DEMOCRATIC Republic of Congo authorities said on Monday that the fastest-growing Ebola outbreak in history has topped 6,000 cases with 2,911 deaths.

The outbreak in eastern DR Congo is spreading under extremely difficult conditions, fuelled by insecurity, displacement and intense population movements. 

Last week, the virus spilled into two new health zones in the region.

The World Health Organisation (WHO) has said that it remains out of control and is on track to surpass the 2014-2016 West Africa Ebola outbreak, the deadliest on record, which killed more than 11,000 people, primarily in Guinea, Liberia and Sierra Leone.

The outbreak is caused by the Bundibugyo virus, a rare type of Ebola that has no approved vaccine or treatment.

Last week, Congo began vaccinating health and other front-line workers with the Ervebo vaccine that was effective in past Ebola outbreaks caused by a different, more common type called Zaire.

Clinical trials are underway to find a licensed vaccine for the Bundibugyo virus.

Efforts to bring the outbreak under control, including limited public gatherings, social distancing and airport closures, have disrupted life in the six provinces, particularly Ituri, which also has been ravaged by rebel violence.

While neighbouring Uganda declared itself free of Ebola last month, the risk of further cross-border spread remains, WHO said last week.