HIV This Week

Foreskin surface area and HIV acquisition in Rakai, Uganda (size matters).

Kigozi G, Wawer M, Ssettuba A, Kagaayi J, Nalugoda F, Watya S, Mangen FW, Kiwanuka N, Bacon MC, Lutalo T, Serwadda D, Gray RH. AIDS. 2009; 23:2209-13.

Male circumcision reduces HIV acquisition in men. The authors assessed whether foreskin surface area was associated with HIV acquisition prior to circumcision. 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. They estimated HIV incidence per 100 person-years prior to circumcision, associated with foreskin surface area categorized into quartiles. 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. The risk of male HIV acquisition is increased among men with larger foreskin surface areas.

For access to abstract click here: 1

Editors’ note: This retrospective cohort study is the first study examining the association between foreskin surface area and risk of HIV acquisition – and its findings are biologically plausible. Removing the foreskin reduces the risk of HIV acquisition by 50 to 60% because the only remaining unkeratinized mucosa on the penis after circumcision is the urethral meatus (opening). Before circumcision, more foreskin means more HIV target cells in the inner mucosa of the prepuce exposed to vaginal fluids during sex, likely more of the traumatic micro lesions that are open doors for HIV, and more genital ulcers that have welcoming mats out for HIV. In this study, risk of HIV acquisition in men with the largest foreskins was more than twice that of those with the smallest, leading to the claim that size matters. The larger your foreskin, the more you should think about getting it removed if you might be exposed to HIV now or later.

Circumcision and risk of HIV infection in Australian homosexual men.

Templeton DJ, Jin F, Mao L, Prestage GP, Donovan B, Imrie J, Kippax S, Kaldor JM, Grulich AE. AIDS. 2009;23:2347-51.

The aim of the study was to assess circumcision status as a risk factor for HIV seroconversion in homosexual men. The Health in Men (HIM) study was a prospective cohort of homosexual men in Sydney, Australia. HIV-negative men (n = 1426) were recruited primarily from community-based sources between 2001 and 2004 and followed to mid-2007. Participants underwent annual HIV testing, and detailed information on sexual risk behaviour was collected every 6 months. The main outcome measure was HIV incidence in circumcised compared with uncircumcised participants, stratified by whether or not men predominantly practised the insertive role in anal intercourse. There were 53 HIV seroconversions during follow-up; an incidence of 0.78 per 100 person-years. On multivariate analysis controlling for behavioural risk factors, being circumcised was associated with a nonsignificant reduction in risk of HIV seroconversion [hazard ratio 0.78, 95% confidence interval (CI) 0.42-1.45, P = 0.424]. Among one-third of study participants who reported a preference for the insertive role in anal intercourse, being circumcised was associated with a significant reduction in HIV incidence after controlling for age and unprotected anal intercourse (UAI) (hazard ratio 0.11, 95% CI 0.03-0.80, P = 0.041). Those who reported a preference for the insertive role overwhelmingly practised insertive rather than receptive UAI. Overall, circumcision did not significantly reduce the risk of HIV infection in the Health in Men cohort. However, it was associated with a significant reduction in HIV incidence among those participants who reported a preference for the insertive role in anal intercourse. Circumcision may have a role as an HIV prevention intervention in this subset of homosexual men.

For access to abstract click here: 1 

Editors’ note: With strategic positioning among gay men on the rise in Australia and the USA (HIV-negative men adopting the insertive role in unprotected anal sex to reduce their risk with HIV-positive partners or those of unknown status), there is increasing interest in the possible protection that male circumcision may provide to primarily insertive men who have sex with men. This first prospective study, following on mixed findings from cross-sectional studies, included systematic validation of circumcision status in a sub-group of participants to assess validity of self-report. Despite lowered study power (only 33% of person-years of exposure were in men with a preference for the insertive role), circumcised men with this preference had significantly reduced HIV incidence. Only randomised controlled trials recruiting uncircumcised men who have sex with men and who predominantly or exclusively practise insertive anal sex in high HIV incidence settings will answer once and for all the question of whether male circumcision reduces the risk of HIV acquisition for primarily insertive men who have sex with men as it does for men who have sex with women.