I was in London this week attending a meeting on the impact of treatment as prevention (TasP) on Key Affected Populations (KAPS), a gathering of minds, I think, that has the potential to be a pivotal moment in the way we decide to respond to HIV/AIDS in those global "hotspots" where sex workers, men who have sex with men (MSM), people who inject drugs (PWID) and transgender people are en masse being denied access to treatment, care and prevention. The end result is that HIV infection rates amongst these groups is in some countries clearly running at rates that we could consider out of control when compared to the rest of the population. As the Millennium Development Goals come to fruition in 2015 we are being faced with a terrible and daunting reality: that these key affected populations are in fact being left behind. The meeting this week in London forms part of an International AIDS Society led initiative to identify strategies that will maximize the treatment and prevention benefits of antiretroviral therapy (ART) for Key Affected Populations. The meeting in London is a joint consultation of the IAS Advisory Groups on Treatment as Prevention and Key Affected Populations along with other key stakeholders and the hope is that the discussions will kick start the development of a finalized "White Paper" containing recommendations to international organizations and the AIDS community to be presented at the AIDS 2014 conference in Melbourne, Australia next July.
I believe the starting point that has brought me and my colleagues to these discussions is the powerful evidence provided by the HPTN 052 trial of 2011 demonstrating that treatment is preventative, that is, that, by decreasing viral load it decreases strongly the "ability" of the treated HIV-positive person to transmit.
Recent cohort studies further suggest that increasing antiretroviral treatment coverage is important to decrease the risk of HIV acquisition at the population level. These results have mobilized the global HIV/AIDS community to accelerate the scale-up of antiretroviral therapy (ART) as both a treatment and a prevention strategy.
I believe that currently the evidence of an effect at the population level is mostly conceptual and based on modelling. The strongest "real world" evidence we can presently refer to is the decrease in incidence in the PWID population in Vancouver, Canada. There is also some suggestive evidence that TasP has been successful in Kwazulu-Natal, South Africa.
Against this backdrop however, we do need to be cognisant of one important fact: there is no precedent for a disease of which the transmission at the population level could be stopped by generalized access to treatment.
The fact that treatment is preventative does not mean that it will and should replace prevention. Prevention interventions remains essential. Treatment is preventative but cannot be the only strategy for prevention. We need to be wary, I believe, of the concept being misinterpreted or even being "hijacked" if you will and avoid playing off one form of prevention against another (e.g. "if treatment is prevention why should we embark into difficult to implement prevention programs such as harm reduction").
The way forward is not an easy one precisely because the issue is one where science, policy and human rights all collide. How we manage that intersect will ultimately determine what kind of solutions will be thrown up. And while we should always acknowledge that the response needs to be thought through and measured (this meeting is a case in point) we'd also do well to acknowledge that the situation facing key affected populations is of the utmost urgency.
For MSM, the fact is that paradoxically the epidemic in this population continues to expand in countries with generalized access to treatment. For the PWID community , there is no doubt that treating as many people as possible is the strategy to move ahead with but in no way should that impact negatively on the need for harm reduction and other proven prevention strategies.. For sex workers, yes, treating them for their own medical needs is absolutely necessary but that does not translate into decreasing their risk at a population level which is mainly dependent on the frequency of infected transmitters among their clients.
I look forward to participating in similar conversations like the one we have had in London this week, elsewhere over the coming year.