WHO Declares Bundibugyo Ebola Outbreak in DRC and Uganda a Public Health Emergency of International Concern

Overview

The World Health Organization declared a Public Health Emergency of International Concern on 17 May 2026 over an outbreak of Ebola disease caused by Bundibugyo virus in the Democratic Republic of the Congo and Uganda. As of 22 May, WHO and the European Centre for Disease Prevention and Control reported 64 confirmed cases in the DRC with 6 deaths among them, alongside over 650 suspected cases including 160 suspected deaths. The outbreak marks the DRC’s seventeenth Ebola epidemic and is notable for involving a viral species for which, according to WHO, “there is no licensed vaccine or specific therapeutics.”

What We Know

The Virus and Its History

The outbreak is caused by Bundibugyo virus (BDBV), classified scientifically as species Orthoebolavirus bundibugyoense, a distinct member of the Ebola family. According to the CDC, previous Bundibugyo outbreaks have carried mortality rates of approximately 25%–50%, and the incubation period ranges from 2 to 21 days after exposure. Patients have presented with fever, generalized body pain, weakness, vomiting, and in some cases bleeding.

Unlike the more widely studied Ebola virus disease, for which a licensed vaccine exists, WHO notes that “unlike Ebola virus disease, there is no licensed vaccine or specific therapeutics against Bundibugyo virus, though early supportive care is lifesaving.” This gap significantly complicates the medical response.

Timeline of the Outbreak

According to WHO Disease Outbreak News, the international community was first alerted on 5 May 2026 to an unknown high-mortality illness in northeastern DRC. The Institut National de Recherche Biomedicale (INRB) analyzed 13 blood samples on 14 May, confirming Bundibugyo virus in 8 of them the following day. On 15 May, the DRC Ministry of Health declared the country’s seventeenth Ebola outbreak. Two confirmed cases, with epidemiological links to affected areas in the DRC, were reported in Kampala, Uganda on 15 and 16 May.

On 17 May, following the convening of an Emergency Committee, the WHO Director-General issued the PHEIC declaration. In his own words at a subsequent media briefing, WHO Director-General stated: “I determined that the situation was not a pandemic emergency, which is the new and highest classification under the amended IHR.”

Geographic Spread

The outbreak originated in Ituri Province in northeastern DRC, spanning the health zones of Bunia, Rwampara, and Mongbwalu, according to WHO. As of 22 May, ECDC reported 60 confirmed cases and 4 deaths in Ituri, and 4 confirmed cases and 2 deaths in North Kivu province, with 1 case reported in South Kivu province, which is partly controlled by M23 rebel forces. Al Jazeera reported that M23, which has never managed a response to a serious epidemic, expressed commitment to working with international partners, though the presence of the virus in densely populated urban areas and armed-group-controlled territory significantly complicates containment.

Two confirmed imported cases were reported in Kampala, Uganda. WHO’s IHR Emergency Committee noted that as of 22 May, no onward transmission among contacts had been documented in Uganda.

Risk Assessment

The WHO IHR Emergency Committee, which held its first meeting on 19 May 2026, assessed risk in the DRC as “very high,” in Uganda and bordering states as “high,” and globally as “low.” The WHO Director-General stated: “WHO assesses the risk of the epidemic as high at the national and regional levels, and low at the global level.”

The CDC assessed the risk of spread to the United States as low, noting that as of 18 May no suspected, probable, or confirmed cases related to the outbreak had been reported in the United States. The ECDC similarly assessed the likelihood of infection for people living in the EU/EEA as “very low.”

A notable diagnostic challenge has been identified: the WHO Emergency Committee confirmed that “the GeneXpert platform cannot detect Bundibugyo virus (BDBV),” a significant constraint given the platform’s widespread use in remote outbreak settings.

Operational and Humanitarian Challenges

The WHO IHR Emergency Committee acknowledged that “the epidemic is occurring in one of the most challenging operational environments possible, therefore, any response must incorporate key contextual information to improve the chances of a successful response.”

The WHO Director-General highlighted approximately 100,000 newly displaced persons due to conflict in the affected region, and healthcare worker deaths indicating nosocomial transmission within health facilities. Al Jazeera reported that first responders lack basic supplies and that cuts by major donors, including the United States, have strained resources. Community tensions over burial protocols — traditional practices have been restricted — pose an additional challenge to containment.

The outbreak’s impact has already reached the diplomatic sphere: the African Union and India postponed a planned summit “due to the ‘evolving health situation in parts of Africa’” to ensure, as Al Jazeera reported, “full participation and engagement of African leaders and stakeholders.”

International Response

WHO has approved $3.9 million in total emergency funding for the response, according to the WHO Director-General’s briefing. The ECDC activated its EU Health Task Force on 21 May to deploy experts, and Africa CDC declared a Public Health Emergency of Continental Security on 18 May. Over 1,000 contacts are being followed up in Ituri, according to ECDC.

The WHO PHEIC declaration calls on affected states to establish emergency operation centers under head-of-state authority, implement cross-border screening at airports and land crossings, restrict international travel for confirmed cases and their contacts, and conduct clinical trials for potential therapeutics and vaccines. Uganda suspended public transport to DRC and planned additional containment measures, while Al Jazeera reported that enhanced screening was implemented at Dulles Airport in the United States.

What We Don’t Know

The trajectory of the outbreak in M23-controlled South Kivu remains unclear, given the limited access international health responders have to territory under rebel control. It is also unknown how rapidly vaccine or therapeutic candidates can be accelerated into clinical trials, given the absence of any approved countermeasures for Bundibugyo virus. The true scale of the outbreak may be significantly larger than confirmed figures suggest — WHO noted suspected cases in isolation were only a fraction of those reported, and detection capacity is constrained by the GeneXpert diagnostic gap and weak surveillance infrastructure in conflict-affected areas.

Analysis

The Bundibugyo outbreak presents a different challenge than the better-known Ebola virus disease outbreaks that have shaped global response frameworks since 2014. The absence of licensed vaccines or therapeutics removes the primary tool that ended previous large outbreaks — the ring vaccination strategy that proved decisive in West Africa in 2014–2016. The WHO Emergency Committee’s observation that the GeneXpert platform, now deeply embedded in field diagnostics globally, cannot detect BDBV means that standard rapid-response toolkits are partly blind to this pathogen.

The overlap with active armed conflict in North and South Kivu, the presence of the virus in M23-held territory, and the documented foreign aid reductions compound an already demanding response. Unlike previous Ebola outbreaks that occurred in zones with at least partial humanitarian access, this episode combines an unfamiliar virus, absent countermeasures, an active conflict zone, and strained international funding — a combination that public health experts have long flagged as high-risk for sustained epidemic spread.