Since 2000 there has been at least one Ebola outbreak almost every year, but the current epidemic stands out. Most recent large outbreaks were caused by the Zaire strain, for which a vaccine exists. This episode, however, is driven by the much rarer Bundibugyo strain, first identified in Uganda in 2007. There is no vaccine or approved treatment for Bundibugyo, which kills roughly one in three people it infects.
The outbreak in eastern Democratic Republic of Congo (DRC) and Uganda is the third and deadliest Bundibugyo epidemic to date. As of Wednesday, the World Health Organization (WHO) reported at least 139 deaths and about 600 suspected cases. WHO Director-General Tedros Adhanom Ghebreyesus said he was deeply concerned about the speed and scale of the spread and warned that numbers are likely to change as surveillance, contact tracing and laboratory testing are intensified.
Tedros declared an international health emergency almost immediately after learning of the situation, foregoing the customary consultation with outside experts. Officials said the decision reflected evidence that the virus had been spreading undetected for weeks, raising the urgency of containment efforts.
Epidemiologists warn the visible cases may represent only a fraction of the true toll. US epidemiologist Eric Feigl-Ding, an early public voice on COVID-19, told DW that the epidemic is killing health workers and already reaching many regions. With limited testing, he said, the counted cases likely underestimate the outbreak’s scale; he also noted the spread appears faster than the 2014 West Africa epidemic in some respects.
Bundibugyo spreads through direct contact with infected individuals or their bodily fluids, so in theory it can be contained with rapid testing, isolation and contact tracing. But experts emphasize that rapid deployment of personnel and resources is critical. Feigl-Ding and others point to the reduced capacity of international aid programs as a factor slowing response.
The US Agency for International Development (USAID) — historically one of the most visible US global health actors — was sharply curtailed beginning in January 2025, when the president issued an executive order freezing aid payments for 90 days and ordering a review of programs. Large numbers of USAID employees were laid off and budget lines were cut by more than 90 percent initially. Although some funding was later restored by Congress, the interruption and staff losses left gaps in programs that support outbreak detection, local clinics and rapid response efforts. Several European governments also reduced development assistance over the same period.
Media reporting and US embassy staff in Kampala told The New York Times that the cancellations and delays worsened an Ebola situation in Uganda. In addition, in February 2025 the head of a US government efficiency office said some containment programs were accidentally terminated for a short time. The article noted not all canceled programs were fully reinstated.
US ties to global health institutions have also changed. After taking steps in 2025 to begin withdrawal, the US formally exited the WHO one year later; previously the US was among the organization’s largest donors. The US Centers for Disease Control and Prevention (CDC) has also been scaled back under the current health leadership, with announced layoffs and cuts to external contracts in April 2025. The CDC says it currently has more than 30 staff working in the DRC to support outbreak response.
Humanitarian and health organizations operating in Congo say the reduction of resources hampers epidemic prevention and detection. Julie Drouet, country director for Action Against Hunger in the DRC, said the impact is real: the identified strain is uncommon in the region, and early tests that targeted the more typical Zaire strain returned negative results. The first known death occurred in the community rather than a health facility, which allowed the virus to circulate longer before authorities recognized and reported the outbreak.
Complicating the response are security and displacement issues. The provinces of North Kivu, South Kivu and Ituri in eastern Congo are rich in resources but plagued by armed conflict and instability. Armed advances in early 2025 prompted population movements that helped the virus spread and made it harder for aid teams to reach affected communities. Cases have now been confirmed in the eastern city of Goma, where control is contested, and in Uganda’s capital, increasing concerns because these urban centers have higher population densities.
Despite these challenges, aid workers say they are doing all they can to contain the epidemic. Humanitarian air bridges have been organized to improve access and speed deliveries. The WHO has provided an initial $3.9 million to bolster national health systems and international partners are urging governments to substantially increase support.
Containing a Bundibugyo outbreak will require rapid, well-coordinated field operations: expanded testing tailored to the correct strain, intensive contact tracing, protection for healthcare workers, and logistical support to operate in conflict-affected zones. Experts warn that interruptions to funding and staffing for global health programs make that rapid deployment harder, and may have contributed to delayed detection and slower response in this outbreak.
Health authorities and aid organizations are racing to expand surveillance, laboratory capacity and community outreach to stop further spread, while calling on international donors to step up funding and technical assistance.