Marburg virus. Colored Transmission Electron Micrograph (TEM) of numerous Marburg viruses, the cause of Marburg virus disease. The disease is also called Green Monkey or Verlet Monkey disease. These elongated viruses are a member of the filovirus group. They are similar in appearance to, but antigenically distinct from, the Ebola virus. The first outbreak occurred in Marburg, Frankfurt, in August 1967, in which seven people died. Since then cases have occurred in Africa. Symptoms of viral hemorrhagic fever include high fever, diarrhea, hemorrhage and a skin rash. Both Marburg and Ebola viruses cause an illness in monkeys that resembles that in humans. Magnification: unknown.