WHO reports the Bundibugyo epidemic has become the largest Ebola outbreak ever recorded in DR Congo

The World Health Organization reported on 10 September 2026, in Disease Outbreak News 2026-DON617, that the Bundibugyo virus disease epidemic in the Democratic Republic of the Congo has "rapidly evolved into a large and geographically expanding epidemic... the largest Ebola disease outbreak ever recorded in the Democratic Republic of the Congo irrespective of Ebola virus species."

As of 7 September 2026, DR Congo had reported 6,757 confirmed cases and 3,267 deaths, a crude case fatality ratio of 48.3 per cent, with 1,590 patients recovered. The global cumulative total was 6,778 confirmed cases and 3,269 deaths, including 20 cases and two deaths in Uganda and one case in France. In the 13 days since the previous Disease Outbreak News, on 28 August 2026, DR Congo added 963 confirmed cases and 481 deaths.

The epidemic covers 61 health zones across six of DR Congo's 26 provinces: Bas-Uélé, Haut-Uélé, Ituri, North Kivu, South Kivu and Tshopo. Ituri is the epicentre, with 5,406 cumulative confirmed cases and 28 of its 36 health zones affected. North Kivu is second with 1,066 cases and one of the highest provincial case fatality ratios, at 65.4 per cent.

The causative agent is Bundibugyo virus, not the Zaire species against which the licensed vaccine and monoclonal antibody treatments were developed. This is only the second documented Bundibugyo outbreak in DR Congo, after 2012. Case fatality in the two prior Bundibugyo outbreaks, Uganda in 2007 and DR Congo in 2012, was 30 per cent and 50 per cent.

The outbreak was first detected in May 2026. Dr Tedros Adhanom Ghebreyesus, WHO Director-General, determined it a public health emergency of international concern on 17 May 2026 under Article 12 of the International Health Regulations, the first time a Director-General has made that determination before convening an Emergency Committee. At the second Emergency Committee meeting, on 18 August 2026, the Committee warned: "Without a rapid change in the trajectory of transmission, the epidemic risks reaching a scale with profound national and regional consequences, with the potential for case numbers and deaths to exceed those seen in the 2013–2016 Ebola disease epidemic in West Africa." Temporary recommendations were issued on 24 August 2026 and the emergency determination was maintained.

Modelling presented to the Committee estimated the true epidemic size at three to four times larger than surveillance data indicate, with a mortality-based doubling time of 21 days and an Rt of 1.55. The outbreak had spread from three health zones on 17 May to 55 by 12 August 2026.

Response capacity remains short of need: roughly 1,000 treatment beds against an estimated 3,000 required, 21 laboratories with Bundibugyo testing capacity, and 274 WHO staff deployed against a target of 455. Contact tracing covered 24,719 contacts requiring follow-up, of whom 21,359 (85.3 per cent) were seen in the prior 24 hours.

WHO's Technical Advisory Group recommended Ervebo, the only licensed Ebola vaccine, for use in a randomised trial on 7 August 2026; on 19 August SAGE concluded evidence remained insufficient for programmatic use, because efficacy against Bundibugyo virus in humans is unknown. By 6 September 2026, 2,007 people had been vaccinated under research protocol across six health zones in Tshopo, Bas-Uélé and Ituri. The PARTNERS therapeutics trial began enrolment on 2 July 2026 and had enrolled over 300 confirmed cases across five clinical management facilities in Ituri.

Healthcare use fell by more than 40 per cent in some transmission areas, and in Ituri maternal deaths have doubled since May 2026, averaging more than six a week. More than 26 million people in DR Congo are in acute food insecurity and roughly one million are internally displaced in Ituri alone.

Africa CDC and WHO announced on 27 August 2026 that Uganda had ended its Bundibugyo outbreak after 42 days without a new case: 20 confirmed cases, 18 recoveries, two deaths and more than 800 contacts monitored. Dr Tedros said: "Uganda has demonstrated that with decisive action, Ebola outbreaks can be brought under control quickly." Dr Jean Kaseya, Director-General of Africa CDC, said: "This is a victory for Uganda and an important lesson for our continent. We must now protect this achievement while accelerating the response in the DRC. We will only be secure when transmission is stopped everywhere."

WHO's risk assessment, reissued on 14 August 2026, is very high in DR Congo, high for bordering countries and low for the rest of the African Region and globally. A revised 180-day DR Congo response plan was launched with partners on 5 September 2026.