Valerie Mizrahi is the Director of the Institute of Infectious Disease and Molecular Medicine at the University of Cape Town, where she has done ground-breaking work on tuberculosis.

It was once thought to be almost eradicated but now it is estimated that a third of the world's population is infected with TB.

It is the biggest killer amongst HIV positive people, claiming nearly two million lives every year.

With its links to Aids it is a controversial subject in South Africa, where Professor Mizrahi pioneers work on HIV and TB.

Join her in conversation AC Grayling, about her zeal for medical research and her determination to bring life saving innovations to the developing world.

(Image: Mycobacterium tuberculosis bacteria. Credit: Science Photo Library) Show less