At least 2,000 people have died in Congo’s Ebola outbreak, the fastest-growing on record, according to the latest data, as rebel conflict, bad roads and work stoppages over payment issues challenge the urgent response in a remote region.

Government data published overnight into Tuesday showed the outbreak has 4,381 confirmed cases, including 2,011 deaths. Starting from the first confirmed case, the death toll was reached almost three times faster than in the 2014-16 Ebola outbreak in West Africa, the worst on record.

The current outbreak was declared on May 15 but health authorities now say sequencing showed it began months earlier, in February.

It took about nine weeks for the outbreak to record the first 1,000 deaths, but it’s taken just around three weeks for the figure to double, as experts say the crisis is moving faster than efforts to track and manage it.

At the epicenter in eastern Congo’s Ituri province, friends and family members gathered in tears on Tuesday for the burial of Jeannine Katusabe, 38, one of the latest to die.