Compartment Models

The active compartments are chosen by the disease_model.parameters.compartments list in the input JSON file. The list order becomes the internal compartment index order.

Common stochastic models include:

Model	Compartments	Notes
SEIRS	S, E, I, R	Waning immunity through R -> S.
SEITRS	S, E, I, T, R	Adds treated infectious T; T is created by antiviral stockpile release.
SEIHRD	S, E, IA, IP, IS, H, R, D	Separates asymptomatic, presymptomatic, symptomatic, hospital, death.

SEITRS Interpretation

In SEITRS, T means treated infectious. It is still infectious, but less so:

infectious pressure = I + rel_inf_T_to_I * T

People do not enter T automatically. The antiviral model moves eligible people from E or I into T subject to available doses and prioritization. This is deliberate: treatment is an intervention constrained by stockpile availability, not a spontaneous clinical transition.