Washing the penis regularly lowers the risk of HIV infection in uncircumcised men, and even among men who are circumcised, according to two papers in the Journal of AIDS for September.

Male circumcision is associated with a reduced prevalence of HIV, according to Dr. Nigel O’Farrell, from Ealing Hospital in London, and colleagues. They now suggest that interventions to improve genital hygiene may also effective in reducing HIV infection risk.

Specifically, they theorized that the presence of “subpreputial penile wetness” - a lanolin-like wetness commonly found under the foreskin in most uncircumcised men - would increase risk, and that washing to keep the area under the foreskin dry would reduce risk.

Their study included 386 uncircumcised men residing in or near Durban, South Africa, who were free of genital lesions or discharge. Clinicians who examined the men observed that half had some degree of wetness around the penis. Approximately 80 percent were judged to be slightly wet, 19 percent as wet, and 2 percent as very wet.

In contrast, only one of 36 circumcised men they examined had wetness.

The prevalence of HIV infection was 66.3 percent among men with penile wetness, versus 45.9 percent in those with no wetness. After adjusting for HIV predictors and confounders, the adjusted odds ratio (OR) for HIV infection was 2.27 when comparing men with wetness versus those who were dry. The degree of wetness did not affect the risk.

The authors note that the HIV prevalence among uncircumcised men without penile wetness was close to that of circumcised men (42.9 percent).

Although many of the factors associated with penile wetness were poverty-related, Dr. O’Farrell’s group suggests that “information, education, and communication programs at a number of levels would be needed: for instance, encouraging washing related to sexual activity - precoital or postcoital or as an everyday life skill.”

In the second Journal report, Dr. King K. Holmes, from Harborview Medical Center in Seattle, and associates interviewed 150 men living in Kenya regarding socioeconomic status and hygiene practices; 15 percent were HIV positive, and 97 percent were circumcised.

Components of hygiene associated with risk included the amount of time spent in a bath (more than 10 minutes) and bathing immediately after sex.

Multivariate analysis revealed three independent risk factors for HIV infection: previous treatment for a serious illness, circumcision, and genital hygiene.

SOURCE: Journal of Acquired Immune Deficiency Syndromes September 2006.