Notes from the Field Outbreak of Ebola Disease Caused by Bundibugyo Virus — Democratic Republic of the Congo and Uganda, May 2026 MMWR
This MMWR Notes from the Field report documents a large May‑2026 outbreak of Bundibugyo virus disease (BVD), a form of Ebola, affecting the Democratic Republic of the Congo (DRC) and Uganda. As of 2 June 2026, 378 laboratory‑confirmed cases (363 in DRC, 15 in Uganda) and 63 deaths (62 in DRC, 1 in Uganda) were reported, primarily among adults 18‑49 years and roughly equally split by sex. Initial cases were identified among health‑care workers in DRC; Uganda’s cases were largely travelers from DRC with secondary transmission to health‑care staff. Laboratory testing confirmed Bundibugyo virus, with genomic sequencing indicating a new spillover from an unknown zoonotic reservoir. Transmission is presumed to occur via direct contact with infected body fluids, with an incubation period of 2‑21 days; supportive care is the only available treatment, as no approved vaccines or therapeutics exist. One U.S. health‑care worker contracted BVD and was evacuated for treatment; six additional U.S. citizens with high‑risk exposures were monitored abroad. The CDC activated a public‑health emergency response, coordinated with WHO, ministries of health, and international partners, issued travel health notices (Level 3 for DRC, Level 2 for Uganda), enhanced airport screening, and provided guidance to U.S. health departments and the public. Ongoing challenges include limited health‑infrastructure, armed conflict, population displacement, and cross‑border movement, suggesting the outbreak may be larger than reported. The report concludes with acknowledgments, author contacts, and references.
Topics
Outbreak Scale and Epidemiology: 378 Confirmed Cases Across DRC and Uganda
Presents the total number of confirmed BVD cases and deaths, geographic distribution, timeline of declaration, and demographic breakdown of affected individuals.
Clinical Presentation Among Health‑Care Workers and Travelers
Details the signs and symptoms observed (fever, vomiting, diarrhea, bleeding) and notes the primary affected groups—health‑care workers in DRC and travelers in Uganda.
Laboratory Confirmation and Genomic Evidence of a New Spillover Event
Describes laboratory testing by DRC’s National Institute of Biomedical Research, species identification, and genomic sequencing indicating a novel zoonotic spillover.
Transmission Pathways, Incubation, and Lack of Specific Therapeutics
Explains presumed transmission via direct contact with body fluids, incubation period range, infectiousness timeline, and the reliance on supportive care due to absence of approved vaccines or antivirals.
U.S. Exposure Cases and CDC’s Clinical and Monitoring Response
Covers the single U.S. health‑care worker infection, evacuation for treatment, monitoring of six additional U.S. citizens, and CDC’s review and policy compliance.
International Coordination, Travel Advisories, and Public‑Health Measures
Outlines CDC’s activation of emergency response, WHO’s PHEIC declaration, travel health notices (Level 3 DRC, Level 2 Uganda), airport screening, and collaboration with ministries of health and other agencies.
Operational Challenges: Conflict, Displacement, and Border Mobility
Highlights how limited infrastructure, armed conflict, population displacement, and cross‑border movement complicate outbreak containment and data accuracy.