Sierra Leone on Thursday took the dramatic step of sealing off districts where more than 1 million people live as it and other West African countries struggle to control the Ebola outbreak that has claimed thousands of lives. With three new districts under quarantine, about one-third of Sierra Leone's 6 million people are now living in areas where their movements are heavily restricted. In parts of Sierra Leone and in neighboring Liberia where these cordons have been used in this outbreak, food...