2026 Ebola Outbreak — DRC (Bundibugyo Virus)

Scale and Speed

The only larger Ebola outbreak in history is the 2014–2016 West Africa epidemic (Zaire ebolavirus), which caused more than 28,600 cases and 11,300 deaths. The 2026 DRC outbreak is now the largest ever recorded in the DRC — surpassing the 2018–2020 Kivu outbreak — and, according to CDC and WHO, the second-largest anywhere.

It is also the fastest-growing on record. CDC reports the outbreak surpassed 1,000 confirmed cases within about 40 days of response activation; by comparison, the 2018 DRC outbreak took roughly 235 days to pass 1,000 cases.

The Growth Curve, From CDC's Own Data File

CDC's situation page carries a chart comparing the first six months of the 2014, 2018 and 2026 outbreaks. The chart is fed by a public data file (updated September 13, 2026; sources DRC INSP and WHO; cases by date reported), which gives the daily cumulative count. Read directly, it shows the 2026 outbreak crossing 1,000 reported cases on day 38 after its first reported case, 4,000 on day 84, and 7,000 on day 120; West Africa in 2014 reached 1,000 on day 119 and 4,000 on day 168, and the 2018 DRC outbreak had 741 cases at day 180. At day 122 — the latest point for 2026 — the counts were 7,200 (2026), 1,093 (2014) and 438 (2018). The full table is on the outbreak history page.

Weekly growth, from the same file (our calculation from consecutive seven-day differences): about 780 new confirmed cases in the week to day 70, then 627, 521, 612, 625, 504, 548 and 600 in the weeks to day 119. The outbreak has been adding roughly 500–630 confirmed cases a week since mid-July — steady, not accelerating, and not yet falling. WHO's reports attribute part of each fortnight's rise to expanded testing and reconciliation of earlier data, so the curve mixes transmission with detection; the two cannot be separated from the published counts.

Where the Cases Are

In DRC, transmission spans six provinces and 61 health zones as of September 7, 2026 (WHO DON 617): Ituri (28 of its 36 health zones affected; 5,406 cumulative cases, 80% of the total), North Kivu (16 of 34 zones; 1,066 cases, and the outbreak's highest provincial CFR at 65.4%, under investigation), Tshopo (7 of 23), Haut-Uélé (6 of 13), Bas-Uélé (3 of 11; first case with onset August 4), and South Kivu (1 of 34; no case since May 29). The newest health zone is Kayna, North Kivu. Fifty-one zones in five provinces reported a case in the 21 days to September 7.

Where CDC and WHO differ. CDC's situation summary (September 14) lists the six affected provinces as Haut-Uélé, Ituri, North Kivu, South Kivu, Sud-Ubangi and Tshopo. WHO's report of the same week lists Bas-Uélé in place of Sud-Ubangi, names its three affected zones (Buta, Ganga, Viadana), and dates its first case. Sud-Ubangi lies in the far west of the country; Bas-Uélé borders Haut-Uélé. We follow WHO's list here because it is the more specific, and we note that the two agencies' pages disagree. We do not know why.

In Uganda, all cases were in the capital, Kampala, and every one traced to DRC: 14 of the 20 confirmed patients were infected in DRC and crossed into Uganda while symptomatic; four Ugandan health workers were infected during the attempted resuscitation of a probable case who was embalmed before testing, and a driver through contact with a body (CDC MMWR 2026;75(35):551). Uganda's last confirmed case was June 21. The Ministry of Health declared the outbreak over on July 28 per WHO (DON 614); CDC's MMWR gives August 26; the 42-day enhanced monitoring period for the last imported patient ended August 27 (DON 616). Of the 20 confirmed Ugandan cases, 2 died — a fatality rate of 10% for the same virus that has killed 48% of confirmed cases in DRC.

Health Workers

Health workers have been hit hard. WHO's counts for DRC: 102 confirmed infections and 25 deaths by July 1; 119 and 36 by July 15; 151 and 44 by July 30; at least 155 infections and 45 deaths by August 9, 2026 (CFR 29%), driven by limited protective equipment, security concerns, and infection-control gaps in a conflict-affected region. WHO's August 28 and September 10 reports did not restate the figure, so no more recent count exists (DON 612–617). The healthcare worker page tabulates the series.

Is the Response Working? CDC's Indicators

CDC tracks the DRC response against operational targets and published the status as of August 21, 2026 (CDC MMWR 2026;75(35):554): 10.6 contacts identified per case against a target of 20 or more; 15–20% of new cases previously known as contacts against a target above 90%; 72% of validated alerts tested against 90%; test positivity 24% against a target of zero; 59% of confirmed deaths occurring outside a treatment unit against a target of zero; and 49% of affected health zones with a safe-burial team against 100%. CDC's conclusion: the indicators "indicate uncontrolled expansion of the outbreak." WHO's risk assessment of August 14 rates the risk as very high in DRC, high for countries sharing a land border, and low for the rest of Africa and globally (DON 617). The prevention page gives the full indicator table.

What CDC Projected in June — and What Happened

On June 11, 2026 CDC published scenario projections (Mooring et al., MMWR): with only 20% of patients isolated and no other interventions, a 65% likelihood of more than 20,000 cases within three months; with 70% isolation, a one-in-twenty chance of 10,000. Three months later, DRC's confirmed count stood at roughly 6,600 (6,342 at day 112 and 6,942 at day 119 of CDC's data file, i.e. September 2–9) — below both thresholds, though the operational review above shows isolation and tracing targets still unmet. The model also placed the spillover event in mid-to-late February 2026; the earliest reconstructed symptom onset is April 24, with laboratory detection 20 days later on May 14 (Elvis Akem et al., PLOS Global Public Health 2026).