Male circumcision reduces men's HIV infection risk by 65%

Feb 25 2007

Routine male circumcision could reduce a man's risk of HIV infection through heterosexual sex by 65%, according to final data from two NIH-funded studies conducted in Kenya and Uganda published in the Feb. 23 issue of the journal Lancet, the New York Times reports (McNeil, New York Times, 2/23).

Early data from the two studies released in December 2006 indicated that circumcision reduced a man's risk of HIV infection by 50%. For the studies, researchers monitored 4,996 men ages 15 to 49 living in Uganda and 2,784 men ages 18 to 24 living in Kenya -- half of whom were randomly assigned to be circumcised and the other half served as a control group -- to determine if circumcision reduced HIV infection. All participants in both studies received counseling on HIV risk reduction and were advised to use condoms. According to researchers, male circumcision eliminates the cells most vulnerable to HIV. In addition, a circumcised penis develops thicker skin that is resistant to HIV infection. The Uganda study found 43 cases of HIV among the uncircumcised men, compared with 22 among the circumcised men -- a 48% reduction of HIV transmission. The Kenya study found 47 cases of HIV among uncircumcised men, compared with 22 among the circumcised men -- a 53% reduction. The results of the studies were so overwhelming that NIH stopped the trials early and offered circumcision to all participants. The results of the Uganda and Kenya studies mirrored similar results of a study conducted in South Africa in 2005 (Kaiser Daily HIV/AIDS Report, 12/14/06). According to the Times, some men assigned to the circumcision groups in Kenya and Uganda never went to clinics to undergo circumcisions, and some men in the control groups had private circumcisions before the study period ended. While re-evaluating the data, the researchers excluded a few men whose HIV status was misdiagnosed during the study. They also combined the results of the Kenya and Uganda trials with the South Africa trial and found that male circumcision might reduce a man's risk of HIV infection through heterosexual sex by 65% (New York Times, 2/23).

Reaction, Next Steps
Kevin de Cock, director of the World Health Organization's HIV/AIDS Department, called the results an "extraordinary development," adding, "Circumcision is the most potent intervention in HIV prevention that has been described." WHO and UNAIDS next month will meet in Switzerland to evaluate the data and decide the next steps in addressing HIV/AIDS, the AP/Globe and Mail reports. Some African countries have met with United Nations agencies to discuss ways to increase access to circumcision. According the AP/Globe and Mail, a 2006 modeling study found that male circumcision could prevent two million HIV cases and 300,000 deaths within the next 10 years (Cheng, AP/Globe and Mail, 2/22). Marie-Louise Newell of the University of KwaZulu-Natal in South Africa and Till Barnighausen of the Harvard School of Public Health in a commentary that accompanied the study said that the findings are "proof of a permanent intervention that can reduce the risk of HIV infection in men." They added that efforts to quickly implement circumcision campaigns should be taken with caution (AFP/Yahoo! News, 2/22). De Cock said that circumcision should not replace other HIV prevention efforts but should be used as an "additional tool" in the fight against HIV/AIDS (AP/Globe and Mail, 2/22). Anthony Fauci, director of NIH's National Institute of Allergy and Infectious Diseases, said that the President's Emergency Plan for AIDS Relief and WHO would look into providing circumcisions in endemic countries but that training and equipment for medical workers performing the circumcisions should be addressed first. Fauci added that he plans to continue using the 50% reduction in risk cited in the December 2006 study because the accuracy of clinical trials depends on following randomized groups and not selected ones (New York Times, 2/23). According to AFP/Yahoo! News, some experts have cautioned against widespread circumcision over concerns about different cultural attitudes toward the practice (AFP/Yahoo! News, 2/22).

The study is available online.