KINSHASA, Aug. 19 (Xinhua) -- The World Health Organization (WHO) said Tuesday that the Ebola outbreak in the Democratic Republic of the Congo (DRC) remains a public health emergency of international concern (PHEIC), as the epidemic surpasses 5,000 cases, spreads into new areas and prompts authorities to pursue experimental vaccines and treatments.

The outbreak is now the second-largest Ebola outbreak ever recorded and is spreading faster than all previous ones, WHO Director-General Tedros Adhanom Ghebreyesus said at an emergency committee meeting.

As of Sunday, 5,021 confirmed cases and 2,378 deaths had been reported across 55 health zones in six provinces, with a case fatality rate of 47.4 percent, according to the latest WHO tally.

The epidemic, caused by the Bundibugyo ebolavirus, has surpassed the 2018-2020 Ebola outbreak in eastern DRC, previously the country's deadliest. The Africa Centers for Disease Control and Prevention (Africa CDC) said Monday that the current outbreak is killing roughly one person every 30 minutes and risks becoming the deadliest Ebola epidemic ever recorded globally if its trajectory is not urgently reversed.

FAR FROM UNDER CONTROL

"We must be frank: the epidemic is far from being under control," Tedros said. "It had a big head start, and we are still playing catch-up."

During the first 95 days of reporting, the seven-day moving average rose to more than 90 confirmed cases a day, substantially higher than at the same stage of the 2014-2016 West Africa epidemic and the DRC's 2018-2020 outbreak, according to a WHO situation report.

The eastern province of Ituri remains the epicenter, accounting for 84.8 percent of cumulative cases, but infections are accelerating in neighboring provinces. The WHO warned that high mortality, deaths outside treatment facilities, a growing surveillance workload and uneven response capacity indicate that current measures are not sufficient to interrupt transmission.

DRC Health Minister Roger Kamba said the outbreak had spread unusually fast despite a "very rapid and very vigorous" response. He suggested that Bundibugyo's less distinctive early symptoms allow infected people to remain in their communities longer before seeking care.

VACCINES, DRUGS MOVE CLOSER TO FRONTLINE

With no approved vaccine or treatment specifically targeting Bundibugyo virus, authorities are turning to experimental and repurposed medical tools.

Two vaccines designed specifically against Bundibugyo virus have entered human trials, Tedros said. A WHO-sponsored PARTNERS treatment trial is also evaluating antiviral remdesivir, the experimental monoclonal antibody MBP134 and their combination. Preliminary results could be available in "about three to four weeks," Kamba said.

Researchers are also studying oral antiviral obeldesivir as post-exposure prophylaxis.

Authorities are meanwhile examining whether Ervebo, the licensed vaccine against Zaire ebolavirus, could provide protection against Bundibugyo virus. Kamba said observations among vaccinated health workers and laboratory studies had suggested possible cross-protection, while stressing that this remains unconfirmed.

Africa CDC on Monday backed a DRC request for controlled expanded use of Ervebo among high-risk frontline workers, alongside a Phase III trial to determine whether it can protect against Bundibugyo virus.

RISKS EXTEND BEYOND DRC

The WHO warned that the risk of further spread within the DRC is still "very high," while the risk of cross-border transmission remains elevated.

Tshopo province and its capital Kisangani are of particular concern because of their road, river and air links, which could facilitate longer-distance transmission toward Kinshasa, the national capital. Kamba said no cases from the current outbreak had been confirmed in Kinshasa.

Authorities have stepped up screening along river routes to Kinshasa.

Tedros said population movement "along roads, rivers and mining routes," combined with insecurity and displacement, was fueling the epidemic.

Uganda, South Sudan and the Central African Republic are considered at particularly high risk of imported cases because of their proximity to affected areas and frequent cross-border population movements, according to the WHO.