Abstract 262 - Bacterial STDs and Sexual Mixing of HIV-Discordant Men Who Have Sex with Men: A Recipe for HIV Transmission.

262 Bacterial STDs and Sexual Mixing of HIV-Discordant Men Who Have Sex with Men: A Recipe for HIV Transmission.

W. L. H. Whitington*, T. Collis, D. Dithmer-Schreck, H. H. Handsfield, R.-W. Wood, K. K. Holmes, and C. Celum.
Univ. of Washington and Public Hlth.—Seattle & King County, Seattle.

Background:In Seattle and elsewhere, bacterial STD incidence has increased among both HIV-positive (HIV⁺) and HIV-negative (HIV^-) men who have sex with men (MSM). Sexual and drug use behaviors, STD prevalence, and sexual mixing between HIV⁺and HIV^-MSM were studied to assess potential for HIV transmission.

Methods:Cross-sectional study at 5 Seattle clinical facilities (STD and HIV-testing clinics, AIDS clinic, private practice, and anal dysplasia study). Behaviors during the prior 2 mo were ascertained by self-administered anonymous questionnaires. Syphilis, gonorrhea and chlamydia testing was offered; HIV testing was optional.

Results:Among 959 MSM enrolled, median age was 36 yr and median number of sex partners (SP) in the prior 2 mo was 3. Of men reporting HIV status, 337 (37%) were HIV⁺and 564 (63%) were HIV^-. HIV⁺men were more likely than HIV^-men to have had receptive anal sex (72% vs 64%, p < 0.05). Of men reporting anal sex, 43% acknowledged inconsistent condom use (never or sometimes). About 40% usually did not discuss HIV serostatus prior to sex. Of HIV⁺men, 150 (45%) reported having sex with known HIV^-SPs and 147 (43%) had sex with SPs of unknown serostatus, and men <36 yr (OR_ADJ1.5, 95% CI 1.0—2.5) were more likely to have an HIV^-SP. Of HIV^-men, 79 (14%) reported sex with HIV⁺SPs and 308 (56%) had sex with SPs of unknown serostatus. HIV^-men with HIV⁺SPs were more likely to be >36 yr (OR_ADJ2.0, CI₉₅1.2—3.3), to have >5 SP during 2 mo (OR_ADJ2.2, CI₉₅1.1—4.2), and to use methamphetamines (OR_ADJ2.3, CI₉₅1.3—2.5). Regardless of subject's serostatus, MSM with SP of unknown serostatus were more likely to recruit SP at bathhouses (OR_ADJ>5) or parks (OR_ADJ>2). Gonorrhea, chlamydia or syphilis was diagnosed in 12% of HIV⁺and 13% of HIV^-men; STD prevalence was similar in men with serodiscordant and serodiscordant SP.

Conclusions:Among these MSM with high STD prevalence, mixing between HIV⁺and HIV^-men occurred frequently and condoms were often used inconsistently or not at all. Interventions in HIV⁺as well as HIV^-MSM must facilitate serostatus discussion, reduce the number of anonymous SP, and increase condom use with anal sex.