Uncircumcised men who have wetness around the head of the penis, beneath the foreskin, have a significantly higher HIV prevalence rate than men with a dry penis, according to a study conducted amongst men attending a sexual health clinic and published in the September edition of Journal of Acquired Immune Deficiency Syndromes. HIV prevalence was 44% higher amongst men with wetness around the glans penis and coronal sulcus than amongst men with a dry penis.
Evidence suggests that male circumcision may be a way of significantly reducing HIV incidence. But it involves a traumatic surgical procedure and is culturally unacceptable to many men. The role of penile hygiene in preventing sexually transmitted infections has received little attention since the First World War, despite there being evidence that wetness under and around the head of the penis can cause inflammation increasing susceptibility to some infections.
Frequent wetness beneath the foreskin may be caused by retention of droplets of urine beneath the foreskin, by failure to wash and dry the penis after sexual intercourse or masturbation, or by the presence of a persistent infection. What is unclear is the role that the environment beneath the foreskin plays in increasing the risk of HIV acquisition.
Investigators therefore conducted a cross-sectional study involving 386 uncircumcised men who attended a sexual health clinic in Durban, South Africa to determine the association between penile wetness and HIV prevalence. Two weeks after their sexual health assessment and treatment, the men returned to the clinic and were assessed for penile wetness. They also answered questions about their demographic background and personal hygiene.
Just under half (49%) of the men were assessed as having some penile wetness, and this was significantly associated with younger age (p = 0.018), low educational attainment (p = 0.009), low income (p = 0.029), higher numbers of lifetime sexual partners (p = 0.031), and not washing after sex (p = 0.05).
Overall HIV prevalence was 56%. However, amongst men with penile wetness, HIV prevalence was 66% compared to 46% HIV prevalence amongst men with no penile wetness (p
After adjusting for potential confounding factors, such as infection with herpes simplex virus-2, the investigators calculated that the risk ratio of HIV infection was 44% higher for men with penile wetness compared to men with a dry penis (p
Although circumcised men were not included in the main analysis, 35 for initially screened for inclusion in the study. HIV prevalence amongst these men was 43%, similar, the investigators emphasise, “to that of uncircumcised men without penile wetness.”
Four possible reasons for the association between penile wetness and increased HIV prevalence are advanced by the investigators:
- Penile wetness might create an environment that increases the risk of penile trauma during sex.
- Wetness could cause microulceration, providing a portal for HIV entry.
- HIV virions may be able to adhere for longer to the surface of target cells if a penis is wet.
- Wetness could cause a local immune reaction leading to the presence of more target cells for HIV.
Providing education about the importance of genital hygiene and greater access to clean water with which to wash could, the investigators suggest, help reduce the prevalence of penile wetness and be an adjunct to more conventional HIV prevention methods.
O’Farrell N et al. Association between HIV and subpreputial penile wetness in uncircumcised men in South Africa. J Acquir Immune Defic Syndr 43: 69 – 77, 2006.