What is known about the Bundibugyo virus that caused the Ebola outbreak in Congo
An outbreak of disease caused by the Bundibugyo virus, a rare member of the Ebolavirus group, has been reported in the Democratic Republic of Congo. As of 19 May 2026 AP, Congo's Health Ministry reported 513 suspected cases and 131 deaths, but authorities stressed that the link between all deaths and the disease was still under investigation.
Bundibugyo is one of the viruses that cause Ebola. It is rarer than the better-known Zaire ebolavirus, making it more difficult to control the outbreak: there is no approved specific vaccine and no separate antiviral treatment yet.
Important: the virus is not airborne like influenza or measles. The main risk comes from close contact with blood and other bodily fluids of a sick or dead person. Therefore, healthcare workers, relatives caring for the sick and people involved in funeral rites involving touching the body are particularly vulnerable in the outbreak area.
Details
WHO said it was notified on 5 May 2026 of an outbreak of an unknown disease with high mortality in Mongbwalu zone in Ituri province in eastern DR Congo. Health workers were among those who died. on 15 May, the National Institute for Biomedical Research in Kinshasa confirmed Bundibugyo virus in samples.
Cases were later confirmed outside the original area as well. According to AP, the virus was detected in several locations, including Bunia, Goma, Mongbwalu, Butembo and Nyakunde. WHO also reported two laboratory-confirmed cases in Uganda, including one fatal, in people travelling from Congo.
The disease, caused by the Bundibugyo virus, is spread in the same way as other forms of Ebola: through direct contact with the bodily fluids of the sick person - blood, vomit, faeces, sweat and other secretions. Objects contaminated with such fluids and contact with the body of the deceased are also dangerous.
According to WHO, in past outbreaks of Bundibugio, the mortality rate has been estimated at about 30-50 per cent. This may be lower than in some Zaire ebolavirus outbreaks, but it still makes the disease extremely dangerous.
The main difficulty in the current outbreak is the lack of readily available specific tools. Vaccines and targeted therapies exist for Zaire ebolavirus, but no such approved tools exist against Bundibugyo. The response is therefore based on classical measures: rapid diagnosis, isolation of patients, contact tracing, protection of health professionals, safe burial and supportive therapy.
Supportive therapy is not a "cure for the virus," but it is important. Patients are given fluids, dehydration is corrected, blood pressure and organ function are maintained, and complications are treated. The earlier a person receives this care, the better the chances of survival. The CDC emphasises that early supportive medical care improves outcomes in Bundibugyo virus disease.
Why it matters
This outbreak is alarming to doctors not only because of the number of cases, but also because of the type of virus. Bundibugio is rare, so there is less experience, less clinical data, and no ready-made vaccine strategy as with the more studied variants of Ebola.
The situation is also complicated by the location of the outbreak. The eastern DR Congo has been plagued by years of armed conflict, displacement, poverty and distrust of authorities and health services. All of this makes it difficult to find people quickly, trace contacts and safely organise treatment. The Guardian also points out that spreading to areas with conflict and misinformation makes containing an outbreak more difficult.
That said, it is important to avoid panic. Ebola is not spread by normal long-distance conversation and is not airborne like respiratory infections. Outbreak control is possible: isolation, protective equipment for healthcare workers, public education, testing and safe burials have helped stop Ebola outbreaks in the region many times before.
Background
Bundibugyo was first identified in 2007 during an outbreak in Uganda. Since then, such outbreaks have been rare. That's why experts emphasise: there is less experience with this virus than with the better-known Ebolavirus species.
DR Congo has faced Ebola more than once: the current outbreak is already called the 17th major outbreak in the country since the Ebola virus was identified in 1976. AP notes that the outbreak likely began weeks before official confirmation, and the first cases could have appeared as early as late April.
WHO described the situation as an outbreak of disease caused by the Bundibugyo virus in DR Congo and Uganda on 16 May 2026. The organisation reported high mortality rates, confirmation of the virus by laboratory tests and the need for increased international coordination.
Source
Material based on Associated Press Devi Shastri's publication on the Bundibugyo virus and the current outbreak in Congo, as well as WHO, CDC, Africa CDC and other official reports as of 19 May 2026. AP reports 513 suspected cases and 131 deaths according to DR Congo's Ministry of Health, while emphasising that the link of all deaths to the disease is still being verified.
Official WHO data indicate that the outbreak was laboratory-confirmed on 15 May 2026, while the CDC stresses the lack of approved specific vaccines and drugs against the disease caused by the Bundibugyo virus.