Preventing Smallpox Epidemics Using a Computational Model

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Preventing Smallpox Epidemics Using a
Computational Model

• By Chintan Hossain and Hiren Patel

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Facts About Smallpox

• Symptoms occur in stages
• Highly contagious (causes epidemics)
• Fatal in ?30 cases
• There is a vaccine
• - Death may occur

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GOAL (Objective)

• Prevent smallpox epidemics via. vaccination.
• Vaccinate as few as possible because
• 1. Minimize reactions
• 2. Reduce cost

HYPOTHESIS Vaccinating certain percentage of the
population may be sufficient to prevent a
smallpox epidemic.
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Stages of Smallpox

• Normal (Susceptible)
• Immune (or vaccinated)
• Incubation
• First Stage
• Early Symptoms
• Late Symptoms
• Death

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Our Model Social Networks

• Cliques Represent
• Families
• Workplaces
• School

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Our Society Generator Algorithm

• Use random numbers to pick a family size.
• Generate a clique of that size.
• Repeat to create more families.
• Use a similar technique to generate schools and
  workplaces.
• Schools and workplaces connect existing vertices,
  not new vertices.

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Our Model Comes Alive!
Normal (Susceptible)

• MARKOV GRAPH SOCIETY NETWORK
• SIMULATION
• Advance time 1 day
• Spread Disease
• Advance Stages
• Death

Infected Stage
Vaccinated / Immune
?
Death
?
?
FIRST
EARLY
LATE
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Procedure

• Run the society generator
• Vaccinate k of people with most friends
  (vertices with the greatest degree)
• Control k 0
• Variable Vary percent, k, vaccinated
• Randomly, infect one person.
• Run simulation, and observe results (percent
  infect and length of epidemic)

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OUR PROGRAM
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Results

• Epidemics intensify, reach a peak, and then
  vanish
• Vaccination reduces intensity and speed.

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Results (cont)

• Vaccinating more people decreases the infected
• The infected becomes small if over 50 are
  vaccinated.

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Conclusion

• Vaccinating 50 of the population effectively
  prevents epidemics.
• Vaccinating less than 50 may not prevent an
  epidemic, but it reduces the severity and speed
  of the epidemic.

• This model can be used for other diseases by
  changing the Markov Graph.