Date Published: June 12, 2013
Publisher: Hindawi Publishing Corporation
Author(s): D. C. Des Jarlais, S. Pinkerton, H. Hagan, V. Guardino, J. Feelemyer, H. Cooper, A. Hatzatkis, A. Uuskula.
After 30 years of extensive research on human immunodeficiency virus (HIV) among persons who inject drugs (PWID), we now have a good understanding of the critical issues involved. Following the discovery of HIV in 1981, epidemics among PWID were noted in many countries, and consensus recommendations for interventions for reducing injection related HIV transmission have been developed. While high-income countries have continued to develop and implement new Harm Reduction programs, most low-/middle-income countries have implemented Harm Reduction at very low levels. Modeling of combined prevention programming including needle exchange (NSP) and antiretroviral therapy (ARV) suggests that NSP be given the highest priority. Future HIV prevention programming should continue to provide Harm Reduction programs for PWID coupled with interventions aimed at reducing sexual transmission. As HIV continues to spread in low- and middle-income countries, it is important to achieve and maintain high coverage of Harm Reduction programs in these locations. As PWID almost always experience multiple health problems, it will be important to address these multiple problems within a comprehensive approach grounded in a human rights perspective.
We now have three decades of experience in HIV prevention for persons who inject drugs (PWID); a vast amount of data has been collected, and much is known. In this paper we will briefly review what has been learned in these three decades and discuss what we believe are several critical issues for future research and public health practice with respect to HIV and injecting drug use. We will not, however, undertake a systematic review of the epidemiology of HIV infection among PWID nor a review of the implementation of various interventions to prevent HIV infection among PWID. For those topics, we would refer readers to the Lancet series  and the most recent UNAIDS Annual Report . (Though we would note much of this epidemiological and service provision information needs to be updated.)
When the first cases of what is now called AIDS were identified among drug injectors in 1981 , it was clear that it was a fearsome disease, but it seemed modest in scale. There was a concentration of cases in New York City and only scattered cases throughout the rest of the USA and Western Europe. The discovery of HIV as the causative agent for AIDS and the development of the antibody test for HIV dramatically changed the scale of the problem. More than half of drug injectors in New York City  and Edinburgh, Scotland , were infected as were a third of injectors in Amsterdam .
The previous examples of highly successful HIV prevention programming are all from high-income countries. Most—but certainly not all—of current HIV transmission is occurring in low- and middle-income countries , and we do not yet have sufficient long-term data from HIV prevention programming in resource-limited settings to draw any firm conclusions with respect to effectiveness. There are multiple reasons for the lack of long-term data on the effectiveness of HIV prevention for PWID in low- and middle-income countries; HIV epidemics among PWID in low- and middle-income countries generally occurred more recently than HIV epidemics among PWID in high-income countries, implementation of HIV prevention in low- and middle-income countries is generally at very low levels , and there have generally been insufficient resources for conducting long-term outcome studies.
In the relative absence of high quality, long-term data on the effectiveness of combined prevention programming for PWID in low- and middle-income countries, modeling of the effects of combined prevention programming may be particularly useful for allocation of the scarce resources. We have conducted modeling for HIV prevention among PWID in Estonia, a small Baltic country that was formerly part of the Soviet Union. Similar to many other newly independent countries, with the dissolution of the Soviet Union, Estonia experienced epidemics of sexually transmitted infections, injecting drug use, and HIV among drug injectors [35, 36]. Estonia recorded the highest per capita rate of HIV infections of any country in Eastern Europe.
With the very real success of HIV prevention for PWID in many high-income countries, the trends to reduce funding for public health activities among many governments throughout the world, the lack of a strong political constituency for PWID, and continuing ideological opposition to some of the most effective prevention programs, there are now pressures to reduce funding for HIV prevention programs among PWID. Even in areas where overall HIV prevention funding is not being reduced, there is pressure to reallocate funding from prevention among PWID to prevention among groups in which HIV incidence is increasing (notably men-who-have-sex-with-men) .
Many persons who inject drugs are sexually active, so HIV infection among PWID raises the possibility of HIV transmission to sexual partners who do not inject drugs and of an HIV injecting drug use concentrated epidemic leading to a heterosexual HIV epidemic. This is, of course, a difficult question on which to conduct research, as studies need to be conducted at a population level and the potential causal lag periods need to be examined carefully. The first international systematic review of possible transitions from IDU concentrated to heterosexual epidemics found that the most important factor in preventing such transitions is having a short period of high HIV incidence among PWID . While additional research is clearly needed on this topic, these first findings provide strong additional rationale for scaling up HIV prevention programming for PWID as early as possible.
After 30 years of research on HIV transmission among persons who inject drugs, we should be in a position to create an “AIDS free generation” . While HIV is readily transmitted through the multiperson use of injecting equipment, when the means for safer behavior are available, drug users have been remarkably adept in reducing their injecting risk behavior. As noted previously, there are many areas in which HIV epidemics have been averted among PWID and many areas in which high HIV prevalence epidemics have been brought under control, with close to zero new infections. However, also as noted previously, HIV continues to spread among PWID in many areas of the world. In part, this is due to the limited resources available in many low and middle-income countries, but drug policy issues are equal, if not more important. Implementation of effective HIV prevention interventions requires an appropriate policy framework.
In 30 years of research on and implementation of HIV prevention for PWID, there have been some remarkable successes. In high-income countries, the reduction of injecting-related HIV transmission has been second only to the reduction in mother to child transmission. HIV is still spreading in many low- and middle-income countries, however, and there are good reasons to expect that both injecting drug use and HIV among PWID will continue to spread to additional countries. Lack of resources is a major problem for HIV prevention in low- and middle-income countries, but stigmatization of drug users and lack of political will to implement evidence-based programs are probably the biggest problems.