Ebola reaches western Congo for the first time as outbreak's death toll tops 3,300

An Ebola outbreak that has already killed more than 3,000 people in the Democratic Republic of Congo has reached a seventh province for the first time, spreading west to a region bordering two other countries and raising fears that a four-month-old epidemic already described by the World Health Organization as "out of control" could cross Congo's borders.

Congolese officials said Friday that laboratory tests had confirmed the Bundibugyo strain of Ebola virus in samples from the Bulu health zone in Sud-Ubangi province, a remote area on the Ubangi River more than 1,200 miles from the outbreak's epicenter in the east. It is the first confirmed case in western Congo since the epidemic began in mid-May.

How the case reached the west

The patient, a 23-year-old man from the town of Gwaka, had traveled an extraordinary distance while infectious, according to Congolese health authorities and local reporting. He left South Kivu province, where scattered cases have been recorded, passed through neighboring Rwanda and Uganda, then crossed back into Congo through Ituri — the epicenter of the outbreak — before continuing northwest through Tshopo and Mongala provinces and finally into Sud-Ubangi. He developed fever and began vomiting blood before dying on Tuesday.

Sud-Ubangi's governor, Jean-Rene Galekwa Vundawe, confirmed the finding, saying Congo's national research institute had detected "traces of the Bundibugyo virus" in samples drawn from the health zone. The province's public broadcaster, Radio Okapi, carried the governor's announcement from Gemena, the provincial capital, on Friday.

A local lawmaker, Jean-Jacques Mbungani, a former national health minister, said the geography of the new case was what worried him most.

"It worries me. … Our province borders Congo-Brazzaville and the Central African Republic. We fear it may spread regionally," Mbungani said.

The numbers

Congo's government put the national toll at 7,022 confirmed cases and 3,398 deaths as of Thursday, figures released Friday that update a World Health Organization outbreak report issued earlier in the week putting the count at 6,942 cases and 3,349 deaths across 61 health zones. The case fatality ratio stands at roughly 48%, and WHO says 85% of the more than 24,000 identified contacts of confirmed patients are currently being monitored. Ituri province, where the outbreak began, still accounts for the large majority of cases. A same-day account of the province's first confirmed case, filed before Friday's revised national count, had put the toll at just under 7,000 cases and roughly 3,300 deaths — a reminder of how quickly the figures have moved even within a single day.

The Bundibugyo species of Ebola virus is rarer and less studied than the Zaire strain behind most past outbreaks, including the 2014-2016 West Africa epidemic that killed more than 11,000 people. No vaccine or treatment is licensed specifically for Bundibugyo virus, which has complicated the response even as Congo has battled Ebola outbreaks — mostly Zaire strain — 16 times before.

A fast-moving epidemic that outran the response

The outbreak was first identified in mid-May in the Mongbwalu health zone of Ituri province and by early August had become, by WHO's count, the fastest-growing Ebola outbreak on record and the second-largest ever, trailing only the West African epidemic a decade ago. The WHO declared it a public health emergency of international concern on May 17, its highest level of alarm, as the World Health Organization's director-general visited the epicenter and pledged the agency's support.

By mid-August, with cases still climbing, WHO Director-General Tedros Adhanom Ghebreyesus told the agency's emergency committee bluntly that the response was falling short.

"We must be frank: the epidemic is far from being under control. It had a big head start, and we are still playing catch-up," Tedros said, according to remarks reported from the emergency committee meeting in August.

Conditions on the ground have only made containment harder. The outbreak is unfolding amid armed conflict and mass displacement in eastern Congo — roughly a million people are internally displaced in Ituri province alone — along with a health workers' strike that has periodically disrupted case reporting and contact tracing, according to the European Centre for Disease Prevention and Control's tracking of the outbreak. The ECDC has repeatedly flagged the risk of the virus crossing into neighboring countries given the scale of population movement, a warning the new Sud-Ubangi case appears to bear out.

The response, and what comes next

Médecins Sans Frontières has deployed more than 1,700 staff to the response, running treatment centers and isolation units and supplying overstretched health facilities across the affected provinces. Because no Bundibugyo-specific vaccine is licensed, Congo has vaccinated more than 2,000 health and frontline workers with Ervebo — a vaccine developed for the more common Zaire strain — under a research protocol. A separate clinical trial enrolling confirmed patients across five facilities in Ituri has already reached more than 300 participants, and a distinct early-stage trial of a vaccine designed specifically for the Bundibugyo strain has begun enrolling healthy volunteers. The Serum Institute of India has said it has already manufactured and stockpiled roughly 620,000 doses of that experimental shot in anticipation of a larger trial and possible emergency use.

None of that assistance has been straightforward to deliver. Since May, several Ebola treatment centers in Ituri have been attacked and at least one set on fire by residents angered by restrictions on traditional burials or convinced the outbreak was a hoax, and health workers repeatedly walked off the job over months of unpaid wages and hazard pay before the strikes were partially resolved. Nationally, more than 26 million Congolese are facing acute food insecurity, according to the WHO outbreak report, and Ituri province alone hosts close to a million people displaced by fighting between the army and armed militias — a population in near-constant motion that has made contact tracing especially difficult and, health officials say, is almost certainly how the virus reached Sud-Ubangi in the first place.

Congolese and international health authorities are now racing to sequence the sample from Sud-Ubangi, trace everyone who had contact with the deceased man along his route through six provinces and two neighboring countries, and determine whether the virus has established local transmission in the west or arrived as an isolated, contained case. WHO's own risk assessment rates the danger to Congo itself as very high, to countries that share its borders as high, and to the rest of the world as low — an assessment that will be tested in the coming days as authorities in Sud-Ubangi, Congo-Brazzaville and the Central African Republic step up surveillance along the province's frontiers. No cases have yet been confirmed outside Congo and Uganda, but health officials in Kinshasa say the coming week, as contact-tracing teams reach Gemena and the Ubangi River border crossings, will determine whether the outbreak's westward reach was a single tragic detour or the start of a new front.