González-Guzmán J
Math Biosci. 1989 Sep;96(1):33-46. doi: 10.1016/0025-5564(89)90081-3.
The modified SIS epidemiological model considers the usual direct transmission (short cycle) and indirect transmission (long cycle) of typhoid fever. Thresholds are determined, and the equilibrium points are shown to be globally stable. Local stability of the equilibrium points is shown in the corresponding model with vaccines. After estimating parameters using current statistical data for typhoid fever in Chile, computer simulations are used to obtain the numerical behavior of this disease and to estimate the effect of several control policies.
改进后的SIS流行病学模型考虑了伤寒热常见的直接传播（短周期）和间接传播（长周期）。确定了阈值，并证明平衡点是全局稳定的。在相应的疫苗模型中展示了平衡点的局部稳定性。利用智利当前伤寒热的统计数据估计参数后，通过计算机模拟来获得该疾病的数值行为，并估计几种控制策略的效果。
