Disease states of the model, and processes connecting them. These are: S susceptible; SV susceptible and not contraindicated for vaccination; E latent; P prodromal; I infectious; R removed; Q isolated; O susceptible under observation; ET latent under observation; V vaccinated. The latent class is populated by transmission from infectious or prodromal cases to susceptibles.
House et al. BMC Infectious Diseases 2010 10:25 doi:10.1186/1471-2334-10-25