Writing in the Huffington Post’s “Global Motherhood” blog, Michel Kazatchkine, the U.N. secretary general’s special envoy on HIV/AIDS in Eastern Europe and Central Asia, recalls a recent International AIDS Society-sponsored meeting in London “on the impact of treatment as prevention (TasP) on Key Affected Populations (KAPS), [which] 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.” He adds, “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.”

While there is some “real world” evidence that TasP can reduce HIV incidence in these populations, “we do need to be cognizant 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,” Kazatchkine writes. “The fact that treatment is preventative does not mean that it will and should replace prevention. Prevention interventions remains essential,” he continues. “[W]hile 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,” he adds (9/19).