Dec. 14, 2006 -- Male circumcision may cut a man's risk of contracting HIV in half, according to two new studies.
The preliminary finding is based on two studies of men living in the African nations of Kenya and Uganda, in areas where heterosexual transmission of the virus is common.
Because of the promising results, the studies were halted early to give all participants the option of getting circumcised.
Bailey, a University of Chicago epidemiology professor, worked on one of the African studies.
However, he cautions, "Circumcision cannot be a stand-alone intervention" against HIV transmission.
"It has to be integrated with all the other things that we do to prevent new HIV infections, such as treating sexually transmitted diseases and providing condoms and behavioral counseling," Bailey says.
Adult Male Circumcision Studies
One study included nearly 5,000 men in Rakai, Uganda; the other almost 2,800 men in Kisumu, Kenya. Both were funded by the U.S. National Institute of Allergy and Infectious Diseases (NIAID).
None of the study participants had been circumcised before the studies started.
The Ugandan men were 15 to 49 years old; the Kenyan men 18 to 24. They were randomly assigned to get circumcision (surgical removal of the foreskin) right away or after a two-year delay.
Trained medical staff performed the circumcisions in an operating room under local anesthesia and provided follow-up care as the men healed from the procedure.
Male Circumcision Halved HIV Risk
Both studies enrolled participants by September 2005 and were scheduled to last until the middle of 2007.
That plan changed on Dec. 12, 2006, when researchers reviewed the studies' interim results, which showed that the men who had gotten circumcised were about half as likely to contract HIV.
In the Ugandan study, the circumcised men were 48% less likely to acquire HIV. In the Kenyan study, they were 53% less likely.
Based on those results, the trials were stopped early so any participant who wanted to could get circumcised.
Circumcision has recognized risks, including infection and blood loss. That's why appropriate medical care is necessary, Bailey says.
"Already, there are large numbers of boys and young men who are seeking circumcision in areas of Africa where men are not traditionally circumcised," Bailey says.
"The danger is that unqualified practitioners will fill a niche by providing circumcision, but with much higher complication rates," he says.
No serious complications were seen in these two studies, but about 2% of the surgeries resulted in mild complications, such as bleeding or infection, according to the University of Chicago.
Implications for U.S.
The African studies "will likely not have a large impact on the incidence of HIV/AIDS in the United States or Europe, where heterosexual transmission is low compared with areas like sub-Saharan Africa and parts of Asia," Bailey says.
The CDC hasn't made any recommendations on male circumcision to reduce HIV transmission and is studying risks and benefits of circumcision as an HIV prevention strategy here.
Most U.S. men -- about 77% -- report having been circumcised, according to the CDC.
The procedure is less common in many parts of Africa and elsewhere in the world.