Ebola virus: A virus which causes a deadly form of hemorrhagic fever, a rise in temperature together with bleeding problems (hemorrhaging). Epidemics have occurred mainly in Sudan and Zaire. The initial symptoms are fever and headache followed by vomiting and diarrhea, muscle pain, rash, and bleeding problems with bloody nose (epistaxis), spitting up blood from the lungs (hemoptysis) and stomach (hematemesis), and bloody eyes (conjunctival hemorrhages). Transmitted by contact with blood, feces or body fluids from an infected person. The incubation period ranges from 2 to 21 days. There is no specific treatment for the disease. Death can occur within 10 days.