DR Congo’s Ebola outbreak may have started months before it was declared

The Democratic Republic of Congo officially declared an Ebola outbreak caused by the Bundibugyo variant on May 15. However, evidence suggests the first infections may have occurred months earlier.

Exactly when the epidemic began remains a matter of debate. However, several international organisations have raised concerns about delays in the initial response by Congolese authorities.

Congo is no stranger to Ebola outbreaks. The country has experienced the disease repeatedly and has previously been praised for its expertise in responding to Ebola emergencies.

Early warnings came from WHO and Africa CDC

A useful starting point for tracing the outbreak is the timeline provided by the World Health Organisation (WHO) in collaboration with the Africa Centres for Disease Control and Prevention (Africa CDC).

According to their data, the first known case, identified retrospectively, was a health worker from Mongbwalu in northeastern Ituri Province. Sources said the person developed symptoms consistent with Ebola around April 24 or 25.

The health worker died at a medical centre in Bunia, the capital of Ituri. To date, 80 per cent of all reported cases have been recorded in the province.

It was not until May 5 that the WHO said it had been informed of “an unknown illness with high mortality reported in Mongbwalu Health Zone.” The organisation then issued its first warning.

DRC’s delayed response questioned as Ebola spread

Ten days later, on May 15, the Congolese government officially announced the Ebola outbreak.

Tests conducted by the National Institute for Biomedical Research in Kinshasa confirmed the presence of the rare Bundibugyo type of Ebola.

Three days later, the Africa CDC raised concerns about the speed of Congo’s response.

About three weeks had passed between the onset of symptoms in the suspected index case and laboratory confirmation, even though the person who died was a health worker.

“This significant delay […] highlights a critically low initial index of clinical suspicion among local healthcare providers, which facilitated wider geographic spread prior to the initiation of containment efforts,” the Africa CDC concluded.

Reports gathered by DW indicate that residents of Mongbwalu had already reported suspicious deaths as early as the end of April.

“Several deaths were reported following high fevers, and the victims often showed traces of blood around various body orifices,” said Dieudonne Lossa Dekhana, the provincial coordinator for civil society in Ituri.

Red Cross reported ‘widespread’ public fear ‘since March 30’

There were other indications that Ebola may have been circulating well before the first confirmed case.

A May 16 report by the Red Cross of the Democratic Republic of the Congo stated: “Since March 30, 2026, there has been widespread fear among the population of the Mongbwalu Health Zone following a series of deaths.”

The symptoms reported were also consistent with Ebola, including high fever, chest pain, severe exhaustion, persistent cough, nosebleeds, vomiting, loss of consciousness, a comatose state and, ultimately, death.

The Red Cross report said the trigger was believed to have been the body of a Mongbwalu resident “who died and was placed in a coffin purchased in Bunia, which was then replaced by another in Mongbwalu.”

US researchers say February outbreak plausible

The funeral, which brought several people into direct contact with the body and the contaminated coffin, is believed to have contributed to a subsequent rise in infections and deaths in Mongbwalu and Bunia.

However, the available data cannot conclusively establish that these deaths were linked to the Bundibugyo virus.

They do, however, show that an unusual health event had already been reported more than six weeks before the outbreak was officially declared on May 15.

Investigations conducted after May 15 have also strengthened the possibility that Ebola was circulating even earlier.

In a study published in the Morbidity and Mortality Weekly Report on June 11, researchers from the US Centres for Disease Control and Prevention (CDC) reconstructed the early stages of the epidemic.

They concluded that an initial transmission from an animal to a human, known as a spillover event, between mid- and late February is “plausible.”

The researchers said a late-April spillover would be difficult to reconcile with the scale of the epidemic already observed by the time of their study.

WHO says genome sequencing points to February outbreak

On August 10, Mohamed Janabi, the WHO Regional Director for Africa, said genome sequencing analyses suggested the outbreak likely began “as early as February 2026.”

He said several early infections were mistakenly attributed to diseases that are much more common in the region, particularly malaria and typhus.

In an August interview, Janabi told DW that there had been a significant gap in case reporting.

“The Ebola situation is catastrophic… In three months, we only had access to one-third of the patients,” he said.

Could ‘pig Ebola’ shed some light on the matter?

Jules Villa, a researcher in the anthropology and ecology of disease emergence at the Pasteur Institute in Paris, points to a phenomenon observed during previous Ebola epidemics.

Villa’s study does not cover the 2026 outbreak. Instead, it examines local reports collected during earlier Ebola outbreaks in northeastern Congo.

The study found that livestock farmers, veterinarians and residents had reported unusually high animal mortality before at least two previous Ebola epidemics in humans.

In 2017, several witnesses reported what they called “pig Ebola” — a high mortality rate among pigs that was ultimately attributed to swine fever.

According to Villa’s research, monitoring livestock among communities could provide useful early warning signs long before a human outbreak is confirmed by laboratory tests.