Ebola virus disease

Ebola virus disease (EVD) is caused by Ebola virus, which current taxonomy places in the species Orthoebolavirus zairense, in the genus Orthoebolavirus and family Filoviridae. Older sources use the names Zaire ebolavirus and Ebolavirus. The World Health Organization uses “Ebola disease” as an umbrella term for illness caused by several related orthoebolaviruses; EVD is the disease specifically caused by Ebola virus. This distinction matters because other members of the group cause separately named diseases, and available vaccines and treatments are not interchangeable across them.

Ebola virus spreads through direct contact with the blood or other body fluids of a person who is ill or has died from the disease, or with objects contaminated by those fluids. Infection can also follow contact with an infected animal. People are not considered contagious before symptoms begin, and the disease is not spread simply by being near someone or through the air like a respiratory infection. Fruit bats are thought to be natural hosts of orthoebolaviruses, although the pathways by which the virus enters human populations involve contact with infected animals. Outbreak control therefore emphasizes early detection, isolation and care, infection prevention, surveillance, contact tracing and community engagement.

Symptoms usually begin between 2 and 21 days after exposure. Early illness may include fever, fatigue, muscle pain, headache and sore throat, followed by symptoms such as vomiting, diarrhoea, abdominal pain and, in some cases, impaired kidney or liver function. Despite the disease's association with haemorrhagic fever, visible bleeding is less common and can occur later. Because early symptoms resemble other infections, clinical signs alone cannot confirm EVD; laboratory testing, including polymerase chain reaction (PCR), is used to establish the diagnosis.

Early intensive supportive care—including fluid and electrolyte replacement and treatment of symptoms—improves the chance of survival. As of 2026, the U.S. Centers for Disease Control and Prevention lists two FDA-approved antibody treatments for disease caused by Orthoebolavirus zairense; they are not approved treatments for all related orthoebolavirus diseases. Vaccines are likewise virus-specific. Public-health measures combine clinical care with infection prevention, safe handling of bodies, surveillance and contact tracing, and vaccination when an appropriate vaccine is available. Community involvement is an important part of outbreak response.