Ealing Hospital, London, UK.
Received 2 November, 2009
Accepted 9 December, 2009
Correspondence to Nigel O'Farrell, Ealing Hospital, Uxbridge Road, London UB1 3HW, UK. E-mail: email@example.com
It was interesting to see the report by Kigozi et al.  in which the authors found that the risk of HIV acquisition is increased in men with larger foreskin surface areas and suggest that providers should avoid leaving excess residual skin tissue after circumcision.
In reviewing their data, it would appear that the incidence of HIV in those less than or equal to 75th centile foreskin surface area (0.80, 0.92 and 0.90 per 100 person-years, respectively) is much lower than those in the highest quartile (2.48 per 100 person-years). These lower incidence rates are similar to those in two-thirds of the intervention groups in the male circumcision intervention trials, including the Rakai population (0.66 and 0.85 per 100 person-years) [2,3]. We have compared the HIV incidence rates in their study in those with a foreskin surface area 75th centile or less against those in the highest quartile in a 2 × 2 table and found a significant difference (relative risk = 2.76, 95% confidence interval 1.5–5.1, P = 0.0003). It must be questionable, therefore, whether it is really worthwhile circumcising those with short foreskin.
We have also assessed the size of the foreskin in a clinical study  to determine factors associated with penile wetness, a clinical finding that may reflect poor genital hygiene . We assessed foreskin length by observing whether men had a visible urinary meatus on direct inspection. We found that penile wetness was associated with not having a visible urinary meatus on direct inspection, that is, in men with longer foreskin . In our study in London, we found that 144/278 had a visible meatus and an additional 68 either sometimes retracted the foreskin when urinating or had phimosis. Thus, at least 144/346 (41.8%) would be classified as having a short foreskin and at much lower risk of HIV.
It would seem that male circumcision is most likely to benefit those with longer foreskins and it may be more cost-effective to leave those with shorter foreskins intact, assuming they have neither penile wetness nor phimosis. This would enable circumcision services that are already stretched to deliver a more timely service to those in more urgent need of the procedure.
1. Kigozi G, Wawer M, Settuba AS, Kagaayi J, Nalugoda F, Watya S, et al
. Foreskin surface area and HIV acquisition in Rakai, Uganda (size matters). AIDS 2009; 23:2209–2213.
2. Auvert B, Taljaard D, Lagarde E, Sobngwi-Tambekou J, Ditta R, Puren A. Randomized controlled intervention trial of male circumcision for reduction of HIV infection risk: the ANRS 1265 trial. PLOS Med 2005; 2:1112–1122.
3. Gray R, Kigozi G, Serwadda D, Makumbi F, Watya S, Nalugoda F, et al
. Male circumcision for HIV prevention in men in Rakai, Uganda: a randomized trial. Lancet 2007; 369:657–666.
4. O'Farrell N, Chung C-K, Weiss HA. Foreskin length in uncircumcised men is associated with subpreputial wetness. Int J STD AIDS 2008; 19:821–823.
5. O'Farrell N, Morison L, Moodley P, Pillay K, Vanmali T, Quigley M, et al
. Association between HIV and subpreputial wetness in uncircumcised men in South Africa. J AIDS 2006; 43:69–77.