DRC's Bundibugyo Ebola outbreak reaches a seventh province and 7,890 cases

The Bundibugyo virus outbreak in the Democratic Republic of the Congo has widened again. In its latest Disease Outbreak News, WHO reports that since the previous notice on 11 September the outbreak has spread to two more health zones, bringing the total to 63 across seven of the country's 26 provinces [s1]. As of 23 September, the DRC had reported 7,890 confirmed cases and 3,799 deaths, a crude case fatality ratio of 48.1% [s1].

That is an additional 1,133 confirmed cases and 532 confirmed deaths since 11 September [s1]. A total of 1,966 patients have recovered to date [s1]. WHO writes that the national daily count of new cases remains high, and that the persistently high fatality ratio — and the continuing rate of deaths occurring in communities rather than in care — points to delays in detecting cases and reaching patients early [s1].

A new province, and a border

The two newly affected zones are the reason WHO flags rising cross-border risk. One is Dungu, in Haut-Uélé province, which borders South Sudan; the other is Bulu, in Sud Ubangi province in the country's north-west [s1]. Sud Ubangi is the seventh province to record a confirmed case of Bundibugyo virus disease, with a single case reported on 10 September [s1]. The full list of affected provinces is now Bas-Uélé, Haut-Uélé, Ituri, North Kivu, South Kivu, Sud Ubangi and Tshopo [s1].

Not all of those provinces are still transmitting. Of the 63 health zones with confirmed cases, 48 — across six provinces — reported at least one case in the last 21 days [s1]. South Kivu, by contrast, has reported no new cases since 29 May [s1]. As of 23 September, 70 new confirmed cases had been reported in the preceding 24 hours, from 26 health zones in Ituri, North Kivu, Haut-Uélé, Bas-Uélé and Tshopo [s1].

Two provinces carry the outbreak

Ituri remains the epicentre. It accounts for 6,032 confirmed cases since the outbreak began, including 868 in the 21 days to 23 September, and 28 of its 36 health zones have reported cases [s1]. WHO says case incidence in Ituri has declined gradually from the peak seen in mid-August, though transmission remains elevated [s1].

North Kivu is the second most affected province, with 1,480 cumulative cases, 567 of them in the last 21 days across 16 of its 34 health zones [s1]. It also carries the outbreak's highest case fatality ratio, 59.7%, and WHO says investigations are under way to understand what is driving that elevated mortality [s1]. Incidence in North Kivu climbed to its highest reported level in mid-September before easing in the most recent days [s1]. Elsewhere, Tshopo is showing renewed activity after a quiet spell, Haut-Uélé has sustained transmission below its late-August peak, and Bas-Uélé remains sporadic [s1].

The remaining provinces sit far behind on the zone tally: Tshopo has cases in 7 of 23 health zones, Haut-Uélé in 7 of 13, Bas-Uélé in 3 of 11, South Kivu in 1 of 34, and Sud Ubangi in 1 of 16 [s1].

The tracing load

The geographic spread has pushed up the number of people needing to be watched. As of 23 September, 32,342 identified contacts required follow-up, and 26,980 — 83.4% — were successfully monitored in the previous 24 hours [s1]. WHO describes that caseload as evidence both of how much exposure exists in affected communities and of the strain on response teams [s1].

The response is running in what WHO calls a challenging humanitarian environment, where conflict, insecurity, displacement and limited access to basic services continue to undercut outbreak control [s1]. Those constraints, the agency says, hamper surveillance, case finding, contact tracing, infection prevention and timely care, and so limit how effective the whole response can be [s1].

The disease

Bundibugyo virus disease is a severe form of Ebola disease caused by one of the Orthoebolavirus species, with fruit bats the suspected natural reservoir [s1]. Human infection is thought to begin through contact with the blood or secretions of infected wildlife such as bats or non-human primates, then to spread person to person through direct contact with the blood, secretions, organs or other body fluids of infected people, or with contaminated surfaces [s1]. Transmission is amplified in health-care settings when infection-prevention measures are inadequate, and during unsafe burials [s1]. The incubation period runs from two to 21 days, and people are not infectious until symptoms begin [s1].

What the 25 September notice does not describe is a turning point. Ituri is easing while North Kivu surges and recedes, Tshopo reawakens, and the map keeps adding zones — including, now, one on an international border. The aggregate national trend, WHO cautions, conceals wide variation from place to place, which is exactly why a single headline figure understates how uneven this outbreak has become.

Sources

• Ebola disease caused by Bundibugyo virus – Democratic Republic of the Congo — World Health Organization (Disease Outbreak News), 25 September 2026