More than 2,000 Ebola cases, including 754 deaths, were recorded in the Democratic Republic of the Congo as a Bundibugyo-strain outbreak spread across five provinces. The World Health Organization warned that the true scale could be between two and four times larger than the official count.
Congolese health authorities released the figures as medical organizations described a sharp acceleration. Médecins Sans Frontières said confirmed cases had tripled in under five weeks and deaths had increased more than fivefold. The aid group said the outbreak was moving into new areas and called for the medical response to expand urgently.
The outbreak was declared on May 15 following cases in Ituri, a mineral-rich northeastern province where armed groups frequently conduct attacks. Conflict and movement into additional provinces complicated surveillance, treatment and contact tracing. The recorded total had already reached more than half the number of cases reported during the DRC’s 2018-2020 Ebola epidemic, despite that earlier emergency lasting nearly two years.
WHO emergencies chief Chikwe Ihekweazu said 80% of new cases were not among known contacts and arose from unidentified transmission chains. He also expressed concern that many newly counted patients had died before reaching health facilities. Those indicators suggested that conventional contact lists were missing much of the outbreak’s spread.
No vaccine or treatment had been approved specifically for the Bundibugyo strain. On July 14, however, researchers began the first clinical trial of an antiviral drug in this outbreak. The EBO-PEP study was evaluating obeldesivir as a post-exposure intervention for people who had contact with confirmed Bundibugyo cases.
Gilead Sciences developed the experimental medicine, which had shown activity against filoviruses in preclinical models. Filoviruses include the viruses responsible for haemorrhagic fevers such as Ebola. The start of enrollment represented a research response, not evidence that obeldesivir was already proven effective or approved.
The official figures described both disease burden and surveillance limits. A count above 2,000 established the documented threshold, while the WHO estimate and the high share of cases outside known contact chains indicated that many infections might not yet have been captured.
Health agencies prioritized expanding treatment access, tracing previously unknown transmission routes and supporting work in newly affected areas. The trial added a potential post-exposure tool to that response, but its effectiveness remained to be determined. With cases across five provinces and many deaths occurring outside facilities, health agencies treated the outbreak as still intensifying rather than nearing containment.
A post-exposure study enrolls people after contact with a confirmed case, rather than treating the trial as a population-wide preventive campaign. That design reflects the urgent need around known contacts. The high proportion of patients outside contact lists, however, also showed why finding exposed people remained difficult even as researchers tested a targeted intervention.
