Epidemic Dynamics of Cholera in Non-homogeneous Environments


主講人:王雪瑩 華盛頓州立大學副教授




主講人介紹:王雪瑩,2009年畢業于美國俄亥俄州立大學(The Ohio State  University)數學系,獲理學博士學位。2009-2010年和2010-2013年先后在美國統計與應用數學科學研究所(Statistical and  Applied Mathematical Sciences Institute)和德克薩斯A&M大學(Texas A&M  University)應用數學與計算科學研究所(Institute of Applied Mathematics and Computational  Science)從事博士后研究。2013年起任職于華盛頓州立大學數學與統計系至今。主要研究方向為生物數學、隨機過程、動力系統、微分方程參數估計等,在SIAM J  Math Anal、J Math Anal Appl、J Math Biol、Math Biosci等權威學術期刊發表論文20多篇。

內容介紹: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.