Effect of HIV Antiretroviral Treatment (ART) as Prevention on HIV Viral Load and ART Resistance Among People Who Inject Drugs

Previous studies have confirmed that antiretroviral therapy (ART) among HIV-infected people who inject drugs (PWID) increases the likelihood of achieving non-detectable HIV viral load (VL); however, few have examined rates of ART resistance in this population. Using prospective data from a cohort of HIV-infected adult PWID engaged in HIV care, researchers examined changes in VL and rates of ART resistance 2006–2014 as part of a treatment-as-prevention (TasP) initiative.

• 819 HIV-infected PWID were included in the study; all had at least one VL observation during the study period. The mean age was 41 years, 276 (34%) patients were women, and 454 (55%) were Caucasian. Individuals included in the analysis did not differ from those excluded by age, gender, ancestry, or CD4+ cell count at baseline.
• Mean VL declined among all individuals from 3.6 to 1.5 log10 c/mL. The mean proportion of individuals with undetectable VL increased from 28% to 63%, and there was an increase in the proportion of individuals with ≥ 95% ART adherence (48% to 54%).
• Drug resistance incidence per 100 person-years declined from 6.2 to 1.8 per year.

Comments:

This analysis confirms that exposure to ART as part of a TasP initiative increases non-detectable VL and decreases ART resistance in HIV-infected PWID. Future studies should attempt to define new strategies to retain this population in treatment, and further delineate other TasP factors which may promote improved HIV treatment outcomes.

Jenna L. Butner, MD† and Jeanette M. Tetrault, MD

Reference:

Milloy MJ, Wood E, Kerr T, et al. Increased prevalence of controlled viremia and decreased rates of HIV drug resistance among HIV-positive people who use illicit drugs during a community-wide Treatment-as-Prevention initiative. Clin Infect Dis. 2015 [Epub ahead of print]. doi: 10.1093/cid/civ929.