Egypt has almost eliminated the 'silent killer' hepatitis C – less than a decade after having the highest number of cases of the virus in the world. A new report from the World Economic Forum details how they managed to screen almost the whole adult population and treated those infected with the virus which can cause liver damage and even cancer. Professor Imam Waked from the National Liver Institute explains how other countries like Rwanda and Georgia are now following suit – but not quite at the rapid pace which Egypt managed. There is currently a rise in cases of cholera in Syria, and outbreaks of malaria and dengue fever in Pakistan, but for opposite reasons. The first is caused by a drought, and the latter by a flood. And what psychology can tell us about the behaviour of crowds when there’s a false alarm but people feel genuine fear. And James Gallagher reveals what nightmares and learning a musical instrument tell us about our brains. Presenter: Claudia Hammond Producer: Paula McGrath (Picture: Labourers line up for Hepatitis C screening at a construction site in Egypt in 2017. Photo credit: Khaled Desouki/AFP/Getty Images.)