关键词: 恙虫病, 时空聚集性, 空间自相关

Abstract: Objective To analyze the epidemiological characteristics and spatiotemporal clustering of scrub typhus in Jiangsu province, China, and to provide a reference for the development of prevention and control strategies and measures of scrub typhus. Methods Descriptive epidemiological method, spatial autocorrelation, and spatiotemporal clustering were used to analyze the spatiotemporal distribution characteristics of scrub typhus and identify high-risk areas in Jiangsu province during 2008-2017. ArcGIS 10.2 software was used to visualize the results. Results A total of 7 950 cases were reported in Jiangsu province during 2008-2017, and the mean annual incidence was 1.01/100 000. Farmers were the high-risk population. Women had a higher incidence rate of scrub typhus than men. The cases were mainly concentrated in the population aged 45-80 years. The global Moran's I index was 0.130 (P=0.023), indicating the presence of a high value or low value clustering area. The local autocorrelation analysis results showed that "High-High" clustering areas were mainly located in Dafeng district, Dongtai city, and Binhai county, and "High-Low" clustering area was mainly located in Jingjiang city. The temporal scan analysis results showed that the distribution of scrub typhus cases in Jiangsu province had obvious temporal clustering and cases occurred primarily from October to November in each year. The spatial scan analysis results showed that the distribution of cases had obvious spatial clustering; the spatial clustering areas during 2008-2017 had an expanding tendency from middle east to west, south, and north, and the radiation radius of the clustering areas and the number of covered districts or counties all reached the maximum during 2014-2016. Spatiotemporal scan analysis found one clustering area with high incidence from October 2013 to December 2017; its center was Jianhu county of Yancheng, and the radiation radius was 166.68 km (risk ratio=14.45, log-likelihood ratio=6 295.90, P<0.01). Conclusion The distribution of scrub typhus cases in Jiangsu province shows clustering in both dimensions of time and space, and the number of clustering areas with high incidence increases gradually. It should be considered to strengthen the monitoring of scrub typhus and the prevention and control of scrub typhus in key areas.

Key words: Scrub typhus, Spatiotemporal clustering, Spatial autocorrelatio