Figure 8.
A comparison between deterministic and stochastic versions of the model with population structure. There are four subpopulations, the total size of the population being N=500, the migration rate is 10−3, and prophylaxis starts on day 10. The smooth curve is the prediction of the deterministic model, and the box and whiskers plots summarize realizations of the stochastic model (again we show here only the realizations in which there was at least one secondary case among the 100 runs). (a) Infected cases over time. (b) Resistant cases over time. Note that with population structure the difference between stochastic and deterministic simulations is mainly due to the stochasticity of migration.