Fig. 2.

Schematic diagram of the disease transmission model. Each circle represents one of model compartments, arrows represent transitions between compartments, and letters above/below arrows represent the rates of those transitions. The pairs $(\nu ,K_1)$ and $(\gamma ,K_2)$ describe, respectively, incubation/latency period and infectious/recovery period, where the first element of each pair is the corresponding rate of transition, which is equal to the inverse of the average corresponding period, and the second element of each pair describes the number of stages in the gamma distribution of that time period.