MICROBIOLOGY

• Family: Filoviridae (as are the Ebola virus species); Genus: Marburgvirus; Species: Marburg marburgvirus
  • Distinct strains:
    • Marburg virus (MARV): the original virus found in 1967
    • Ravn virus (RAVV): genetically distinct with 20% genetic divergence from MARV
• Virus structure: Filamentous, enveloped, non-segmented, single-stranded, negative-sense RNA genome encoding: Glycoprotein (GP), the solitary protein on the cell surface and the primary target for medical countermeasure (MCM) development (vaccines, biologics, antivirals, and diagnostic tests); nucleoprotein (NP), Viral proteins (VP24, VP30, VP35, VP40), and an RNA-dependent RNA polymerase.
• Replication: 1) The virus enters host cells via macro-pinocytosis (cell engulfs extracellular fluid and particles); 2) viral RNA is transcribed and replicated in the cytoplasm; 3) new virus particles assembled and bud from the host cell membrane, which provides the envelope for the virus
• Natural Reservoir: The primary reservoir is presumed to be Rousettus aeyptiacus, the Egyptian fruit bat. Viruses can be transmitted to humans through direct contact with these bats or their excretions.