OUTBREAK: Ebola

Background

Ebola Virus Disease (EVD) is a highly infectious, potentially lethal zoonotic disease caused by the Ebola virus (EBOV), also known as the Zaire virus, belonging to the Filoviridae viral family. It was first discovered in 1976 after two almost simultaneous outbreaks occurred in South Sudan and the Democratic Republic of the Congo (DRC), resulting in over 500 cases. Since then, there have been over 20 EVD outbreaks in Africa. The DRC has experienced the most EVD outbreaks. The average case fatality rate (CFR) is 50% (range 25% to 90%), and healthcare workers are especially at risk. The animal reservoir for EBOV is yet to be confirmed. However, fruit bats are believed to be the natural hosts.

EVD is transmitted to humans through close contact with the blood and bodily fluids of infected animals. Human-to-human transmission occurs through direct contact with the blood and bodily fluids of an infected, symptomatic human or objects they may have contaminated. There is also evidence that sexual transmission can occur even after recovery, as the virus is present in the blood. Ebola causes a severe disease with complications, including multiorgan failure, haemorrhage, and shock. There are licensed vaccines (rVSV-ZEBOV and Ad26.ZEBOV/MVA-BN-Filo) and therapeutics (Inmazeb and Ebanga) against EVD. 

Current Outbreak

On 4 September 2025, the DRC declared an EVD outbreak in the Kasai Province. The suspected index case was a pregnant woman who developed fever, vomiting, haemorrhage, and multiorgan failure leading to her death on 25 August 2025. Laboratory testing on 3 September 2025 confirmed EVD in samples from five suspected cases and one probable death. As of 12 October, there have been 64 cases (53 confirmed, 11 probable) and 425deaths (CFR: 70.3%). Healthcare workers account for five of the confirmed cases and three deaths. The Bulape health zone is the epicenter of this outbreak and while it is a rural area, movement from this area to more populous cities within the Kasai province is common. The outbreak was initially driven by nocosomial transmission and cases linked to the funeral of the presumed index case. Since declaring the EVD outbreak and initiating response activities, cases and deaths have declined. As of 12 October, no confirmed cases have been reported over the last two weeks.

As of 4 September 2025, the WHO has assessed the overall public health risk as high at the national level, moderate at the regional level, and low at the global level. The DRC is responding to multiple health emergencies, limiting its response capacity. The WHO, Africa CDC, and several other international partners have stated that they are providing support to the DRC, including technical and financial support. A Regional Strategic Preparedness and Response Plan was also developed to guide efforts. As of 28 September, 31 cases have received thetherapeutic mAb114 and 4,115 individuals, including healthcare workers and contacts, have been administered the vaccine Ervebo.

For more information about Ebola in the DRC, click here.

Key public health and research updates

September 2025:

• Therapeutic mAb114 and vaccine Ervebo are being administered.
• Filoviridae CORC meeting held on 5 September to give stakeholders an update on this outbreak – resulting research priorities available here and a recoring of the meeting available here.
• WHO publishes a Regional Strategic Preparedness and Response Plan for EVD in the DRC which outlines response priorities.
• On 4 September, the DRC declared an EVD outbreak in the Kasai province. 

March 2025:

• Filoviridae CORC meeting held on the update of the WHO-AFIRM Roadmap.

October 2024:

• WHO published a CORE protocol for testing therapeutic candidates against Filoviruses

July 2024: 

• WHO published ‘Pathogens prioritization: a scientific framework for epidemic and pandemic preparedness’ listing Filoviridae viruses as a high PHEIC (Public Health Emergency of International Concern) risk.

March 2024: 

• WHO published a CORE protocol for testing vaccine candidates against Filoviruses

August 2022:

• DRC declared an EVD outbreak in the North Kivu province. 

June 2022:

• WHO published a Strategic Agenda for Filovirus Research and Monitoring (2021-2031) (WHO-AFIRM).

January 2019:

• The WHO R&D Blueprint team published a Research and Development Roadmap on Ebola and Marburg.

December 2008:

• DRC declared an EVD outbreak in the Kasai province.

Outbreak-specific research priorities

The Filovirus CORC has published a list of ten research priorities specific to this outbreak, on 12 September. 

The WHO R&D Blueprint team published a Roadmap outlining research priorities for Ebola/Marburg in 2019. A more updated WHO-Strategic Agenda for Filovirus Research and Monitoring (WHO-AFIRM)(2021-2031) was published in 2021. This outlines strategic goals and milestones for Filovirus research under three pillars: Anticipation (to prevent and control outbreaks), Reinforcement (to develop and evaluate vaccines), and Cure (to develop post-exposure therapies). 

Relevant Links

• Filoviridae CORC Scientific Consultation – Research Priorities in Response to the Ebola Outbreak in DR Congo and Future Filovirus
• Regional Strategic Preparedness and Response Plan for Ebola Virus Disease in the Democratic Republic of the Congo
• A WHO-Strategic Research Agenda for Filovirus. Research and Monitoring (WHO AFIRM). WHO-AFIRM Strategy Roadmap 2021-2031.
• Ebola/Marburg Research and Development (R&D) Roadmap. January 2019 – Advanced draft.

Pandemic PACT data

See below our data visualisations for Ebola research grant funding.