Ebola Ebola hemorrahagic fever is a 20 year old virus that, with a mortality rate of 50% to 90%, is one of the world's deadliest viruses. Its causative organism is called Ebola virus. Ebola virus is a member of filoviridae, a family of negative-strained RNA viruses. The filoviridae family consists of five known members, Marburg, Ebola Zaire, Ebola Sudan, Ebola Reston, and Ebola Tai. Ebola virus is spread in a number of ways. An outbreak starts when an infected animal or insect, called a vector, transmits the virus to a human. Scientists know that monkeys are both a vector and victim of Ebola, but other vectors are unknown. The natu