Prevention and treatment produced large decreases in HIV incidence in a model of people who inject drugs

Abstract

In the United States, people who inject drugs continue to be at greatly increased risk of HIV infection. To estimate the effectiveness of various prevention scenarios, we modeled HIV transmission in a dynamic network of drug users and people who did not use drugs that was based on the New York Metropolitan Statistical Area population. We compared the projected HIV incidence in 2020 and 2040 if current approaches continue to be used to the incidence if one or more of the following hypothetical interventions were applied: increased HIV testing, improved access to substance abuse treatment, increased use of needle and syringe programs, scaled-up treatment as prevention, and a "high impact" combination scenario, consisting of all of the strategies listed above. No strategy completely eliminated HIV transmission. The high-impact combination strategy produced the largest decrease in HIV incidence-a 62 percent reduction compared to the status quo. Our results suggest that increased resources for and investments in multiple HIV prevention approaches will be required to eliminate HIV transmission among people who inject drugs.

Keywords: AIDS/HIV; Epidemiology; Mental Health/Substance Abuse; Public Health; Special Populations.

EXHIBIT 2. Historical (1992-2011) and projected (2012-2040) HIV incidence (per 1,000 person-years) among PWID in residing in the New York metropolitan area, for various HIV prevention strategies

Sources: Black solid line represents previously published calibrated output. Empirical data (shown in gray) obtained from Des Jarlais (2005. Notes: Hypohetical prevention strategies as described in Exhibit 1. Abbreviations: HIV – human immunodeficiency virus; PWID – people who inject drugs; NSP – needle and syringe exchange program; SA – substance abuse; TAsP – treatment as prevention.

EXHIBIT 2. Historical (1992-2011) and projected (2012-2040) HIV incidence (per 1,000 person-years) among PWID in residing in the New York metropolitan area, for various HIV prevention strategies

Sources: Black solid line represents previously published calibrated output. Empirical data (shown in gray) obtained from Des Jarlais (2005. Notes: Hypohetical prevention strategies as described in Exhibit 1. Abbreviations: HIV – human immunodeficiency virus; PWID – people who inject drugs; NSP – needle and syringe exchange program; SA – substance abuse; TAsP – treatment as prevention.

EXHIBIT 3. Projected HIV incidence (per 1,000 person-years) at 2040 among PWID residing in the New York metropolitan area, for hypothetical HIV prevention strategies

Notes: Hypohetical prevention strategies as described in Exhibit 1. Abbreviations: HIV – human immunodeficiency virus; PWID – people who inject drugs; NSP – needle and syringe exchange program; SA – substance abuse; TAsP – treatment as prevention.

EXHIBIT 4. Projected HIV incidence (per 1,000 person-years) at 2040 among PWID residing in the New York metropolitan area for hypothetical “dual” HIV prevention strategies

Notes: Hypohetical prevention strategies as described in Exhibit 1. Abbreviations: HIV – human immunodeficiency virus; PWID – people who inject drugs; NSP – needle and syringe exchange program; SA – substance abuse; TAsP – treatment as prevention.