Circumcision Not Effective In Preventing HIV Among MSM, Study Finds

Despite research showing circumcision can reduce a man's risk of HIV during heterosexual intercourse, a study published Wednesday in the Journal of the American Medical Association found that the procedure offers little protection against the virus for men who have sex with men, AFP/Yahoo! News reports. According to the study, there was minimal difference in HIV infections between those MSM who were circumcised and those who were not (AFP/Yahoo! News, 10/7).

For the study, researchers at CDC, led by Gregorio Millett, reviewed 15 previous studies on circumcision that included 53,567 MSM from Australia, Great Britain, Canada, India, the Netherlands, Peru, Taiwan and the U.S. Circumcised MSM were 14% less likely to be HIV-positive than those who were not, a rate that was not statistically significant, according to the researchers. Millett said, "You can't necessarily say with confidence that we're seeing a true effect there," adding, "Overall, we're not finding a protective effect associated with circumcision" for MSM (Dunham, Reuters, 10/7).

However, when examining studies carried out before the introduction of highly active antiretroviral therapy in 1996, the researchers found evidence that circumcision in the past had a protective effect for MSM, BBC News reports. The researchers said one explanation for the reduced effectiveness of circumcision among MSM following the introduction of HAART is that the efficacy of drugs diminished the perceived need to practice safer sex to avoid contracting HIV. In addition, the study noted that HAART might help reduce the risk of HIV transmission to a level that circumcision does not provide further benefits. The researchers also said that there may have been a smaller proportion of men in the pre-HAART trials who engaged primarily in receptive anal sex, which carries the greatest risk of HIV among MSM (BBC News, 10/7).

CDC's Peter Kilmarx, who was not involved in the study, said the agency is set to release a draft of formal recommendations on circumcision early next year. Although Millett said circumcision cannot be recommended as a strategy for HIV prevention among MSM in the U.S., he added that there are signs the procedure could protect certain MSM depending on sexual practices. For example, Millett said that studies in Australia and Peru have shown that men who engaged only in insertive anal sex and were not being penetrated by male sex partners experienced a greater level of protection from circumcision (Reuters, 10/7). However, Millett said, "Even if we find that insertive men are protected, that might be such a small proportion that we wouldn't get the effect on the overall population that we'd like. As it stands now, circumcision is unlikely to have the same kind of benefit [in the U.S.] that it's projected to have in Africa" (Lauerman, Bloomberg, 10/7).

According to the authors, more research might be needed to determine the amount of protection provided by circumcision for insertive MSM (AFP/Yahoo! News, 10/7). "These studies weren't designed to answer this question in the first place, and it's possible that they're too varied to show an effect," Millet said, adding, "The idea makes sense, but there just aren't enough data out there right now to show whether there's a benefit" (Bloomberg, 10/7). In a related editorial also published in JAMA, a team of peer reviewers from Vanderbilt University wrote that "circumcision would likely be insufficiently efficient to be universally effective in reducing HIV and will have to be combined with other prevention modalities to have a substantial and sustained prevention effect" (AFP/Yahoo! News, 10/7).

The study is available online. The related editorial also is available online.