Figure 1.

Finite state machine representation allows for a flexible representation of a disease process. Each state determines the duration in that state, level of symptoms, susceptibility, and infectiousness. For example, susceptible individuals have a 75% chance that upon exposure to an infectious contact and successful infection they will transition to the latent Exposed state in ILI Manifestation 1; after 1 to 2 days they will then transition to one of the more Infectious states with a 50% chance of having symptoms.