ABSTRACT
Objective To investigate the spatio-temporal distribution characteristics of syphilis epidemic in Main-land China in 2005-2011.Methods Geographic information system was established based on the data of syphilis epidemic and demographic information from online reporting system of 3 1 provinces,municipalities and autonomous regions of Mainland China from 2005 to 2011,global indication of spatial autocorrelation(GISA),local indication of spatial autocorrelation (LISA),and spatial-temporal cluster analysis were conducted by GeoDa 0.95i and SaTScan 9.1 .1 software,high risk areas of spatial-temporal distribution of syphilis were determined.Results The number of syphilis in Mainland China in 2005-2011 were 1 841 217 cases,annual incidence was 20.07/100 000,suggesting a sign of obvious cluster distribution.Except 2011,GISA coefficient Moran’s I were statistically different.Accord-ing to LISA analysis,Jiangsu,Shanghai,Zhejiang and Fujian lay in high-high region in 2005-2009,Chongqing lay in high-low region in 2006-2008,and in 2011,no area was found in high-high region.Spatio-temporal cluster anal-ysis showed that the most likely cluster was in Shanghai and Zhejiang (2009-2011);the secondary cluster distribu-ted in five areas,including Guangdong,Guangxi and Hainan (2009-2011),Xinjiang (2009-2011),Liaoning and Jilin (2010-2011),Gansu,Ningxia,Shaanxi,Sichuan,Chongqing,Shanxi and Inner Mongolia (2011),Beijing and Tianjin (2008-2010).Conclusion Significant spatio-temporal cluster pattern is found for the distribution of syphilis in mainland China,which can be meaningful for pertinent control.