On Sunday, the World Health Organization declared the ebola outbreak in Congo and Uganda "a public health emergency of international concern". We speak with infectious disease correspondent, Helen Branswell with Stat News, and Dr. Joanne Liu, a physician and professor at McGIll University's School of Population and Global Health, and former International President Médecins Sans Frontières, who led the international response to the West African Ebola epidemic from 2014-2016.