105 / 2019-10-30 09:52:44

Spatial distribution and risk factors analysis for different stage of syphilis in Mainland of China in 2012-2016

syphilis, spatial analysis, cluster detection, stage of syphilis

Backgrounds: China has recently experienced an increase in the incidence of syphilis, and there was a varied spatial distribution of reported syphilis cases across cities. This study provided a national-level insight into the distribution of hot spots using cities as the geographic units by examining spatial patterns.
Methods: We obtained the new cases of different stages of syphilis (primary syphilis, secondary syphilis, tertiary syphilis) in mainland China recorded from 2012 to 2016. Incidence maps and trend surface analysis map were made to describe the spatial patterns of syphilis. Local Moran’s I, Local Getis and temporal-spatial analysis were combined to detect clusters and hotspots. Then a univariate analysis was performed to find potential environmental risk factors.
Results: Syphilis was severe year by year from period 2012 to 2016. The incidence rates increased from west to east and decreased from south to north each year. P&S syphilis was the major cause of the disproportionate distribution while tertiary syphilis was more evenly distributed. The southeastern China formed the largest hotspot of syphilis. The number of cities becoming hospots increased greatly, from 29 to 43. Zhenjiang, Nanjing, Suzhou, Jiaxing, Hanghzou, Guilin, Zhongshan, Shenzhen etc. were hotspots that should be focus for the prevention and control. There a positive relationship between syphilis incidence with transportation. Secondary and tertiary syphilis cases got closer to railway/highway artery while primary to the contrary.
Conclusion: Southeastern China formed the largest hotspot, transportation has different effects on different stage of syphilis. Our study findings may be useful for designing syphilis prevention and control measures.