Causes of Ebola
Ebola is caused by an infection with the Ebola virus. There are four identified subtypes of Ebola virus: Ebola-Zaire, Ebola-Sudan, Ebola-Ivory Coast, and Ebola-Reston. All but the Ebola-Reston subtype are known to have caused disease in humans. There are no other known causes of Ebola. Human-to-human transmission of Ebola occurs through direct contact with patients who have Ebola, or their body fluids (such as blood or secretions).
There is only one cause of Ebola. The cause of Ebola is an infection with the Ebola virus. There are no other causes of Ebola.
The Ebola virus got its name from a river in the Democratic Republic of the Congo (formerly Zaire), in Africa, where it was first recognized. Ebola virus is one of two members of a family of RNA viruses known as Filoviridae. There are four identified subtypes of Ebola virus. Three of the four have caused disease in humans:
- Ebola-Ivory Coast.
The fourth Ebola virus subtype, Ebola-Reston, has caused disease in nonhuman primates, but not in humans.
The exact origin, locations, and natural habitat (known as the natural reservoir) of Ebola virus remain unknown; however, on the basis of available evidence, and the nature of similar viruses, researchers believe that the Ebola virus lives in an animal host that is native to the African continent. They continue to search for the exact animal.
Just as scientists are unsure of the animal host for the Ebola virus, they are also unsure how an outbreak of Ebola virus occurs. Researchers have hypothesized that the first patient becomes infected with Ebola virus through contact with an infected animal.