MYVR-PARAINFLUENZA

• Family = Paramyxoviridae

  Genus and types

  • PIV 1 and 3 = Paramyxovirus
  • PIV 2 and 4 = Rubulavirus

  Incubation = 1-7 days

  Transmission

  • PIV 1 = most often in the fall every other year
  • PIV 2 = every 2 years alternating with PIV 1; lower incidence than 1 and 3
  • PIV 3 = almost every year (spring and summer; year-round)
  • PIV 4 = seldom
  • PIV 1, 2, 4 = common during cold weather
• CLINICAL PRESENTATIONS

  • 2nd most common cause of lower respiratory tract infection in young children
  • Rhinitis, pharyngitis, laryngotracheitis, bronchiolitis, and pneumonia
  • PIV 1 = primary cause of croup (laryngotracheobronchitis) in children
  • PIV 1 and 2 = cause the most serious illness in children between 2-4 years old
  • PIV 3 = cause bronchiolitis and pneumonia in infants; associated with otitis media
  • PIV 4 = mild respiratory tract infection
• MORPHOLOGY

  • enveloped, ssRNA
  • nonsegmented
  • spherical; 150-300 nm
  • glycoprotein spikes = HN and F

  Surface Antigens

  • Hemagglutinin-Neuraminidase (HN) = Adhesion
  • Fusion (F) Antigen = fusion of the virus to the cell
• LABORATORY DIAGNOSIS

  • Specimen = nasopharyngeal swabs, washings, aspirates --> taken as early as possible; keep cold
  • Microscopy = direct fluorescence antibody staining of respiratory secretions
  • Serology = EIA, hemadsorption technique
  • Cell culture = PMK/LLC-MMK2 (rhesus monkey kidney epithelial cell)
  • Molecular = nucleic acid-based PCR

  Treatmen

  • aerosolized ribavirin
  • no vaccine available