The Discovery of Ebola Virus, 1976: The story of the discovery of Ebola virus starts with the history of the development of biocontainment facilities at the U.S. Centers for Disease Control in Atlanta. After working on Marburg virus in 1967, in the midst of the lethal outbreaks of hemorrhagic fever caused by this virus in Europe, it became clear that CDC needed permanent biocontainment facilities. So plans were drawn up for a “tin building,” a Maximum Security Laboratory, which was completed in 1968. This lab became a part of my Viral Pathology Branch, in the Division of Viral Diseases. In 1968 we faced the emergence of Lassa fever in West Africa. Work on Lassa virus at Yale University was terminated after one person died and another nearly died. We worked to characterize Lassa virus and Tom Monath moved to West Africa and discovered the reservoir host of the virus, a rodent, and showed how prevalent the human infection was. The work expanded from an emphasis on diagnostics to work on the pathogenesis of the viral hemorrhagic fevers. In my lab, Washington Winn and David Walker developed animal models of several highly pathogenic human viruses, including Lassa virus. In 1976, Karl Johnson and Patricia Webb came to CDC to take over the old Maximum Security Laboratory and to open a new facility, another “tin building,” which was to be the first high containment lab to make use of “space suits” (positive pressure personnel protection suits, invented by Karl Johnson).
In the meantime, in October 1976, Ebola virus appeared while we were still using the old Maximum Security Laboratory, but at least we had Karl and Patricia Webb with all their experience and wisdom, and we had the great technical skills of Bill Gary, Jim Lange and Herta Wulff. There were two nearly simultaneous epidemics of hemorrhagic fever, one in Zaire (now Democratic Republic of Congo), the other in Sudan. The outbreak in the Sudan was as dramatic as that in Zaire, but it is the latter that stands out in my memory as if it were yesterday. We heard that the Zaire epidemic was centered at a missionary hospital in the village of Yambuku and seemingly all the staff of the hospital had died. The whole region was being quarantined by the army and there were rumors of devastation over a large area. CDC sent a team into the area and found that things were bad enough, but not quite as bad as the rumors. Between the Zaire and Sudan epidemics there were 550 cases of severe hemorrhagic fever and 430 deaths. The CDC team was delayed in getting out with specimens by a regional quarantine. Nevertheless, on October 11, specimens were received in Atlanta and Patricia Webb used all of her acumen to save the day. When she opened the package she found that the tubes containing blood and tissues from patients were broken. Instead of taking the whole box to the autoclave, she carefully (wearing a single pair of surgical gloves, surgical gown and mask) squeezed out a drop of fluid from the surrounding cotton packing material. She inoculated this into Vero cell cultures, along with a double dose of antibiotics. Two days later the cells showed traces of cytopathology, so she gave me a few drops of the supernatant fluid from the cultures. Wearing the same sort of garb (surgical gown, mask, gloves) and working in a “hood” (CDC’s old Biological Safety Cabinet, BSC, quite primitive by today’s standards), I prepared specimens for examination by negative contrast electron microscopy. I put the electron microscopy grids in a sealed box, told the staff not to go near the hood room where I had worked and trundled off to the electron microscope lab. What I saw “raised the hairs on the back of my neck!” I saw telltale long filaments and was sure it was Marburg virus. I was the only one still at CDC who had worked on Marburg virus when it appeared in 1967. I had also done a project on Marburg virus in 1977 with David Simpson and his colleagues from Porton Down, the British high containment lab, so I thought I really knew all about this unique virus. I shut down the electron microscope and went back to the room in which I had prepared the specimen. I “cloroxed the hell” out of the hood where I had done the preparation, carried my discard pan with gown and gloves, etc., to the autoclave and ran it myself. Then I went back to the electron microscope and called Karl and Patricia to come and take a look. I shot a cassette of pictures and with the wet negatives (not good for the enlarger) I made prints, which were available within minutes. Along with Karl I carried these dripping prints to the office of the director of the CDC. It was a dramatic moment: the director, David Sencer, CDC’s best director ever, was sitting at the far end of the very long table in the conference room along with a guest. He said he’d be with us in a moment. As we gathered at the other end of the table, others started coming in and it got a bit noisy as plans were made about what to do next. When the noise got out of hand, David Sencer and his guest joined us. The dripping prints seemed to say it all. Marburg virus was the only virus that looked like the virus particles in the pictures. As we sat at the table discussing the ramifications of our findings, Patricia came in and whispered in Karl’s ear... it was not Marburg virus, it was something new...
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