title: Risk factors for HIV seroconversion in men who have sex with men in Victoria, Australia: results from a sentinel surveillance system.
abstract: OBJECTIVE
  HIV diagnosis rates in men who have sex with men (MSM) began increasing in Australia 10 years ago, and there has been a major resurgence of syphilis. We determined predictors of HIV positivity and seroconversion among MSM in Victoria, Australia.
  
  
  METHODS
  We conducted a retrospective longitudinal analysis of data from MSM who underwent HIV testing between April 2006 and June 2009 at three primary care clinics. Logistic regression was used to determine predictors of HIV positivity and seroconversion.
  
  
  RESULTS
  During the study period, 7857 MSM tested for HIV. Overall HIV positivity was 1.86% (95% confidence interval (CI): 1.6-2.2). There were 3272 repeat testers followed for 4837 person-years (PY); 60 seroconverted and HIV incidence was 1.24 (95% CI: 0.96-1.60) per 100 PY. Independent predictors of HIV seroconversion were: an infectious syphilis diagnosis within the last 2 years (adjusted hazard ratio (AHR)=2.5, 95% CI: 1.1-5.7), reporting six or more anal sex partners in the past 6 months (AHR=3.3, 95% CI: 1.8-6.3), reporting an HIV-positive current regular partner (AHR=3.4, 95% CI: 1.1-10.6) and reporting inconsistent condom use with casual partners in the past 6 months (AHR=4.4, 95% CI: 1.7-11.5).
  
  
  CONCLUSIONS
  Our results call for HIV prevention to target high-risk MSM, including men with a recent syphilis diagnosis or a high numbers of partners, men who have unprotected anal sex with casual partners and men in serodiscordant relationships. The HIV incidence estimate will provide a baseline to enable public health officials to measure the effectiveness of future strategies.
authors.affiliation: National Centre in HIV Epidemiology and Clinical Research, 45 Beach Street, Coggee, NSW 2031, Australia. Rguy@nchecr.unsw.edu.au
authors.forename: Rebecca J
authors.initials: RJ
authors.lastname: Guy
authors.forename: Tim
authors.initials: T
authors.lastname: Spelman
authors.forename: Mark
authors.initials: M
authors.lastname: Stoove
authors.forename: Carol
authors.initials: C
authors.lastname: El-Hayek
authors.forename: Jane
authors.initials: J
authors.lastname: Goller
authors.forename: Christopher K
authors.initials: CK
authors.lastname: Fairley
authors.forename: David
authors.initials: D
authors.lastname: Leslie
authors.forename: Bk
authors.initials: B
authors.lastname: Tee
authors.forename: Norman
authors.initials: N
authors.lastname: Roth
authors.forename: Andrew E
authors.initials: AE
authors.lastname: Grulich
authors.forename: Margaret E
authors.initials: ME
authors.lastname: Hellard
mesh_terms: D017088:AIDS-Related Opportunistic Infections / Q000453:epidemiology / Q000635:transmission; D000328:Adult; D017280:Condoms / Q000706:statistics & numerical data; D003430:Cross-Sectional Studies; D006679:HIV Seropositivity / Q000453:epidemiology* / Q000635:transmission; D018451:Homosexuality, Male / Q000706:statistics & numerical data*; D006801:Humans; D015994:Incidence; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D011320:Primary Health Care / Q000706:statistics & numerical data; D012189:Retrospective Studies; D012307:Risk Factors; D018571:Sentinel Surveillance; D012747:Sexual Partners; D013587:Syphilis / Q000453:epidemiology; D047568:Unsafe Sex / Q000706:statistics & numerical data; D014739:Victoria; D055815:Young Adult