Pandemic Watch iOS App

Ebola disease: a complete guide

Ebola is a severe, often fatal viral illness caused by a family of filoviruses native to equatorial Africa. This page is a working reference: what ebola is, the four species that cause human disease, how it spreads, what to watch for, what we can do about it, and the major outbreaks that have shaped our understanding. For the live outbreak picture, visit the dashboard or outbreak map.

What is ebola?

Ebola is the common name for any disease caused by viruses in the genus Ebolavirus, family Filoviridae, order Mononegavirales. These are filamentous, single-stranded RNA viruses whose natural reservoirs are suspected to be fruit bats of family Pteropodidae. Each species has its own ecology and geographic distribution, but all produce similar clinical disease in humans: filovirus hemorrhagic fever, ICD-11 code 1D60.

Four ebolavirus species cause human disease: Zaire ebolavirus (ZEBOV), the most lethal and the cause of the 2014-2016 West Africa epidemic; Sudan ebolavirus (SUDV), endemic to Uganda and South Sudan; Bundibugyo ebolavirus (BDBV), first identified in 2007 and the cause of the 2026 DRC/Uganda PHEIC; and Tai Forest ebolavirus (TAFV), with only one documented human case from 1994. A fifth species, Reston ebolavirus, circulates in cynomolgus macaques and pigs in Southeast Asia but has never been shown to cause human disease.

Ebola was first identified in 1976 during near-simultaneous outbreaks in northern Zaire (now the Democratic Republic of the Congo) and southern Sudan. The two clusters were initially assumed to share a virus until subsequent work established they were distinct species. The Zaire outbreak in Yambuku killed 280 of 318 reported cases — an 88 percent case-fatality rate that set the early reputation of Ebola as among the most lethal known viral infections. The virus was named for the Ebola River near Yambuku.

Symptoms and clinical course

Ebola begins after an incubation period of two to twenty-one days (typically eight to ten) with a non-specific febrile illness that resembles many other tropical fevers. The early phase is sometimes called the "dry phase" because gastrointestinal symptoms have not yet developed.

The dry phase (days 0-3)

The wet phase (days 3-10)

The transition to the gastrointestinal phase is what distinguishes ebola from less severe febrile illnesses. Patients develop:

This is where most deaths occur. The volume of fluid loss is extreme: patients with severe disease can lose more fluid in a day than cholera patients, and without aggressive intravenous replacement they progress to hypovolemic shock within days.

The hemorrhagic phase (in some patients, days 5-12)

Roughly half of patients with severe disease develop overt hemorrhagic manifestations: petechial rash, conjunctival hemorrhage, bleeding from venipuncture sites, gastrointestinal bleeding, and (in the most severe cases) disseminated intravascular coagulation. Hemorrhage is not the dominant cause of death — that remains hypovolemic shock and multi-organ failure from fluid loss and the inflammatory response — but bleeding marks a poor prognosis.

When to seek emergency care: after travel to an outbreak region, or known contact with a symptomatic patient, any fever followed by gastrointestinal symptoms is a medical emergency. Tell the clinician about the exposure history immediately. Ebola is rare enough in non-outbreak settings that, without that history, the syndrome is easily mistaken for severe gastroenteritis, malaria, or sepsis from another cause until the diagnosis is forced by progression.

How ebola is transmitted

The primary route is direct contact with the blood, vomit, diarrhea, or other body fluids of a symptomatic patient, entering through broken skin or mucous membranes (eyes, nose, mouth). The virus is not transmitted through casual conversational contact, and there is no documented evidence of efficient airborne transmission in community settings. However, aerosol-generating medical procedures — intubation, suctioning, certain types of mechanical ventilation — can release infectious particles in hospital environments and account for some of the historical healthcare-worker transmission.

Other documented routes:

Ebola is not transmitted by mosquitoes, ticks, fleas, or other arthropods. Bloodborne transmission from an asymptomatic person is not documented; transmission requires symptomatic disease in the source case.

Ebolavirus species and global distribution

Four species cause human disease. Each has its own ecology and geographic distribution, with distinct case-fatality profiles and outbreak histories.

Reservoir: fruit bats (suspected, Pteropodidae) Distribution: DRC, Gabon, Republic of Congo, West Africa Mortality: 44–90%

The most lethal ebolavirus and the cause of the 2014-2016 West Africa epidemic (28,616 cases, 11,310 deaths). The only ebolavirus species with a licensed vaccine (Ervebo) and licensed monoclonal antibody therapeutics (Inmazeb, Ebanga). Full reference →

Reservoir: fruit bats (suspected, Pteropodidae) Distribution: Uganda, South Sudan Mortality: 41–71%

The second most lethal species. Eight documented outbreaks since 1976. No licensed vaccine or therapeutic — candidate vaccines deployed under emergency-use protocols during the 2022 Mubende outbreak. Endemic to the Uganda-South Sudan border region. Full reference →

Reservoir: fruit bats (suspected, Pteropodidae) Distribution: Uganda, DRC Mortality: 25–40%

The lowest-mortality ebolavirus, discovered in 2007 in western Uganda. The cause of the 2026 DRC/Uganda PHEIC outbreak, currently tracked on this site's dashboard. No licensed vaccine yet, though trivalent candidates covering ZEBOV, SUDV, and BDBV are in development. Full reference →

Reservoir: fruit bats (suspected, Pteropodidae) Distribution: Cote d'Ivoire, possibly Liberia Mortality: unknown (1 case)

The rarest human-pathogenic ebolavirus. Only one documented human case — a Swiss ethologist who recovered after exposure during a chimpanzee necropsy in 1994. Circulates in West African chimpanzee populations; sporadic spillover risk remains. Full reference →

Is there Ebola in the US or UK? Ebola outside Africa

Ebola outbreaks happen almost entirely in equatorial Africa, where the suspected fruit-bat reservoir lives. Outside that region, essentially every case on record has been imported — a traveler or medically-evacuated patient infected in an outbreak zone — and not one country outside Africa has ever experienced sustained community transmission. That distinction is the answer to the most common questions searched about Ebola's location.

Ebola in the United States

There is no active Ebola outbreak in the United States, and there never has been one that spread within the country. The only US cases came during the 2014-2016 West Africa epidemic. In September 2014, Thomas Eric Duncan traveled from Liberia to Dallas, Texas, fell ill, and was diagnosed with Ebola; he died on October 8, 2014. Two nurses who cared for him, Nina Pham and Amber Vinson, contracted the virus and both recovered — the only cases of Ebola ever transmitted on US soil. Separately, several American aid workers and a physician (Dr. Craig Spencer, diagnosed in New York City after returning from Guinea) were either medically evacuated for treatment at specialized biocontainment units or diagnosed shortly after return. Every case was contained. The much earlier Reston, Virginia event of 1989 involved Reston ebolavirus in imported monkeys; some animal workers seroconverted but nobody became ill, because Reston virus does not cause disease in humans.

Ebola in the UK and Europe

The United Kingdom has never had Ebola spread within its borders. Two British healthcare workers infected while volunteering in Sierra Leone — William Pooley in 2014 and Pauline Cafferkey in 2014-2015 — were treated at the Royal Free Hospital in London and survived. Across the rest of Europe, patients were treated in France, Spain, Italy, Germany, Norway, and Switzerland during 2014-2016, almost all of them evacuated volunteers. The one instance of onward transmission in Europe was in Madrid, Spain, where a nursing assistant was infected caring for a repatriated missionary in 2014; she recovered with no further spread. A French nurse evacuated from Liberia was also treated in France that year and recovered.

Where Ebola outbreaks actually occur

The countries with recurring Ebola outbreaks are in Central and West Africa. The Democratic Republic of the Congo has had more outbreaks than anywhere else; Uganda, South Sudan (the 1976 discovery site of Sudan ebolavirus, in what was then Sudan), Gabon (several Zaire ebolavirus outbreaks between 1994 and 2002), the Republic of the Congo, and the West African trio of Guinea, Sierra Leone, and Liberia (the 2014-2016 epicenter) account for the rest. The event currently tracked on this site is a Bundibugyo ebolavirus outbreak in the DRC and Uganda. For live case counts and the specific countries affected right now, see the live outbreak dashboard or the outbreak map.

Prevention and outbreak response

Ebola prevention operates on three levels: prevent spillover from the wildlife reservoir, prevent person-to-person spread once a spillover has occurred, and protect healthcare workers from nosocomial transmission. The third level matters disproportionately because outbreak amplification in healthcare settings — where infected patients concentrate and where contact is sustained and intimate — has driven the majority of every major Ebola event.

Healthcare infection prevention and control

Community-level response

For travelers to outbreak regions

Vaccines and therapeutics

The Ebola response toolkit has changed dramatically in the past decade. Before 2014, no licensed vaccine or therapeutic existed for any ebolavirus; supportive care was the entire arsenal. Today there are licensed pharmaceutical interventions for Zaire ebolavirus, and candidate products are advancing for the other species.

Ervebo (rVSV-ZEBOV)

Ervebo, a recombinant vesicular stomatitis virus (rVSV) vaccine expressing the Zaire ebolavirus glycoprotein, was licensed by the FDA in 2019 after demonstrating ~100 percent efficacy against Zaire virus disease in a ring-vaccination cluster-randomized trial during the 2014-2016 West Africa epidemic. It is the cornerstone of the modern WHO outbreak response: deployed under ring-vaccination protocols around every Zaire ebolavirus outbreak since 2018. It is approved for adults; pediatric and pregnancy data have accumulated under emergency-use protocols. The vaccine is currently stockpiled by Gavi and WHO.

Inmazeb and Ebanga

Two monoclonal antibody therapies are FDA-licensed for Zaire ebolavirus disease. Inmazeb (atoltivimab/maftivimab/ odesivimab) is a three-antibody cocktail; Ebanga (ansuvimab-zykl) is a single antibody. Both target the viral glycoprotein and were tested head-to-head against two other candidates in the 2018-2020 DRC PALM trial. The two monoclonal arms substantially outperformed the comparator arms in mortality reduction and were licensed in 2020. Inmazeb and Ebanga are the standard of care for confirmed Zaire virus disease in well-resourced treatment units.

Candidate products for Sudan, Bundibugyo, and Tai Forest

No licensed vaccine or therapeutic exists for Sudan, Bundibugyo, or Tai Forest ebolaviruses. Candidate vaccines include cAd3-SUDV (chimpanzee adenovirus-vectored Sudan virus glycoprotein, deployed under ring vaccination in the 2022 Mubende outbreak) and trivalent vaccines covering Zaire, Sudan, and Bundibugyo simultaneously. The 2026 DRC/Uganda PHEIC has accelerated emergency-use trials of these candidates. Monoclonal antibody candidates for SUDV and BDBV are in preclinical and early-clinical development.

Clinical treatment and prognosis

Even with modern pharmacological interventions, supportive care remains the foundation of ebola treatment and accounts for much of the historical mortality improvement.

Most survivors recover, but recovery can be slow and complicated. Post-Ebola syndrome — joint pain, vision changes (uveitis), hearing loss, fatigue, and psychological sequelae — is documented in a substantial fraction of survivors and may persist for months to years. Twelve-month follow-up programs are standard in major response operations.

Prognosis hinges on three factors: which species (Bundibugyo and Tai Forest carry lower mortality than Zaire and Sudan), how quickly the patient reaches a treatment facility with capacity for aggressive fluid management, and whether pathogen-specific therapeutics are available (currently Zaire-only). The 2018-2020 DRC outbreak demonstrated that with ring vaccination, dedicated treatment units, and monoclonal antibody therapy, Zaire ebolavirus case-fatality can be driven below 25 percent in well-resourced settings — a dramatic improvement over the historical baseline.

Major outbreaks in history

A non-exhaustive selection of ebola events that shaped the modern understanding of the disease.

1976 — Yambuku, Zaire (now DRC)
The discovery outbreak. 318 cases, 280 deaths in and around a Catholic mission hospital whose staff reused needles for antenatal injections. Zaire ebolavirus was named for the nearby Ebola River. The companion 1976 Nzara/Maridi outbreak in southern Sudan identified what would later be classified as Sudan ebolavirus.
1995 — Kikwit, Zaire
315 cases, 254 deaths. The first major outbreak to draw sustained international response and modern infection- control investigation. Established many of the protocols still used today.
2000 — Gulu, Uganda
425 cases, 224 deaths from Sudan ebolavirus. Shaped modern outbreak response: the WHO Global Outbreak Alert and Response Network deployed at scale, and Lacor Hospital's ring infection-control model became a template for subsequent outbreaks.
2007 — Bundibugyo, Uganda
149 cases, 37 deaths. Initially assumed to be Sudan virus, sequencing revealed a new species — Bundibugyo ebolavirus — sufficiently divergent to warrant the designation.
2014–2016 — West Africa (Guinea, Sierra Leone, Liberia)
The largest Ebola epidemic in history. 28,616 reported cases, 11,310 deaths across three countries with imported cases reaching Nigeria, Senegal, Mali, the United Kingdom, Spain, Italy, and the United States. Drove the development of Ervebo, the Inmazeb and Ebanga therapeutics, and the modern ring-vaccination response model.
2018–2020 — North Kivu, DRC
3,481 cases, 2,299 deaths. The second-largest Ebola outbreak in history, complicated by ongoing armed conflict. First widespread deployment of Ervebo under ring-vaccination protocols, and the PALM trial that established Inmazeb and Ebanga as licensed therapeutics.
2022 — Mubende, Uganda
164 confirmed cases, 55 deaths from Sudan ebolavirus. Prompted the first ring-vaccination trial of a candidate Sudan-virus vaccine (cAd3-SUDV).
2026 — DRC and Uganda (current)
The Bundibugyo ebolavirus outbreak declared a Public Health Emergency of International Concern by the WHO Director-General on May 16, 2026. International spread to Kampala (Uganda) via an imported case from Ituri Province (DRC). The largest Bundibugyo virus event ever documented. Track the live case count on the dashboard.

Frequently asked questions

Is there Ebola in the United States right now?

There is no active, community-spreading Ebola outbreak in the United States, and there never has been. The only Ebola cases ever recorded in the US were imported or travel-associated during the 2014-2016 West Africa epidemic: Thomas Eric Duncan, who traveled from Liberia and was diagnosed in Dallas in September 2014 (he died; two nurses who cared for him were infected and both recovered), plus a small number of aid workers and a physician who were either medically evacuated for treatment or diagnosed shortly after returning from West Africa. All were contained with no sustained transmission. For the current global picture, check the live dashboard on this site or WHO Disease Outbreak News.

Is there Ebola in the UK?

No. The United Kingdom has never had community transmission of Ebola. During the 2014-2016 West Africa epidemic, two British healthcare workers who were infected while volunteering in Sierra Leone were treated at the Royal Free Hospital in London — William Pooley (2014) and Pauline Cafferkey (2014-2015); both survived, though Cafferkey later experienced a relapse from viral persistence. These were imported cases in returning volunteers, not spread within the UK.

Was there an Ebola outbreak in Reston, Virginia?

In 1989, a strain now called Reston ebolavirus was discovered in crab-eating macaque monkeys imported from the Philippines to a research quarantine facility in Reston, Virginia — the events dramatized in the book 'The Hot Zone.' Several animal-care workers were exposed and developed antibodies to the virus, but none became ill. Reston ebolavirus is the one ebolavirus species not known to cause disease in humans. So while there was a Reston, Virginia Ebola event, it was an animal outbreak with no human illness — not a human Ebola outbreak.

Has Ebola ever spread in Europe?

Europe has recorded only imported and medically-evacuated Ebola cases, never sustained local transmission. During the 2014-2016 epidemic, patients were treated in the United Kingdom, France, Spain, Italy, Germany, Norway, and Switzerland. The single instance of Ebola transmission on European soil was in Madrid, Spain, in 2014, when a nursing assistant, Teresa Romero, was infected while caring for a repatriated missionary; she recovered, and no further spread occurred. ('Ebola Frankrike' and 'ebola France' searches refer to a French MSF nurse evacuated from Liberia and treated in France in 2014, who also recovered.)

Where is Ebola right now, and which countries have Ebola outbreaks?

Ebola outbreaks occur almost exclusively in equatorial Africa, where the fruit-bat reservoir lives. The Democratic Republic of the Congo has had more Ebola outbreaks than any other country; Uganda, South Sudan, Gabon, the Republic of the Congo, Guinea, Sierra Leone, and Liberia have all had significant outbreaks. Sudan ebolavirus is associated with Uganda and the South Sudan border region; Gabon saw several Zaire ebolavirus outbreaks between 1994 and 2002. The current tracked event is a Bundibugyo ebolavirus outbreak in the DRC and Uganda. For live case counts and the countries currently affected, see the dashboard on this site.

Is there a vaccine for ebola?

A licensed vaccine exists for Zaire ebolavirus only — Ervebo (rVSV-ZEBOV), approved by the FDA and WHO-prequalified. It is highly effective at preventing Zaire virus disease when deployed under a ring-vaccination strategy around confirmed cases. No licensed vaccine exists for Sudan, Bundibugyo, or Tai Forest ebolaviruses; candidate vaccines for those species are in clinical trials and have been deployed under emergency-use protocols during the 2022 Mubende outbreak (Uganda, Sudan virus) and the 2026 PHEIC (DRC/Uganda, Bundibugyo virus).

How deadly is ebola?

Case-fatality varies substantially by species and access to supportive care. Zaire ebolavirus has averaged 44 to 90 percent across documented outbreaks, with the lower end seen in the 2014-2016 West Africa epidemic where Médecins Sans Frontières treatment centers offered aggressive supportive care. Sudan ebolavirus has averaged 41 to 71 percent. Bundibugyo ebolavirus is the least lethal at 25 to 40 percent. Modern licensed Zaire-virus therapeutics (Inmazeb, Ebanga) have further reduced mortality among treated patients in well-resourced settings.

How is ebola transmitted between people?

Through direct contact with the blood, vomit, diarrhea, or other body fluids of a symptomatic patient — entering through broken skin or mucous membranes (eyes, nose, mouth). The virus is not airborne in the casual sense (it does not spread efficiently through normal respiratory droplets at conversational distance), but aerosol-generating medical procedures can release infectious material. Sexual transmission has been documented, and the virus persists in semen for months after recovery. Contaminated objects (needles, bedding, contaminated PPE) and unsafe burial practices that involve washing or touching the deceased account for a substantial fraction of historical transmission.

What is the natural reservoir of ebola?

Fruit bats of the family Pteropodidae are strongly suspected to be the natural reservoir — particularly Hypsignathus monstrosus, Epomops franqueti, and Myonycteris torquata. Antibody evidence has been documented in these species across West and Central Africa, and a small number of viral isolations have been reported. Spillover into humans is thought to occur both directly (contact with bats roosting in homes or trees, or with their droppings) and indirectly through hunting and butchering primates or other forest mammals that have themselves been infected by bat material.

What's the difference between the ebola species?

Four ebolavirus species cause human disease. Zaire ebolavirus (ZEBOV) is the most lethal and the cause of the 2014-2016 West Africa epidemic; it is also the species with licensed vaccine and therapeutics. Sudan ebolavirus (SUDV) circulates in Uganda and South Sudan; no licensed vaccine exists for it. Bundibugyo ebolavirus (BDBV), discovered in 2007 and the cause of the 2026 DRC/Uganda PHEIC, has the lowest mortality. Tai Forest ebolavirus (TAFV) has produced only one documented human case, a Swiss researcher who survived after exposure during a chimpanzee necropsy in 1994. A fifth species, Reston ebolavirus (RESTV), circulates in Southeast Asian primates and pigs but has not caused human disease.

How quickly does ebola spread within a community?

Reproduction numbers (R) in the field have ranged from roughly 1.5 to 2.5 during active outbreak phases. Spread is rapid in healthcare settings without rigorous infection control (the 1995 Kikwit and 2014 West Africa outbreaks both saw substantial nosocomial transmission) and at funerals where bodies are washed by hand (a major amplification route in many West African outbreaks). With ring vaccination, contact tracing, dedicated treatment units, and safe burials, R can be driven below 1 within weeks — that is what ended the 2018-2020 DRC outbreak.

Is there a cure for ebola?

Two licensed monoclonal antibody therapies exist for Zaire ebolavirus disease: Inmazeb (a three-antibody cocktail) and Ebanga (a single antibody). Both target the viral glycoprotein, were tested in the 2018-2020 DRC PALM trial, and showed substantial mortality reductions versus historical controls. They are FDA-approved and form the backbone of modern Zaire-virus treatment. No licensed monoclonal therapies exist for Sudan, Bundibugyo, or Tai Forest ebolavirus, though candidates are in trials. Across all species, aggressive supportive care — aggressive intravenous fluid replacement, electrolyte correction, oxygen, treatment of secondary infections — remains foundational and accounts for substantial mortality reduction even before pathogen-specific therapeutics.

Can ebola survivors transmit the virus after they recover?

Yes, in some cases. The virus persists in immune-privileged sites — eye, central nervous system, testis — for months after clinical recovery, and survivors can experience recrudescent disease (flare cases) or transmit through sexual contact. Several documented outbreak resurgences have been traced to survivors months or years after the original outbreak was declared over. Modern survivor follow-up programs include periodic testing of semen and counseling on barrier-method use until cleared, typically over twelve months.


Information on this page is synthesized from the World Health Organization Ebola virus disease fact sheet, the U.S. Centers for Disease Control and Prevention Ebola Disease pages, the European Centre for Disease Prevention and Control surveillance and outbreak documentation, and primary epidemiological literature. It is intended as a reference for the general public and is not a substitute for individual medical advice. If you have been exposed to a confirmed or suspected case and develop symptoms, contact a healthcare professional immediately.

Continue exploring: live outbreak dashboard · outbreak map · latest news · about hantavirus