title: Foreskin surface area and HIV acquisition in Rakai, Uganda (size matters).
abstract: BACKGROUND
  Male circumcision reduces HIV acquisition in men. We assessed whether foreskin surface area was associated with HIV acquisition prior to circumcision.
  
  
  METHODS
  In two randomized trials of male circumcision, the surface area of the foreskin was measured after surgery using standardized procedures. Nine hundred and sixty-five initially HIV-negative men were enrolled in a community cohort who subsequently enrolled in the male circumcision trials, provided 3920.8 person-years of observation prior to circumcision. We estimated HIV incidence per 100 person-years prior to circumcision, associated with foreskin surface area categorized into quartiles.
  
  
  RESULTS
  Mean foreskin surface area was significantly higher among men who acquired HIV (43.3 cm2, standard error 2.1) compared with men who remained uninfected (36.8 cm, standard error 0.5, P = 0.01). HIV incidence was 0.80/100 person-years (8/994.9 person-years) for men with foreskin surface areas in the lowest quartile (< or =26.3 cm2), 0.92/100 person-years (9/975.3 person-years) with foreskin areas in the second quartile (26.4-35.0 cm2), 0.90/100 person-years (8/888.5 person-years) with foreskin area in the third quartile (35.2-45.5 cm2) and 2.48/100 person-years (23/926.8 person-years) in men with foreskin surfaces areas in the highest quartile (>45.6 cm2). Compared with men with foreskin surface areas in the lowest quartile, the adjusted incidence rate ratio of HIV acquisition was 2.37 (95% confidence interval 1.05-5.31) in men with the largest quartile of foreskin surface area.
  
  
  CONCLUSIONS
  The risk of male HIV acquisition is increased among men with larger foreskin surface areas.
authors.affiliation: Rakai Health Sciences Program, Entebbe, Uganda. gkigozi@rhsp.org
authors.forename: Godfrey
authors.initials: G
authors.lastname: Kigozi
authors.forename: Maria
authors.initials: M
authors.lastname: Wawer
authors.forename: Absalom
authors.initials: A
authors.lastname: Ssettuba
authors.forename: Joseph
authors.initials: J
authors.lastname: Kagaayi
authors.forename: Fred
authors.initials: F
authors.lastname: Nalugoda
authors.forename: Stephen
authors.initials: S
authors.lastname: Watya
authors.forename: Fred Wabwire
authors.initials: FW
authors.lastname: Mangen
authors.forename: Noah
authors.initials: N
authors.lastname: Kiwanuka
authors.forename: Melanie C
authors.initials: MC
authors.lastname: Bacon
authors.forename: Tom
authors.initials: T
authors.lastname: Lutalo
authors.forename: David
authors.initials: D
authors.lastname: Serwadda
authors.forename: Ronald H
authors.initials: RH
authors.lastname: Gray
mesh_terms: D000293:Adolescent; D000328:Adult; D002944:Circumcision, Male; D052816:Foreskin / Q000033:anatomy & histology* / Q000821:virology; D015658:HIV Infections / Q000453:epidemiology / Q000517:prevention & control* / Q000635:transmission; D015497:HIV-1 / Q000302:isolation & purification*; D006801:Humans; D008297:Male; D008875:Middle Aged; D014454:Uganda / Q000453:epidemiology; D019562:Viral Load; D055815:Young Adult