Ebola virus. Colored Transmission Electron Micrograph (TEM) of the Ebola virus, the cause of Ebola fever. Elongated in shape, it is a member of the filovirus group of viruses. A number of major outbreaks of Ebola infections have occurred in equatorial Africa since 1976, causing severe and frequently fatal viral hemorrhagic fever. The virus is morphologically similar to, but antigenically distinct from, the Marburg virus, the cause of green monkey disease. Symptoms produced by these two viruses are very similar with high fever, diarrhea, hemorrhage and a skin rash. Both viruses cause an illness in monkeys resembling that in humans. Magnification: unknown.