title: Sex with older partners is associated with primary HIV infection among men who have sex with men in North Carolina.
abstract: BACKGROUND
  Studies from the 1990s suggested sex with older partners was associated with HIV infection. We evaluated the hypothesized association between primary HIV infection (PHI) and having older sexual partners among men who have sex with men (MSM).
  
  
  METHODS
  MSM with PHI and HIV-uninfected MSM completed audio computer-assisted self-interviews exploring behaviors involving their 3 most recent sexual partners before enrollment (if uninfected) or diagnosis (if PHI).
  
  
  RESULTS
  Of 74 men reporting any lifetime sex with men, 20 had PHI (27%). Demographics (including age) were similar between groups; 39% were non-white and 74% identified as gay. The mean age of sex partners differed significantly: men with PHI had partners on average 6 years older than themselves, whereas uninfected men's partners were 4 months their junior (P < 0.001). After adjusting for race, sex while intoxicated, and having a serodiscordant/serostatus unknown partner, a participant had twice the odds of PHI if his sex partner was 5 years his senior (odds ratio 2.0, 95% confidence interval: 1.2 to 3.3).
  
  
  CONCLUSIONS
  Among a sample of young MSM, the odds of HIV infection increased significantly as the age of sexual partners increased. These findings can inform behavioral interventions in communities of at-risk MSM and secondary prevention efforts among those already living with HIV.
authors.affiliation: Department of Medicine, Division of Infectious Diseases, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7030, USA. churt@med.unc.edu
authors.forename: Christopher B
authors.initials: CB
authors.lastname: Hurt
authors.forename: Derrick D
authors.initials: DD
authors.lastname: Matthews
authors.forename: Molly S
authors.initials: MS
authors.lastname: Calabria
authors.forename: Kelly A
authors.initials: KA
authors.lastname: Green
authors.forename: Adaora A
authors.initials: AA
authors.lastname: Adimora
authors.forename: Carol E
authors.initials: CE
authors.lastname: Golin
authors.forename: Lisa B
authors.initials: LB
authors.lastname: Hightow-Weidman
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D016001:Confidence Intervals; D015658:HIV Infections / Q000453:epidemiology / Q000635:transmission*; D018451:Homosexuality, Male; D006801:Humans; D007407:Interviews as Topic; D008297:Male; D008875:Middle Aged; D009657:North Carolina / Q000453:epidemiology; D016017:Odds Ratio; D012307:Risk Factors; D012725:Sexual Behavior; D012747:Sexual Partners; D055815:Young Adult