Five distinct species of Ebolavirus have been identified. Each has different lethality, geographic range, and outbreak history. Compare them side by side.
Case-Fatality Rate · side-by-side
% of confirmed cases that die
Zaire ebolavirus is the most lethal, killing up to 90% of those infected. Reston has never caused disease in humans.
DRC · Guinea · Liberia · Sierra Leone · Gabon · Republic of Congo
Transmission
Direct contact with blood and bodily fluids of infected people or animals. Bushmeat handling, unsafe burials, and nosocomial spread in healthcare facilities are major amplifiers.
Clinical course
Sudden onset of fever, intense weakness, muscle pain, headache, sore throat, followed by vomiting, diarrhoea, rash, impaired kidney/liver function, and in some cases internal and external bleeding.
Notable outbreaks
1976
Yambuku, DRC
First identified outbreak — 318 cases, 280 deaths (88% CFR). Transmitted via reused needles at a mission hospital.
2014–16
West Africa
Largest Ebola outbreak in history — 28,616 cases, 11,310 deaths across Guinea, Liberia, and Sierra Leone.
2018–20
Eastern DRC
Second-largest outbreak — 3,481 cases, 2,299 deaths in North Kivu and Ituri provinces during armed conflict.
Sudan ebolavirus (SUDV)
Sudan ebolavirus
Discovered 1976 (Nzara, South Sudan)
CFR
40–60%
🦇 Natural host
Unknown (bats suspected)
🌍 Geography
East Africa
Sudan · South Sudan · Uganda
Transmission
Direct contact with bodily fluids. Initial outbreaks traced to cotton factory workers with bat exposure. No approved vaccine — rVSV-ZEBOV targets Zaire species only.
Clinical course
Similar to Zaire but with slightly lower fatality. Fever, headache, joint/muscle pain, diarrhoea, vomiting. Haemorrhagic manifestations occur in severe cases.
Notable outbreaks
1976
Nzara, South Sudan
284 cases, 151 deaths. Concurrent with but independent of the Yambuku outbreak — initially mistaken for the same virus.
2000–01
Gulu, Uganda
425 cases, 224 deaths — the largest Sudan ebolavirus outbreak to date.
2022
Central Uganda
164 cases, 77 deaths. No vaccine or therapeutic approved for Sudan species, complicating the response.
Bundibugyo ebolavirus (BDBV)
Bundibugyo ebolavirus
Discovered 2007 (Bundibugyo, Uganda)
CFR
25–35%
🦇 Natural host
Unknown (bats suspected)
🌍 Geography
Central Africa
Uganda · DRC
Transmission
Direct contact with bodily fluids. Less well studied than Zaire and Sudan species due to fewer outbreaks.
Clinical course
Similar to other Ebola species but with lower fatality rate. Fever, haemorrhage, multi-organ failure in severe cases.
Notable outbreaks
2007
Bundibugyo, Uganda
149 cases, 37 deaths (25% CFR). Initially misidentified; genome sequencing confirmed a new species.
2012
Isiro, DRC
36 cases, 13 deaths. Linked to bushmeat consumption.
Taï Forest ebolavirus (TAFV)
Taï Forest ebolavirus
Discovered 1994 (Taï National Park, Côte d'Ivoire)
CFR
0% (1 case)
🦇 Natural host
Unknown (chimpanzees as intermediate host)
🌍 Geography
West Africa
Côte d'Ivoire
Transmission
Single known human case acquired through necropsy of a dead chimpanzee. The species is known to cause fatal infections in chimpanzees.
Clinical course
The single human case presented with dengue-like illness — fever, headache, myalgia, diarrhoea. Patient survived after evacuation to Switzerland.
Notable outbreaks
1994
Taï National Park, Côte d'Ivoire
A Swiss primatologist was infected while performing a necropsy on a dead chimpanzee. Only known human case — survived.
Philippines, China (animal cases); USA (imported primates)
Philippines · China · United States
Transmission
Identified in cynomolgus monkeys imported from the Philippines to a research facility in Virginia. Causes severe disease in non-human primates but appears asymptomatic in humans. Workers developed antibodies without illness.
Clinical course
No clinical disease documented in humans. Seroconversion (antibody development) has been found in animal handlers and pig farmers with no symptoms.
Notable outbreaks
1989
Reston, Virginia, USA
Discovered in imported Philippine monkeys at a quarantine facility. Several workers seroconverted but none became ill. Inspired the book 'The Hot Zone'.
2008
Philippines
Found in domestic pigs — first time Ebola was detected in swine. Six pig farm workers had antibodies but no illness.
Want to see live cases? The main tracker shows all confirmed and suspected outbreaks worldwide. For the full history see /history.
