The Ebola outbreak in the Democratic Republic of the Congo has claimed 600 lives, the World Health Organization confirmed on Thursday, only three days after the toll surpassed 500. With 1,759 confirmed cases and a case fatality rate of 34 percent, the epidemic is now the fastest-growing on record, according to the Africa Centres for Disease Control and Prevention. Congolese health authorities reported 51 new cases and 20 deaths in the preceding 24 hours, while 304 suspected cases remain under investigation.

The outbreak, declared on 15 May, is driven by the rare Bundibugyo species of the virus, for which no licensed vaccine or treatment exists. In response, a clinical trial began on 2 July in Bunia, Ituri province, evaluating the monoclonal antibody MBP134 and the antiviral remdesivir, both alone and in combination. The WHO has also granted emergency-use authorisation for the first molecular diagnostic test specific to this strain. The trial’s sample size has not been disclosed, and researchers caution that the true scale of the outbreak is not yet fully established, as the virus likely circulated undetected for weeks before the official declaration.

The epicentre remains the mineral-rich Ituri province, but the virus has now reached four provinces, including North Kivu, South Kivu, and, for the first time, Tshopo, where two suspected cases were reported in the city of Kisangani. Uganda has recorded 20 cases and two deaths, while France confirmed a case in a doctor returning from the DRC. Response efforts are severely complicated by armed conflict: the M23 rebel group controls large areas of North and South Kivu, and population displacement is continuous. In Ituri, front-line healthcare workers have begun withholding labour over unpaid wages, with some telling the Associated Press they have not been paid since the outbreak began. Treatment centres are operating at roughly 90 percent capacity, the WHO representative in the DRC, Anne Ancia, said, adding that humanitarian needs for food, civilian protection, and essential health services remain acute.

The WHO declared a Public Health Emergency of International Concern on 17 May. The next situation report, expected within days, will indicate whether containment measures are slowing transmission in the newly affected zones. Meanwhile, the clinical trial’s enrolment phase will be a critical milestone, as will any preliminary safety data from the two experimental therapies.