The Ebola virus is spreading at an unprecedented rate this year.
In the first five months since the outbreak began in the Democratic Republic of Congo (DRC), the World Health Organization (WHO) reported 9,415 confirmed cases and 4,536 deaths in the country. While the virus remains relatively contained across the DRC’s border, case numbers are also climbing (albeit more slowly) in neighboring Kenya and Uganda. There are 20 confirmed cases in Uganda and eight in Kenya, with borders tightened across much of Central and East Africa.
The last Ebola outbreak of this magnitude began in 2014 and lasted until 2016 in West Africa. It ultimately killed more than 11,000 people throughout West Africa during this period. Nearly four years later, a smaller outbreak broke out in Congo’s North Kivu region, killing 2,229 people before it was contained.
The crisis in 2026 has not yet reached the level when it broke out in 2014, but it will spread much faster.
As shown in the figure below, approximately 150 days after the outbreak in West Africa in 2014, 2,599 Ebola cases were reported. At the same time this year, the number of cases reached 8,978 and continues to rise.
There is no direct explanation for this rapid spread
One of the reasons the recent epidemic has been so difficult to slow down can be traced to the fact that it is a different strain of the virus (called Bundibugyo) than the one behind previous epidemics.
Bundibugyo virus is in the same family as the Ebola virus that caused the 2014 West Africa and 2018 Congo outbreaks, causing the fatal fever associated with Ebola. But this rare strain is so different that it doesn’t respond to the same medical solutions. While Zaire virus has brought vaccines and treatments to mitigate the spread, we still don’t have a vaccine for Bundibuggio.
But that doesn’t mean Bundibugyo is entirely new. The 2026 outbreak is the third linked to the Bundibugyo strain: a small outbreak occurred in Uganda in 2007, and the eastern province of Congo, now the epicenter of the outbreak, had a small number of cases in 2012.
Fortunately, both outbreaks were contained within months, largely due to the efforts of the country’s Ministry of Health and international aid partnerships with the World Health Organization, the United States Agency for International Development (USAID), and international humanitarian organizations such as UNICEF and the Red Cross.
More than a decade later, these efforts were severely curtailed by cuts to USAID. Tracing requires physical testing capabilities: the tests themselves, protective equipment for health workers and those treating suspected cases. For a strain like Bundibugyo, reduced access to such resources is particularly dangerous—and in the absence of an effective vaccine, tracking the spread of the disease and isolating potential contacts of the disease is especially important.
But cuts in aid covering disease surveillance made it more difficult to identify this year’s Bundibugyo outbreak until it was too late, creating “a critical four-week testing gap between the onset of symptoms in the presumed index case… and laboratory confirmation of the outbreak,” according to a May situation report from the World Health Organization.
In August, the United States planned to provide an additional $242 million on top of the $23 million originally pledged in May to fill at least part of the vacuum.
In addition to international efforts, the Democratic Republic of the Congo faces additional internal conflicts and humanitarian crises. The eastern province, including Ituri, has experienced years of conflict that has weakened public infrastructure, including the health care system. Last year, nearly 25% of Congolese people faced food insecurity and 4.5 million children were clinically malnourished, making the country’s population particularly vulnerable to illness. The violence has also overwhelmed hospitals and displaced millions of people, disrupting the public health response, especially as mistrust of health authorities is also widespread.
While emergency trials of a vaccine are underway, many of the factors that promote the rapid spread of the virus could make treatment and rollout more difficult. It is difficult to predict when the current outbreak will be dealt with, and how many more people will be affected before then.