Cholera Simulation

1 collaborator

Jesse PANTIN (Author)

WHAT IS IT?

This model shows a community which starts with 100 people and a water source. As time passes, people with cholera may infect the water source or other people; however, those who are vaccinated will not be affected by the virus. The chance of the water being disinfected can also be modified, simulating efforts to clear the water source of the disease.

HOW TO USE IT

Using the sliders to the right of the display, one can change the initial number of people infected and people vaccinated, as well as the likelihood of the water becoming disinfected. The plot below the sliders shows the population over time.

THINGS TO NOTICE

Will running the model while changing the different variables with the sliders, one should notice the effect of the number of people vaccinated and infected on the outcome of the experiment.

WHAT CAN BE LEARNED?

Using this model, one can, though not accurately, see the effect of efforts to disinfect water and vaccinations on a population exposed to an infected water source. Patterns can be noticed with the graph, and behaviour space can be used to find a correlation between the population and the various adjustable factors.

RELATIONSHIPS BETWEEN VARIABLES

One can notice, a higher disinfection rate will reduce the amount of cholera and the likelihood people will be infected by it. On the other hand, a higher vaccinated population will also reduce the spread, but it may also help prevent the population from diminishing.

ABOUT CHOLERA

Cholera is a water-born disease, thus it will be spread if one ingests infected water. Water can also transmit the infection. Cholera is also highly contageous, so being too close to someone who is infected may also put an unvaccinated person at risk. The likelihood of survival varies depending on the country, and the duration often changes based on region as well.

REALISTIC WAYS TO STOP THE SPREAD OF CHOLERA

Based on information on this model, and it may seem obvious, but the best way to prevent the spread of cholera is not only investing in a better disinfection rate, but also making an effort to vaccinate more people. While one keeps the population healthy, the otehr also makes it possible for the people to have access to a healthy water source.

SOURCES

Road, Clifton. “Cholera - Vibrio Cholerae Infection.” Centers for Disease Control and Prevention, Centers for Disease Control and Prevention, 11 May 2018, www.cdc.gov/cholera/general/index.html.

Comments and Questions

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Click to Run Model

patches-own [infected?]
turtles-own [cholera gender age]

to setup
  ca
  reset-ticks
  setup-patches
  setup-turtles
  colors
end 

to go
  colors
  infect-water
  infect-people
  birth
  ask turtles [
    wiggle
    set age (age + 1) ; their age is in weeks
    if (age > 3910) [die] ; since ticks are weeks and 3910 are the average weeks a person lives in their life, they will die after 3910 weeks
  ]
  tick
  if (count turtles > 5000 or count turtles < 1) [stop]
end 

to wiggle ; moving of the people
  fd 1
  lt random 61 - 30
end 

to infect-water ; determines whether or not the water is infected
  ask patches with [infected? = 0] [ ; infecting water
    if (any? turtles-here with [cholera = 1]) [set infected? 1]
  ]
  ask patches with [infected? = 1] [
    if (random 100 < Disinfect) [set infected? 0] ; disinfecting water
  ]
end 

to infect-people ; determines whether or not someone is infected
  ask turtles with [cholera = 0] [
    if (pcolor = violet) [
      set cholera 1 ; infecting people from water
    ]
    if (any? turtles-here with [cholera = 1]) [set cholera 1] ; infecting people from other people
  ]
    ask turtles with [cholera = 1] [ ; rate of survival, death or continuing with the disease
      if (random 100 < 10) [die]
    if (random 100 < 10) [set cholera 0]
    ]
end 

to colors ; shows who and which patches are infected
  ask patches [
    if (infected? = 1) [set pcolor violet]
    if (infected? = 0) [set pcolor blue]
    if (infected? = -1) [set pcolor black]
  ]
  ask turtles [
    if (cholera = 1) [set color red]
    if (cholera = 0) [set color green]
    if (cholera = -1) [set color grey]
  ]
end 

to birth ; reproducing population
  ask turtles with [gender = 1] [
    if (any? turtles-here with [gender = -1] and random 100 >= 90) [hatch 1
      [set cholera 0
       set age 0
        ifelse (random 2 = 0) [set gender 1] [set gender -1]
      ]
    ]
  ]
end 

to setup-patches
    ask patches [set infected? -1]
  ask patches with [pxcor > -5 and pxcor < 5 and pycor > -5 and pycor < 5]
  [set infected? 0] ; creates water
end 

to setup-turtles
  ask turtles [set gender 0]
  set-default-shape turtles "person"
  crt 100 [ ; creates people
    setxy random-xcor random-ycor
    set age random 3910
    set cholera 0
  ]
  ask turtles ; creates vaccinated and infected people
  [if (random 100 < numVaccinated) [set cholera -1]
    if (cholera = 0 and random 100 < numInfected) [set cholera 1]
  ]
  ask n-of 50 turtles [set gender 1] ; creating genders
  ask turtles with [gender = 0] [set gender -1]
end

There is only one version of this model, created over 6 years ago by Jesse PANTIN.

Attached files

File	Type	Description	Last updated
Cholera Simulation.png	preview	Preview for 'Cholera Simulation'	over 6 years ago, by Jesse PANTIN	Download

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