Multilevel and spatial analysis of syphilis in Shenzhen, China, to inform spatially targeted control measures
- Xiaobing Wu1,
- Joseph D Tucker2,3,
- Fuchang Hong1,
- Jane Messina4,
- Lina Lan1,
- Yufeng Hu1,
- Tiejian Feng1,
- Michael E Emch4,
- Xiaoli Liu1,
- Chunlai Zhang1,
- Lizhang Wen1
- 1Shenzhen Center for Chronic Disease Control, Shenzhen, China
- 2Infectious Diseases Unit, Massachusetts General Hospital, Boston, Massachusetts, USA
- 3Division of Infectious Diseases, School of Medicine, UNC Chapel Hill, Chapel Hill, North Carolina, USA
- 4Department of Geography, University of North Carolina Chapel Hill, Chapel Hill, North Carolina, USA
- Correspondence to Tiejian Feng, Associate Director, Shenzhen Center for Chronic Disease Control and Prevention, No.2021, Buxin Road, Luohu District, Shenzhen, Guangdong, China;
Contributors XW, FH, TF and XL were local medical staffs and contributed to designing the study, coordinating data collection, supervision and making important comments of the manuscript. JDT contributed to data interpretation, drafting the article and revising it critically for important intellectual content. JM contributed to acquisition and interpretation of data, drafting the article and revising it critically for important intellectual content. ME contributed to the conception and design of the study, interpretation of the data, drafting the article and revising it for important intellectual content. LL, YH, CZ and XW contributed to doing literature review, designing the questionnaire and collecting data. All authors approved the final version of the manuscript.
- Accepted 5 February 2012
- Published Online First 29 February 2012
Objectives The present study investigates the varied spatial distribution of syphilis cases in Shenzhen, China, and explores the individual-, neighbourhood- and district-level factors affecting the distribution.
Methods This study uses spatial analysis and multi-level generalised estimating equations to explore the spatial distribution of reported syphilis cases among individuals in Shenzhen, Guangdong Province, China. The spatial distribution of primary/secondary and latent cases was investigated using the Moran's I-statistic. Primary/secondary syphilis cases were compared with all syphilis cases using a three-level model with individual (n=6496), neighbourhood (n=55) and district (n=6) levels.
Results A total of 6496 syphilis cases were reported in 2009 with 35.8% primary and secondary syphilis cases. Both primary/secondary syphilis cases (Moran's I value=0.33, p<0.01) and latent syphilis cases (Moran's I value=0.19, p<0.01) showed significant spatial clustering at the neighbourhood level. Adjusting for the number of reporting hospitals, the best model found that the following characteristics were associated with primary/secondary syphilis infection: individuals who are younger in age (p=0.003), male (p<0.001), migrant labourers (p=0.047) and those who live in districts with a higher gross domestic product (p<0.001).
Conclusions There is substantial clustering of primary and secondary syphilis cases at the neighbourhood level in Shenzhen, suggesting the need for greater STD health service provision in these clustered neighbourhoods. Spatially targeted syphilis control measures may be useful to optimise testing, treatment and partner services.
- sexual behaviour
- sexual health
- social/policy perspectives
Funding This work was supported by grants from the Shenzhen Municipal Health Bureau for STI Prevention and Control Program, the Mega Project of China National Science Research for the 11th 5-year Plan (2008ZX10001-005) and an NIH Fogarty Career Development Award (US NIH 1K01TW008200-01A1).
Competing interests None.
Provenance and peer review Not commissioned; externally peer reviewed.