Scientist declared Wednesday that the deadly Ebola virus in the Democratic Republic of Congo this year is from a different source than the epidemic across West Africa.
Even though the two deadly Ebola outbreaks have separate animal origins, the report in the New England Journal of Medicine nevertheless raises concern about the emergence of the often fatal hemorrhagic fever across the African continent.
Ebola was first identified in 1976, and had returned in waves. The latest outbreak in West Africa is history's largest, killing more than 4,400 people since the beginning of the year.
A separate, smaller outbreak in the DRC began over the summer, and has killed 49 people of the 69 believed infected between late July and October 7, the NEJM report said.
An analysis of the virus's genome showed that it is a type called Ebola Zaire, and is 99.2 percent related to a 1995 variant that emerged in Kikwit in the DRC.
It was less similar (96.8 percent related) to the Ebola Zaire virus in West Africa.
"The causative agent is a local Ebola virus variant, and this outbreak has a zoonotic origin different from that in the 2014 epidemic in West Africa," said the report by World Health Organization researchers in Gabon and the DRC, along with scientists from Institut Pasteur in France and the public health agency of Canada.
The report confirms the WHO's assertion that the two outbreaks were not linked, mainly because there was no history of travel to West Africa by the people who were sickened in the DRC.
The outbreak in the DRC has been traced to a pregnant woman from Ikanamongo Village who "butchered a bush animal that had been killed and given to her by her husband," the World Health Organization has said in its report on the situation.
She died of a then-unidentified fever on August 11, and "local customs and rituals associated with death meant that several health-care workers were exposed and presented with similar symptoms in the following week."
The DRC outbreak peaked in August and cases have since dropped off dramatically.
The outbreak in West Africa has been traced to a two-year-old boy in Guinea who may have come in contact with an infected bat in December 2013.
The worst Ebola outbreak on record has claimed 4,447 lives, out of 8,914 recorded cases since the start of the year, most of them in Liberia, Sierra Leone and Guinea.
The WHO said Tuesday the infection rate could reach 10,000 a week by December, in a worst-case scenario.