Date and version of current assessment: 06 June 2026, v3
Date(s) and version(s) of previous assessment(s): 15 May 2026, V1; 22 May 2026,V2
Risk statement
Following the publication of the second Rapid Risk Assessment (RRA) on 22 May 2026, the Bundibugyo virus disease (BVD) outbreak has continued to expand, particularly in the Democratic Republic of the Congo and, to a lesser extent, in Uganda.
During this period, a case was reported in a Congolese national who travelled from the Democratic Republic of the Congo, via Uganda, to the United Arab Emirates and then back to Uganda.
WHO is working with public health authorities in the United Arab Emirates and Uganda to gather additional information to assess the risk of exposure and facilitate contact tracing through the National International Health Regulations (IHR) Focal Point mechanism.
Following notification of the case, the United Arab Emirates authorities rapidly implemented risk assessment, contact tracing activities, follow-up of identified contacts, public health investigations, enhanced preparedness measures at points of entry, and coordination with relevant national and international partners.
Epidemiological investigations to date have not identified any secondary cases, local transmission, or evidence of onward spread in the country.
Additionally, as of 6 June, the outbreak in the Democratic Republic of the Congo has expanded considerably; the number of reported affected health zones has increased from 16 to 25, while the number of laboratory-confirmed cases increased from 63 to 515 and the number of confirmed deaths from four to 91 (CFR 17.7%).
The increase in the number of confirmed cases reflects both ongoing transmission and improvements in case detection through expanded testing and intensified contact tracing activities.
The number of reported suspected cases decreased from 661 to 117 following the testing of a backlog of samples and subsequent reclassification of suspected cases to either confirmed cases or noncases.
So far, at least 16 healthcare workers are among the confirmed cases.
Cases have been reported across all age groups, with most occurring among adults aged 20–49 years, and a slightly higher proportion among males.
To date, 12 patients have recovered.
The outbreak has also expanded geographically, with transmission reported in additional health zones in Ituri and North Kivu provinces.
The outbreak is now reported across 25 health zones in Ituri (17), North Kivu (seven), and South Kivu (one) provinces, with new affected areas identified in both Ituri and North Kivu.
In Uganda, as of 6 June, the number of reported confirmed cases increased from two to 19 (14 imported and five acquired in Uganda), including two deaths in imported cases.
All reported cases are from two districts (Kampala and Wakiso).
Five healthcare workers are among the confirmed cases, indicating transmission in healthcare settings.
To date, all cases in Uganda have been linked to importation from the Democratic Republic of the Congo or secondary cases linked to these; there has been no documented community transmission in Uganda.
In light of the continued evolution of the outbreak and newly available information, including the increase in the number of reported cases, geographic expansion, cross-border transmission to Uganda, and ongoing response activities, this RRA has been updated.
Based on these developments and the WHO Temporary Recommendations issued by the WHO Director-General following the declaration of a Public Health Event of International Concern (PHEIC) for the Ebola disease epidemic caused by Bundibugyo virus (BDBV) in the Democratic Republic of the Congo and Uganda, the risk for countries sharing land borders with countries with documented BDBV detection, currently the Democratic Republic of the Congo and Uganda, has been separated out from the risk for other countries in the African Region: the risk in countries sharing land borders remains high, while the risk for other countries in the African region is assessed as low.
Countries sharing land borders with the Democratic Republic of the Congo and/or Uganda have not reported confirmed cases to date.
Neighbouring countries have strengthened surveillance and point-of-entry (PoE) measures, although the extent of implementation may vary across countries.
The risk globally remains unchanged and is assessed as low.
The risk in the Democratic Republic of the Congo remains 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 key factors underpinning this assessment include:
• The outbreak has continued to expand rapidly since the previous assessment. Between 22 May and 6 June 2026, the number of confirmed cases increased more than eightfold from 63 to 515 cases, while the number of health zones with confirmed cases has increased by 56 % (from 16 to 25), indicating intensified transmission and geographic spread.
• The detection of cases in additional health zones in Ituri and North Kivu provinces and ongoing transmission among healthcare workers suggest that the outbreak continues to pose a very high risk of further spread within the Democratic Republic of the Congo.
• In Ituri province, 17 of the 36 health zones are now affected, with Aungba, Damas, Gety, Komanda, Lita, Mambasa and Mangala among the newly affected health zones. In North Kivu province, confirmed case detections in the Beni and Kyondo health zones have increased the number of affected health zones to seven out of 35.
• According to the most up-to-date sub-national risk stratification analysis, which will be used to further inform operational response priorities, there are a total of 159 health zones currently deemed affected or at risk; this classifies the level of community transmission and underscores the large geographic scale of response needed to control this outbreak.
o 25 health zones with confirmed cases, including 17 ‘hotspot’ health zones and eight ‘active’ health zones{2}
o 19 high-risk health zones
o 115 at-risk health zones
• Epidemiological links and the full chain of transmission are not yet clearly established, and the source of the outbreak remains under investigation.
• Retrospective investigations identified suspected viral haemorrhagic fever cases occurring back in March 2026, several weeks before outbreak confirmation, suggesting prolonged undetected transmission prior to May 2026 and the establishment of multiple disconnected transmission chains across affected communities and provinces.
• The affected area is characterized by intense population mobility linked to mining activities, trade, social ties and care seeking, with movement between rural and urban centres and across neighbouring provinces.
• Reports of patients avoiding or leaving treatment facilities, together with evidence of ongoing community mistrust of BVD prevention and response measures, raise concerns about reduced healthcare-seeking behaviour and under-detection of cases. As observed during previous Ebola disease outbreaks, community fear and misinformation have hindered case detection, contact tracing, and isolation efforts, contributing to sustained transmission. Such challenges may facilitate ongoing spread within affected communities and complicate outbreak control measures.
• Reports of numerous community deaths and challenges in the implementation and community acceptance of safe and dignified burial (SDB) practices are of concern. Traditional burial practices often involve direct contact with the deceased, which may facilitate transmission and contribute to the persistence of community-based transmission chains.
• Ongoing conflict in Ituri and North Kivu provinces restricts the movement of surveillance teams, limits the deployment of Rapid Response Teams, and hinders the secure transport of laboratory samples, as well as posing challenges to contact tracing, safe and dignified burials and control of movement of high-risk contacts in those conflict zones.
• Limited healthcare infrastructure, combined with inadequate and insufficient Ebola Treatment Centre (ETC) and isolation capacity, may hinder effective case management and infection prevention and control measures. The mixing of suspected and confirmed cases in healthcare facilities increases the risk of nosocomial transmission and may further amplify the outbreak.
• Delays in laboratory confirmation resulting from stockouts of testing supplies and limited diagnostic capacity have hindered the timely detection, isolation, and management of cases.
• Infection among at least 16 healthcare workers, including a laboratory technician, together with low infection prevention and control (IPC) scorecard performance in affected areas, indicate a high risk of exposure in healthcare settings and significant gaps in IPC.
• Early and intensive supportive care remains the only treatment option for BVD, for which no licensed vaccine or specific therapeutics are currently available for prevention and treatment.
• Community protection capacities remain insufficient in several affected areas, including limited social listening, community feedback mechanisms, rumour management, engagement of trusted local leaders and Community Health Workers (CHWs), and systematic use of community insights to inform operational decision-making. These gaps may contribute to delayed care-seeking, underreporting, reduced acceptance of response measures and continued transmission.
The level of risk for Uganda is still assessed as High due to:
• Confirmed cross-border spread through imported cases to Uganda.
• As of 6 June 2026, Uganda had reported 19 cases linked to the outbreak in the Democratic Republic of the Congo, following the importation of two cases who travelled to Uganda to seek medical care. Among the reported cases, five are healthcare workers, indicating transmission in healthcare settings.
• Despite the suspension of passenger transport services between Uganda and the Democratic Republic of the Congo, including flights, buses, and ferries, cross-border population movement is likely to continue through informal and uncontrolled crossing points. The porous border, together with intense cross-border mobility associated with mining, trade, family visits, healthcare-seeking, displacement or population movements linked to insecurity, increases the likelihood of continued cross-border transmission.
• Potential for undetected chains of transmission in border communities.
• Preliminary analyses of population movement and cross-border mobility patterns have identified Kisoro, Kabale, Kanungu, Rukungiri, Kasese, Kikuube, Hoima, Pakwach, Nebbi, Arua, Zombo, Koboko, and Yumbe as the districts at increased risk of importation and subsequent transmission of BVD from the Democratic Republic of Congo.
• Ongoing epidemiological links along the eastern Democratic Republic of the Congo–western Uganda corridor, historically affected by Ebola outbreaks, including Bundibugyo and Sudan virus disease outbreaks.
The risk for countries with land borders adjoining countries with documented BDBV detection, is assessed as high based on the following factors:
• Sustained population mobility across porous borders linked to cross-border trade and mining activities, combined with operational constraints resulting from insecurity, displacement, and limited healthcare access, increase the risk of continued transmission and hinder outbreak control measures.
• Insufficient laboratory capacity, coupled with limited experience in BVD surveillance, case management, infection prevention and control, contact tracing, and outbreak response, may reduce the ability of some neighbouring countries to rapidly detect and contain imported cases.
• Variable levels of readiness for community engagement, community-based surveillance, social listening, rumor management and community feedback systems may limit the ability of some neighbouring countries to rapidly identify, understand and respond to community concerns following an imported case.
• There are variations in capacities and experiences across these countries.
The level of risk for the rest of the Africa region and at the global level is assessed as low due to:
• At present the outbreak remains geographically limited to the Democratic Republic of the Congo, with exportation of cases only to Uganda.
• No evidence suggests sustained international transmission of BVD beyond the Democratic Republic of the Congo and Uganda border areas currently.
• The exportation of cases through international travel, particularly during the asymptomatic incubation period, is possible and may be anticipated; however, this does not change the overall risk assessment, and the risk of global spread remains low.
(...)
1 Confidence refers to the level of confidence in the data/information or the quality of the evidence available at the time the RRA is conducted. Poor quality information may increase the overall perceived risk due to the incertitude in the assessment.
2 ‘Hotspot’ health zones refer to those with the highest burden of active transmission among those with confirmed cases reported; ‘active’ refers to all other health zones with confirmed cases reported
(...)
Source:
Link: https://www.who.int/publications/m/item/who-rapid-risk-assessment-ebola-disease-caused-by-bundibugyo-virus--democratic-republic-of-the-congo--uganda-and-countries-with-land-borders-adjoining-countries-with-documented-bdbv-detection-v3
____