Wang Xiunan, Zhao Xiao-Qiang
Department of Mathematics and Statistics, Memorial University of Newfoundland, St. John's, NL, A1C 5S7, Canada.
Bull Math Biol. 2017 May;79(5):1155-1182. doi: 10.1007/s11538-017-0276-3. Epub 2017 Apr 7.
Malaria is an infectious disease caused by Plasmodium parasites and is transmitted among humans by female Anopheles mosquitoes. Climate factors have significant impact on both mosquito life cycle and parasite development. To consider the temperature sensitivity of the extrinsic incubation period (EIP) of malaria parasites, we formulate a delay differential equations model with a periodic time delay. We derive the basic reproduction ratio [Formula: see text] and establish a threshold type result on the global dynamics in terms of [Formula: see text], that is, the unique disease-free periodic solution is globally asymptotically stable if [Formula: see text]; and the model system admits a unique positive periodic solution which is globally asymptotically stable if [Formula: see text]. Numerically, we parameterize the model with data from Maputo Province, Mozambique, and simulate the long-term behavior of solutions. The simulation result is consistent with the obtained analytic result. In addition, we find that using the time-averaged EIP may underestimate the basic reproduction ratio.
疟疾是一种由疟原虫寄生虫引起的传染病,通过雌性按蚊在人类之间传播。气候因素对蚊子的生命周期和寄生虫发育都有重大影响。为了考虑疟原虫外在潜伏期(EIP)的温度敏感性,我们构建了一个具有周期时滞的延迟微分方程模型。我们推导了基本再生数[公式:见原文],并根据[公式:见原文]建立了关于全局动态的阈值型结果,即如果[公式:见原文],则唯一的无病周期解是全局渐近稳定的;如果[公式:见原文],则模型系统存在唯一的全局渐近稳定的正周期解。在数值上,我们用来自莫桑比克马普托省的数据对模型进行参数化,并模拟解的长期行为。模拟结果与得到的解析结果一致。此外,我们发现使用时间平均的EIP可能会低估基本再生数。