Virus

Paramyxovirus

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Paramyxovirus, Paramyxoviridae

  • See Also
  1. Measles
  2. Mumps
  3. Metapneumovirus
  4. Respiratory Syncytial Virus
  5. Parainfluenza VIrus
  6. Virus
  • Pathophysiology
  1. Paramyxovirus characteristics
    1. Single stranded, negative sense RNA virus
    2. Helical symmetry
    3. Fusion Protein (F Protein)
      1. Induces infected host cells to fuse together in multinucleated giant cells (syncytial cells)
      2. F Protein is also found in Herpesvirus and Retrovirus
  2. Paramyxovirus organisms are similar to Orthomyxovirus (Influenza)
    1. Both replicate in the upper respiratory tract, binding to 2 Glycoprotein receptors by 1 spike Protein (HN)
      1. Hemagglutinin Activity (HA)
      2. Neuraminidase Activity (NA)
    2. However and in contrast to Orthomyxovirus
      1. Paramyxovirus HA and NA Glycoproteins are on the same surface spikes (HN)
      2. Single stranded (non-segmented RNA), unlike Orthomyxovirus RNA (segmented into 8 bound strands)
      3. Fusion Protein is not found in Orthomyxovirus
  • Types
  • Important Paramyxoviridae in Human Disease
  1. Systemic, hematogenous spread (viremia) AND Vaccine preventable diseases (MMR Vaccine)
    1. Measles
      1. Prodromal Upper Respiratory Infection (cough, Coryza, Conjunctivitis) and high fever
      2. Morbiliform rash spreading from head to trunk to extremities (inc. palms, soles), mouth Koplik Spots
      3. Complicated by Pneumonia, Myocarditis, Glomerulonephritis, Encephalitis (and death in 0.1%)
    2. Mumps
      1. Prodromal fever, malaise, myalgias, then Parotitis, Orchitis and variable maculopapular truncal rash
      2. Complicated by Male Infertility, Meningitis/Encephalitis, Deafness
  2. Bronchiolitis, Viral Pneumonia and croup in children (Upper Respiratory Infections in adults)
    1. Metapneumovirus
      1. Reclassified as of 2016 into the family Pneumoviridae
    2. Parainfluenza VIrus
    3. Respiratory Syncytial Virus
      1. Differs from other Paramyxoviridae, in that it lacks the HN Glycoproteins (HA, NA)
  • References
  1. Gladwin, Trattler and Mahan (2014) Clinical Microbiology, Medmaster, Fl, 245-9
  2. Park (2023) Paramyxovirus, StatPearls +PMID: 33620863 [PubMed]