Model Presets

What are model presets?

Model presets are built-in compartmental epidemic models that you can use without defining compartments or transitions yourself. Each preset comes with a set of compartments, default parameters, and transition rules.

You can list all available presets:

curl https://epyscenario-api.isi.it/api/v1/models/presets

SIR

The Susceptible-Infected-Recovered model. A basic epidemic model where recovered individuals gain permanent immunity.

Compartments

• Susceptible: individuals who can be infected
• Infected: individuals who are currently infectious
• Recovered: individuals who have recovered and are immune

Transitions

• Susceptible → Infected: mediated by transmission_rate and the number of Infected individuals
• Infected → Recovered: spontaneous at recovery_rate

Default parameters

Parameter	Default	Description
transmission_rate	0.3	Rate at which susceptible individuals become infected through contact with infectious individuals
recovery_rate	0.1	Rate at which infected individuals recover (1 / infectious period in days)

curl -X POST https://epyscenario-api.isi.it/api/v1/simulations \
-H "Content-Type: application/json" \
-d '{
  "model": {
    "preset": "SIR",
    "parameters": {"transmission_rate": 0.3, "recovery_rate": 0.1}
  },
  "population": {"name": "Italy"},
  "simulation": {"start_date": "2024-01-01", "end_date": "2024-04-01", "Nsim": 10}
}'

SEIR

The Susceptible-Exposed-Infected-Recovered model. Extends SIR with an exposed (latent) period before individuals become infectious.

Compartments

• Susceptible: individuals who can be infected
• Exposed: individuals who are infected but not yet infectious (latent period)
• Infected: individuals who are currently infectious
• Recovered: individuals who have recovered and are immune

Transitions

• Susceptible → Exposed: mediated by transmission_rate and the number of Infected individuals
• Exposed → Infected: spontaneous at incubation_rate
• Infected → Recovered: spontaneous at recovery_rate

Default parameters

Parameter	Default	Description
transmission_rate	0.3	Rate at which susceptible individuals become exposed through contact with infectious individuals
incubation_rate	0.2	Rate of progression from exposed to infectious (1 / incubation period in days)
recovery_rate	0.1	Rate at which infected individuals recover (1 / infectious period in days)

curl -X POST https://epyscenario-api.isi.it/api/v1/simulations \
-H "Content-Type: application/json" \
-d '{
  "model": {
    "preset": "SEIR",
    "parameters": {"transmission_rate": 0.3, "incubation_rate": 0.2, "recovery_rate": 0.1}
  },
  "population": {"name": "United_States"},
  "simulation": {"start_date": "2024-01-01", "end_date": "2024-06-01", "Nsim": 10}
}'

SIS

The Susceptible-Infected-Susceptible model. Individuals return to the susceptible state after recovery, with no lasting immunity.

Compartments

• Susceptible: individuals who can be infected
• Infected: individuals who are currently infectious

Transitions

• Susceptible → Infected: mediated by transmission_rate and the number of Infected individuals
• Infected → Susceptible: spontaneous at recovery_rate

Default parameters

Parameter	Default	Description
transmission_rate	0.3	Rate at which susceptible individuals become infected through contact with infectious individuals
recovery_rate	0.1	Rate at which infected individuals recover and return to the susceptible state (1 / infectious period in days)

curl -X POST https://epyscenario-api.isi.it/api/v1/simulations \
-H "Content-Type: application/json" \
-d '{
  "model": {
    "preset": "SIS",
    "parameters": {"transmission_rate": 0.4, "recovery_rate": 0.2}
  },
  "population": {"name": "United_Kingdom"},
  "simulation": {"start_date": "2024-01-01", "end_date": "2024-12-31", "Nsim": 10}
}'