RIO DE JANEIRO — Adult circumcision may protect against infection with HIV in heterosexual men, according to the first randomized controlled trial to test the procedure.
After 21 months of follow-up observation, “Circumcision prevented 6 to 7 out of 10 potential HIV infections” in young heterosexual South African men who were circumcised as adults, compared with those who were not, said Bertran Auvert, M.D., at the International AIDS Society Conference on HIV Pathogenesis and Treatment.
Circumcision was found to be so effective at preventing infection with HIV that the trial was stopped early so that all the young men in the study could be offered the procedure, said Dr. Auvert, professor of public health at the University of Versailles Saint Quentin, France.
A feasibility study that was conducted prior to the trial demonstrated that approximately 70% of uncircumcised young men will opt to undergo the procedure if it has been shown to reduce the risk of HIV infection.
Observational studies dating back to the 1980s, and a more recent metaanalysis suggesting that circumcision may be protective against HIV, led to the randomized trial of 3,128 men, aged 18–24 years, Dr. Auvert said.
The participants lived in a neighborhood outside of Johannesburg, South Africa, that has historically high rates of HIV transmission.
The men, 90% of whom were sexually active, were randomly assigned either to undergo the procedure or to remain uncircumcised.
In the intervention group, circumcision was performed by trained physicians using sterile surgical procedures to remove the penile foreskin under local anesthesia.
After 21 months, 51 men who had not been circumcised had been infected with HIV, compared with only 18 of the men who had undergone the procedure. This translates into a statistically significant 65% protective effect—an outcome that remained unchanged even after controlling for sexual behavior variables, Dr. Auvert said.
Upon hearing the findings, other researchers expressed cautious optimism.
Helene Gayle, M.D., president of the International AIDS Society and director for HIV, TB, and reproductive health at the Bill and Melinda Gates Foundation, said, “If [the] results are confirmed by other ongoing studies, this could be an important tool for HIV prevention.”
“But it would be premature to recommend widespread circumcision for HIV prevention at this time,” she said. The findings come at a time when only one in five at-risk persons have access to prevention, she noted.
Dr. Gayle advised clinicians to caution young patients that circumcision should not be used as an excuse for unsafe sex or other risky behaviors. “We want to make sure people do not develop a false sense of security and increase their high-risk behaviors,” she said.
Dr. Auvert agreed, adding that since all the men were heterosexual, the results apply only to transmission from women to men; no conclusions can be drawn regarding male-to-male transmission or male-to-female transmission. Also still unknown is whether the findings will hold up over the long term. Last year, there were 5 million new HIV infections worldwide—more than in any other year.