Anal Sexually Transmitted Infections and Risk of HIV Infection in Homosexual Men.

Anal Sexually Transmitted Infections and Risk of HIV Infection in Homosexual Men.

Jin et al examined a range of common bacterial and viral sexually transmitted infections as risk factors for HIV seroconversion in a community-based cohort of HIV-negative homosexual men in Sydney, Australia. Detailed information about HIV risk behaviours was collected by interview twice yearly. Participants were tested annually for HIV, anal and urethral gonorrhoea and chlamydia, herpes simplex virus types 1 and 2, and syphilis. In addition, they reported annual diagnoses of these conditions and of genital and anal warts. Among 1427 enrolled participants, 53 HIV seroconverters were identified, giving an incidence of 0.78 per 100 person-years. After controlling for number of episodes of insertive and receptive nonseroconcordant unprotected anal intercourse, there were independent associations with anal gonorrhoea (adjusted hazard ratio = 7.12, 95% confidence interval: 2.05 to 24.79) and anal warts (hazard ratio = 3.63, 95% confidence interval: 1.62 to 8.14). Anal gonorrhoea and anal warts were independently associated with HIV acquisition. The added HIV prevention value of more frequent screening of the anus to allow early detection and treatment of anal sexually transmitted infections in homosexual men should be considered.

For the most part, the anal gonorrhoea diagnosed in this study of men who have sex with men was asymptomatic, suggesting that it was of relatively long standing. It may have caused a low-grade inflammation that would attract HIV target cells. Likewise, anal warts themselves and/or their treatment can disrupt natural defences, allowing HIV easier access to its prey. Given that these two infections were independently associated with HIV acquisition, it is important to assess the potential impact on HIV incidence in men who have sex with men of frequent sexual health screening and treatment of anal gonorrhoea and anal warts.