Bundibugyo Ebola Outbreak in DRC and Uganda Declared Public Health Emergency of International Concern
Key Insights
As of June 2, 2026, a total of 378 confirmed Bundibugyo virus disease (search) cases and 63 confirmed deaths have been reported across DRC and Uganda, with the outbreak declared a PHEIC by WHO on May 17, 2026.
The outbreak is caused by the Bundibugyo strain of Ebola (search), absent for over a decade, with an estimated fatality rate of around 30% and no approved vaccines or antivirals available.
CDC (search) initiated a public health emergency response including U.S. entry restrictions, enhanced airport screening, and a Level 3 Travel Health Notice for affected DRC provinces.
A multinational outbreak of Ebola (search) disease caused by the Bundibugyo virus (species Orthoebolavirus bundibugyoense) is unfolding across the Democratic Republic of Congo (DRC) and Uganda, prompting the World Health Organization (WHO) to declare a Public Health Emergency of International Concern (PHEIC) on May 17, 2026. As of June 2, a total of 378 confirmed cases—363 in DRC and 15 in Uganda—and 63 confirmed deaths (62 in DRC and one in Uganda) have been reported, primarily among adults aged 18–49 years, with cases approximately evenly distributed between females and males.
The outbreak marks the re-emergence of the Bundibugyo strain, which has been absent for over a decade and carries an estimated fatality rate of around 30%. No approved medications or vaccines exist against Bundibugyo virus disease (search) (BVD), leaving supportive care as the sole treatment option.
Initial Clusters and Clinical Presentation
The initial clusters of BVD cases were identified among health care workers in DRC, whose signs and symptoms included acute fever, vomiting, diarrhea, and, in some cases, bleeding. Uganda's outbreak has primarily involved travelers arriving from DRC, with secondary transmission to health care workers. Laboratory analysis by the DRC National Institute of Biomedical Research (search) confirmed the Bundibugyo virus, and initial genomic sequencing was consistent with a new spillover event from an unknown zoonotic host.
Transmission Dynamics and Incubation
Based on evidence from other Ebola (search) disease outbreaks, Bundibugyo virus is likely transmitted through direct contact with body fluids of an infected person, including blood, vomitus, feces, urine, tears, sweat, saliva, breast milk, amniotic fluid, vaginal secretions, or semen. The incubation period is expected to range from 2 to 21 days, and patients are considered most infectious in the late stages of the disease and after death, when high concentrations of virus are present in body fluids.
U.S. and International Response
On May 17, 2026—the same day as the WHO's PHEIC determination—the CDC (search) initiated a public health emergency response to support U.S. preparedness, the international outbreak response, and U.S. public health response coordination. On May 18, the U.S. Department of Homeland Security (search) and CDC announced new public health measures that included temporary U.S. entry restrictions. The following day, CDC released a health advisory, initiated enhanced airport screening, and issued interim guidance for U.S. health departments managing travelers in their jurisdictions.
CDC (search) also issued a Level 3 Travel Health Notice for DRC, recommending that travelers reconsider nonessential travel to provinces with cases, and a Level 2 Travel Health Notice for Uganda, advising enhanced precautions.
Among U.S. citizens affected, one health care worker in DRC who developed symptoms received a positive test result for Bundibugyo virus and was transported to Germany for treatment. Six other U.S. citizens—health care workers and their close contacts—who had high-risk exposures to BVD in DRC were transported to Germany and Czechia for monitoring. No BVD cases have been reported in the United States.
Laboratory and Diagnostic Capacity
To bolster domestic preparedness, CDC (search)'s Laboratory Response Network is supporting diagnostic testing capacity at more than 40 U.S. laboratories. When needed, CDC offers clinical consultation for suspected Ebola (search) cases and exposure risk assessments for U.S. citizens abroad who are returning to the United States.
Challenges to Containment
The ongoing BVD outbreak is occurring in geographic areas that have limited public health infrastructure and are affected by armed conflict, frequent population displacement, and cross-border movement. The scope of the outbreak is likely larger than that represented by available data and might prove challenging to contain and control. These factors increase the risk of continued transmission and regional spread, complicating surveillance, contact tracing, and health care delivery.
Broader Context of Infectious Disease Emergencies
The Bundibugyo outbreak highlights the rising frequency of infectious disease emergencies globally, driven by factors including increased global travel, urbanization, climate change, and population growth. Deforestation, land-use changes, and wildlife trade increase contact between humans and animals, raising the chances of pathogen spillover events. Weak health systems, poor sanitation, conflict, displacement, and rising antimicrobial resistance further complicate detection and containment efforts.
CDC (search) is collaborating with international partners and country offices in DRC and Uganda by providing assistance with epidemiologic investigations and contact tracing, laboratory testing, data management, infection prevention and control, border health surveillance, and risk communication and community engagement. The agency has also worked with international partners to complete readiness assessments in bordering countries and is coordinating with the Administration for Strategic Preparedness and Response (search) and the National Institutes of Health to guide interagency recommendations on medical countermeasures for BVD.