The Bundibugyo Ebola outbreak in the Democratic Republic of the Congo has become the deadliest in the country’s history. The DRC has now recorded close to 5,000 confirmed cases and more than 2,300 deaths since the outbreak was confirmed in May, and the daily reports are still adding to both figures.

What “deadliest in the country’s history” means

The DRC is where Ebola was first identified, near the Ebola River in 1976, and it has had more outbreaks than anywhere else — more than a dozen. Passing the previous national record therefore means passing outbreaks that were themselves large, including the 2018–2020 epidemic in the east that killed more than 2,000 people.

The comparison worth making is not with those numbers but with what has changed since. The 2018 response eventually had a licensed vaccine, therapeutic treatments and a ring-vaccination strategy. This one does not, and the reason is a detail of virology rather than a failure of will.

The species problem

Ebola is not one virus. There are several species, and the licensed vaccines and treatments target Zaire ebolavirus, the species behind most previous large outbreaks. This outbreak is Bundibugyo, for which there is no licensed vaccine and no specific treatment. Candidates are being tested; nothing is available at scale.

That removes the single most effective tool used in the last epidemic and puts the response back on methods that are older and much more demanding: finding cases, tracing contacts, isolating patients, and burying the dead safely. All of these depend on manpower, access and public trust rather than on a cold chain.

Where the cases are

Recent daily reporting has put the large majority of new confirmed cases in Ituri province, with smaller numbers in North Kivu, Haut Uele and Tshopo. Hundreds of patients are hospitalised in isolation at any given time, and around a thousand people have recovered.

WHO has described the setting bluntly: a humanitarian crisis, an area both remote and densely populated, insecurity, and high levels of population and trade movement — including across the border with Uganda, where the outbreak was also confirmed in May. The organisation’s Director-General opened a high-level cross-border consultative meeting on the risk on 17 August.

Health workers have also been infected in substantial numbers, and earlier in the outbreak staff took industrial action over unpaid wages. An outbreak response is a workforce before it is anything else.

Reading the numbers honestly

Two cautions apply to every figure quoted here. Confirmed cases are those that reached a laboratory, so the true number of infections is higher, by an unknown margin, in an area where many people will never reach a health facility. And a case fatality ratio calculated during an outbreak is provisional: it excludes untested cases, which pushes it down, and counts patients whose outcome is not yet known, which pushes it up.

What is not ambiguous is the direction. Three months in, the curve has not turned. The single most informative indicator published is the share of identified contacts actually under follow-up — recently reported at around 85 per cent. The missing fraction is where the next chains of transmission come from, and if that percentage falls, the numbers above will get worse before they get better.

Sources

• ECDC — daily updates on the DRC and Uganda outbreak
• WHO — Ebola outbreak, DRC 2026, and the cross-border meeting
• CNN — the outbreak becomes the deadliest in the country’s history