Men who have sex with men (MSM) do not have significantly lower rates of HIV infection if they are circumcised.

The US Centres for Disease Control conducted a meta-analysis of data from 15 studies on more than 53,000 MSM.

52% of them were circumsised.

While there were less HIV+ men in the circumcised group, the rate was not statistically significant.

The study was published in the October 8th issue of the Journal of the American Medical Association.

Circumcision may have had a protective effect in studies carried out before the introduction of antiretroviral therapy HAART in 1996, researchers said.

“It has been well documented that beliefs that HAART limits HIV transmissibility are associated with increases in sexual risk behaviour among MSM and that the era since the advent of HAART has been defined by higher rates of sexual risk behaviors among MSM, outbreaks of STIs, and increasing rates of HIV infection,” said the CDC study.

“Pooled analyses of available observational studies of MSM revealed insufficient evidence that male circumcision protects against HIV infection or other STIs.

“The comparable protective effect of male circumcision in MSM studies conducted before the era of highly active antiretroviral therapy, as in the recent male circumcision trials of heterosexual African men, supports further investigation.”

“This research adds weight to the evidence that circumcision isn’t an effective method of HIV prevention for men who have sex with men,” said Will Nutland, head of health protection at Terrence Higgins Trust.

“The majority of HIV infections in men who have sex with men are as a result of receptive anal intercourse and circumcision would make no difference in these cases.

“Rather than encouraging gay men to be circumcised, investment in prevention in the UK should focus on targeted education programmes, condom provision and easy access to testing.”

Lest year two contrasting studies on HIV and circumcision were presented at the International AIDS Society Conference on HIV Pathogenesis, Treatment and Prevention in Sydney.

The first, conducted amongst MSM in South America, found that circumcision would be acceptable as a method of HIV prevention.

The second found that circumcised and uncircumcised gay men in Sydney had the same risk of becoming infected with HIV.

Dr. Juan Guanira of the AsociaciĆ³n Civil Impacta Salud y EducaciĆ³n, Peru, reported on a study looking at whether South American MSM would be willing to participate in a circumcision trial.

Over five months in the first half of 2006, 2,048 participants who were unaware of their HIV status were recruited from three cities in Peru and one in Ecuador.

Participants responded to a questionnaire and were tested for HIV and syphilis, with 11% testing HIV-positive and 8% diagnosed with early syphilis.

The overall circumcision rate among participants was 3.7%, with slightly higher rates in larger cities (around 5%).

Among men reporting only insertive anal sex, there was a trend for circumcised men to have a lower prevalence of HIV, but numbers were too low to draw any meaningful conclusion from this finding.

The second study found that circumcision would not be an effective HIV prevention tool for gay men.

The presentation, reported by David Templeton of the National Centre in HIV Epidemiology and Clinical Research, University of New South Wales, gave details of a study looking at circumcision status and HIV seroconversion in the Health in Men (HIM) cohort of homosexual men in Sydney.

The HIM cohort follows 1,427 initially HIV-negative men recruited between 2001 – 2004.

Data was collected on circumcision status, sexual risk behaviour, and the incidence of sexually transmitted infections.

Annual HIV tests were also performed. At enrolment, two-thirds (66%) of cohort participants reported being circumcised.

In a substudy, 247 men had a physical examination to determine if men were able to accurately report their circumcision status.

This study found that 100% of men were able to correctly determine if they were circumcised or not.

In 2006, there were 49 seroconversions among cohort participants (29 in circumcised men, 13 in uncircumcised men), representing an incidence of 0.80 per 100 patient years.

There was no difference in the incidence of HIV infection between circumcised and uncircumcised men.

This remained true when the analysis controlled for age, anorectal sexually transmitted infections, and insertive or receptive unprotected anal intercourse (UAI) with someone who was HIV-positive.

Among the men who reported not having receptive UAI, there were nine seroconversions, for an incidence of 0.35 per 100 patient years.

Once again, there was no difference in the risk of HIV infection between circumcised and uncircumcised men.

The researchers conclude: “Although statistical power was limited, among men who were more likely to acquire through insertive UAI, there was no relationship [between circumcision and HIV seroconversion].

“As most HIV infections in homosexual men occur after receptive anal sex, circumcision is unlikely to be an effective HIV prevention intervention in Australian gay men.”