Date Published: October 10, 2017
Publisher: Public Library of Science
Author(s): Nelli Westercamp, Supriya D. Mehta, Walter Jaoko, Timothy A. Okeyo, Robert C. Bailey, Robert K Hills.
Penile coital injuries are one of the suggested mechanisms behind the increased risk of HIV among uncircumcised men. We evaluated the prevalence and correlates of self-reported penile coital injuries in a longitudinal community-based cohort of young (18–24 years old), newly circumcised and uncircumcised men in Western Kenya.
Self-reported penile coital injuries were assessed at baseline, 6, 12, 18 and 24 months of follow-up, and were defined as scratches, cuts or abrasions during sex, penile soreness during sex, and skin of the penis bleeding during sex. Associations between penile coital injuries, circumcision, sexual satisfaction, and other covariates were estimated with mixed effect models.
Between November 2008 and April 2010 3,186 participants were enrolled (1,588 into circumcision group and 1,598 as age-matched controls). Among 2,106 (66%) participants sexually active at baseline, 53% reported any penile injury, including 44% scratches, cuts or abrasions; 32% penile pain/soreness; and 22% penile bleeding. In multivariable modeling, risk was lower for circumcised men than uncircumcised men for scratches, cuts and abrasions (aOR = 0.39; 95% CI 0.34–0.44); penile pain/soreness (aOR = 0.58; 95% CI 0.51–0.65), penile bleeding (aOR = 0.53; 95% CI 0.46–0.62), and any penile coital injuries (aOR = 0.47; 95%CI 0.42–0.53). Other significant risk factors included increasing age, history of STIs and genital sores, and multiple sex partners, while condom use was protective. Coital injuries were significantly associated with lower levels of sexual satisfaction in longitudinal analyses (scratches, cuts or abrasions: aOR = 0.87, 95% CI: 0.76–0.98; penile pain/soreness: aOR = 0.82, 95% CI: 0.72–0.93; and penile bleeding: aOR = 0.65, 95% CI: 0.55–0.76).
Self-reported penile coital injuries were common and decreased significantly following circumcision. Improving sexual experience through the removal of a potential source of sexual discomfort may resonate with many men targeted for circumcision services. The role of penile coital injuries in sexual satisfaction, HIV, HSV-2, and as a motivator for seeking circumcision services should be explored further.
Three randomized control trials (RCT) of male circumcision (MC) for HIV prevention in Kenya , Uganda , and South Africa , have demonstrated the protective effect of male circumcision against heterosexually-acquired HIV infection in men beyond any reasonable doubt [4, 5]. While the exact biological mechanism by which MC affords this protection is not known , there are a number of plausible explanations based on the cellular composition and environment of the inner foreskin. The earliest hypotheses concerned the gross anatomy of the uncircumcised penis, including the feasibility of potentially infectious secretions being trapped in facilitating conditions beneath the foreskin [4, 7] and the increased surface area of the inner foreskin [8, 9]. With the recognition that ulcerative STIs and other causes of genital tract inflammation increase the risk of HIV infection [10, 11], the association between these infections and circumcision offers additional possible explanation [7, 12–14]. Histologic examination and specific immune responses of the foreskin, and differences in the penile microbiome of circumcised and uncircumcised men offers another set of mechanisms [15–18]. Like most biologic mechanisms, the protective effect of circumcision almost certainly represents a complex system incorporating multiple explanatory factors [19–22].
In our study comparing recently circumcised men and uncircumcised men in western Kenya, we confirm previous observations that circumcised men are less likely to report penile coital injuries, with significantly decreased risk observed as early as 6 months after surgery and decreasing further over 24 months [27, 32]. Factors other than circumcision associated with penile coital injury included increasing age, increasing number of sexual partners, application of substances to the penis before sex, and self-reported history of STIs. The differences in prevalence of penile coital injuries at the baseline among otherwise similar groups indicates that it is likely that men reporting penile coital injuries were more likely to seek VMMC services. This study is the first to identify an association between self-reported penile coital injuries and decreased sexual satisfaction.
Penile coital injuries have logical and observable associations with increased risk of HIV and STI infection [25, 38, 44, 45]. While their prevention may be important in that regard alone, the potential motivational force for circumcision may also be of value. In our study we found that men reporting penile coital injuries were more likely to seek VMMC services and observed a significant decline in coital injuries following circumcision. Further, men seeking circumcision services had consistently lower levels of pre-procedure sexual satisfaction  and those with penile coital injuries had lower levels of sexual satisfaction both at the baseline and across follow-up. Improvement of the sexual experience through the removal of a potential source of sexual discomfort may resonate with a significant portion of men targeted for VMMC [25, 38, 44, 45, 47]. The accumulation of evidence indicating an independent role of penile coital injuries in decreased sexual satisfaction, HIV , and HSV-2 , merits comprehensive study to clinically and etiologically define penile coital injuries for potential intervention targets.