Reducing human immunodeficiency virus (HIV) infection rates in persons who inject drugs (PWID) has been one of the major successes in HIV prevention in the United States. Estimated HIV incidence among PWID declined by approximately 80% during 1990-2006 (1). More recent data indicate that further reductions in HIV incidence are occurring in multiple areas (2). Research results for the effectiveness of risk reduction programs in preventing hepatitis C virus (HCV) infection among PWID (3) have not been as consistent as they have been for HIV; however, a marked decline in the incidence of HCV infection occurred during 1992-2005 in selected U.S. locations when targeted risk reduction efforts for the prevention of HIV were implemented (4). Because syringe service programs (SSPs)* have been one effective component of these risk reduction efforts for PWID (5), and because at least half of PWID are estimated to live outside major urban areas (6), a study was undertaken to characterize the current status of SSPs in the United States and determine whether urban, suburban, and rural SSPs differed. Data from a recent survey of SSPs(†) were analyzed to describe program characteristics (e.g., size, clients, and services), which were then compared by urban, suburban, and rural location. Substantially fewer SSPs were located in rural and suburban than in urban areas, and harm reduction services(§) were less available to PWID outside urban settings. Because increases in substance abuse treatment admissions for drug injection have been observed concurrently with increases in reported cases of acute HCV infection in rural and suburban areas (7), state and local jurisdictions could consider extending effective prevention programs, including SSPs, to populations of PWID in rural and suburban areas.

AIDS among persons who inject drugs, first identified in December 1981, has become a global epidemic. Injecting drug use has been reported in 148 countries and HIV infection has been seen among persons who inject drugs in 61 countries. Many locations have experienced outbreaks of HIV infection among persons who inject drugs, under specific conditions that promote very rapid spread of the virus. In response to these HIV outbreaks, specific interventions for persons who inject drugs include needle/syringe exchange programs, medicated-assisted treatment (with methadone or buprenorphine) and antiretroviral therapy. Through a ‘combined prevention’ approach, these interventions significantly reduced new HIV infections among persons who inject drugs in several locations including New York City, Vancouver and France. The efforts effectively ended the HIV epidemic among persons who inject drugs in those locations. This review examines possible processes through which combined prevention programs may lead to ending HIV epidemics. However, notable outbreaks of HIV among persons who inject drugs have recently occurred in several countries, including in Athens, Greece; Tel-Aviv, Israel; Dublin, Ireland; as well as in Scott County, Indiana, USA. This review also considers different factors that may have led to these outbreaks. We conclude with addressing the remaining challenges for reducing HIV infection among persons who inject drugs.

Persons who inject drugs (PWID) are at an elevated risk for human immunodeficiency virus (HIV) and hepatitis C virus (HCV) infection. In many high-income countries, needle and syringe exchange programs (NSP) have been associated with reductions in blood-borne infections. However, we do not have a good understanding of the effectiveness of NSP in low/middle-income and transitional-economy countries.