2013-2014年中国地区人感染H7N9禽流感疫情空间分布格局及时空聚集模式研究

A research on the spatial distribution structure and spatiotemporal clustering of A (H7N9) human infections in China during 2013 and 2014

目的了解2013年3月~2014年12月期间中国地区人感染H7N9禽流感疫情的时空聚集模式和时空传播特点。方法利用整理好的疫情病例数据,基于描述性统计分析、标准差椭圆分析及时空扫描聚类分析方法,对我国人感染H7N9禽流感各月疫情的时空分布特点、空间分布格局以及时空聚集模式进行研究。结果研究期间每年的冬春季为疫情流行的相对高峰期,疫情高发区域集中于中国东部及东南沿海一带地区(如浙江、广东、江苏、福建及上海),疫情的空间分布格局经历了初始于中国东部局部地区——沿中国东部向东南沿海地区蔓延——由东南沿海地区向中部及西部地区扩散的过程;2013年4月探测到一个最有可能的疫情时空聚集(P<0.001)及一个次要的疫情时空聚集(P=0.029),此外2014年1月、2014年2月及2014年4月各发现一个最有可能的疫情时空聚集(均有P<0.05)。结论由于中国地区人感染H7N9禽流感疫情空间分布格局与时空聚集模式之间的差异性,疫情的传播呈现出总体扩张但局部聚集的不平衡的特性,同时疫情具有明显的季节性流行特点,相关部门应根据疫情传播特点科学制定防控措施。

Objective To investigate the development of spatiotemporal clustering and spreading characteristics of A（H7N9） human infections from March 2013 to December 2014 in China. Methods Data were collected from processed A （H7N9） infection cases. Descriptive statistics analysis, standard deviation ellipse analysis and space-time scan clustering analysis method were used to study the spatiotemporal distribution characteristic, the spatial distribution structure and spatiotemporal clustering of H7N9 outbreaks in each month in China. Results During the study period, the HTN9 epi- demics peaked in winter and spring of each year. The high-risk areas of the outbreak concentrated in the eastern and southeast coastal areas of China （such as Zhejiang, Guangdong, Jiangsu, Fujian and Shanghai）. The spatial distribution structure of HTN9 outbreaks originated from the eastern areas of China, spread along eastern areas to the southeast coastal of China and finally expanded to the central and western regions of China. The scan test identified a most likely cluster（ P 〈 0. 001 ） and a secondary cluster（P = 0. 029） of H7N9 outbreaks in April 2013, in addition, there was a most likely cluster in each month of January 2014, February 2014 and April 2014 （ all P 〈 0. 05）. Conclusions Due to the differences between the spatial distribution structure and spatiotemporal clustering pattern of A（HTNg） human infections in China, the spread process of the epidemic presented an unbalanced characteristic with a combination of the overall expansion and the local accumulation, and the outbreak has obvious seasonal epidemic characteristics. Therefore, relevant departments should develop prevention and control strategies scientifically based on the spreading characteristics of H7N9 epidemic.