Friday, August 03, 2007

Circumcision Not Protective Against HIV Seroconversion in Homosexual Men

Bonnie Darves

August 2, 2007 (Seattle) — Circumcision status may have little effect on whether men who have sex with men go on to develop HIV, according to the results of a new study of more than 1400 homosexual men, presented here at the 17th Meeting of the International Society for Sexually Transmitted Diseases Research. Although several recent randomized controlled trials of heterosexual men have found that adult circumcision reduces the risk of HIV acquisition by 50% or more, little is known about the association between circumcision and HIV risk in homosexual men, said the study's chief author, David Templeton, MD, from the University of New South Wales, Sydney, Australia.
"The data on circumcision and heterosexual men are compelling, but there are few data on circumcision and HIV risk in homosexual men," said Dr. Templeton. "We found no relationship at all between circumcision and HIV seroconversion in this cohort." That lack of association or protective effect, he added, may be because most HIV occurs "following receptive rather than insertive intercourse," but further studies would be needed to confirm that theory.
"Based on these findings, we cannot make a recommendation for circumcision in homosexual men" as a protective measure against HIV seroconversion, Dr. Templeton said.
The longitudinal study of 1427 initially HIV-negative homosexual Australian men, initiated in 2001, found that in the 49 who developed HIV, circumcision status appeared to have no effect (risk ratio was 1.07, with a confidence interval of 95%). At baseline, 66% of participants reported being circumcised, mostly as infants, and circumcision was more prevalent among men aged 45 or older (83%) than in men aged 25 or younger; only 50% of the latter group reported being circumcised. Circumcision status in all participants was later validated by physical examination.
Although the Australian study's results showed no benefit in circumcision for homosexual men as a means of protecting against HIV, the association might merit further study in light of the findings of larger African trials about the potentially protective effect of circumcision overall, said Matthew Hogben, PhD, a research scientist from the Centers for Disease Control and Prevention's National Center for HIV, STD, and TB Prevention, Atlanta, Georgia.
"The Australian study showed that circumcision was not a factor one way or the other in whether [individuals] developed HIV, which probably makes sense," said Dr. Hogben, who moderated the session. He added that although "receptor sex" was "clearly was the manner of acquisition," in the Australian study, it's understandable that "with the findings of the trials that ran in Africa, [researchers] might want to expand study of the association to see to what extent they could take advantage of those findings to look at secondary effects. It might be worthwhile to see whether there's less transmission or 'burden' with a foreskin intervention, but I suspect we would need more data, and more clean data, to confirm this."
Dr. Templeton and Dr. Hogben report no relevant financial relationships.
17th Meeting of the International Society for Sexually Transmitted Diseases Research: Abstract 215. Presented July 30, 2007.

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