consequences of landscape fragmentation on lyme disease risk a cellular automata approach景观破碎度的后果对莱姆病风险元胞自动机的方法.pdfVIP

Consequences of Landscape Fragmentation on Lyme Disease Risk: A Cellular Automata Approach 1 1 2 1 Sen Li *, Nienke Hartemink , Niko Speybroeck , Sophie O. Vanwambeke ˆ ´ 1 Georges Lemaıtre Centre for Earth and Climate Research, Earth and Life Institute, Universite catholique de Louvain, Louvain-la-Neuve, Belgium, 2 Institute of Health and ´ Society (IRSS), Universite catholique de Louvain, Brussels, Belgium Abstract The abundance of infected Ixodid ticks is an important component of human risk of Lyme disease, and various empirical studies have shown that this is associated, at least in part, to landscape fragmentation. In this study, we aimed at exploring how varying woodland fragmentation patterns affect the risk of Lyme disease, through infected tick abundance. A cellular automata model was developed, incorporating a heterogeneous landscape with three interactive components: an age- structured tick population, a classical disease transmission function, and hosts. A set of simplifying assumptions were adopted with respect to the study objective and field data limitations. In the model, the landscape influences both tick survival and host movement. The validation of the model was performed with an empirical study. Scenarios of various landscape configurations (focusing on woodland fragmentation) were simulated and compared. Lyme disease risk indices (density and infection prevalence of nymphs) differed considerably between scenarios: (i) the risk could be higher in highly fragmented woodlands, which is supported by a number of recently published empirical studies, and (ii) grassland could reduce t