What Happened to Ebola Outbreak?

Ebola virus disease (EVD) was first identified in 1976 following nearly simultaneous outbreaks in what is now the Democratic Republic of Congo (DRC) and Sudan. Named after the Ebola River, the virus is a severe, often fatal illness in humans and other primates, transmitted through contact with infected animals and bodily fluids of infected persons. After a period of fewer reported cases between 1979 and 1994, outbreaks have occurred with increasing frequency, primarily in Central and West Africa.

The most significant and widespread Ebola outbreak in history occurred in West Africa between 2014 and 2016, affecting Guinea, Liberia, and Sierra Leone most severely. This epidemic, which began in December 2013, resulted in over 28,600 reported cases and more than 11,300 deaths, and was the first to see intense transmission in urban areas. The World Health Organization (WHO) declared it a Public Health Emergency of International Concern (PHEIC) in August 2014, mobilizing an unprecedented international response.

Following the West African crisis, the DRC has experienced numerous subsequent outbreaks. Notable among these was the Kivu Ebola epidemic from 2018 to 2020, which was the second-largest in history, with 3,470 reported cases. Other outbreaks in the DRC included one in Équateur Province in 2020 (11th outbreak), another in North Kivu in 2021 (13th outbreak), and a 16th outbreak in Kasai Province in September 2025, which was declared over in December 2025. Uganda also faced a significant Sudan ebolavirus outbreak from September 2022 to January 2023, resulting in 164 cases and 55 confirmed deaths.

As of May 17, 2026, a new and concerning Ebola outbreak has been confirmed in the Democratic Republic of Congo's Ituri Province, with suspected cases also reported in Uganda. This 17th outbreak in the DRC is caused by the Bundibugyo ebolavirus, a strain for which there are currently no licensed vaccines or treatments, unlike the Zaire strain. Preliminary reports indicate 246 suspected cases and 65 deaths in DRC's Ituri province as of May 15, 2026, with two confirmed cases in Kampala, Uganda, from individuals traveling from the DRC. The WHO declared this outbreak a PHEIC on May 17, 2026, citing significant uncertainties regarding the true number of infected persons and geographic spread, compounded by insecurity and population movement in the region.

Despite the current challenges with the Bundibugyo strain, significant advancements have been made in Ebola preparedness and response. Two vaccines, Ervebo® and Zabdeno/Mvabea®, are approved for the Zaire ebolavirus, and a global stockpile exists to facilitate rapid deployment during outbreaks. In January 2026, the Coalition for Epidemic Preparedness Innovations (CEPI) committed $30 million to support the development of an updated Zaire ebolavirus vaccine with improved affordability and accessibility, and clinical trials for new vaccines targeting Ebola, Marburg, and Lassa viruses are underway. Preventive vaccination programs for frontline workers in high-risk areas have also been launched by Gavi since June 2024.