Research results suggest that the widespread practice of male circumcision could limit the spread of HIV in regions with a high prevalence of HIV, low prevalences of male circumcision, and heterosexual epidemics. The challenge is to transform scientific knowledge into public health strategies that will improve programmes and policies and promote better health.
Research background — randomised controlled trials
Three clinical trials conducted in sub-Saharan Africa have shown that medically performed circumcision is safe and can reduce men's risk of HIV infection during vaginal sex by about 60 percent.
In each trial, uncircumcised men were randomly assigned to one of two groups. Participants in one group were offered immediate circumcision (the treatment group), while those in the other group (the control group) were offered circumcision at the end of the trial. During regular follow-up visits, each participant received HIV testing and counselling, condoms and safer sex counselling.
All three trials were halted early because the evidence of a protective effect was so strong that it was considered unethical to ask the study participants in the control group to continue waiting to be circumcised.
The results revealed a much lower rate of new HIV infections among men in the circumcised groups compared to the men assigned to remain uncircumcised during the trials:
- In South Africa, a trial in Orange Farm enrolled 3,000 men ages 18 to 24. The circumcised men were approximately 60 percent less likely to acquire HIV than the uncircumcised men (1).
- In Uganda’s Rakai District, in a study among 4,996 men ages 15 to 49, circumcision reduced the risk of HIV infection by approximately 51 percent (2).
- In Kenya, 2,784 men ages 18 to 24 joined a study in Kisumu. HIV risk was reduced by approximately 59 percent among those who were circumcised (3). An ongoing follow-up study found that this protective effect was sustained over 42 months, reducing men’s chances of becoming infected with HIV by 64 percent (4).
Further analyses of the data from these studies suggest an even greater protective effective against HIV. Some participants assigned to be circumcised did not undergo the procedure, while some in the comparison groups went to other providers to get circumcised before their trial participation had ended. When data on these men were excluded from the analysis, the average reduction in risk of HIV across trials was approximately 65 percent.
The only randomised controlled trial to date to investigate whether male circumcision protects women was conducted in Rakai, Uganda. The study was closed early because it was not going to be able to answer the question with sufficient statistical power. The interim results of this clinical trial suggest that if a couple does not abstain from sex until the surgical wound from the man’s circumcision has completely healed, the woman may be at increased risk of acquiring HIV if her partner is HIV positive (5).
Ongoing and planned research
Much of the ongoing research on male circumcision and HIV prevention is operations research to identify the safer, more effective ways to deliver male circumcision services and evaluation research to assess the safety and impact of those services. Most of this research is being undertaken in the three sites in Kenya, South Africa, and Uganda, where the randomised controlled trials (RCTs) were conducted.
Although the RCTs confirmed the protective effect of male circumcision for HIV prevention, a number of unanswered questions remain. Further research on male circumcision is needed to:
- Clarify the risks and benefits of male circumcision for preventing HIV transmission in female or male partners of HIV-positive men and to assess whether male circumcision offers any protection against HIV in the context of heterosexual anal sex.
- Document changes in HIV-related individual and community perceptions and behaviours as a result of the expansion of male circumcision services.
- Determine the best models and packages for service delivery in different epidemic settings, for different populations and at different ages.
- Identify the resources required to expand safe male circumcision services.
- Refine mathematical models for assessing the impact of different programmatic options on HIV epidemics.
- Investigate other potential benefits or risks of male circumcision, including its potential protective effects on other sexually transmitted infections.
- Develop and assess simpler, safer methods for performing male circumcision in resource-limited settings, including the use of suture-less, blood-free procedures and devices.
- Better understand variations in the time it takes for healing and keratinisation after male circumcision and identify the factors that contribute to these differences.
Clinical Wound Healing Definition
This document (PDF, 87 KB) provides a definition of clinical wound healing after VMMC. It is intended to be used by researchers engaged in VMMC studies as a standardized way to assess VMMC clinical wound healing by visual inspection, to ensure comparability between studies. This definition was developed through an iterative consultation process with an expert committee including VMMC researchers, consulting urologists, and program leaders.
MCC Research Briefs
The Male Circumcision Consortium (MCC) conducted research from 2008 to 2013 to inform the scale-up of voluntary medical male circumcision (VMMC) services in Kenya. This series of briefs presents the results of nine studies and their implications for Kenya’s VMMC programme. Study findings are being used to strengthen Kenya’s VMMC programme and may also be useful to other countries that are scaling up VMMC.
- "Assessment of the Use of the PrePex Device in Kenya," (PDF, 908 KB)
- "Using Research to Improve Voluntary Medical Male Circumcision Services," (PDF, 649 KB)
- "Assessing Sexual Health Attitudes and Behaviors after Male Circumcision," (PDF, 839 KB)
- "Impact of Voluntary Medical Male Circumcision Services in Kenya," (PDF, 870 KB)
- "Variations in Counseling Men about HIV-Risk Reduction," (PDF, 655 KB)
- "Interventions to Address Barriers to Voluntary Medical Male Circumcision," (PDF, 656 KB)
- "Healing and Resumption of Sex after Male Circumcision," (PDF, 744 KB)
- "Safety and Acceptability of Infant Male Circumcision in Kenya," (PDF, 613 KB)
- "Communicating Male Circumcision’s Partial Protection from HIV," (PDF, 646 KB)
- "Monitoring and Evaluating the Scale-up of Male Circumcision in Kenya" (PDF, 748 KB)
Male Circumcision Research and Evaluation (2012, PDF, 339 KB). Population Council, 2012.
Community Perceptions of Prevention of Mother-to-child Transmission Services and Safe Male Circumcision in Six Focal States in Nigeria. AIDSTAR-One/Nigeria, 2012.
New data on male circumcision and HIV prevention: policy and programme implications (2007, PDF, 1.11 MB). Conclusions and recommendations from "Technical consultation on male circumcision and HIV Prevention: research implications for policy and programming", Montreux, 6-8 March 2007. WHO/UNAIDS, 2007.
Meeting Report: Civil Society Dialogue on Male Circumcision for HIV Prevention: Implications for Women (PDF, 208 KB). Mombasa, Kenya, 22-23 June 2008. AVAC, 2008.
Male circumcision and HIV prevention: operations research implications. Report of an international consultation (PDF, 522 KB). Nairobi, Kenya, 21-22 June 2007. WHO/
United Nations Information Package on Male Circumcision. Insert 5: Implications for Women (PDF, 836 KB). WHO/UNAIDS, 2008.
- Auvert B, Taljaard D, Lagarde E, et al. Randomized, controlled intervention trial of male circumcision for reduction of HIV infection risk: The ANRS 1265 trial. PLoS Medicine 2005;2(11):e298.
- Gray, RH, Kigozi G, Serwadda D, et al. Male circumcision for HIV prevention in men in Rakai, Uganda: a randomised trial. The Lancet 2007;369:657-666.
- Bailey RC, Moses S, Parker CB, et al. Male circumcision for HIV prevention in young men in Kisumu, Kenya: a randomised controlled trial. The Lancet 2007;369:643-656.
- Bailey RC, Moses S, Parker CB, et al. (Abstract only) The protective effect of male circumcision is sustained for at least 42 months: results from the Kisumu, Kenya trial. XVII International AIDS Conference, Mexico City, August 3-8, 2008.
- Wawer M, Kigozi G, Serwadda D, et al. Trial of Male Circumcision in HIV+ Men, Rakai, Uganda: Effects in HIV+ Men and in Women Partners. 15th Conference on Retroviruses and Opportunistic Infections, Boston, MA, USA, February 3-6, 2008.