Circumcision HIV benefit divided
2008-10-08 14:21
Washington - There is not enough evidence
to say circumcision protects men from getting the AIDS virus
during sex with other men even as studies show it protects them
when having sex with women, US researchers said on Tuesday.
A review of 15 studies involving 53 567 gay and bisexual
men in the United States, Britain, Canada, Australia, India,
Taiwan, Peru and the Netherlands failed to show a clear benefit
for those who were circumcised, researchers from the US
government's Centres for Disease Control and Prevention said.
Circumcised men were 14% less likely to be infected
with the human immunodeficiency virus, or HIV, than those who
were uncircumcised, but the finding was not statistically
significant, the CDC researchers said.
"You can't necessarily say with confidence that we're
seeing a true effect there," said the CDC's Gregorio Millett,
who led the study that appeared in the Journal of the American
Medical Association.
Cells susceptible to HIV infection
"Overall, we're not finding a protective effect associated
with circumcision for gay and bisexual men," Millett said in a
telephone interview.
Studies involving men in Africa, where the Aids epidemic is
primarily spread by sex between men and women, showed that male
circumcision halved the risk of female-to-male HIV infection.
Experts say this reduced HIV risk may be because cells on
the inside of the foreskin, the part of the penis cut off in
circumcision, are especially susceptible to HIV infection.
The
virus also may survive better in a warm, wet environment like
that found beneath the foreskin.
But whether circumcision might lower the risk of HIV
infection in sex between men had remained unclear. Gay and
bisexual men play a much larger role in Aids in many countries
outside of Africa, the epidemic's epicentre.
Not recommended
For example, the CDC last week said 48% of the 1.1
million Americans infected with HIV are men who have sex with
men. More than three-quarters of US men are circumcised.
"We really cannot recommend overall male circumcision as a
strategy for men who have sex with men in the United States,"
Millett said.
The CDC's Dr Peter Kilmarx, who was not involved in the
research, said the agency is preparing formal recommendations
on circumcision in the United States, with a draft due to be
made public early next year.
Millett said there are signs circumcision might protect
certain gay and bisexual men depending on sexual practices.
The virus can be transmitted through blood or semen.
Studies in Australia and Peru showed that men who engaged
in insertive anal sex only and were not being penetrated by
male sex partners got a significant protective effect from HIV
infection from being circumcised, Millett said.
Turned into a chronic disease
"Of course, if you're being penetrated by a partner during
sex, you being circumcised is not going to protect you from HIV
infection," Millett said.
Millett said two US studies and one in Peru conducted
before the introduction in 1996 of combination drug treatment
for HIV infections, called highly active antiretroviral
therapy, or Haart, showed that circumcised men were 53%
less likely to be infected with HIV than uncircumcised men.
He said it is possible that since the advent of Haart,
which helped turn HIV infection into a chronic disease rather
than a death sentence for many people, some gay and bisexual
men may have felt freer to engage in risky sexual practices.
- Reuters