Democratic Republic of Congo has started using the experimental mAb114 Ebola treatment to counter the latest flare-up of the virus, health officials said on Tuesday, the first time it has been deployed against an active outbreak.

Forty-one people are believed to have died from the hemorrhagic fever in Congo's tenth Ebola outbreak since it was discovered in the 1970s.

The outbreak has spread from its epicenter in North Kivu province to neighboring Ituri province after an infected person returned home, Congo's health ministry said, complicating containment in a region beset by widespread militia violence.