Armed with bracing logic, wit and her "public-health nerd" glasses, Elizabeth Pisani reveals the myriad of inconsistencies in today's political systems that prevent our dollars from effectively fighting the spread of HIV. Her research with at-risk populations -- from junkies in prison to sex workers on the street in Cambodia -- demonstrates the sometimes counter-intuitive measures that could stall the spread of this devastating disease.

Elizabeth Pisani: Sex, drugs and HIV -- let's get rational

Sex, drugs and HIV -- let's get rational

Rational addiction choices: Drug users share needles to avoid jail, not ignorance of HIV risks, shifting the policy focus.

Margaret Thatcher's needle exchange program shows aligned public health and user incentives can drastically reduce HIV among addicts.

Condom use in intimate relationships is rare compared to commercial sex; romance and trust often outweigh health considerations.