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

Abstract

Background: Although treatment-as prevention (TasP) is a new cornerstone of global human immunodeficiency virus (HIV)-AIDS strategies, its effect among HIV-positive people who use illicit drugs (PWUD) has yet to be evaluated. We sought to describe longitudinal trends in exposure to antiretroviral therapy (ART), plasma HIV-1 RNA viral load (VL) and HIV drug resistance during a community-wide TasP intervention.

Methods: We used data from the AIDS Care Cohort to Evaluate Exposure to Survival Services study, a prospective cohort of HIV-positive PWUD linked to HIV clinical monitoring records. We estimated longitudinal changes in the proportion of individuals with VL <50 copies/mL and rates of HIV drug resistance using generalized estimating equations (GEE) and extended Cox models.

Results: Between 1 January 2006 and 30 June 2014, 819 individuals were recruited and contributed 1 or more VL observation. During that time, the proportion of individuals with nondetectable VL increased from 28% to 63% (P < .001). In a multivariable GEE model, later year of observation was independently and positively associated with greater likelihood of nondetectable VL (adjusted odds ratio = 1.20 per year; P < .001). Although the proportion of individuals on ART increased, the incidence of HIV drug resistance declined (adjusted hazard ratio = 0.78 per year; P = .011).

Conclusions: We observed significant improvements in several measures of exposure to ART and virologic status, including declines in HIV drug resistance, in this large long-running community-recruited cohort of HIV-seropositive illicit drug users during a community-wide ART expansion intervention. Our findings support continued efforts to scale up ART coverage among HIV-positive PWUD.

Keywords: HIV drug resistance; people who use illicit drugs; plasma HIV-1 RNA viral load; treatment-as-prevention.

Figure 1.

A, Box plot of plasma human immunodeficiency virus type 1 RNA viral load (VL; log₁₀ transformed) by study period. B, Proportion of all individuals with VL <50 copies/mL plasma by study period. C, Proportion of all individuals in period in discrete antiretroviral therapy (ART) exposure categories (Lightest grey = ART naive; Second-lightest grey = ART exposed and 0 days in period; Second-darkest grey = ART exposed and 1 or more days in period and <95% adherence; and Darkest grey = ART exposed and ≥95% adherence). Abbreviation: pVL, plasma viral load.

Figure 2.

Incidence rates of drug resistance detected per annum per 100 person-years of antiretroviral therapy (ART; circle) with 95% confidence intervals among 773 ART-exposed human immunodeficiency virus–positive people who use illicit drugs, 2006–2014.