Transcript of "Reductions in injection-related risk behaviors following successful virologicsuppression among IDUs treated with HAART"
Reductions in injection-related risk behaviors following successful virologic suppression among IDUs treated with HAART Ryan P. Westergaard, MD, MPH Department of Medicine University of Wisconsin School of Medicine & Public Health
Disclosures No relevant financial interests to discloseref
Objectives 1. To review the utilization of HIV RNA testing for epidemiologic research 2. To illustrate an example of using serial HIV RNA measurements to the association between HIV viral suppression and risk behavior changeref
HIV RNA predicts infectiousnessQuinn TC, NEJM. 2000; 342:921-9
Suppression of HIV RNA prevents infectionCohen M. IAS 2011; Rome. Abstract MOAX0102
Community Viral Load (cVL) • Aggregate measure of HIV RNA (e.g. mean, total, max) for a defined geographic or demographic population • General Principle: Increased HAART uptake reduced cVL lower HIV incidenceWood E et al. BMJ. 2009; 338:1649
Community Viral Load (cont.)Das M et al. PLoS ONE. 2010; 5:e11065
AIDS Linked to the IntraVenous Experience The ALIVE Study Community-based, prospectivecohort study of injection drugusers in Baltimore, MD~4,500 IDUs recruited since198825% HIV seroprevalenceSemi-annual follow-up withextensive data collection: - HIV RNA - CD4+ cell count - Risk behavior screens
Community viral load in ALIVEKirk GD, CROI 2011; Boston. Abstract #484
Reductions in injection-related risk behaviors following successful virologic suppression among IDUs treated with HAARTAnalysis of longitudinal HIV RNA and risk behavior data from ALIVE
Research questionIs effective HAART associated with changes in thefrequency of HIV transmission risk behaviors?• Behavioral risk compensation a common concern related to HIV prevention interventions (HIV vaccine trials, medical circumcision)• Is this a concern relevant to “treatment as prevention”
Research designRisk behavior assessment: • Any injection drug use • Needle sharing Assessed any occurrence of • “Shooting gallery” use behavior in preceding 6 mo. • Number of sex partners • STI diagnosisMain exposure of interest:Receipt of HAART and undetectable HIV RNA at the time of eachsemiannual study visit.Potential Confounders: • Age • CD4+ cell count (disease stage) • Gender
Analysis• Compared self-reported engagement in 5 risk behaviors at study visits where HIV RNA <400/mL and visits when HIV RNA > 400/mL• Logistic regression with generalized estimating equations (GEE) used to adjust for intra-person correlation due to repeated measurements
Results• 767 IDUs accounted for 7,278 visits when HIV RNA was measured • 67% male • 94% African-American • 61% HAART-experienced % reporting behavior (6m) Risk behavior p-value HIV RNA < 400 HIV RNA Elevated Any IDU 25.7 47.4 <0.001 Needle sharing 13.2 25.2 <0.001 Shooting gallery 2.3 4.8 <0.001 STI 3.3 2.5 0.046 Number of sex NS NS NS partners• Multivariate model: adjusted OR for needle sharing = 1.25 (p<0.001) i.e. Odds of NS increase by 25% for every increase log HIV RNA
Conclusions• No evidence of injection-related behavioral risk compensation for IDUs successfully treated with HAART• Conversely, all 3 measures of injection risk behavior were significantly lower when HIV RNA <400 copies/mL• STIs more frequent when HIV RNA suppressed, but association not significant in adjusted model
Limitations• Self-reported risk behaviors may not accurately reflect transmission probability • Recall bias • Socially-desirable reporting • Undiagnosed or asymptomatic STIs not captured• External generalizability may be limited • Older, well-studied cohort of mostly Black IDU
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