No evidence of increased sexual risk behaviour after initiating antiretroviral therapy among people who inject drugs.

Objective: Although antiretroviral therapy (ART) dramatically reduces viral load and improves survival among HIV-infected injection drug users (IDUs), several short-term studies have raised concerns that ART initiation may result in increases in sexual risk behaviour among IDUs.
Design: We used data from a long-running cohort of HIV-positive IDUs to examine whether ART initiation was associated with increases in several measures of sexual risk behaviour. The date of ART initiation was determined through a validated linkage to a centralized ART dispensation pharmacy.
Methods: We used generalized linear mixed-effects modelling to examine whether sexual activity, unprotected intercourse, and multiple sexual partnerships were more likely in the 12-month period following ART initiation.
Results: Among 457 individuals who were ART naive at baseline, the median age was 34 [interquartile range (IQR) 28-41] and 202 (44.2%) were women. Between May 1996 and April 2008, 260 (56.7%) participants initiated ART. In multivariate analyses, ART initiation was not associated with sexual activity [adjusted odds ratio (AOR) = 0.87, 95% confidence interval (CI) 0.60-1.25], unprotected intercourse (AOR = 0.82, 95% CI 0.51-1.31), or multiple sexual partnerships (AOR = 0.93, 95% CI 0.61-1.40).
Conclusion: In this study of HIV-positive IDUs, we failed to detect an increase in sexual risk behaviour during the period following ART initiation. In light of this evidence, and given the known positive effect of ART on survival and its potential role in reducing HIV transmission, concerns regarding potential increases in sexual risk-taking should not undermine the delivery of ART to IDUs.