Ebola and Marburg viruses, members of the family Filoviridae, cause a severe and often fatal hemorrhagic fever. In April and May of 1995, an outbreak of Ebola virus hemorrhagic fever occurred in Kikwit, Zaire, and of 318 known cases, approximately 77% died. The ultrastructural pathology associated with filoviruses has been well described in non-human primates. On the other hand, ultrastructural studies on human tissues have been relatively few, and limited for the most part to examination of the liver. We report here our ultrastructural observations of autopsy tissues from the liver, as well as lung, skin, and testes of infected patients by using both thin section electron microscopy (EM) and immunogold labeling electron microscopy (IEM).

At the hospital in Kikwit, strict barrier precautions were employed to collect tissue specimens. These were diced into small blocks, placed into fixative, and later transferred to phosphate buffer. Specimens were hand-transported to the CDC in Atlanta, gamma-irradiated, and embedded in either Epon-substitute/Araldite for standard EM, or in LR White for IEM.