Skip to content
Briefings are running a touch slower this week while we rebuild the foundations.See roadmap
Pandemics and Biosecurity
2JUN

Ebola passes 1,000 cases in DRC

3 min read
09:17UTC

WHO bulletin DON605 logged 1,040 Bundibugyo Ebola cases and 241 deaths on 29 May, up from 831 and 186 eight days earlier. Laboratory-confirmed cases jumped 58%, from 85 to 134.

← Back to Ebola money arrives, the cure does notJump to analysis ↓
ScienceDeveloping
Key takeaway

Bundibugyo Ebola has passed 1,040 cases and 241 deaths, with confirmed cases up 58% in eight days.

The World Health Organization published Disease Outbreak News bulletin DON605 on Friday 29 May, recording 1,040 total Bundibugyo Ebola cases and 241 deaths in the Democratic Republic of Congo and Uganda 1. The WHO is the United Nations health agency coordinating the international response; Disease Outbreak News is its formal channel for reporting verified outbreak data. Eight days earlier, DON603 had logged 831 cases and 186 deaths , so the burden rose roughly 25% in cases and 30% in deaths in a single week.

The sharpest movement was in laboratory-confirmed cases, which climbed from 85 to 134, a 58% rise, with confirmed deaths up from 10 to 18. Confirmed numbers grew faster than total numbers partly because testing caught up after the 17 May emergency declaration , so some of the jump reflects faster case-finding rather than faster transmission. The outbreak is centred on Ituri Province in north-eastern DRC, the zone bordering Uganda.

Bundibugyo ebolavirus is one of six Ebola species and last caused a large outbreak in Uganda in 2007. The human stakes sit in the total burden, not the headline percentage: 241 people have now died, and 906 of the 1,040 cases are still awaiting laboratory confirmation, a backlog that keeps the true picture ahead of the record.

Deep Analysis

In plain English

Ebola outbreaks grow in two separate counts: total suspected cases (anyone with fever and Ebola symptoms) and laboratory-confirmed cases (people where a blood test came back positive). The WHO bulletin of 29 May shows 1,040 total suspected cases but only 134 confirmed ones. That gap matters because the confirmed figure is what gets counted as the official outbreak total for international purposes. The jump of 58% in confirmed cases between 21 and 29 May happened partly because more lab tests are now being processed, and partly because the virus was already spreading in communities before the outbreak was formally identified in early May. Think of it like turning on a light in a dark room: the cases were always there; the light just revealed them. Ituri Province, where almost all cases are concentrated, is a remote part of north-eastern Democratic Republic of Congo. The roads are poor and armed groups are active in the area, making it hard for health workers to reach sick people or trace their contacts.

Deep Analysis
Root Causes

The nine-day lag between the 5 May WHO signal and the 14 May INRB species confirmation reflects a structural bottleneck in the DRC reference laboratory system: INRB in Kinshasa is the sole body certified to confirm Ebola species in DRC, and sample transport from Ituri Province requires cold-chain logistics across 2,000 km of poorly maintained roads. The Ituri provincial health system lacks a BSL-3 laboratory capable of running filovirus PCR assays independently.

A second structural cause is low contact-tracing coverage: DON603 (21 May) recorded only 21% of named contacts being followed up, a direct consequence of insecurity from ADF and CODECO armed-group activity in the Djugu territory at the outbreak's core.

The Tom Frieden-originated 7-1-7 benchmark (seven days to detect, seven days to notify, seven days to respond) requires a functional community health worker system and safe access to index patients' contacts. Both conditions were absent for at least six weeks of pre-detection transmission.

What could happen next?
  • Risk

    A 25% total-case rise in eight days, combined with only 21% contact-tracing coverage, indicates the transmission chain is ahead of the surveillance and isolation effort.

  • Consequence

    At the current seven-day doubling trajectory for confirmed cases, the outbreak could exceed 2,000 total cases within three to four weeks without a step-change in containment.

Sources:World Health Organization
Mentions:World Health Organization →Ituri Province →DON 600 →Inmazeb →Uganda →Africa CDC →PHEIC →Neil Ferguson →Anne Cori →Ebanga →Imperial College London →Ervebo →Jean Kaseya →Zaire ebolavirus →United Nations →CDC →DR Congo →Bundibugyo ebolavirus →
First Reported In

Update #5 · Ebola money arrives, the cure does not

World Health Organization· 2 Jun 2026
Read original →
Causes and effects
Caused by
WHO declares Ebola PHEIC, no committee
The 17 May PHEIC declaration triggered accelerated case-finding which partly drove the 58% confirmed-case rise recorded in DON605.
Occurred 17 May 2026
Read story →
Bundibugyo Ebola: 831 cases, 186 dead
DON603's 831/186 baseline is the starting point from which DON605's 1,040/241 total is measured.
Occurred 21 May 2026
Read story →
This Event
Ebola passes 1,000 cases in DRC
Total burden has crossed 1,000 cases and 241 deaths, and the confirmed-case curve is still climbing eight days on.
Different Perspectives
Imperial College London / Cori and Ferguson
Imperial College London / Cori and Ferguson
Anne Cori and Neil Ferguson place the case-fatality ratio at 30 to 40 per cent and read the 6.8-to-1 suspected-to-confirmed ratio as evidence that the laboratory figure understates true lethality. Many people die before a swab reaches them.
Uganda / Diana Atwine
Uganda / Diana Atwine
Diana Atwine's ministry traced the imported Kampala index case and leant on protocols rehearsed in Uganda's 2022 Sudan ebolavirus response, which contained 142 cases in 113 days without a vaccine. Nine confirmed cases now test whether that playbook holds across two districts.
United States / HHS
United States / HHS
Washington imposed a 21-day entry ban on DRC, Uganda and South Sudan nationals against WHO advice, and sought a 50-bed quarantine site in Nairobi that a Kenyan court suspended on 29 May. The posture rests on a thin federal bench with vacant senior public-health roles.
WHO / Tedros Adhanom Ghebreyesus
WHO / Tedros Adhanom Ghebreyesus
Tedros Adhanom Ghebreyesus called the outbreak 'outpacing us' on 25 May and visited Ituri on 28 May, arguing that stopping transmission depends entirely on humanitarian access. WHO opposes any restriction of travel to or trade with DRC or Uganda.
Africa CDC / Jean Kaseya
Africa CDC / Jean Kaseya
Jean Kaseya declared the continental emergency before WHO and opposed the US travel ban as punishment by passport rather than by exposure. The Africa CDC raised nearly $500 million in days and frames the response as African-led, coordinated from Addis Ababa rather than waiting on Geneva.
European Union / ECDC
European Union / ECDC
ECDC activated an EU Health Task Force, assessed European Bundibugyo import risk as very low, and flagged the recombinant clade Ib/IIb mpox strain in four countries as a surveillance watch item. Both calls reflect the same post-2024 IHR mandate: ECDC acts as a continental early-warning layer rather than waiting for WHO Disease Outbreak News guidance.