Epidemic Dynamics of Cholera in Non-homogeneous Environments

主讲人：王雪莹 华盛顿州立大学副教授

时间：2019年6月19日15：30

地点：3号楼332室

举办单位：数理学院

主讲人介绍：王雪莹，2009年毕业于美国俄亥俄州立大学（The Ohio State  University）数学系，获理学博士学位。2009-2010年和2010-2013年先后在美国统计与应用数学科学研究所（Statistical and  Applied Mathematical Sciences Institute）和德克萨斯A&M大学（Texas A&M  University）应用数学与计算科学研究所（Institute of Applied Mathematics and Computational  Science）从事博士后研究。2013年起任职于华盛顿州立大学数学与统计系至今。主要研究方向为生物数学、随机过程、动力系统、微分方程参数估计等，在SIAM J  Math Anal、J Math Anal Appl、J Math Biol、Math Biosci等权威学术期刊发表论文20多篇。

内容介绍：The transmission of cholera, a water- and food-borne intestinal infection,  involves complex interactions among human hosts, pathogens, and the environment.  This talk will address the epidemic dynamics of cholera in non-homogenous  environments, with a focus on the spatial variation, seasonal fluctuation and  bacterial hyperinfectivity, using partial differential equation models. The  presentation will consist of two parts. In the first part, we will discuss  seasonality and spatial heterogeneity. The model we employ is built on a  reaction-convection-diffusion system to represent the spatial movement of the  hosts and pathogens, and incorporates time-periodic parameters to describe the  seasonality of the disease transmission and bacterial growth. Using the next  generation method, we define and analyze the basic reproduction number of this  model, based on which we establish the threshold type results for cholera  transmission in a spatiotemporally heterogeneous environment. In the second  part, we develop a new modeling framework to study the effect of bacterial  hyperinfectivity on cholera epidemics in a spatially non-homogeneous  environment. For the second model, the global threshold dynamics is established.  The global attractivity of the unique endemic equilibrium is derived in a  special case. We then investigate the dependence of the basic reproduction  number on model parameters by theoretical and numerical means. Our findings  highlight the importance of seasonality, hyperinfectivity and their interplay  with spatial variation. The result indicate that the prevention and intervention  strategies need to take into account the non-homogeneity of the environments in  order to effectively control cholera while optimize the use of available  resources.