(a) Solution of the stochastic SEUIR
equations (5.2)
with initial conditions S = 106, E = 102, U = 0, I = 0, R = 0. The parameter settings are β = 0.9, z = 0.3, w = 0.2, d = 0.5. (b) Ratios U(t)/E(t) and I(t)/E(t) (blue traces) compared with b = 0.16 and c = 0.32 calculated from
(5.4), shown in red. (Color available online.)