WHO declares Congo Ebola emergency as rare Bundibugyo virus kills 100+, spreads to Uganda

In late April, a health worker in Bunia, a city in Congo's northeastern Ituri Province, fell ill with a fever that would not break. By the time authorities recognized what was happening, the person was dead—and the body had already been moved. That single transport to a nearby mining town called Mongbwalu would seed an outbreak that would eventually kill more than 100 people across two countries and force the World Health Organization to declare a global health emergency.

The delay in recognizing the outbreak came from an unusual source: the virus itself. When health officials first tested samples in late April, they came back negative for the Zaire strain of Ebola, the familiar culprit in previous Congo outbreaks. It took two more weeks of investigation before laboratories confirmed what was actually spreading through the region—the Bundibugyo virus, a rarer member of the Ebola family that had not been the primary driver of recent outbreaks in Congo. By the time the identification was made, the virus had already moved beyond Mongbwalu into surrounding health zones, and at least one person had crossed an international border.

On May 5, the WHO was alerted to what it called a "high-mortality" outbreak of unknown origin in Mongbwalu. Local reports suggested around 50 deaths already. Health workers were among the dead. The Congolese health minister would later acknowledge that the first victim's body, transported from Bunia to Mongbwalu, likely triggered the cluster there—a grim reminder that bodies of Ebola patients remain highly contagious even after death.

A week later, a 59-year-old Congolese man arrived at a hospital in Kampala, Uganda's capital, roughly 700 kilometers from where the outbreak had begun. He had crossed the border with fever and body aches. On May 14, he died in the Ugandan hospital. His body was sent back to Congo. When Ugandan health authorities tested a sample taken after his death, it came back positive for Bundibugyo virus—confirmation that the outbreak had jumped borders.

On May 15, laboratories in Kinshasa, Congo's capital, confirmed Bundibugyo virus in eight of thirteen blood samples from suspected cases in the Rwampara health zone. The same day, the Congo Health Ministry formally declared an Ebola outbreak. The Africa CDC reported 246 suspected cases and 65 deaths. Within days, those numbers had climbed to more than 300 cases and more than 100 deaths. Uganda reported its outbreak as limited to two cases, both travelers from Congo.

Two days later, on May 17, the WHO made the formal declaration: a public health emergency of international concern. The organization was careful to note that the outbreak did not meet the threshold of a pandemic emergency like COVID-19, and it advised countries not to close their borders. But it urged nations sharing a land border with Congo or Uganda to strengthen disease surveillance and ensure health workers could recognize and manage Ebola cases.

This was the seventeenth significant Ebola outbreak Congo had experienced since the virus was first identified in 1976. The Bundibugyo strain has no approved treatment and no vaccine. By May 18, an American doctor working in a hospital in Bunia had been confirmed as one of the cases. The outbreak, born from a rare virus variant that delayed its own identification, had already crossed borders and claimed health workers trying to contain it. The question now was whether neighboring countries could mount a response fast enough to prevent further spread.