The Democratic Republic of Congo officially declared an Ebola outbreak on May 15 after laboratory tests confirmed the rare Bundibugyo variant. Evidence reviewed by DW indicates the virus may have been circulating for several months before that announcement, although the exact starting point remains uncertain.
The first known case identified retrospectively was a health worker from Mongbwalu in northeastern Ituri Province. According to a timeline compiled by the World Health Organization and the Africa Centres for Disease Control and Prevention, the worker developed Ebola-like symptoms around April 24 or 25 and later died at a medical center in Bunia. Ituri has accounted for 80% of reported cases, according to the source material.
The WHO said it was informed on May 5 of an unidentified illness with a high mortality rate in Mongbwalu. Ten days later, the Congolese government announced the outbreak. The Africa CDC subsequently criticized the response, noting that roughly three weeks had passed between the suspected index case’s symptoms and laboratory confirmation. It said the delay reflected a low initial level of clinical suspicion and may have allowed the disease to spread geographically before containment began.
Reports gathered by DW indicate that residents had described suspicious deaths in Mongbwalu as early as late April. Dieudonne Lossa Dekhana, the civil society coordinator for Ituri, said several people had died after high fevers and displayed bleeding. A Red Cross report dated May 16 said widespread fear had existed in the area since March 30 following a series of deaths involving symptoms consistent with Ebola. The report linked the increase in deaths to a funeral involving a potentially contaminated body and coffin, but the source stressed that a connection to the Bundibugyo virus could not be confirmed.
Further analysis has pointed to an even earlier origin. A CDC study published on June 11 called an animal-to-human transmission between mid- and late February plausible, while WHO Africa director Mohamed Janabi said genome sequencing suggested the outbreak may have begun as early as February 2026. Janabi also said many early infections had been mistaken for more common illnesses such as malaria and typhus, and told DW that only one-third of patients had been reached in the first three months.
Research cited by DW on earlier Ebola outbreaks in northeastern Congo suggests that unusual animal deaths could provide an earlier warning. Pasteur Institute researcher Jules Villa found reports of high livestock mortality before at least two previous human outbreaks, though his study did not cover the 2026 epidemic.