Tuberculosis has been with us so long that traces appear in mummies. But today, the challenge is different: how do we respond to TB that's resistant to modern drugs? 

Professor Salome Charalambous tells Alisha Wainwright about the challenges of treating the half-million people with drug-resistant TB, and Professor Nazir Ismail explains how it gets harder in countries where resources are scarce. 

But there may be hope on the horizon. Salome gives a glimpse of the new tests and treatments already saving lives, and we hear from Enalkachew Fekadu, a drug-resistant TB survivor who now advocates for others with the disease.