Disease Outbreak News

Ebola disease caused by Bundibugyo virus - Democratic Republic of the Congo

28 August 2026
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Situation at a glance

Since the last Disease Outbreak News was published on 14 August 2026, the outbreak has spread from 54 to 60 health zones. The number of affected provinces stands at six out of 26 provinces of the country: Bas-Uélé, Haut-Uélé, Ituri, North Kivu, South Kivu, and Tshopo. Six additional health zones reported cases since the last update - Ganga and Viadana health zones in Bas-Uélé province, Biena, Manguredjipa, and Mutwanga in North Kivu, and Tshopo health zone in Tshopo province. As of 26 August 2026, a total of 5794 confirmed cases, including 2786 deaths, have been reported, corresponding to a crude case fatality ratio (CFR) of 48.1%. These figures demonstrate a substantial increase in the scale and geographic extent of the outbreak over the past three months. The crude case fatality ratio of 48% underscores the severity of the disease and ongoing challenges related to timely case detection, access to and quality of clinical care, and effective interruption of viral transmission. Delays in recognizing cases increase the likelihood of onward transmission within households, communities and healthcare facilities. The outbreak remains a public health emergency of international concern, following the advice of Emergency Committee meeting convened on 18 August.

Description of the situation

Since the previous Disease Outbreak News was published on 14 August 2026, additional confirmed cases and deaths of BVD have been reported only in the Democratic Republic of the Congo.  

Cumulatively as of 26 August 2026, 5815 confirmed cases have been reported: 5794 in the Democratic Republic of the Congo (including two cases diagnosed in the Democratic Republic of the Congo and subsequently treated in Germany), 20 in Uganda and one in France. A total of 2788 deaths have been reported, including two in Uganda. As of 26 August, at least 1314 patients have recovered, including 1293 in the Democratic Republic of the Congo, 18 in Uganda, two in Germany and one in France.  

As of 27 August, the 42-day enhanced monitoring period, as per international guidance, has been completed in both France and Uganda.  

The continuing intensity of transmission in the Democratic Republic of the Congo means that the risk of further exportation across international borders remains. Entry and exit health screening and surveillance measures are in place at airports, ports and official land border crossings; however, movement through informal border crossing routes may occur, presenting an ongoing risk of virus exportation, importation and onward transmission. Therefore, cross‑border collaboration, and sustained surveillance and preparedness are essential to prevent further regional spread and ensure an effective public health response. 

On 27 August, vaccination of health care workers using the Ervebo vaccine was initiated in the Democratic Republic of the Congo in some areas, including in Kisangani, Tshopo province. Although Ervebo is a safe vaccine, and effective against Ebola virus disease, it is not known whether it provides protection against the Bundibugyo virus in humans. Thus, starting a clinical trial of the vaccine, alongside this wider use, is key to provide important new evidence and inform future use of the vaccine. 

The second IHR Emergency Committee meeting regarding the epidemic of Ebola Bundibugyo virus disease in the Democratic Republic of the Congo took place on 18 August. Following the advice of the Committee, the Director-General agreed that the ongoing outbreak remains a Public Health Emergency of International Concern, and issued updated temporary recommendations to countries. 

Figure 1. Distribution of cumulative confirmed cases of Bundibugyo virus disease in the Democratic Republic of the Congo, as of 26 August 

Democratic Republic of the Congo  

Since 14 August 2026 when the last Disease Outbreak News was published, an additional 1129 confirmed cases, including 602 confirmed deaths, have been reported in the Democratic Republic of the Congo. Although part of this increase likely reflects expanded surveillance, enhanced laboratory testing, improved diagnostic capacity, and periodic data backlog reconciliation, the sustained rise in number of cases and deaths are the result of continued transmission and substantial outbreak expansion. As of 26 August 2026, a total of 5794 confirmed cases, including 2786 deaths (CFR 48.1%), have been reported in the Democratic Republic of the Congo. To date, 1293 patients have recovered. 

Cases have been reported from 60 health zones (HZ) across six provinces. Ituri has 28 health zones affected out of 36, followed by North Kivu (15/34), Haut-Uélé (6/13), Tshopo (7/23), South Kivu (1/34) and Bas Uélé (3/11). The most recently affected province, Bas-Uélé, started reporting cases since 12 August. The most recently affected health zones are Biena and Manguredjipa in North Kivu province. As of 26 August, of the 60 affected health zones, 81 new confirmed cases were reported in the last 24 hours from 19 health zones in Ituri, North Kivu, Haut-Uélé, and Tshopo provinces. Ituri remains the epicentre of the outbreak, with 4802 confirmed cases reported since the start of the outbreak, including 52 new confirmed cases reported in the last 24 hours, as of 26 August. Nord-Kivu is the second most affected province, with a cumulative number of 775 confirmed cases, including 22 reported in the last 24 hours, as of 26 August. The highest CFR (68%) in this outbreak has been reported from North Kivu province; the reasons for this high CFR are under investigation. 

The number of individuals requiring contact monitoring has also increased substantially as the outbreak has expanded. As of 26 August, the proportion of contacts followed up in the last 24 hours is at 82.3% (22 091 seen out of 26 850 to follow up). The large number of contacts reflects the scale of potential exposure within affected communities. 

The outbreak is unfolding in a conflict-affected humanitarian context marked by insecurity, armed violence, and large-scale displacement. More than 26 million people face acute food insecurity, and an estimated one million internally displaced people live in Ituri Province alone. Insecurity and displacement disrupt access to health care and essential services, restrict access for response teams, and impede surveillance, case investigation and contact follow-up. Overcrowding, limited water, sanitation and hygiene services, and restricted access to healthcare in mining communities, informal settlements and sites for internally displaced people further hinder early detection, infection prevention, and appropriate care. These conditions also make it harder to implement response measures consistently and to reach affected populations.  

Figure 2: Number of confirmed Bundibugyo virus disease cases in the Democratic Republic of the Congo, by date of notification, as of 26 August 2026

Figure 3: Number of deaths among confirmed Bundibugyo virus disease cases in the Democratic Republic of the Congo by date of notification, as of 26 August 2026

  

Between 18 May and 28 August 2026, enhanced public health intelligence conducted by WHO identified 76 Ebola-related signals across 23 countries and territories, supporting rapid verification, risk assessment and information sharing with national authorities through IHR National Focal Points. Most signals, 92% (70/76), including suspected cases among travellers and health-care workers and reports circulating in public sources, were subsequently ruled out through investigation and laboratory testing. The remaining six were confirmed as Ebola events. 

Epidemiology

Bundibugyo virus disease (BVD) is a severe Ebola disease caused by the Bundibugyo virus, one of the Orthoebolavirus species. It is a zoonotic disease, with fruit bats suspected to be the natural reservoir. 

Human infection is thought to occur through close contact with the blood or secretions of infected wildlife, such as bats or non-human primates, and it subsequently spreads from person-to-person through direct contact with the blood, secretions, organs, or other bodily fluids of infected individuals or contaminated surfaces and materials. Transmission is particularly amplified in health-care settings when IPC measures are inadequate and during unsafe burial practices involving direct contact with deceased individuals. 

The incubation period for BVD ranges from two to 21 days, and infected individuals are not infectious until symptom onset. Early symptoms such as fever, fatigue, muscle pain, headache, and sore throat are non-specific, which complicates clinical diagnosis and can delay detection. These symptoms then progress to gastrointestinal symptoms, organ dysfunction, and, in some cases, haemorrhagic manifestations. 

CFRs in the past two BVD outbreaks, reported in Uganda and in the Democratic Republic of the Congo in 2007 and 2012, were 30% and 50%, respectively. 

Differentiating BVD from other endemic febrile illnesses such as malaria is challenging without laboratory confirmation using PCR or antigen- or antibody-based assays. Outbreak control relies on rapid case identification, isolation and care, contact tracing, safe burials and strong community engagement, as no approved vaccines or specific treatments currently exist for BVD. 

Since first detected in May 2026, this BVD outbreak has rapidly evolved into a large and geographically expanding epidemic in the Democratic Republic of the Congo, with sustained transmission, high mortality and an increasing risk of further international spread. The current outbreak is the second documented Bundibugyo virus disease outbreak in the country, after the 2012 outbreak, and the largest Ebola disease outbreak ever recorded in the Democratic Republic of the Congo irrespective of Ebola virus species. The population at greatest risk of exposure is concentrated in communities living in and moving through areas with active transmission.  

Public health response

For detailed information about the ongoing public health response actions by the Ministry of Health, WHO and partners please refer to the latest situation reports published by the WHO Regional Office for Africa: Ongoing outbreak in the Democratic Republic of the Congo | WHO | Regional Office for Africa  

Health authorities in the Democratic Republic of the Congo, in collaboration with WHO and partners, are continuing to implement and coordinate extensive public health measures, including disease surveillance, laboratory testing, infection prevention and control, clinical care, community engagement, research, logistics and support for response interventions and essential health services, engaging donors and mobilizing additional resources to address critical funding gaps and sustain response operations across affected and at-risk areas. A substantial scale-up is ongoing across all response pillars to get ahead of the outbreak.  

WHO risk assessment

On 14 August 2026, WHO reassessed the risk of the outbreak of BVD to incorporate newly available information. The risk for countries sharing land borders with the Democratic Republic of the Congo was separated from the risk for other countries in the African Region. 

The risk in the Democratic Republic of the Congo was assessed as very high due to ongoing transmission and the continued expansion of the outbreak into new health zones, increasing the potential for further national and regional spread. The main considerations supporting this assessment include the substantial increase in the number of cases and considerable geographic extension of the outbreak since the previous risk assessment, and potential further increase in CFR as additional deaths are investigated and outcomes are established. In addition, reported transmission among healthcare workers, ongoing conflict and insecurity, laboratory capacity constraints, and absence of licensed vaccine or specific antiviral treatment were also considered as factors maintaining the very high risk. 

The risk for countries sharing land borders with the Democratic Republic of the Congo was again assessed as high due to sustained population mobility linked to cross-border trade and mining activities, variation in capacities and experience of BVD response, and variable levels of readiness. Uganda, the Central African Republic and South Sudan are of particular concern for importation given their proximity, high population mobility and connectivity with areas of the Democratic Republic of the Congo currently experiencing intense transmission. For the Central African Republic and South Sudan, these risks are further compounded by high humanitarian needs, population displacement, insecurity and underlying limitations in health-system capacity. 

The risk for the rest of the African region and at the global level was again assessed as low. 

WHO advice

Based on the currently available information, WHO advises against any restriction of travel to, or trade with, affected countries. WHO continues to closely monitor and, where necessary, verify travel and trade measures in relation to this event. 

The updated Temporary Recommendations issued to States Parties on 24 August 2026 underscore the importance of coordinated outbreak control, strengthened cross‑border collaboration, and sustained surveillance and preparedness to prevent further regional spread and ensure an effective public health response. Rapid recognition of cases, testing and optimized supportive care can reduce mortality, and improve community perceptions and acceptance of health care within the response. 

On 7 August, the WHO Technical Advisory Group on candidate vaccine prioritization released a report regarding possible candidate vaccines for Bundibugyo virus disease.  The members recommended that Ervebo, the only licensed Ebola vaccine (previously known as ebolavirus Zaire), be prioritized for inclusion in a randomized clinical trial in the context of the ongoing outbreak in the Democratic Republic of the Congo.  

In addition, WHO is sponsoring a clinical trial to find effective treatments against BVD. The trial began enrollment on 2 July. The trial, known as the PARTNERS trial, is now open in three different clinical management facilities in Ituri province and has enrolled over 250 people who are confirmed cases.  

Further information

Regular Information products on the outbreak of Bundibugyo virus disease  

Additional information 

Current outbreak: declarations and status 

WHO Rapid risk assessments 

Epidemiological updates and situation reports 

Published Disease Outbreak News (current outbreak) 

Clinical management, IPC, and occupational safety 

 Vaccines 

Training 

Prior Bundibugyo virus disease events, DRC (2012) 

Background and reference 

Ebola disease fact sheet 

Ebola vaccines 

Citable reference: World Health Organization (31 July 2026). Disease Outbreak News; Bundibugyo Virus Disease, Democratic Republic of the Congo and Uganda. Available at  

World Health Organization (1 August 2026). Disease Outbreak News; Bundibugyo Virus Disease, Democratic Republic of the Congo and Uganda. Available at  

World Health Organization (14 August 2026). Disease Outbreak News; Bundibugyo Virus Disease, Democratic Republic of the Congo. Available at:  https://www/who.int/emergencies/disease-outbreak/news/item/2026-DON615 

World Health Organization (28 August 2026). Disease Outbreak News; Bundibugyo Virus Disease, Democratic Republic of the Congo. Available at:  https://www/who.int/emergencies/disease-outbreak/news/item/2026-DON616