中国鼠疫宿主鼠类丰富度格局及疫区环境因子分析

Analysis on species richness pattern of plague host rodents and the environmental factor in plague epidemic areas in China

鼠疫等媒介疾病地理分布规律的认识对于疫病防控具有重要意义,分析影响疾病地理分布的因素进而预测疾病发生趋势已经成为目前研究的热点。本文在分析鼠间鼠疫及其宿主鼠类地理分布数据以及相关环境数据的基础上,探讨了鼠疫宿主丰富度与环境因子的关系以及影响鼠间鼠疫发生的主要环境因素。我国的鼠疫宿主鼠类在干旱区和季风区过渡带的县级行政单元中物种丰富度最高,物种丰富度与高度差正相关性最高。发生鼠间鼠疫的地区,宿主鼠类丰富度较高,未发生鼠间鼠疫的地区,宿主鼠类丰富度较低。影响鼠间鼠疫发生的主要环境因子包括蚤类物种数、年均气温、年降雨量、年均相对湿度和年日照时数和气候因子,其次是包括高度差、植被类型数、土壤类型数和地貌类型数的景观因子,以及反映海拔和宿主鼠类物种数的地形和宿主鼠类因子。在未来全国气候变干变暖条件下,我国鼠间鼠疫发病区可能随宿主鼠类的迁移而扩展。

Understanding the geographical distribution of plague and other vector diseases is helpful for the disease prevention and control. It is important to analyze the factors affecting the geographic distribution of the vector diseases,and then to predict their occurrence trends. In this study,the relationship between the species richness of host rodents and environment factors nationwide,and the principal factors that affected the rodent plague,were analyzed on the basis of environment data and the geographical distribution of rodent epizootic and host rodents. The results show that the highest species richness of host rodents was in the boundaries of arid and monsoon regions,with the highest positively correlated to altitude difference. The species richness of host rodents was relatively higher in regions where rodent plague had occurred,and relatively lower in non-plague regions. Factor analysis on the environmental variables which affected the occurrence of rodent plague reveals that numbers of vector fleas,annual temperature,rainfall,average relative humidity and sunny hours are factors and the climate factor played a dominant role; that landscape factor,which was composed of altitude differences and numbers of vegetation,soil and geomorphic types was another principal factor; and that the third factor was topography and host. Regions where rodent plague may occur might spread together with the migration of the host rodents under conditions of national climate change to more aridity and warmth.