title: Male circumcision and risk of HIV acquisition among MSM.
abstract: OBJECTIVE
  To assess the association between male circumcision, insertive anal sex practices, and HIV acquisition in a cohort of MSM.
  
  
  METHODS
  Data were from 1824 HSV-2-seropositive, HIV-seronegative MSM, 1362 (75%) from Peru and 462 (25%) from the US, who participated in a randomized placebo-controlled trial of HSV-2 suppression for HIV prevention (HPTN 039). Circumcision status was determined by examination at enrollment. HIV testing was done every 3 months for up to 18 months. Partner-specific sexual behavior for up to the last three partners during the previous 3 months was analyzed.
  
  
  RESULTS
  There was no significant association between male circumcision and HIV acquisition in univariate analysis [relative risk (RR) = 0.84, 95% confidence interval (CI) 0.50-1.42]. In a prespecified multivariate analysis that assumed a linear relationship between the proportion of insertive acts and effect of circumcision on HIV acquisition, the interaction between circumcision and proportion of insertive acts was not significant (P = 0.11). In an exploratory analysis that categorized behavior with recent partners by proportion of insertive acts (<60 or ≥60% insertive acts), circumcision was associated with a nonstatistically significant 69% reduction in the risk of HIV acquisition (RR = 0.31, 95% CI 0.06-1.51) among men who reported at least 60% of insertive acts with recent male partners.
  
  
  CONCLUSIONS
  Circumcision does not have a significant protective effect against HIV acquisition among MSM from Peru and US, although there may be reduced risk for men who are primarily insertive with their male partners. This association needs to be investigated across diverse cohorts of MSM.
authors.affiliation: Asociacion Civil Impacta Salud y Educacion, Lima, Peru. jsanchez@impactaperu.org
authors.forename: Jorge
authors.initials: J
authors.lastname: Sánchez
authors.forename: Victor G
authors.initials: VG
authors.lastname: Sal Y Rosas
authors.forename: James P
authors.initials: JP
authors.lastname: Hughes
authors.forename: Jared M
authors.initials: JM
authors.lastname: Baeten
authors.forename: Jonathan
authors.initials: J
authors.lastname: Fuchs
authors.forename: Susan P
authors.initials: SP
authors.lastname: Buchbinder
authors.forename: Beryl A
authors.initials: BA
authors.lastname: Koblin
authors.forename: Martín
authors.initials: M
authors.lastname: Casapia
authors.forename: Abner
authors.initials: A
authors.lastname: Ortiz
authors.forename: Connie
authors.initials: C
authors.lastname: Celum
mesh_terms: D000328:Adult; D002944:Circumcision, Male / Q000706:statistics & numerical data*; D015658:HIV Infections / Q000453:epidemiology* / Q000517:prevention & control; D006558:Herpes Genitalis / Q000453:epidemiology* / Q000517:prevention & control; D018258:Herpesvirus 2, Human; D018451:Homosexuality, Male / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010568:Peru / Q000453:epidemiology; D012725:Sexual Behavior; D012747:Sexual Partners; D014481:United States / Q000453:epidemiology