The disease caused by the Ebola virus (formerly known as Ebola fever) is a febrile hemorrhagic pathology caused by a virus of the Ebolavirus genus, which affects humans and non-human primates (monkeys, gorillas and chimpanzees). Other animals are carriers of the virus but do not develop the disease.
The natural carrier of the Ebola virus is as yet unknown. However, based on the evidence available and the nature of other similar viruses, researchers believe that this virus is transmitted by animals and that the most likely carrier is the fruit bat. The Ebolavirus genus is comprised of five different species, identified in different outbreaks: Bundibugyo (BDBV), Zaire (EBOV), Sudan (SUDV), Reston (RESTV) and Tai Forest (TAFV). It was described for the first time in 1976, in two simultaneous outbreaks in the Democratic Republic of the Congo, close to the River Ebola, and in Sudan. Four of the five known sub-types are found in a host animal native to Africa.
The Ebola virus causes a serious disease with a high rate of fatality. However, it is difficult to contract since it can only be transmitted through very close contact with a person infected and with symptoms or through contaminated biological material. It is not an airborne virus.
The current outbreak (originating from the Zaire Ebola strain), despite being the most prolonged and with the most people affected, is one of the outbreaks that, to date, has had the lowest mortality rate (below 50%).
Timeline of main outbreaks of the disease caused by Ebola virus
|Year||Country||Species of the virus||No. Cases||Deaths||Mortality rate|
|2014||Sierra Leone*||Zaire Ebola||3,706||1,259||34%|
|2012||Democratic Republic of the Congo||Bundibugyo Ebola||57||29||51%|
|2008||Democratic Republic of the Congo||Zaire Ebola||32||14||44%|
|2007||Democratic Republic of the Congo||Zaire Ebola||264||187||71%|
|1995||Democratic Republic of the Congo||Zaire Ebola||315||254||81%|
|1994||Ivory Coast||Cote d’Ivoire Ebola||1||0||0%|
|1977||Democratic Republic of the Congo||Zaire Ebola||1||1||100%|
|1976||Democratic Republic of the Congo||Zaire Ebola||318||280||88%|
(*) The figures corresponding to each country are periodically updated. Source: World Health Organization