technological Choice: C# .NET (as a programming language) WindowsForms and MonoDesktop (to create graphic interface and grid animations during simulations) Modules: The speci?cation module. The simulation module. The visualization module. Hector Cuesta-Arvizu (CeCERA) Epidemic and Endemic Outbreak Simulator October 24, 2011 10 / 16
  • 11. Outbreak Simulator Outbreak Simulator Speci?cation and simulation modules Hector Cuesta-Arvizu (CeCERA) Epidemic and Endemic Outbreak Simulator October 24, 2011 11 / 16
  • 12. Outbreak Simulator Outbreak Simulator Visualization module In ?gure A we can observe the SEIR Epidemic Curve and in ?gure B we can observe the SEIRS Endemic Curve. (A) (B) Hector Cuesta-Arvizu (CeCERA) Epidemic and Endemic Outbreak Simulator October 24, 2011 12 / 16
  • 13. Intervention Strategies Vaccination Strategies Vaccination Strategies Figure A.- Vaccination in SEIR Model Figure B.- Vaccination in SEIRS Model Hector Cuesta-Arvizu (CeCERA) Epidemic and Endemic Outbreak Simulator October 24, 2011 13 / 16
  • 14. Intervention Strategies Vaccination Strategies Vaccination Strategies Scheduling Vaccination Infected Population-Trigger Vaccination Figure C.- Plot of Vaccination Strategies Hector Cuesta-Arvizu (CeCERA) Epidemic and Endemic Outbreak Simulator October 24, 2011 14 / 16
  • 15. Conclusions Conclusions and Future Work Conclusions and Future Work Simulation help to understand spread of diseases. Also we can observe di?erent outcomes from intervention strategies. Future Work: Try di?erent kinds of contact models. Integrate Seasonality. Hector Cuesta-Arvizu (CeCERA) Epidemic and Endemic Outbreak Simulator October 24, 2011 15 / 16
  • 16. Conclusions Questions?? Questions ??? Hector Cuesta-Arvizu (CeCERA) Epidemic and Endemic Outbreak Simulator October 24, 2011 16 / 16