The Democratic Republic of Congo said Saturday it was free of Ebola, three months after the deadly virus appeared in the country, resulting in the deaths of nearly 50 people. Health Minister Felix Kabange Numbi, who made the announcement, warned that the country could still be in danger if the strain ravaging Guinea, Liberia and Sierra Leone-- different from the DRC's-- made its way into Central Africa. There was no immediate confirmation of the announcement from international health agencies. The DRC's success contrasts with the continuing suffering of the three West African nations that have been at the epicenter of the epidemic. The World Health Organization on Friday noted a slight rise in the death toll, reporting 5,177 deaths and 14,413 confirmed cases worldwide, since the start of the current outbreak. Most of those cases are in West Africa. The agency also said there has been a steep increase in the number of cases in Sierra Leone, including 421 new infections reported this week. Meanwhile, an American doctor working in Sierra Leone was reported to have Ebola symptoms and was being evacuated to the United States, to the Nebraska Medical Center, which is specially equipped to handle Ebola patients. Martin Salia, a Sierra Leonean native who lives in the United States, had been working as a general surgeon at a Freetown hospital when he was diagnosed. On Friday, officials in Mali announced they were trying to trace at least 200 contacts of people linked to Ebola patients in that country. Mali shares a border with Guinea and has recently had reports of at least five cases. The first victim of Mali's recent outbreak was a two-year-old girl from Guinea. In London, pop musicians such as Bono, the lead singer of the band U2, and the popular boy band One Direction, began recording a song to benefit the fight against Ebola. Organized by Irish musician Bob Geldof, some 30 musicians were to record a new version of the song "Do They Know It's Christmas," a song first released 30 years ago as a charity record for the famine in Ethiopia. Geldof said the United Nations contacted him for help raising money to prevent the spread of Ebola.