The World Health Organization says the rate of Ebola infection is slowing in Liberia, the country hardest hit by the disease. The assessment comes three months after the organization declared West Africa’s Ebola outbreak a global emergency. WHO officials said they now believe that the response “is getting an upper hand on the virus,” but warned against complacency, saying the international fight must continue. Officials also expressed concern that some areas thought to have been purged of the disease might become re-infected. They said just a few mishandled burials could start a whole new “transmission chain,” with the disease trending upward again.