KAMPALA, Uganda — The head of the World Health Organization said Tuesday the scale and speed of the deadly Ebola outbreak in the Democratic Republic of Congo and Uganda "warrants serious concern," as healthcare workers struggle to reach hundreds of thousands of people displaced by conflict in hard-to-reach in parts of the region. WHO Director-General Dr. Tedros Adhanom Ghebreyesus said that more than 130 deaths are thought to be linked to the outbreak, with more than 500 suspected cases.