Ebola could top 10,000 cases by late August without stronger response

As Ebola infections edge closer to 2,000, scientists are warning that the outbreak could be entering its most dangerous phase yet, with new projections suggesting cases could surpass 10,000 by late August if efforts to contain the virus are not rapidly intensified.

A modelling study by the US Centers for Disease Control and Prevention (CDC) suggests the ongoing  Bundibugyo Ebola outbreak in the Democratic Republic of Congo (DRC) and Uganda could expand dramatically over the next three months unless health authorities quickly identify, isolate and treat infected patients.

The warning comes as the DRC remains the epicentre of the outbreak, reporting 1,759 confirmed cases, 600 deaths and 285 recoveries. Uganda has confirmed 20 cases, including two deaths and 17 recoveries, while France has reported one imported case, with the patient recovering.

Overall, the outbreak has reached 1,780 confirmed cases, 602 deaths and 303 recoveries, underscoring the urgency of containing transmission before it accelerates further.

The CDC analysis is based on outbreak data from 24 May 2026 and models how the epidemic could evolve over the following three months.

Researchers stress that these are not predictions. Rather, they are projections showing what could happen under different response scenarios.

Think of it like watching dark clouds gather before a storm. You cannot say with certainty that it will rain, but you can prepare because the conditions suggest it might.

Disease modelling works in much the same way. Scientists map where infections are occurring, who has been in contact with whom and how quickly the virus is spreading. Computers then test different "what if" scenarios: What if more patients are identified and isolated early? What if many infections continue to go undetected? The answers help governments prepare before an outbreak grows beyond control.

The approach became widely known during the Covid-19 pandemic, when disease models helped governments estimate hospital demand, oxygen requirements and the impact of interventions such as vaccination, movement restrictions and mask mandates. While those models did not predict the future with certainty, they gave health systems valuable time to prepare.

For Dr Moses Masika, Consultant Virologist and Senior Lecturer in the Department of Medical Microbiology and Immunology at the University of Nairobi, the latest projections reflect what frontline experts have increasingly been observing on the ground.

"The concern is that we are now seeing many people testing positive who are outside the known contact networks," he said.

"If everybody who was testing positive was within our circle, you know they were in contact with somebody who is sick, then you know you have the disease almost under control. But when more than half of the people testing positive are new to the network, it means the network is much broader than we have control over."

According to Dr Masika, that is one of the biggest differences between the outbreaks in Uganda and eastern DRC.

"In Uganda, they have largely been able to trace where people got the disease from within a certain network. In the DRC, that has not been the case. That means transmission in the community is much broader than what we are seeing."

He says the outbreak's geography is also working against responders.

"It has spread across about four provinces bordering South Sudan, Uganda, Rwanda and Burundi. It is a vast area that is remote and poorly connected."

Dr Masika added that mistrust of healthcare workers during the early stages of the outbreak may have allowed the virus to circulate unnoticed.

"Initially, many communities did not trust healthcare workers, so they were not providing information or turning up when they became sick. It means the disease may have been circulating for longer than we realised."

Those concerns echo warnings from the World Health Organization.

WHO Representative in the Democratic Republic of Congo Dr. Anne Ancia says the outbreak has yet to stabilise.

"It is still in the expansion phase, unfortunately. We would like to say it is stabilising but, frankly, we cannot say it yet," she said, adding that many patients are still arriving for treatment too late, allowing the virus to spread within families before they seek medical care.

The CDC modelling paints a similar picture.

Rather than forecasting a single outcome, researchers simulated hundreds of possible outbreak trajectories under different levels of public health intervention, examining how rapidly identifying and isolating infected patients could change the epidemic's course.

"If approximately 70 percent of symptomatic patients are rapidly identified and isolated, only about one in twenty simulations projected an outbreak exceeding 10,000 cases within three months," the researchers wrote.

The contrast between the different scenarios was striking.

If only 20 percent of symptomatic patients are rapidly identified and isolated, the study found there is a 65 percent probability the outbreak will exceed 20,000 cases within three months.

By contrast, increasing rapid isolation to around 70 percent reduces the probability of the outbreak surpassing 10,000 cases to just five percent, or roughly one in every 20 simulations.

"Our findings highlight the importance of rapidly scaling up case detection, isolation, treatment, contact tracing and community engagement," the report states.

Researchers assessed intervention effectiveness ranging from only 20 percent of symptomatic patients being isolated to as high as 95 percent, demonstrating that every patient identified early has the potential to prevent multiple new infections.

The findings reinforce WHO's assessment that the outbreak continues to outrun containment efforts.

WHO Director-General Dr Tedros Adhanom Ghebreyesus has warned that "the outbreak is still outpacing the response," citing insecurity, attacks on health workers and community mistrust as major obstacles to bringing transmission under control.

The outbreak is caused by the Bundibugyo strain of Ebola, one of several known species of the Ebola virus.

Although many people are more familiar with the Zaire strain, Dr Masika says patients infected with either virus develop almost identical illness.

"They cause the same illness and very similar symptoms. Without laboratory analysis, you cannot distinguish them. It is only when you examine their genetic makeup that the differences become apparent."

He notes that Bundibugyo has caused only a handful of outbreaks compared with the Zaire strain, although scientists are still studying why the latter has historically spread more widely.

Unlike the Zaire strain, there is currently no licensed vaccine specifically targeting Bundibugyo Ebola, leaving health workers to rely heavily on surveillance, rapid diagnosis, patient isolation, infection prevention, contact tracing and community engagement to interrupt transmission.

Even so, WHO says progress is being made in developing treatments. Announcing the launch of a therapeutic trial in the DRC, Dr Tedros said:

 

"This is a critical step forward in our response to this outbreak. While we continue to strengthen surveillance, testing, treatment and infection prevention, generating evidence on effective therapies is essential to saving lives."

The projections also come as doctors and frontline health workers in eastern DRC warn that treatment centres are under growing pressure from rising patient numbers, insecurity and shortages of resources, making rapid response increasingly difficult.

For neighbouring countries, including Kenya, the findings reinforce the need to maintain vigilant surveillance at points of entry, strengthen laboratory capacity and ensure health facilities are prepared to rapidly identify and isolate suspected cases.

Health authorities continue to emphasise that Ebola spreads through direct contact with the blood or other bodily fluids of an infected person or someone who has died from the disease, making early detection one of the most effective ways to break chains of transmission.

The latest projections are not a prediction that tens of thousands of people will become infected. They are a warning of what could happen if the virus continues to outrun the response.