Security forces went house-to-house in Sierra Leone's capital Thursday looking for Ebola patients and others exposed to the disease as the death toll from the worst recorded outbreak in history surpassed 700 in West Africa. Liberia's president on Wednesday also instituted new measures aimed at halting the spread of Ebola, including shutting down schools and ordering most public servants to stay home from work. Two Peace Corps workers are under isolation outside the U.S.