The outbreak’s scale and timeline

National authorities declared the outbreak on May 15, 2026, after unusual clusters of illness and community deaths were identified. WHO declared the epidemic a Public Health Emergency of International Concern two days later, on May 17.

It is the DRC’s 17th recorded Ebola outbreak since the virus was first identified in 1976. The death toll has now surpassed the 2,299 deaths recorded during the country’s 2018–2020 outbreak, previously its deadliest Ebola epidemic.

The figures should be read as reported confirmed cases, not a complete count of everyone infected. WHO has described intense, sustained transmission, with many cases occurring outside known contact lists and a high proportion of deaths taking place in communities rather than treatment units. Those patterns suggest that some transmission chains may not yet have been detected.

Why the Bundibugyo virus matters

The outbreak is caused by Bundibugyo virus, a species distinct from the Zaire ebolavirus responsible for several previous Ebola epidemics. That difference has major consequences for the response: WHO says there is currently no approved vaccine or specific treatment for Bundibugyo virus disease.

Existing Ebola countermeasures were developed or licensed for other Ebola species, so the immediate clinical response relies on rapid diagnosis, isolation, infection prevention and control, and intensive supportive care. Candidate vaccines and treatments are being assessed, but they are not the same as having an approved, widely available medical countermeasure.

How Ebola transmission is being addressed

Ebola response teams focus on finding cases quickly and interrupting the routes by which the virus moves through households, health facilities and communities. Key measures include:

• laboratory testing and case investigation;
• tracing and following people who may have been exposed;
• rapid isolation and clinical care;
• infection-prevention measures for health workers and caregivers;
• safe and dignified burials; and
• community-led surveillance, referrals and risk communication.

These measures are especially important when people become ill at home or when deaths occur before diagnosis. Delayed care can make it harder to identify contacts and safely manage exposure, while unsafe handling of bodies can create additional transmission risks.

Why containment is difficult

WHO and its partners are responding in a setting shaped by insecurity, displacement, remote communities and intense population movement along roads, rivers and mining routes. The outbreak also involves highly mobile and cross-border populations, while misinformation and mistrust can undermine contact tracing, care-seeking and safe-burial efforts.

Those conditions make the official totals potentially incomplete. The available evidence supports concern about undercounting, but it does not establish a precise total number of hidden infections or deaths. Claims about a specific proportion of deaths occurring outside hospitals or about more than 1,000 recoveries should therefore be treated cautiously unless confirmed by an updated official situation report.

What WHO’s international warning means

WHO has said the risk of further national and international spread remains high and that the outbreak is not under control. That is a warning about the seriousness of the current transmission and the need for faster response—not a prediction that international spread is inevitable.

The wider response is being coordinated by DRC authorities with WHO, Africa CDC and other partners. It includes expanded surveillance, laboratory capacity, contact follow-up, clinical preparedness, supplies, infection-control support and community engagement, along with cross-border preparedness in neighboring countries.

The central challenge is that the outbreak is growing rapidly while the virus involved lacks an approved vaccine or specific treatment. Until response teams can find missed transmission chains and communities can access trusted, timely care, the DRC epidemic will remain a major international health emergency.

The outbreak’s scale and timeline

National authorities declared the outbreak on May 15, 2026, after unusual clusters of illness and community deaths were identified. WHO declared the epidemic a Public Health Emergency of International Concern two days later, on May 17.

It is the DRC’s 17th recorded Ebola outbreak since the virus was first identified in 1976. The death toll has now surpassed the 2,299 deaths recorded during the country’s 2018–2020 outbreak, previously its deadliest Ebola epidemic.

The figures should be read as reported confirmed cases, not a complete count of everyone infected. WHO has described intense, sustained transmission, with many cases occurring outside known contact lists and a high proportion of deaths taking place in communities rather than treatment units. Those patterns suggest that some transmission chains may not yet have been detected.

Why the Bundibugyo virus matters

The outbreak is caused by Bundibugyo virus, a species distinct from the Zaire ebolavirus responsible for several previous Ebola epidemics. That difference has major consequences for the response: WHO says there is currently no approved vaccine or specific treatment for Bundibugyo virus disease.

Existing Ebola countermeasures were developed or licensed for other Ebola species, so the immediate clinical response relies on rapid diagnosis, isolation, infection prevention and control, and intensive supportive care. Candidate vaccines and treatments are being assessed, but they are not the same as having an approved, widely available medical countermeasure.

How Ebola transmission is being addressed

Ebola response teams focus on finding cases quickly and interrupting the routes by which the virus moves through households, health facilities and communities. Key measures include:

• laboratory testing and case investigation;
• tracing and following people who may have been exposed;
• rapid isolation and clinical care;
• infection-prevention measures for health workers and caregivers;
• safe and dignified burials; and
• community-led surveillance, referrals and risk communication.

These measures are especially important when people become ill at home or when deaths occur before diagnosis. Delayed care can make it harder to identify contacts and safely manage exposure, while unsafe handling of bodies can create additional transmission risks.

Why containment is difficult

WHO and its partners are responding in a setting shaped by insecurity, displacement, remote communities and intense population movement along roads, rivers and mining routes. The outbreak also involves highly mobile and cross-border populations, while misinformation and mistrust can undermine contact tracing, care-seeking and safe-burial efforts.

Those conditions make the official totals potentially incomplete. The available evidence supports concern about undercounting, but it does not establish a precise total number of hidden infections or deaths. Claims about a specific proportion of deaths occurring outside hospitals or about more than 1,000 recoveries should therefore be treated cautiously unless confirmed by an updated official situation report.

What WHO’s international warning means

WHO has said the risk of further national and international spread remains high and that the outbreak is not under control. That is a warning about the seriousness of the current transmission and the need for faster response—not a prediction that international spread is inevitable.

The wider response is being coordinated by DRC authorities with WHO, Africa CDC and other partners. It includes expanded surveillance, laboratory capacity, contact follow-up, clinical preparedness, supplies, infection-control support and community engagement, along with cross-border preparedness in neighboring countries.

The central challenge is that the outbreak is growing rapidly while the virus involved lacks an approved vaccine or specific treatment. Until response teams can find missed transmission chains and communities can access trusted, timely care, the DRC epidemic will remain a major international health emergency.