title: Stages of syphilis in South China - a multilevel analysis of early diagnosis.
abstract: Early diagnosis of syphilis and timely treatment can effectively reduce ongoing syphilis transmission and morbidity. We examined the factors associated with the early diagnosis of syphilis to inform syphilis screening strategic planning.
  
  
  
  In an observational study, we analyzed reported syphilis cases in Guangdong Province, China (from 2014 to mid-2015) accessed from the national case-based surveillance system. We categorized primary and secondary syphilis cases as early diagnosis and categorized latent and tertiary syphilis as delayed diagnosis. Univariate analyses and multivariable logistic regressions were performed to identify the factors associated with early diagnosis. We also examined the factors associated with early diagnosis at the individual and city levels in multilevel logistic regression models with cases nested by city (n = 21), adjusted for age at diagnosis and gender.
  
  
  
  Among 83,944 diagnosed syphilis cases, 22% were early diagnoses. The city-level early diagnosis rate ranged from 7 to 46%, consistent with substantial geographic variation as shown in the multilevel model. Early diagnosis was associated with cases presenting to specialist clinics for screening, being male and attaining higher education level. Cases received syphilis testing in institutions and hospitals, and diagnosed in hospitals were less likely to be in early diagnosis. At the city-level, cases living in a city equipped with more hospitals per capita were less likely to be early diagnosis.
  
  
  
  To enhance early diagnosis of syphilis, city-specific syphilis screening strategies with a mix of passive and client/provider-initiated testing might be a useful approach.
authors.affiliation: University of North Carolina Project-China, Guangzhou, China.|Institute for Global Health & Infectious Diseases, University of North Carolina at Chapel Hill, Chapel Hill, USA.
authors.forename: Ngai Sze
authors.initials: NS
authors.lastname: Wong
authors.affiliation: Guangdong Provincial Center for Skin Diseases and STI Control, Guangzhou, China.
authors.forename: Shujie
authors.initials: S
authors.lastname: Huang
authors.affiliation: Guangdong Provincial Center for Skin Diseases and STI Control, Guangzhou, China.
authors.forename: Heping
authors.initials: H
authors.lastname: Zheng
authors.affiliation: Guangdong Provincial Center for Skin Diseases and STI Control, Guangzhou, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Chen
authors.affiliation: Guangdong Provincial Center for Skin Diseases and STI Control, Guangzhou, China.
authors.forename: Peizhen
authors.initials: P
authors.lastname: Zhao
authors.affiliation: University of North Carolina Project-China, Guangzhou, China.|Institute for Global Health & Infectious Diseases, University of North Carolina at Chapel Hill, Chapel Hill, USA.
authors.forename: Joseph D
authors.initials: JD
authors.lastname: Tucker
authors.affiliation: Guangdong Provincial Center for Skin Diseases and STI Control, Guangzhou, China.
authors.forename: Li Gang
authors.initials: LG
authors.lastname: Yang
authors.affiliation: Guangdong Provincial Center for Skin Diseases and STI Control, Guangzhou, China.|Royal London Hospital, London, UK.
authors.forename: Beng Tin
authors.initials: BT
authors.lastname: Goh
authors.affiliation: Guangdong Provincial Center for Skin Diseases and STI Control, Guangzhou, China. yangbin101@hotmail.com.
authors.forename: Bin
authors.identifier: 0000-0002-7155-6079
authors.initials: B
authors.lastname: Yang
mesh_terms: D000328:Adult; D002681:China / Q000453:epidemiology; D003140:Communicable Disease Control / Q000379:methods*; D042241:Early Diagnosis; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D055361:Multilevel Analysis; D013587:Syphilis / Q000175:diagnosis* / Q000453:epidemiology
keywords: China; Diagnosis; Screening; Syphilis