Hector Cuesta-Arvizu presented an epidemic and endemic outbreak simulator at the University of North Texas on October 24, 2011. The simulator uses a global stochastic cellular automata approach to model the spread of infectious diseases. It incorporates SEIR and SEIRS disease models and allows simulation of different intervention strategies like vaccination programs. The simulator was developed using C# and allows visualization of epidemic and endemic curves during outbreak simulations.
1 of 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
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
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