DR Congo declares its 16th Ebola outbreak over after 64 cases and 45 deaths

The Ministry of Health of the Democratic Republic of the Congo declared an end to the country's Ebola virus disease outbreak on 1 December 2025, closing an epidemic that had been declared on 4 September and that killed 45 of the 64 people it is known to have infected [s1].

The declaration follows the standard rule: 42 days — two consecutive maximum incubation periods — since the last confirmed patient tested negative and was discharged, which happened on 19 October [s1].

What the outbreak looked like

All 64 cases, 53 confirmed and 11 probable, came from the Bulape Health Zone in Kasai Province, spread across six health areas: Bambalaie, Bulape, Bulape Com, Dikolo, Ingongo and Mpianga [s1]. The case fatality ratio was 70.3% [s1].

That figure deserves to be read carefully rather than dramatically. Case fatality ratios in small Ebola outbreaks are unstable — a denominator of 64 means each additional death moves the number by more than a percentage point — and they reflect how quickly patients reached care as much as they reflect the virus. But 70.3% is at the severe end of the historical range for Zaire ebolavirus, and it happened in an outbreak where vaccine and therapeutics were available.

Full genome sequencing of the sample from the first confirmed case indicated the outbreak was most likely the result of a spillover event from a zoonotic reservoir, rather than resurgence from a survivor or a chain persisting from an earlier epidemic [s1]. That distinction matters for what comes next: a spillover-origin outbreak says nothing about whether the response left transmission smouldering, but it also means the underlying risk — animal-to-human contact in the region — is unchanged by the outbreak's end.

The response

WHO reports that 47,577 people received the rVSVΔG-ZEBOV-GP vaccine (Ervebo) across three health zones, delivered through a ring vaccination strategy targeting contacts and high-risk workers [s1]. Confirmed patients were offered monoclonal antibody treatment; WHO's recommended options in this category are Inmazeb and Ebanga [s1].

WHO deployed 112 experts and responders to support national authorities and launched a US$21 million appeal for response operations [s1].

Ring vaccination — vaccinating the contacts of a confirmed case, and the contacts of those contacts — targets the transmission network rather than the general population. Nearly 48,000 doses administered around an outbreak of 64 known cases is a high ratio by design: the strategy trades doses for speed, on the logic that the people most likely to be infected next are a defined and findable group.

It also explains why the vaccination figure spans three health zones [s1] while every case came from one [s1]. Rings extend outward along contact chains, not along administrative boundaries, and they are drawn wider than the known outbreak because the point is to get ahead of chains that have not yet been detected.

What the response cannot demonstrate is counterfactual. An outbreak that ends after 64 cases and 88 days is consistent with an effective response; it is also consistent with a spillover that seeded limited onward transmission. Nothing in the outbreak record separates those two explanations. What is on the record is that all 64 cases stayed within six health areas of a single health zone [s1] — an outbreak that never reached a second province.

The sixteenth

This was the DRC's 16th Ebola outbreak since the virus was first identified there in 1976 [s1]. The interval between outbreaks in DRC has been short enough in recent years that "the outbreak is over" is a statement about one epidemic, not about the country's exposure.

Three features of this one are worth carrying forward. It was geographically contained to a single health zone. It was declared and closed inside three months. And it was fatal in roughly seven of every ten known cases despite the availability of a licensed vaccine and licensed therapeutics — which points at how much of Ebola outcome depends on time-to-treatment rather than on whether a treatment exists at all.

What to watch

Whether surveillance in Kasai holds up now that the emergency structures stand down. Ebola outbreaks have been re-declared after apparent closure when a survivor's persistent infection seeds a new chain; WHO's sequencing finding here points to zoonotic spillover as the origin of this epidemic, but survivor follow-up remains part of standard post-outbreak care.

Also worth watching: whether the US$21 million appeal was met, and what share of the response cost was ultimately covered — a question with more weight than usual in a year when external health financing to low- and middle-income countries has been contracting.

Sources

• [s1] World Health Organization, "Ebola virus disease – Democratic Republic of the Congo," Disease Outbreak News, 1 December 2025. https://www.who.int/emergencies/disease-outbreak-news/item/2025-DON589