HARDtalk - Elizabeth Pisani, Epidemiologist

Tens of billions of dollars are being spent in the global effort to combat HIV. Money for prevention, treatment, and all the administrative bureaucracy which goes with it. Elizabeth Pisani is a journalist turned epidemiologist who spent more than a decade working inside what she now calls the 'Aids mafia'. She claims many anti-HIV strategies have failed. Stephen Sackur asks her how so many experts can have got it so wrong.