KINSHASA, Aug. 26 (Xinhua) -- The Ebola outbreak in the Democratic Republic of the Congo (DRC) has yet to see its epidemic curve bend despite a slowdown in its rapid acceleration, a World Health Organization (WHO) expert said Wednesday, as over 5,600 confirmed cases have been reported.
"We have slowed the acceleration (of the outbreak), but we have not yet bent the curve," Marie Roseline Belizaire, a WHO expert, told an online briefing held by the WHO Regional Office for Africa.
As of Monday, the DRC had recorded 5,656 confirmed cases and 2,715 deaths, putting the case fatality ratio at about 48 percent, Belizaire said, adding that a total of 58 health zones across six provinces have been affected, while 1,245 patients have recovered.
The current outbreak, declared in May, has since become the country's largest and deadliest Ebola epidemic on record and the second-largest globally, behind the 2014-2016 epidemic in West Africa.
Sequencing data suggested the virus had been circulating since around February, months before it was confirmed in May, while some anthropological evidence pointed to possible circulation as early as December 2025, according to Belizaire.
The delay in detection, continued community transmission, unsafe burials, infection-control breaches, insecurity and extensive population movement have all contributed to the scale of the outbreak, she said.
One major concern is the high proportion of deaths occurring in communities rather than Ebola treatment centers, where patients can be isolated and their contacts traced.
"When people die at home, they died where they were not isolated, their contacts were not traced, and unsafe burial can seed new chains of transmission," Belizaire said.
Despite the scale of the epidemic, surveillance and treatment capacity have expanded. Contact follow-up rate has risen from about 40 percent to roughly 85 percent, while 21 laboratories are now operating with a combined capacity of around 3,000 tests a day.
Forty-nine treatment centers with more than 1,300 active beds are operating across affected areas, with about 800 confirmed patients currently hospitalized. Capacity is expected to reach nearly 1,700 beds by mid-September, said Belizaire.
But the WHO cautioned that medical countermeasures remain limited.
"There is no confirmed cross-protection between the existing Zaire Ebola vaccine and Bundibugyo," she said.
The vaccine, Ervebo, is licensed and recommended for outbreaks caused by the Zaire ebolavirus but has not been approved for the Bundibugyo virus.
Earlier this month, the International Coordinating Group on Vaccine Provision approved the release of 70,000 doses of Ervebo following a request from the DRC government.
Of the allocation, 20,000 doses will be used in a Phase 3 clinical trial to assess the vaccine's impact against the Bundibugyo virus, while 50,000 doses are intended for frontline and health workers.
Belizaire said the Phase 3 trial would begin soon. Phase 1 trials of vaccine candidates targeting the Bundibugyo virus are also being prepared, although Belizaire said it would "take months".
Clinical trials of potential treatments and post-exposure prophylaxis are also underway. "Until those clinical trials can deliver ... our life-saving tools remain early detection, isolation and quality supportive care," she said.
The situation contrasts sharply with neighboring Uganda, where the WHO said Wednesday marked 42 days since the last confirmed Ebola patient was discharged, equivalent to two full incubation periods and marking the end of the outbreak there.
Uganda recorded 20 confirmed cases, including 15 imported from the DRC.
On July 28, Uganda's health ministry first declared the Ebola outbreak over, noting that advances in epidemiological investigations and the fully characterized nature of the outbreak provided sufficient scientific evidence that transmission had been interrupted.
Although Uganda has contained the outbreak, the risk of further cross-border spread remains. Belizaire said the Central African Republic is now considered the country at highest risk of spillover, followed closely by South Sudan, as the DRC outbreak has expanded toward border areas.
"The immediate challenge remains the very large and geographically expanding outbreak in the DRC," she said.
