HIV Prevention
Overview of HIV Prevention

Released: September 17, 2020

Expiration: September 16, 2021

Joseph J. Eron
Joseph J. Eron, Jr., MD
Sharon L. Hillier
Sharon L. Hillier, PhD
Daniel R. Kuritzkes
Daniel R. Kuritzkes, 医学博士

Activity

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The role of male circumcision in the prevention of HIV infection has been investigated for at least a decade. Initially, several epidemiologic studies documented a reduced prevalence of HIV among circumcised men. However, there was no consensus among experts about whether circumcision status was a surrogate for sexual risk-taking or whether the presence of the foreskin was a biological risk factor for HIV infection. Therefore, 3 randomized trials were undertaken to assess whether male circumcision could reduce HIV infection in men. These trials demonstrated that male acquisition of HIV is reduced following circumcision.3-5 Follow-up analyses have documented that the reduction in HIV incidence persists for years following study participation, lending further support to the long-term benefits of this procedure.55-57 Despite the consistent evidence of a 60% reduction in HIV incidence in these trials, programs to make male circumcision broadly available to men have been faced with several challenges in many regions, including a lack of facilities for male circumcision, negative cultural views toward circumcision, and lack of governmental support. However, new devices that minimize the training needed to safely perform medical male circumcision have enabled broader implementation of this prevention strategy in areas with high HIV incidence. Secondary analyses have provided further data suggesting that male circumcision reduces the incidence of trichomoniasis, bacterial vaginosis, and genital ulcers in women, which could in turn reduce a woman’s risk of HIV acquisition.58 Although male circumcision provided some benefits to women, it has not been shown to reduce HIV transmission from infected men to uninfected women.59,60

Some researchers had posited that male circumcision would reduce the risk of acquiring a sexually transmitted infection, and hence, the incidence of sexually transmitted infections was evaluated among men aged 18-24 years who had participated in a randomized trial of male circumcision.61 However, the results showed that circumcised men had no fewer gonococcal, chlamydial, or Trichomonas infections than uncircumcised men.

A report from the CDC suggests that circumcision does not reduce the risk of HIV infection among MSM.62 The data from 4889 participants from a trial of an investigational HIV vaccine were reanalyzed to assess whether circumcision was associated with a decreased risk of HIV infection in this population. The results revealed that there was a trend toward increased HIV risk among uncircumcised men who had insertive anal intercourse with a partner with HIV (adjusted HR: 1.78; P = 09). Most (86%) of the men in this study were circumcised, which limited the statistical power of the study to detect a difference in risk between those circumcised and those not. In addition, a meta-analysis of 53,567 MSM did not find a statistically significant association between circumcision and reduced risk of HIV infection (odds ratio 0.95; 95% CI: 0.81-1.11), although studies judged to be of higher quality in this meta analysis did tend to show an association between circumcision and decreased HIV.63 These findings will likely lead to further debate regarding the protective benefits of circumcision for MSM.