Fig. 1
From: Estimating tuberculosis drug resistance amplification rates in high-burden settings
Structure of four strain Mtb transmission model. The symbols S, LA, LB, I and R represent uninfected/susceptible, early latent, late latent, infected and recovered health states, respectively. The subscript “X” used in LA and LB compartments and other parameters, indexes the drug resistance patterns, with S, H, R and M representing susceptible, isoniazid mono-resistance, rifampicin mono-resistance and multidrug resistance respectively. The infectious compartment is elaborated in the figure to show the amplification flows of INH and RIF respectively, parameterized with αH and αR (red arrows). The green arrows represent infection/transmission flows, black arrows represent constant progression flows. Compartments stratified according to resistance profiles are shown in blue. (π–birth rate, λX—force of infection, ε–rate of early progression, κ–rate of late progression, ν–reactivation rate, γ–spontaneous recovery rate, θX–risk of re-infection once latently infected, μ–mortality rate, μi–TB-specific mortality rate, τX–treatment rate, δX—risk of re-infection after recovery)