Ebola is a rare and deadly disease caused by infection with one of the Ebola virus strains. There are four ebolaviruses within the genus Ebolavirus that cause Ebola disease in humans. The ebolaviruses were first discovered in 1976 when two consecutive outbreaks of fatal hemorrhagic fever occurred in different parts of Central Africa. The first outbreak occurred in the Democratic Republic of Congo (formerly Zaire) in a village near the Ebola River, which gave the virus its name. The second outbreak occurred in what is now South Sudan, approximately 500 miles (850 km) away. Scientists believe that the virus is animal-borne and most likely comes from bats, which transmit the Ebola virus to other animals and humans. Once infected, a person can spread the virus to other people through contact with the body fluids of the infected person, such as saliva, urine, feces, or semen. The virus can also be spread by touching things that have been contaminated with these fluids.