Infectious Disease Outbreak (COVID-19)--HealthCare, Isolation and Quarantine

;;
;; This model is developed by Dr. Lin Xiang at the University of Kentucky. Contact: lin.xiang@uky.edu
;;
;; If you see this page rather than a "download" button when downloading the model, click the "download" icon
;; in your browser to download this model file.
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turtles-own[day infected susceptible hospitalized symptom]
Globals [RM LM num-beds x y max-daily-cases]
breed [persons person]
breed [doctors doctor]

to-report hospital   ;label the divider patches
  report patches with [ pycor < max-pycor and pycor > 16 and pxcor > min-pxcor and pxcor < max-pxcor]
end 

to-report susceptible-people     ;call all suscepitble people
  report turtles with [infected = false and susceptible = true and symptom = false and hospitalized = false]
end 

to-report carriers   ;call all people who are infected but have not shown symptoms
  report turtles with [infected = true and susceptible = false and symptom = false and hospitalized = false]
end 

to-report infected-with-symptom   ;call all people who are infected and have shown symptoms
  report turtles with [infected = true and susceptible = false and symptom = true]
end 

to-report patients   ;call all people who are infected and have shown symptoms and have been hospitalized
  report turtles with [infected = true and susceptible = false and symptom = true and hospitalized = true]
end 

to-report current-patients
  report count patients
end 

to-report recovered-people   ;call all people who have recovered
  report turtles with [infected = false and susceptible = false and symptom = false]
end 

to-report available-beds ; availble inpatient beds
  report num-beds - count persons with [pcolor = 9.9]
end 


;;;;;;;;;;;;;;;;;;;;main setup procedures;;;;;;;;;;;;;;

to setup
  clear-all
  setup-patches
  setup-turtles
  reset-ticks
end 

to setup-patches

  ask patches with [ abs pxcor = max-pxcor ] [set pcolor 116]   ;setup boundary
  ask patches with [ abs pycor = max-pycor ] [set pcolor 116]   ;setup boundary
  ask patches with [ pycor = 16 ] [set pcolor 116]  ;setup boundary
  ask hospital  [set pcolor 9.9]    ;set hospital area
end 

to setup-turtles

  create-persons Population-size
  [set color 68
    set size 1.75
    set shape "person-1"
    set day 0
    set infected false
    set susceptible true
    set hospitalized false
    set symptom false
    set-position
  ]

 set num-beds Population-size * 0.05
  set x -21
  set y 18

   create-doctors 1
  [ set color 37
    set size 3
    set shape "person doctor"
    setxy 22.5 26.5
  ]
end 

to set-position  ;set people position
  setxy random-xcor random-ycor
  if pcolor != 0 [set-position]
end 

to set-beds   ;set hispital bed positions
   setxy x y
   if any? other turtles-here [
    (ifelse
      x < 21 [set x x + 3]
      x = 21 [set x -21 set y y + 3])
      set-beds]

   set x -21
   set y 18
end 

;;;;;;;;;;;;;;;;;;;;main go procedures;;;;;;;;;;;;;;

to go

  if ticks >= Days [stop]

  move
  transmission
  sickness
  isolation
  ifelse Hospitalization? [hospitalization-recovery-death][recovery-death]
  find-max-daily-cases
  tick
end 

to move
  ask persons with [hospitalized = false and shape = "person-1"]    ;Keep patients and isolated people from moving
  [ifelse [pcolor] of patch-ahead 1 = 0 [forward Mobility rt random 360] [set heading heading - random 180]]
end 

to add-a-carrier
  create-persons 1
  [set size 1.75
    set shape "person-1"
    set color 68
    set infected true
    set susceptible false
    set symptom false
    set hospitalized false
    set-position]
end 

to transmission       ;set up transmission
  ask persons with [infected = true and shape = "person-1"]  ;shape of "person" excludes the isolated carriers
  [let healthy-person one-of other turtles in-radius 1.5 with [susceptible = true]
    if healthy-person != nobody
    [ask healthy-person [
      if random 100 < 90  ;transimission rate is 90%
      [set infected true set susceptible false set symptom false]]]  ;susceptible people first become carriers.
  ]
end 

to sickness     ;process of developing symptoms
  ask persons with [infected = true]
  [
    ifelse Show-carriers? = true    ;allow switch to show and hide carriers
    [ifelse symptom = false [set color gray][set color orange]]
    [ifelse symptom = false [set color 68][set color orange]]

    set day day + 1  ;accumulate days
    if random 100 < (10 * day - 30) [set symptom true set color orange]   ; The infected people show symptoms after 3 days and the chance increase 10% every day after.

  ]
end 

to watch-a-sick-person ; can be either a carrier or a sick person
  watch one-of persons with [infected = true]
end 

to hospitalization-recovery-death
  ask persons with [infected = true and symptom = true]  ; call sick people
  [if available-beds > 0 [
    set shape "patient"
    set hospitalized true
    set-beds]

  if day >= 15
    [ifelse hospitalized = true
      [ifelse random 100 < 20 * 0.5
          [set LM LM + 1 die  ]
          [set infected false set hospitalized false set susceptible false set symptom false set color blue set shape "person-1" set-position]]
      [ifelse random 100 < 20
          [set LM LM + 1 die  ]
          [set infected false set hospitalized false set susceptible false set symptom false set color blue set shape "person-1" set-position]]
      ]
  ]
end 

to recovery-death
   ask persons with [infected = true and symptom = true]
     [if day >= 15
      [ifelse random 100 < 20
          [set LM LM + 1 die  ]
          [set infected false set hospitalized false set susceptible false set symptom false set color blue set shape "person-1" set-position]]
      ]
end 

to isolation
  ask persons with [infected = true and symptom = true and hospitalized = false]
      [if random 100 < %-isolated [set shape "house"]]
  ask carriers
      [if random 100 < %-quarantined [set shape "house"]]
end 

to find-max-daily-cases
  if count turtles with [color = orange ] > max-daily-cases        ;Count the infectious. If it is greater than the current record of max daily cases
  [set max-daily-cases count turtles with [color = orange ]]       ;update the max daily case
end