With male circumcision showing effectiveness in reducing female-to-male HIV transmission among African heterosexual men, some are questioning whether the tool might also be effective in other populations affected by HIV, including gay men and other groups of men who have sex with men (MSM).
Two contrasting studies examining this issue were presented on July 25th to the 4th 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, however, found that circumcised and uncircumcised gay men in Sydney, Australia, had the same risk of becoming infected with HIV.
Dr Juan Guanira of the Asociación Civil Impacta Salud y Educación, 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%).
Amongst men reporting only insertive anal sex, there was a trend (p = 0.07) for circumcised men to have a lower prevalence of HIV, but numbers were too low to draw any meaningful conclusion from this finding.
Just over half (54.3%) of participants said they would be willing to participate in a circumcision trial. Residents of the larger cities Lima and Guayaquil, Ecuador, were even more willing to participate. Willingness was also higher amongst men who had received more education.
When asked to outline their concerns, men stated they worried about undergoing surgery (62%), enduring side effects related to surgery (72%), and encountering partners who would insist on having sex without a condom (75%).
The authors concluded that this high rate of willingness combined with low circumcision rates “provide an excellent opportunity to implement a circumcision trial in the Andean region where the HIV epidemic is concentrated in the MSM population.” Whether circumcision would reduce HIV transmission in the population remains to be seen.
Circumcision, gay men and HIV incidence in Sydney
The second study found that circumcision would not be an effective HIV prevention tool for gay men, at least in Australia. 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 were 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.”
Guanaria J et al. How willing are gay men to “cut off” the epidemic? Circumcision among MSM in the Andean region. Fourth International AIDS Society Conference on HIV Pathogenesis, Treatment and Prevention, abstract WEAC102, Sydney, 2007.
Temptleton DJ et al. Circumcision status and risk of HIV seroconversion in the HIM cohort of homosexually active men in Sydney. Fourth International AIDS Society Conference on HIV Pathogenesis, Treatment and Prevention, abstract WEAC103, Sydney, 2007.