Objective: To analyze the spatial and temporal clustering characteristics of typhoid and paratyphoid fever and its change pattern in Yunnan, Guizhou and Guangxi provinces in southwestern China in recent years. Methods: The incidence data of typhoid and paratyphoid fever cases at county level in 3 provinces during 2001-2012 were collected from China Information System for Diseases Control and Prevention and analyzed by the methods of descriptive epidemiology and geographic informatics. And the map showing the spatial and temporal clustering characters of typhoid and paratyphoid fever cases in three provinces was drawn. SaTScan statistics was used to identify the typhoid and paratyphoid fever clustering areas of three provinces in each year from 2001 to 2012. Results: During the study period, the reported cases of typhoid and paratyphoid fever declined with year. The reported incidence decreased from 30.15 per 100 000 in 2001 to 10.83 per 100 000 in 2006(annual incidence 21.12 per 100 000); while during 2007-2012, the incidence became stable, ranging from 4.75 per 100 000 to 6.83 per 100 000 (annual incidence 5.73 per 100 000). The seasonal variation of the incidence was consistent in three provinces, with majority of cases occurred in summer and autumn. The spatial and temporal clustering of typhoid and paratyphoid fever was demonstrated by the incidence map. Most high-incidence counties were located in a zonal area extending from Yuxi of Yunnan to Guiyang of Guizhou, but were concentrated in Guilin in Guangxi. Temporal and spatial scan statistics identified the positional shifting of class Ⅰ clustering area from Guizhou to Yunnan. Class Ⅰ clustering area was located around the central and western areas (Zunyi and Anshun) of Guizhou during 2001-2003, and moved to the central area of Yunnan during 2004-2012. Conclusion: Spatial and temporal clustering of typhoid and paratyphoid fever existed in the endemic areas of southwestern China, and the clustering area covered a zone connecting the central areas of Guizhou and Yunnan. From 2004 to 2012, the most important clustering area shifted from Guizhou to Yunnan. Findings from this study provided evidence for the identifying key areas for typhoid and paratyphoid fever control and prevention and allocate health resources.
目的： 分析云南、贵州、广西3省（自治区）伤寒/副伤寒流行的时空分布特点及变迁规律。 方法： 收集3省（自治区）2001－2012年以县为单位的伤寒/副伤寒发病数据，分析其时空分布特征并绘制病例分布地图。采用SaTScan时空聚类统计学方法分析3省（自治区）伤寒/副伤寒发病的时空聚集性。 结果： 2001－2012年3省（自治区）伤寒/副伤寒发病呈现总体下降趋势，2001－2006年发病率由30.15/10万降至10.83/10万（年均发病率21.12/10万）；2007－2012年发病率趋于稳定，波动于4.75/10万~6.83/10万之间（年均发病率5.73/10万）。夏秋季为3省（自治区）伤寒/副伤寒流行的高发季节。发病地图显示，3省（自治区）伤寒/副伤寒发病的聚集性明显：云南、贵州两省的高发县集中于玉溪至贵阳的带状区域，广西壮族自治区高发县集中于桂林地区。时空扫描统计分析显示，2001－2003年3省（自治区）伤寒/副伤寒发病的一级聚集区位于贵州省中西部的遵义、安顺等县（市）；2004－2012年一级聚集区迁移并固定于云南省中部的玉溪等县（市）。 结论： 我国西南3省（自治区）伤寒/副伤寒发病存在时空聚集性，高发聚集区位于贵州、云南两省中部的带状区域。2004年以后主要发病聚集区由贵州省转移至云南省。.
Keywords: Clustering; Spatial and temporal characteristics; Typhoid and paratyphoid fever.