Does Circumcision Decrease the Transmission of HIV?

December 18, 2006

Recently, two large clinical trials in Kenya and Uganda that examined the role of circumcision in men to prevent the spread of HIV were halted on the grounds that not offering circumcision to men taking part in the trial would be unethical.  The trials involved nearly 3,000 heterosexual men in Kenya and nearly 5,000 men in Uganda, none of whom were infected with HIV prior to starting the trial.  In the Kenayn trial, men who were circumcised had a 53% relative risk reduction (2% absolute risk reduction, number needed to treat 50) in new HIV infection; the reduction was 48% in the Ugandan trial.  These two trials validate an earlier South African study that showed a reduction of 60% in circumcised men.

The underside of the foreskin is rich in Dendritic or Langerhans cells which can become antigen presenting cells once the HIV virus is phagocytosed.  These cells inadvertantly cause HIV to infect and spread within a host.  This is believed to be one of the key reasons why circumcision can prevent some of the spread of HIV.  Another reason is that the foreskin also suffers small “micro tears” during intercourse allowing the HIV virus access to the hosts blood stream.

While the results of these two trials are hailed as “very exciting” and have the potential to “save many lives” experts also cautioned that circumcision is “not a magic bullet, but a potentially important intervention.”  Circumcision only lessens the chance that a man will catch the virus, but it is expensive compared to condoms or other methods of prevention and has serious risks if the surgery is not performed by sterile technique and trained surgeons.

However, it does appear that two of the largest agencies dedicated to fighting AIDS, including the Global Fund to Fight AIDS, will be willing to pay for cicumcisions to help prevent the spread of HIV in Africa as well as training people to perform the surgery in rural communities and hospitals.


New York Times 12/14/06 article

Commentary by Josh Remick PGY-2

Remick, J. Clinical Correlations (NYU Internal Medicine Residency Blog) Dec. 18, 2006. Available from