Ebola is a virus that causes a hemorrhagic fever. Thought to have been long present in animals, the Ebola virus was first identified in humans in Zaire in 1976. Following an incubation period of between two and 21 days, the disease begins with a severe headache, muscle pains, and high fever. A rash develops and there is severe diarrhea and vomiting, with chest pain and abdominal cramps; hemorrhaging occurs from internal organs. Ebola is acquired through contact with contaminated body fluids. There is no specific treatment and the death rate can be as high as 90%.