title: Systematic differences in risk behaviors and syphilis prevalence across types of female sex workers: a preliminary study in Liuzhou, China.
abstract: BACKGROUND
  Female sex workers (FSWs) have become one of the key populations for HIV/STI control in China. Categorization of FSWs can help prioritize HIV/STI intervention efforts. We examined 2 possible categorizations of FSWs and the relationship with syphilis infection risk in Liuzhou City, China.
  
  
  METHODS
  From October 2009 to February 2010, a total of 583 FSWs recruited by respondent-driven sampling in a cross-sectional survey were tested for syphilis and interviewed to collect sociodemographic and behavioral information. Respondents were categorized based on transaction price for vaginal sex and type of sex work location. The relationship between the 2 categorizations and syphilis infection risk was assessed using univariate and multivariate logistic regression analysis.
  
  
  RESULTS
  The prevalence rates of lifetime and active syphilis infection were 8.6% and 4.1%, respectively. Lifetime and active syphilis prevalence was higher among FSWs in the lowest price category (52.7% and 25.4%, respectively) and those working in streets (69.7% and 39.8%, respectively) or through telephone (46.3% and 17.0%, respectively). Multivariate analysis showed that lifetime syphilis prevalence was significantly higher among street- (adjusted odds ratio [AOR]: 38.7, 95% confidence intervals [CI]: 10.7-139.9) and telephone-based FSWs (AOR: 10.8, 95% CI: 3.3-35.1), and that active syphilis prevalence was significantly higher among street-based FSWs (AOR: 15.2, 95% CI: 3.7-62.1) after adjusting for demographic and behavioral factors.
  
  
  CONCLUSIONS
  Categorization based on sex work location was more closely related to the risk of syphilis infection than the price classification. Street- and telephone-based FSWs had significantly higher risk of syphilis infection. Focused interventions among these particular high-risk FSWs subgroups are warranted.
authors.affiliation: National Center for STD Control, Chinese Academy of Medical Science & Peking Union Medical College Institute of Dermatology, Nanjing, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.forename: Xiang-Sheng
authors.initials: XS
authors.lastname: Chen
authors.forename: M Giovanna
authors.initials: MG
authors.lastname: Merli
authors.forename: Sharon S
authors.initials: SS
authors.lastname: Weir
authors.forename: Gail E
authors.initials: GE
authors.lastname: Henderson
mesh_terms: D000293:Adolescent; D000328:Adult; D002681:China / Q000453:epidemiology; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008875:Middle Aged; D015995:Prevalence; D012307:Risk Factors; D011477:Sex Work; D060386:Sex Workers / Q000145:classification* / Q000706:statistics & numerical data; D013587:Syphilis / Q000453:epidemiology* / Q000635:transmission; D047568:Unsafe Sex; D055815:Young Adult