To clarify, the 6,000 infections every week in east and southern Africa are for the cohort of 15 to 24-year-old women and are not all due to sex work. The studies that have been done in five countries in eastern and southern Africa have basically averaged out that with a cash transfer payment you can reduce prevalence by 30% to 60% from that same cohort. What this suggests is that there is an economic rationale for infections, but not necessarily all from sex work though.
On April 28th, 2015. See this statement in context.