A Mauritanian national, Ban Ki-moon, has been appointed on Thursday to head the UN Ebola mission, set up two months ago by the UN to combat the world's worst outbreak of the virus.
Ismail Ould Cheikh Ahmed, who currently serves as number two at the UN mission in Libya, will succeed American Anthony Banbury as head of the UN Mission for Ebola Emergency Response (UNMEER).
Ould Cheikh Ahmed takes over the mission as the number of infections continues to rise in Sierra Leone, overtaking Liberia as the hardest-hit country.
The year-long Ebola epidemic has left nearly 6,400 people dead, with close to 18,000 infections in eight countries, although West Africa remains the epicenter of the crisis.
Ould Cheikh Ahmed, 54, has worked for various UN development and humanitarian agencies in Syria, Yemen, Nairobi and Georgia.
Ban decided to create the first UN mission focused on a health emergency to coordinate the international response to the epidemic following criticism from non-governmental organizations that not enough was being done.
UNMEER is headquarters in Ghana, but has country offices in Liberia, Sierra Leone, Guinea and Mali.