BUTEMBO, Congo (AP) — A nurse was killed and a health worker severely injured after being attacked while responding to an Ebola alert in Congo, according to the World Health Organization. It was the latest in a series of attacks on health workers and responders that authorities say is hampering efforts to slow the fastest-growing Ebola outbreak in the world. The attack took place Saturday in the town of Bafwasende in the country's eastern Tshopo province, WHO Director General Tedros Adhanom...