High Rates of Sexually Transmitted Infections (STIs) Among a Sample of Methamphetamine-Using MSM Seeking Post-Exposure Prophylaxis (PEP) for HIV in Los Angeles County (LAC)

Background: The majority of HIV infections in LAC are among MSM. Methamphetamine use is a major factor driving new infections, primarily as a result of concurrent high-risk sexual behaviors. HIV prevention strategies directed at this population requires addressing both methamphetamine use and HIV exposure. Post-exposure prophylaxis (PEP) for HIV is recommended for sexual and injection drug exposures, and consists of 28 days of antiretroviral therapy administered within 72-hours of exposure. Contingency Management (CM) provides incentives for documented abstinence from methamphetamine use. This study combines PEP after high-risk exposure to HIV with CM.

Objectives: To assess prevalence rates of STIs and sexual risk-taking behavior among methamphetamine-using MSM enrolled in a pilot HIV prevention study.

Methods: Interim baseline data was used to estimate point-prevalence of STIs and sexual risk-taking behavior.

Results: Nineteen participants enrolled between March 2009 and September 2009. Data was frozen on 9/4/2009 for this analysis. Mean age of participants was 35.5(SD 7.3) years, and mean duration of self-reported heavy methamphetamine use was 5.0(SD 5.6) years. Prior Chlamydial infection was reported by 8/19(42%), prior genital or rectal gonorrheal infection by 7/19(37%), and prior syphilis by 4/19(21%). Prevalent STIs diagnosed at baseline testing included 2 cases of chronic hepatitis B(10.5%), 1 syphilis(5.3%), 2 dual-site rectal and pharyngeal gonorrhea(10.5%), and 1 urethral Chlamydia(5.3%). Participants reported a mean of 6.0(SD 4.3) and 24.0(SD 29.1) sexual partners in the previous 30 days and 6 months, respectively. Eleven of 19(57.9%) participants initiated PEP.

Conclusions: Historical and prevalent STI rates were high in this interim analysis of HIV-uninfected, methamphetamine-using MSM enrolling in a biobehavioral risk-reduction intervention.

Implications for Programs, Policy, and/or Research: Despite high STI rates, this population remains HIV-uninfected. Future studies will examine the potential biological basis for this observation and the role of behavioral economics in implementing biomedical HIV prevention strategies among methamphetamine-using MSM.