Although access to antiretroviral therapy (ART) for HIV infection in low- and middle-income countries has tremendously improved over the last decade, it remains far from optimal in most settings when it comes to the treatment of marginalised populations, such as sex workers, injection drug users and men who have sex with men. Small-scale demonstration projects indicate that ART can be successfully implemented among sex workers, with satisfactory immunological and virological responses, good treatment compliance levels, and maintenance or even improvement of safe sex behaviour. Some of the studies carried out so far underline the importance of strongly linking prevention with care through the integration of HIV/STI care services and community-based prevention packages. Scaling-up treatment programmes for marginalised, hard-to-reach populations, will undoubtedly be challenging. Nevertheless, in addition to the health equity issues related to access to ART for such populations, the application of targeted “test and treat” strategies could substantially impact HIV prevention at the general population level, given recent trial data showing that the implementation of this strategy among sero-discordant couples led to a 96% reduction in HIV transmission. Such a strategy should however be carefully evaluated in the target population before implementation and scale-up, and would require specific adherence support and community involvement.

It is in this context that this symposium will present practical experiences in implementing ART programmes among female sex workers in the context of generalised, concentrated and mixed epidemics. Modelling studies of the preventive impact of such programmes across different epidemic contexts, and with different criteria for ART initiation (including “test and treat”), will also be presented. A similar study about injection drug users in the context of a concentrated epidemic will complete the presentations in this symposium that should stimulate a fruitful discussion period between the participants and the speakers.