Seven Thousand Cases Later, What It Takes to Turn the Tide on Ebola
Epidemiologist Dr. Henry Kyobe Bosa explains the operational principles needed to bring an escalating Ebola epidemic under control
Published September 16, 2026
By Syra Madad, D.H.Sc., M.Sc., MCP, CHEP
As the Democratic Republic of the Congo confronts an escalating Ebola epidemic, epidemiologist Dr. Henry Kyobe Bosa explains why controlling Ebola depends not only on medical technology, but on finding every case, supporting every contact and building a response with affected communities.
The Democratic Republic of the Congo’s latest Ebola outbreak has crossed a threshold that should command the world’s attention.
As of September 13, Congolese authorities reported 7,200 confirmed cases of Ebola disease caused by Bundibugyo virus, including 3,475 deaths. A total of 62 health zones in seven provinces had been affected.
These figures make this the largest Ebola outbreak in the DRC’s history and the second-largest recorded anywhere, after the 2013 – 2016 West African epidemic. Yet the reported cases may represent only part of the emergency. In August, a World Health Organization emergency committee warned that many infections might be going undetected and estimated that the true number could be three to four times the reported total.
The outbreak has also produced important operational lessons across the region. After cases were imported from the DRC and secondary transmission occurred, Uganda contained local transmission in approximately 73 days.
During the outbreak, Uganda reported 20 confirmed cases of Ebola disease caused by Bundibugyo virus following the declaration of the outbreak on May 15, 2026. Fifteen cases were imported from the DRC, while five were acquired locally among contacts and health workers linked to imported cases. Eighteen people recovered and two died. More than 800 contacts were identified and monitored. Uganda subsequently completed the required 42-day period without a new confirmed case after its last patient, an imported case, was discharged on July 16.
The circumstances of every outbreak are different. Eastern DRC is confronting armed conflict, displacement, restricted humanitarian access and a health system under exceptional strain. Even so, experience across outbreaks reinforces a central truth: a pathogen’s biology matters, while operational speed, contact management, community partnership and the adaptability of the response are also critical to interrupting transmission.
Dr. Henry Kyobe Bosa has spent more than two decades examining that divide.
A Ugandan physician, epidemiologist and epidemic-response leader, he began his infectious-disease career caring for patients during Uganda’s 2007 Bundibugyo Ebola outbreak. He has since worked from the clinical front line to national emergency leadership and continental health security.
In this edited interview, he discusses lessons from previous outbreaks, the support urgently needed for the current response and why every missed transmission chain is both an epidemiological warning and a sign that the human story behind a case is not yet fully understood.
What lessons from Uganda’s experience are relevant to controlling Ebola transmission?
Uganda’s success was the result of several factors, beginning with progressive investment in tested preparedness. Uganda had confronted two Sudan virus outbreaks during the preceding five years. That experience preserved institutional memory.
But retained memory is useful only when it is accompanied by adaptation. Our response architecture remained flexible and was adjusted using evidence from the outbreak.
We understood early that interrupting transmission required a tight grip on contacts. More than 800 contacts, approximately 20 for every confirmed case, were identified and monitored for the full 21-day incubation period.
This allowed us to detect infected people on the first or second day of symptoms, during what we sometimes call the “dry” phase. We could act before vomiting, diarrhea and other later manifestations created greater opportunities for exposure to infectious body fluids. It also reduced the risk of losing contacts to follow-up in an urban setting, where people move frequently and transmission networks can spread quickly.
Uganda also recognized the danger of urban transmission early. The initial drivers were largely imported infections. We treated each importation not as an isolated clinical event, but as the possible beginning of an urban transmission network.
No response model can be transferred wholesale. Ituri’s insecurity, population displacement, geography and health-system constraints fundamentally shape what is operationally possible. But the core principles remain relevant: identify contacts comprehensively, support them so they can complete follow-up, detect symptoms immediately and investigate every unexplained infection as evidence of a transmission chain that has not yet been found.
What international assistance is needed most urgently?
Although Uganda’s outbreak has ended, transmission remains intense and progressive in several parts of the DRC. Ugandan and Congolese teams continue to work together in areas including Aru and Kasenyi in Ituri.
The operational and logistical requirements are enormous. Treatment facilities and response teams need reliable supplies of gloves, personal protective equipment, intravenous fluids, administration sets and laboratory consumables. These are basic materials, but an Ebola response can fail when basic materials do not arrive in the right place at the right time.
Support also cannot be restricted to Ebola.
This outbreak is occurring in communities whose health systems were already under severe strain. People still need treatment for malaria, HIV, hepatitis, malnutrition and diabetes. Women still need safe maternity care. Children still need routine health services.
If the Ebola response consumes or disrupts the rest of the health system, preventable deaths from other conditions will rise and public confidence will deteriorate. The WHO emergency committee has warned that disruption to essential services risks increasing deaths from malaria, diarrheal diseases, maternal causes and other conditions.
The Congolese Ministry of Public Health, Hygiene and Social Welfare has prioritized a village-based approach in its 180-day plan. This is a promising design because it brings surveillance, prevention and decision-making closer to affected communities. But direct financing appears insufficient to implement the model at the required speed and scale.
The world must do more to help the DRC interrupt transmission. A prolonged outbreak threatens neighboring countries first, but it also threatens countries farther away. Cross-border and international spread has already occurred. Ebola control in Ituri is not a peripheral humanitarian concern, it is an investment in regional and global health security.
What might the response still be missing?
This outbreak is unprecedented in the 50-year history of Ebola in the DRC. Transmission is occurring intensely and diffusely across several fronts. Many transmission chains and networks have not been characterized.
Loss to follow-up complicates the response, particularly because some contacts may have experienced multiple exposures. Late presentation and deaths in the community have also led to deaths that might otherwise have been prevented.
When many new patients are identified outside known transmission networks, it tells us that surveillance is seeing the outbreak late. Community deaths and delayed presentation tell us the same thing. Together, these indicators suggest that the response has not yet gained control of the epidemic.
We must use that information to redirect surveillance, contact tracing and, where appropriate, vaccination or research strategies toward the places and networks where unexplained transmission is occurring.
Scientists have documented genomic changes in the outbreak virus, and questions remain about its emergence and evolution. But mutations alone do not demonstrate that the virus has become more transmissible or that a new animal reservoir is driving the epidemic.
The WHO emergency committee has said that current epidemiological, clinical and genomic evidence does not indicate a fundamental change in the virus’s known biology, routes of transmission or clinical characteristics. The more immediate explanation is operational: infections are being missed, patients are reaching care late, and essential interventions have not achieved sufficient coverage.
How does the lack of an approved Bundibugyo-specific vaccine or treatment change the response?
It would be difficult to conclude that the scale of this outbreak is attributable simply to the absence of a vaccine. Ebola outbreaks have been controlled without vaccines.
The drivers of transmission are diverse and contextual. Insecurity, humanitarian conditions, community acceptance and the adaptability of the health system all interact. What stands out in this outbreak is the number of community deaths and missed transmission chains. These indicate that the response is still trying to catch up.
We need to suppress transmission, regain control and reverse the trend. In practical terms, every case and every death must have a complete story.
Where did the person travel? Who cared for them? What exposures occurred? How long were they ill? Did they have underlying conditions? What prevented them from seeking care? Why was diagnosis delayed? Who participated in preparing or burying the body?
Each case history contributes to our understanding of the epidemic’s drivers. Only when we understand those granular details can we align interventions with the conditions sustaining transmission. That remains true even when vaccines are available.
There is no vaccine licensed specifically against Bundibugyo virus and no approved Bundibugyo-specific treatment. In August, however, 70,000 doses of Ervebo, a vaccine licensed against Ebola virus, formerly called Zaire ebolavirus, were allocated to the DRC. Of those, 20,000 were designated for a Phase 3 clinical trial and 50,000 for health and frontline workers.
Whether Ervebo protects humans against Bundibugyo virus remains unknown, although laboratory and animal evidence suggests it may offer some protection. People offered the vaccine must therefore receive clear information about its potential benefits, risks and limitations and provide informed consent.
Experimental tools may strengthen the response, but they cannot replace rapid diagnosis, isolation, supportive care, comprehensive contact follow-up, infection prevention and control, or safe and dignified burials.
How do you lead amid uncertainty, insecurity and limited resources?
Serving as deputy incident manager for a technical agency is different from serving as incident manager of a national response.
In national leadership, you can move decisions as quickly as the system permits. You sit at the center of decision-making and are responsible for implementing difficult choices. In a technical agency, the role is more advisory. You support and implement national decisions, including decisions that, in another role, you might have prescribed yourself.
Even so, it is an extraordinary responsibility in a dynamic environment. It requires constant thought and close attention to technical and operational detail.
You keep a keen eye on the numbers, but also on the story behind each number—and on the stories the numbers have missed.
We work with experts from across the world, although most are from Africa. They bring different forms of expertise but share enormous energy and determination to end the outbreak. They work long hours and sleepless nights, often in difficult settings, alongside partners with different mandates and capabilities.
Leadership in that environment is not only about issuing instructions. It is about aligning people, detecting what the data conceal, identifying where implementation needs to improve and helping the response act before the next set of numbers confirms what should already have been seen.
The world must finance the work required to control Ebola
The DRC does not need another cycle in which alarm rises with the case count and recedes before response systems are fully financed. It needs predictable funding delivered through an integrated, costed national plan, reliable supply chains, protected humanitarian access, expanded treatment and diagnostic capacity and sustained support for essential health services.
It also needs a response in which communities exercise meaningful power.
Trust cannot be produced through messaging alone. People must be able to see that seeking care leads to humane treatment, that isolation does not mean abandonment, that families can participate safely in decisions about burial, and that local concerns change how operations are conducted.
The WHO emergency committee has called for a response built with affected communities and supported by trusted local leaders and organizations. It has emphasized community-based surveillance, meaningful participation, transparent communication and mechanisms through which community concerns can rapidly influence operations.
Experience with Bundibugyo virus shows that local transmission can be interrupted even without a vaccine licensed specifically for it. Achieving that goal in the current outbreak requires approaches adapted to insecurity, displacement, missed chains of infection and severe pressure on the health system.
More than 7,000 confirmed cases into this outbreak, the interventions required are well understood. What matters now is mobilizing the resources, coordination and sustained operational capacity needed to deliver them with the speed and coverage that Ebola demands.
Every case must be found. Every contact must be supported. Every death must be understood. And every affected community must be a full partner in shaping a response that is trusted, legitimate and effective.
