The Bundibugyo virus disease outbreak in the Democratic Republic of the Congo has intensified dramatically, with 4,665 confirmed cases and 2,184 deaths recorded as of August 12, 2026, according to the World Health Organisation.
The scale and speed of the outbreak have heightened concerns about further transmission within the country and the possibility of international spread, particularly amid population displacement, insecurity and increased cross-border movement.
The outbreak, which was first detected in the Mongbwalu health zone in Ituri Province, has now reached 54 health zones across six provinces — Ituri, North Kivu, South Kivu, Haut-Uélé, Tshopo and Bas-Uélé.
The reported figures represent a crude case fatality ratio of 46.8 per cent, underscoring the severity of the outbreak. WHO described it as the largest Bundibugyo virus disease outbreak ever reported in the DRC and noted that it is spreading faster than previous Ebola outbreaks in the country.
Weekly cases reach record high
The outbreak has shown a particularly sharp increase in recent weeks.
During epidemiological week 32, covering August 3 to 9, health authorities recorded 579 cases and 304 deaths — the highest weekly totals reported since the outbreak began.
WHO said the continued rise in infections, expansion into new geographic areas and persistently high mortality point to a rapidly evolving public health emergency requiring intensified control measures.
Bas-Uélé became the latest province to report an infection after one confirmed case was detected in the Buta health zone.
According to WHO, the patient had travelled from Haut-Uélé and developed symptoms on August 4, raising further concerns about the role of population movement in transmitting the disease between affected areas.
The development means the outbreak is increasingly moving beyond isolated transmission points and taking the form of sustained transmission across interconnected geographic clusters.
WHO said this pattern was complicating efforts to contain the outbreak, as health authorities face the challenge of identifying cases and contacts across increasingly dispersed communities.
Humanitarian crisis complicates response
The worsening outbreak is unfolding against the backdrop of a broader humanitarian crisis in the DRC.
WHO said insecurity, population displacement, high mobility and cross-border movements were creating additional obstacles to the public health response while increasing opportunities for the virus to spread to new areas.
The movement of people between affected communities can make surveillance and contact tracing more difficult, particularly in areas where health services are already under pressure.
The expansion across six provinces also presents logistical challenges for response teams, which must coordinate surveillance, case management, infection prevention and control, community engagement and other interventions across a large geographical area.
National authorities, working alongside WHO and other partners, have continued to implement response measures, but the rapid increase in cases and deaths has prompted calls for a significant intensification of containment efforts.
With transmission continuing to expand and weekly infections reaching their highest level since the outbreak began, health authorities face mounting pressure to prevent further geographic spread and reduce the unusually high mortality associated with the outbreak.