Introduction: 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 cm2, 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 (≤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.
Conclusion: The risk of male HIV acquisition is increased among men with larger foreskin surface areas.