Measuring Population Transmission Risk for HIV: An Alternative Metric of Exposure Risk in Men Who Have Sex with Men (MSM) in the US

• Type of Material: Article
• Authors: Colleen Kelley, Emory University; Eli S Rosenberg, Emory University; Brandon M. O'Hara, Emory University; Paula Frew, Emory University; Travis Sanchez, Emory University; John L. Peterson, Georgia State University; Carlos Del Rio, Emory University; Patrick S Sullivan, Emory University
• Language: English
• Date: 2012-12-28
• Publisher: Public Library of Science
• Publication Version: Final Published Version
• Copyright Statement: © 2012 Kelley et al.
• License: Creative Commons Attribution 4.0 International
• Final Published Version (URL): http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0053284
• Title of Journal or Parent Work: PLoS ONE
• ISSN: 1932-6203
• Volume: 7
• Issue: 12
• Start Page: e53284
• End Page: e53284
• Grant/Funding Information: The study was supported by the National Institutes of Health R01-MH085600 and R01-HD067111 to PSS, KL2 RR025009 to CFK, and the Emory Center for AIDS Research P30 AI050409.
• Research Categories: Health Sciences, Public Health; Theology

Abstract

Background Various metrics for HIV burden and treatment success [e.g. HIV prevalence, community viral load (CVL), population viral load (PVL), percent of HIV-positive persons with undetectable viral load] have important public health limitations for understanding disparities. Methods and Findings Using data from an ongoing HIV incidence cohort of black and white men who have sex with men (MSM), we propose a new metric to measure the prevalence of those at risk of transmitting HIV and illustrate its value. MSM with plasma VL>400 copies/mL were defined as having ‘transmission risk’. We calculated HIV prevalence, CVL, PVL, percent of HIV-positive with undetectable viral loads, and prevalence of plasma VL>400 copies/ml (%VL400) for black and white MSM. We used Monte Carlo simulation incorporating data on sexual mixing by race to estimate exposure of black and white HIV-negative MSM to a partner with transmission risk via unprotected anal intercourse (UAI). Of 709 MSM recruited, 42% (168/399) black and 14% (44/310) white MSM tested HIV-positive (p<.0001). No significant differences were seen in CVL, PVL, or percent of HIV positive with undetectable viral loads. The %VL400 was 25% (98/393) for black vs. 8% (25/310) for white MSM (p<.0001). Black MSM with 2 UAI partners were estimated to have 40% probability (95% CI: 35%, 45%) of having ≥1 UAI partner with transmission risk vs. 20% for white MSM (CI: 15%, 24%). Discussion Despite similarities in other metrics, black MSM in our cohort are three times as likely as white MSM to have HIV transmission risk. With comparable risk behaviors, HIV-negative black MSM have a substantially higher likelihood of encountering a UAI partner at risk of transmitting HIV. Our results support increasing HIV testing, linkage to care, and antiretroviral treatment of HIV-positive MSM to reduce prevalence of those with transmission risk, particularly for black MSM.