Male Circumcision: The New HIV/AIDS Vaccine?

In March 2007, the Centers for Disease Control and Prevention (CDC) released a report indicating that male circumcision showed considerable benefit in reducing HIV incidence in men. In areas where HIV-1 prevalence constitutes a population epidemic, male circumcision could have a dramatic life-saving effect at the population level. Prevention expert Thomas J. Coates, PhD, professor in residence at the University of California at Los Angeles, commented that "male circumcision is the best thing that has happened in HIV prevention since the prevention of mother-to-child transmission. This is a fantastic result." For this reason, circumcision is the perfect issue to stimulate new thinking on prevention interventions that combine behavioral, social, and biomedical approaches.¹ More importantly, circumcision is not just an issue for the developing world where there is a high prevalence of infection. It is becoming an issue for the developed world as well. For example, the rate of circumcision in the United States has declined to about 50% of all adult men, and it is lowest among the younger age groups in which half of HIV infections occur.¹

The implications of the decline in male circumcision in the developed world are significant. The recent focus on antiretroviral treatment -- although necessary and appropriate -- has made primary prevention a secondary issue. Renewed interest in HIV prevention is welcome. A recent article in the New York Times Magazine astutely pointed out that an AIDS vaccine, when and if it arrives, is likely to be imperfect, with efficacy rates somewhere around 60%.² The result is that a vaccine will become "one more tool in our arsenal to be used along with condoms and all our other tools."² Male circumcision, therefore, takes on new importance because of the failure of scientists to develop a vaccine to prevent HIV infection and AIDS. Combining male circumcision with prevention strategies known to reduce transmission rates -- for example, the use of antiretroviral drugs -- would further reduce new infections.

There is a caveat, however, to this positive proof of a permanent intervention that can reduce the risk of HIV transmission in men: Does male circumcision have a protective effect against HIV infection for women? The studies that have examined this question have so far yielded conflicting results. It is biologically plausible that women who have circumcised partners have a lower risk of HIV infection and that uncircumcised men could be more likely to transmit HIV. Such transmission could occur because the cells contained in the foreskin are capable of shedding HIV; the foreskin also provides an environment where microorganisms can grow. Moreover, studies have shown that uncircumcised men are more likely to have genital ulcers, the presence of which can facilitate the transmission of HIV.

A study conducted in Uganda and Zimbabwe, the results of which were published in AIDS, indicated that male circumcision has "little influence" on a woman's HIV risk.³ The investigators found that low-risk women had a similar risk of HIV infection, regardless of their partner's circumcision status. Nevertheless, the study did show that high-risk women were slightly less likely to contract HIV if their partners were circumcised, and the investigators suggested that this finding should be explored in additional studies. On the other hand, female partners of newly circumcised men were sometimes at increased risk of HIV infection if the couples resumed sex before the circumcision was fully healed, usually in about a month.

Regardless of these conflicting results, the World Health Organization has endorsed the procedure. Today, multiple challenges and opportunities related to male circumcision remain that need to be addressed before widespread implementation of the practice becomes the norm. Sawires et al.⁴ have suggested the following as important areas for development:

1. Determining the acceptability of circumcision among diverse populations
2. Communicating the benefits of the procedure
3. Defining risk, benefit, and harm reduction
4. Developing a framework for a combination prevention strategy including circumcision
5. Increasing funding for social and behavioral research on fighting gender inequality
6. Defining the effect of male circumcision on women
7. Determining the impact of religious and cultural practices
8. Evaluating when to circumcise
9. Separating the benefit of male circumcision from the generally harmful practice of female genital mutilation
10. Evaluating the safety of and risk for medical complications
11. Calculating the strain on the resources of health systems, including Medicaid reimbursements for neonatal circumcisions in the U.S.
12. Intensifying the linkages between sexual and reproductive health
13. Addressing perceptions of inequitable power relations

References

1. Medscape. Experts Advise Focus on HIV Prevention. Accessible at: www.medscape.com/viewarticle/552840.
2. Rosenberg T. A Real-World AIDS Vaccine? Jan 14, 2007. Section 6.
3. Turner AN et al. AIDS. 2007;21:1779-1789.
4. Sawires SR, Dworkin SL, Fiamma A et al. Lancet. 2007;369:708-713.

An article published by the CDC summarizes all of the recent findings on the risks and benefits of circumcision. It can be found here.