Marburg hemorrhagic fever: report of a case studied by immunohistochemistry and electron microscopy.

The histologic and ultrastructural findings in a fatal human case of Marburg hemorrhagic fever are reported. Marburg virus was isolated from fluids and tissues and was identified in tissues by immunohistochemistry and electron and immunoelectron microscopy. The distribution of viral antigen by light level immunohistochemistry correlated with histologic lesions and also with the ultrastructural localization of virions. The tissue distribution and lesions of Marburg virus in this patient were consistent with the disease described in other human Marburg infections. Immunocytochemistry and ultrastructural examination revealed several previously unreported findings. A striking predilection for viral infection of the pancreatic islet cells was noted. In other tissues, macrophages were the primary cellular target for Marburg virus infection, with hepatocytes, adrenal cortical and medullary cells, and fibroblast-like cells also serving as important sites of viral replication. This case demonstrates the value of transmission electron microscopy as a tool for assisting in the definitive diagnosis of Marburg or Ebola hemorrhagic fever, as well as providing insight into the pathogenesis of these agents.