Ebola

Primary reference(s)

WHO, 2025. Ebola virus disease. World Health Organization (WHO). Accessed 26 May 2025.

Annotations

Key relevant UN convention / multilateral treaty

International Health Regulations (2005), 3rd ed. (WHO, 2016b).

United Nations. 2023. UN Recommendations on the Transport of Dangerous Goods - UN Model Regulations. (UNECE, 2023).

Drivers

It is thought that fruit bats of the Pteropodidae family are natural Ebola virus hosts. Ebola is introduced into the human population through close contact with the blood, secretions, organs or other bodily fluids of infected animals such as fruit bats, chimpanzees, gorillas, monkeys, forest antelope or porcupines found ill or dead or in the rainforest (WHO, 2023a).

Ebola then spreads through human-to-human transmission via direct contact (through broken skin or mucous membranes) with blood or body fluids of a person who is sick with or has died from Ebola, or objects that have been contaminated with body fluids (such as blood, faeces, vomit) from a person sick with Ebola or the body of a person who died from Ebola (WHO, 2023a).

Health-care workers have frequently been infected while treating patients with suspected or confirmed EVD. This occurs through close contact with patients when infection control precautions are not strictly practised. Burial ceremonies that involve direct contact with the body of the deceased can also contribute to the transmission of Ebola. People remain infectious as long as their blood contains the virus. After recovery, there is the possibility of sexual transmission, which can be reduced with support and information for survivors (WHO, 2023a).

Pregnant women who get acute Ebola and recover from the disease may still carry the virus in breastmilk, or in pregnancy-related fluids and tissues. This poses a risk of transmission to the baby they carry, and to others. Women who become pregnant after surviving Ebola disease are not at risk of carrying the virus.

Impacts

The symptoms of Ebola disease can be sudden and include fever, fatigue, malaise, muscle pain, headache and sore throat. These are followed by vomiting, diarrhoea, abdominal pain rash, and symptoms of impaired kidney and liver functions. It is important for health and care workers to be on the lookout for these symptoms. Despite a perception that bleeding is a common symptom, this is less frequent and can occur later in the disease. Some patients may develop internal and external bleeding, including blood in vomit and faeces, bleeding from the nose, gums and vagina. Bleeding at the sites where needles have punctured the skin can also occur. The impact on the central nervous system can result in confusion, irritability and aggression (WHO, 2025). 

After recovering from Ebola, some people may have symptoms for two years or longer. These symptoms can include, feeling tired, headache, muscle and joint pain, eye pain and vision problems, weight gain, belly pain and loss of appetite, hair loss and skin problems, trouble sleeping, memory loss, hearing loss, depression and anxiety (WHO, 2023a).  

Rivera & Massoudi (2016), in their review of EBOV pathogenesis, current vaccine and therapeutic candidates, and mechanisms of viral persistence and long‐term health sequelae for Ebola disease survivors, reported that the virus pathogenesis has identified that the virus initially and preferentially infects monocytes, macrophages impairs leading to the robust expression of inflammatory mediators. However, fundamental questions still remain, about how Ebola disables innate immunity (Rivera & Massoudi, 2016).

Multi-hazard context

Raising awareness of risk factors and protective measures is essential to reduce multi hazard impacts (WHO, 2025). As a result, individuals can take is an effective way to reduce human transmission and preventing disease spread (WHO,

2025). Risk reduction messaging should focus on several factors:

• Reduce the risk of wildlife-to-human transmission from contact with infected fruit bats or monkeys/apes and the consumption of their raw meat (WHO, 2025).
• Reduce the risk of human-to-human transmission arising from direct or close contact with infected people, particularly with their body fluids. Close physical contact with Ebola patients should be avoided. Patients should be isolated in a designated treatment center for early care and to avoid transmission at home (WHO, 2025).
• Communities should be well informed, both about the disease itself and how to control the outbreak. This is done best when they are involved in the response and there is open discussion (WHO, 2025).
• Outbreak containment measures include safe and dignified burial of the deceased, identifying people who may have been in contact with someone infected with Ebola disease and monitoring their health for 21 days, separating the healthy from the sick to prevent further spread and providing care to confirmed patients. Maintaining good hygiene and a clean environment are also important (WHO, 2025).

Risk Management

People with symptoms of Ebola should get medical care immediately. Early care improves a person's chances of surviving Ebola. It is not safe to care for people with Ebola at home, because the person may make other people sick. At home, they will not receive the same level of care they can get from professionals. Simple interventions early on can significantly improve chances of survival. This includes rehydration with fluids and body salts (given orally or intravenously), and treatment of specific symptoms such as low blood pressure, vomiting, diarrhoea and infections. WHO has made strong recommendations for the use of two monoclonal antibody treatments in treating Ebola: mAb114 (Ansuvimab; Ebanga) and REGN-EB3 (Inmazeb). (WHO, 2025). 

Community engagement is key to successfully controlling outbreaks. Working with communities to reduce risk factors for Ebola transmission is critical to controlling outbreaks. Burial ceremonies that involve direct contact with the body of the deceased can contribute to the transmission of Ebola (WHO, 2025). 

Good outbreak control relies on applying a package of interventions, including case management, surveillance and contact tracing, a good laboratory service, safe burials and social mobilisation. Community engagement is key to successfully controlling outbreaks. Raising awareness of risk factors for Ebola infection and protective measures (including vaccination) that individuals can take is an effective way to reduce human transmission. Risk reduction messaging should focus on several factors: reducing the risk of wildlife-to-human transmission; reducing the risk of human-to-human transmission; outbreak containment measures; reducing the risk of possible sexual transmission; reducing the risk of transmission from pregnancy-related fluids and tissue; and controlling infection in health-care settings (WHO, 2025). 

Ervebo was licensed in November 2019 by the European Medicines Agency and prequalified by WHO. The United States Food and Drug Administration licensed the vaccine in December 2019. Since then, Burundi, Central African Republic, the Democratic Republic of Congo, Ghana, Guinea, Rwanda, Uganda and Zambia have also approved the vaccine. The vaccine is safe and protective against the species Zaire ebolavirus. It is recommended by the Strategic Advisory Group of Experts (SAGE) on Immunization as part as a broader set of Ebola outbreak response tools (WHO, 2020b). 

In May 2020, the European Medicines Agency recommended granting  marketing authorisation to a second new vaccine delivered in 2 doses called Zabdeno (Ad26.ZEBOV) and Mvabea (MVA-BN-Filo) for individuals 1 year and older. The vaccine is delivered in 2 doses: Zabdeno is administered first and Mvabea is given approximately 8 weeks later as a second dose. This prophylactic 2-dose regimen is therefore not suitable for an outbreak response where immediate protection is necessary. For individuals at imminent risk of exposure to Ebola (for example, health care professionals and those living in or visiting areas with an ongoing Ebola virus disease outbreak) who completed the Zabdeno and Mvabea 2-dose vaccination regimen, a Zabdeno booster vaccination should be considered if more than 4 months have passed since the second dose was administered (WHO, 2020b).

Monitoring

The section and the table below offer an overview of monitoring for Ebola. This information can be used for forecasting within a national early warning system (EWS). Since EWS capacities and processes differ across countries, the most current and specific information regarding EWS should be obtained from the appropriate national or regional agency/authority responsible for disaster management.

WHO supports countries to conduct all-hazards strategic risk assessment in the contexts of health emergencies and disasters, which results in the development of a country risk profile. Empowered with the country risk profile, inclusive of a seasonal risk calendar, countries can anticipate potential emergencies before they occur to trigger early alerts and inform early actions (WHO, 2021).

WHO's Early Warning, Alert and Response System (EWARS) has been designed to improve disease outbreak detection in emergency settings, such as in countries in conflict or following a disaster from natural hazards. It is a simple and cost-effective way to rapidly set up a disease surveillance system. EWARS is deployed during an emergency as an adjunct to the national disease surveillance system. WHO works with Ministries of Health and health sector partners to train local health workers to use the system. After the emergency, EWARS should re-integrate back into the national system (WHO, 2023b).