Bundibugyo virus is a rare species of the virus family that causes Ebola disease, and it is the species behind the Democratic Republic of the Congo (DRC) outbreak that passed 11,000 confirmed cases on 10 November 2026. Government data released that day put the outbreak at 11,042 confirmed cases and 5,387 deaths, making it the second-largest and second-deadliest Ebola outbreak ever recorded. There is no licensed vaccine and no approved specific treatment for Bundibugyo virus disease: the only approved Ebola vaccine, Ervebo, protects against a different species, Zaire Ebola virus. The virus spreads through direct contact with the body fluids of a person who is sick or has died, not through the air, and people are not infectious until symptoms begin.

What is Bundibugyo virus?

Bundibugyo virus is one of the viruses that cause Ebola disease, a severe and often fatal illness. The World Health Organization (WHO) says three viruses have caused large Ebola outbreaks: Ebola virus, Sudan virus and Bundibugyo virus. All belong to the filovirus family, and all cause a similar illness, but they are distinct species, which matters because a vaccine or treatment proven against one species cannot be assumed to work against another. Bundibugyo virus was first recognised in an outbreak in Bundibugyo District in western Uganda in 2007. The US Centers for Disease Control and Prevention (CDC) records 131 cases and 42 deaths in that outbreak, a fatality rate of about 32 per cent. A second, smaller outbreak followed in 2012, and the WHO puts the fatality rates of the 2007 and 2012 outbreaks at about 30 per cent and 50 per cent respectively. Before 2026, Bundibugyo virus disease had therefore been rare and geographically limited. The current outbreak in the DRC has changed that completely: it is now the largest Bundibugyo outbreak by a wide margin, and the largest Ebola outbreak ever recorded in the DRC.

How big is the 2026 outbreak?

The DRC Ministry of Health declared the outbreak on 15 May 2026, after laboratory analysis confirmed Ebola disease caused by Bundibugyo virus. The WHO declared it a public health emergency of international concern on 17 May 2026, and that emergency status was confirmed at a second meeting of the WHO emergency committee on 18 August 2026. Case numbers have risen steeply ever since, and the figures change as new reports arrive, so the date of each count matters.

By 20 October, 66 health zones across eight of the DRC's 26 provinces had reported confirmed cases, and 2,595 people had recovered, according to the Australian Centre for Disease Control's situation report of 26 October 2026. The eight affected provinces are Ituri, Nord-Kivu, Sud-Kivu, Tshopo, Haut-Uélé, Bas-Uélé, Sud-Ubangi and Nord-Ubangi. Reuters reported on 10 November 2026 that many deaths have occurred outside treatment centres, and that delayed detection, conflict and strained health services have led to faster spread than in previous outbreaks. The same report noted that the disease has now been reported in East, Central and West Africa, giving it the widest geographic spread of any Ebola outbreak on the continent to date. The overall case fatality rate in the current outbreak is 48.3 per cent, according to the Australian Centre for Disease Control. That figure is calculated from confirmed cases and confirmed deaths only, and it can move as patients still in care recover or die.

How does Bundibugyo Ebola spread?

Bundibugyo virus disease spreads from animals to humans and then between people, through direct contact with infected body fluids. Fruit bats are thought to be the natural hosts of the viruses that cause Ebola disease. People can first be infected through close contact with the blood, secretions or organs of infected animals, including bats and non-human primates found ill or dead. Once a person is ill, the virus spreads through direct contact, through broken skin or mucous membranes, with the blood or body fluids of a person who is sick or has died, or with objects and surfaces contaminated with those fluids. Body fluids in this context include blood, vomit, diarrhoea, saliva, urine, sweat, breast milk and semen. The WHO says people cannot transmit the disease before they have symptoms, and they are considered infectious from the onset of symptoms. Ebola is not spread through the air like influenza, measles or Covid-19, so it cannot be caught simply by being near someone who is infected. Spread is amplified in health facilities where infection control is weak, and at burials that involve touching the body. More than 150 health workers were among the confirmed cases by late October 2026, according to the Australian Centre for Disease Control, indicating health-care-associated transmission. Contact tracing is a central part of the response: by 20 October, 30,130 contacts had been identified for follow-up, with a follow-up rate of 79.7 per cent, but the same report said tracing remains challenging because of population movement and ongoing conflict. Available modelling suggests substantial under-detection, with the true number of infections potentially three to four times higher than the confirmed count.

What are the symptoms of Bundibugyo Ebola?

Symptoms usually appear between two and 21 days after exposure, and most often within about a week, according to the US CDC. The illness usually starts with non-specific, flu-like symptoms: sudden fever, fatigue, muscle pain, headache and a sore throat. In that early stage it can look like malaria, typhoid fever or another febrile illness, so laboratory blood tests are needed to make the diagnosis. In some cases the illness progresses to vomiting, diarrhoea and abdominal pain, a rash, and signs of kidney and liver impairment. Bleeding and other haemorrhagic manifestations can occur later in the illness, but they are less common than many people believe and tend to come later rather than at the start. The Australian Centre for Disease Control's situation report of 26 October 2026 describes the same course: early symptoms of fever, muscle pain, fatigue and sore throat, progressing in some cases to gastrointestinal symptoms, organ dysfunction and haemorrhagic manifestations. Because early symptoms are so non-specific, health authorities advise clinicians to consider recent travel to affected countries when assessing patients with compatible symptoms, particularly travel to the DRC within the previous 21 days. Anyone who has had contact with a person with Ebola does not transmit the virus unless they themselves become ill; contacts become infectious only with the onset of symptoms.

Is there a vaccine or treatment for Bundibugyo Ebola?

There is currently no licensed vaccine specifically approved for Bundibugyo virus disease and no approved antiviral treatment for it. That is the single most important difference between this outbreak and the Ebola outbreaks most people remember. The vaccine Ervebo, approved by the US Food and Drug Administration in 2019, prevents disease caused by Zaire Ebola virus only, and the two monoclonal antibody treatments approved in 2020, Inmazeb and Ebanga, are also for Zaire Ebola virus infection. Research is under way. The Australian Centre for Disease Control reported on 26 October 2026 that clinical trials of Bundibugyo-specific vaccines and therapeutics are ongoing, supported by the WHO, and that a clinical trial evaluating the potential cross-protective effect of the Zaire Ebola virus vaccine has begun in the DRC, alongside vaccination of health workers as part of the outbreak response. It is not yet known whether Ervebo protects against Bundibugyo in humans, although early laboratory and animal data suggest some protection. Until a specific vaccine or treatment is proven, care is supportive: patients are treated in isolation, given fluids and treatment for their symptoms, and monitored closely, which improves the chances of survival. Early presentation to a treatment centre matters, and the high proportion of deaths occurring outside treatment centres in this outbreak is one reason the fatality rate has stayed high.

How is Bundibugyo different from Zaire Ebola?

The two species cause the same kind of illness, but they differ in history, in how deadly they have been, and in what medical tools exist against them. Zaire Ebola virus caused the 2014 to 2016 West African epidemic, the largest Ebola outbreak on record, with more than 28,600 people infected and more than 11,000 killed, according to Reuters. It has also caused almost all of the DRC's previous outbreaks. Bundibugyo virus had caused only two previously reported outbreaks before 2026, and its historical fatality rate has been lower: about 30 per cent in 2007 and about 50 per cent in 2012, according to the WHO, compared with up to 90 per cent for untreated Zaire Ebola virus infection, according to the US CDC. In the current outbreak, however, the Bundibugyo fatality rate is 48.3 per cent, which the Australian Centre for Disease Control says may reflect delayed detection and late presentation to health facilities rather than increased severity of the virus itself. The practical difference that matters most is medical: Zaire Ebola virus has a licensed vaccine and approved antibody treatments, while Bundibugyo virus has neither.

Why is this outbreak so large?

Several factors have combined. The outbreak was detected late, and many patients have died outside treatment centres, which means infectious people were not isolated quickly and their contacts were not always traced. Conflict and insecurity in eastern DRC have constrained access for response teams, disrupted surveillance and increased the risk of undetected transmission, according to the Australian Centre for Disease Control. Health services are strained, and more than 150 health workers have themselves become infected. The virus has also spread further geographically than in earlier outbreaks: eight provinces in the DRC, with limited cross-border spread to Uganda, and cases reported in Kenya and Nigeria. Kenya had reported nine cases, including one death, as of 20 October 2026, after an initial case who had travelled from the DRC through Uganda arrived in Kenya on 6 October. Nigeria reported its first confirmed case, imported, on 20 October 2026. Uganda's outbreak was declared over on 27 August 2026 after 42 days without an additional case, although enhanced surveillance remains in place because of the risk of re-importation. Modelling cited by the Australian Centre for Disease Control suggests the true number of infections may be three to four times the confirmed count, because many cases are never detected or tested.

What is the risk outside the DRC?

The WHO assesses the risk as very high for the DRC, high for countries with land borders adjoining countries with documented cases, and low for the rest of the Africa region and low at the global level, according to the Australian Centre for Disease Control's situation report of 26 October 2026. The WHO continues to advise that no country should close its borders or place restrictions on travel and trade, noting that such measures can have unintended effects on the response and on population movement. The risk to any individual country depends on travel links and on whether cases are detected quickly; Ebola spreads only through direct contact with a sick person or their body fluids, which makes casual importation unlikely, but travellers returning from affected areas within the previous 21 days who develop fever or other compatible symptoms should seek medical care promptly and mention their travel history. Sources: Reuters, 10 November 2026; Australian Centre for Disease Control, Situation Report 16, 26 October 2026, which summarises WHO Disease Outbreak News of 23 October 2026.

Frequently asked questions

Can Bundibugyo Ebola spread through the air? No. It spreads through direct contact with the body fluids of a person who is sick or has died, or with contaminated objects and surfaces. It is not spread through the air like influenza or measles.

Is there a vaccine for Bundibugyo Ebola? No. There is no licensed vaccine specifically for Bundibugyo virus disease. The approved Ebola vaccine, Ervebo, is licensed only for Zaire Ebola virus, and a trial is testing whether it offers cross-protection against Bundibugyo.

How long after exposure do symptoms appear? Symptoms usually appear between two and 21 days after exposure, most often within about a week, according to the US CDC.

How deadly is the current outbreak? The case fatality rate among confirmed cases is 48.3 per cent, according to the Australian Centre for Disease Control, with 5,387 deaths among 11,042 confirmed cases in DRC government data reported on 10 November 2026. That is lower than the fatality rate of up to 90 per cent reported for untreated Zaire Ebola virus infection, but far higher than most infectious diseases.

Should travellers cancel trips because of the outbreak? The WHO advises against closing borders or restricting travel and trade, and assesses the global risk as low. Travellers should follow their own government's travel advice for the DRC and neighbouring countries, and anyone returning from an affected area who develops symptoms within 21 days should seek medical care promptly and mention their travel history.