Is it time for treatment as prevention among people who inject drugs?

Approximately 5% of the global population, or 230 million people have used drugs. 1 An estimated 15.9 million individuals in 148 countries inject various drugs of abuse; 3 million of these are estimated to be HIV infected. Although injection drug use only impacts 0.34% of the global population, it represents approximately 10% of the global HIV epidemic! This disparity is due to the frequency with which individuals inject themselves and the efficiency with which injection transmits HIV. This link between drug injection and HIV has been well described since the beginning of the HIV pandemic. With this understanding, global efforts were (and are being) mobilized to address this through key HIV prevention interventions, including needle and syringe programs and medication-assisted treatment (e.g., buprenorphine and methadone). Initially, drug users were not provided with antiretroviral therapy (ART) at a similar frequency as other key populations such as men who have sex with men. This was the result of fears regarding nonadherence and the development of resistance. Although the 1990’s were home to complex regimens with notable side-effect profiles (eg, full dose ritonavir) that were difficult for anyone to take, nonadherence seemed focused on people who inject drugs (PWID). Although such information resulted in the deferral of treatment for many drug users, it motivated some to develop interventions to improve adherence to ART among drug users who struggle with adherence. Others challenged the assumption of nonadherence and examined larger data sets to reveal that resistance was as common among PWID as those who do not. Today, ART has revolutionized the clinical course of HIV and HIV Prevention Trials Network 052 demonstrated that ART is both treatment for the infected person and effective HIV prevention for the uninfected sexual partner in serodiscordant couples. The data are so convincing that the HIV-infected partner in a serodiscordant couple should be offered treatment irrespective of CD4 count to reduce the risk of HIV transmission. Naturally, individuals speculate on the application of these results to other risk groups, such as injection risk. And, assuming similar efficacy among PWID, it would be time to ask, “Should PWID be considered a special population to provide immediate access to ART? ” Gupta et al recently reviewed ART guidelines in 70 countries and found that none of the countries viewed PWID as requiring any special level of ART attention. Only 4 countries even mention ART for PWID (Guyana, Myanmar, Russia, and Vietnam), and all 4 apply the same criteria to start ART as for the general population, suggesting that thoughts on 052’s application to PWID has not been considered in policy measures to date. Of critical importance is the realization that statements and their actual operationalization are not always concordant, as is evidenced by the obstacles in Russia for PWID that prevent access to HIV therapy despite officially qualifying for treatment. And this brief history sets the stage for the article by Kato et al in this issue of JAIDS that raises critical questions regarding the appropriate allocation of resources among key populations toward addressing the overall HIV epidemic. Kato M, Granich R, Duc Bui D, Tran HV, Nadol P, Jacka D, Sabin K, Suthar AB, Mesquita F, Lo YR, Williams B. The potential impact of expanding antiretroviral therapy and combination prevention in Vietnam: Towards elimination of HIV transmission. J Acquir Immune Defic Syndr 2013. Kato et al used mathematical modeling to gauge the impact of various strategies for HIV prevention on the largely PWID-driven HIV epidemic in the Can Tho province of Vietnam. The strategies examined include periodic HIV testing with immediate ART, targeting of specific populations, and the use of combined strategies, such as methadone