Strain · BDBV

Bundibugyo virus

A rare ebolavirus species that, before 2026, had caused only two recognised outbreaks (Uganda 2007–2008, DRC 2012). The 2026 DRC + Uganda outbreak, declared a Public Health Emergency of International Concern by WHO on 17 May 2026, is the third recorded Bundibugyo outbreak. No vaccines or therapeutics approved for human use are known to be effective against Bundibugyo virus.

Last updated 2026-10-13

What is Bundibugyo virus?

Bundibugyo virus (BDBV) is the ebolavirus species behind the May 2026 PHEIC. No approved vaccine or therapeutic targets it.

Bundibugyo ebolavirus was first identified in 2007 in Bundibugyo District, western Uganda, where it caused 149 cases and 37 deaths (CFR around 25%). A second outbreak followed in 2012 in DRC's Orientale Province (57 cases, 29 deaths, CFR around 51%). The third recognised outbreak began in early 2026 in Ituri Province, DRC, with confirmed cross-border spread to Kampala, Uganda; WHO declared a Public Health Emergency of International Concern on 17 May 2026. None of the four FDA-approved Ebola products (Ervebo, Zabdeno + Mvabea, Inmazeb, Ebanga) are licensed for Bundibugyo virus; all target Zaire ebolavirus glycoprotein.

Sources: CDC outbreak chronology,WHO Disease Outbreak News,ICTV taxonomy.

Profile

Scientific name: Bundibugyo ebolavirus
Abbreviation: BDBV
Discovered: 2007 · Bundibugyo District, western Uganda
Pathogenic in humans: Yes
Case fatality (historical): 25–51%
Recognised outbreaks: 3
Natural host: Reservoir not identified. Fruit bats remain hypothesised by analogy to other ebolaviruses.
CFR notes: CFR has historically been the lowest among pathogenic ebolavirus species. Uganda 2007–2008: 25%. DRC 2012 Orientale Province: 51%.

Recognised outbreaks of Bundibugyo virus

Year	Location	Cases	Deaths	CFR	Notes
2026Active	DRC, UgandaIturi Province - Bunia, Rwampara, Mongbwalu, Nizi, Nyankunde, Mambasa, Fataki, Drodro, Mandima, Niania and other affected zones; North Kivu Province - Beni, Butembo, Katwa, Kayna, Alimbongo, Goma, Musienene and other zones; South Kivu Province - Miti-Murhesa; Haut-Uele Province - Wamba, Isiro, Pawa, Rungu, Boma Mangbetu, Dungu; Tshopo Province - Kisangani and six further zones; Bas-Uele Province - Buta, Viadana, Ganga, Dakwa; Sud-Ubangi Province - Bulu; Uganda - Kampala, Wakiso (outbreak declared over 28 July 2026); Kenya - Nairobi (one imported fatal case, October 2026, outside the headline)	9,086	4,383	48.2%	Bundibugyo virus outbreak declared a PHEIC on 17 May 2026. The deadliest Ebola outbreak recorded in DRC and the second largest anywhere, centred on Ituri with spread to six further provinces including Sud-Ubangi in the north-west. DRC passed 9,000 confirmed cases on 11 October, and Kenya confirmed its first imported case, fatal, on 6 October. No approved vaccine or therapeutic targets this strain; a frontline-worker campaign using the Zaire-licensed vaccine Ervebo began on 27 August alongside a trial, with no evidence of Bundibugyo efficacy, and Bundibugyo-specific candidates are still in Phase 1 trials.Full briefing
2012	DRCOrientale Province	57	29	50.9%	Second recognised Bundibugyo virus outbreak. The 2026 outbreak shares geographic proximity (Ituri Province sits in the former Orientale Province area).
2007–2008	UgandaBundibugyo District	149	37	24.8%	First recognised Bundibugyo virus outbreak. The only one in the species record until the 2012 DRC and 2026 DRC + Uganda outbreaks.