Do you put West Africa under quarantine? As Ebola spreads, with Air France and British Airways both halting flights to Freetown's Lungi Airport, the argument is raging between airlines. In neighbouring Liberia, where schools have been shut and turned into quarantine stations for citizens suspected of carrying the deadly virus, the closing-off of entire neighbourhoods of the capital has sparked anger. How do you stop the spread of Ebola? What's the risk of contagion?