title: Human parainfluenza virus type 4 infections: a report of 20 cases from 1998 to 2002.
abstract: BACKGROUND
  Human Parainfluenza Viruses (HPIV) type 4 are responsible for respiratory infections. Unlike HPIV types 1-3, they are associated with mild infections and appear to be infrequent. Thus, they often go undetected.
  
  
  METHODS
  From 1998 to 2002, in 20 respiratory samples of hospitalised patient, we isolated viruses presenting a large syncytial cytopathic effect when inoculated on LLC-MK2 cells. Most of the patients (16/20) were young infants and all of them presented with respiratory infections.
  
  
  RESULTS
  We detected 18 cases during autumn and winter, 1 case during spring and 1 during summer. We could not identify these viruses using the panel of routine assays. Samples were then analysed by specific HPIV 4 RT-PCR and IF assays. All the samples were scored positive with both methods.
  
  
  CONCLUSIONS
  We conclude that HPIV 4 infections are probably underestimated. Their role in viral respiratory infections should be carefully investigated using techniques adapted to their detection and culture.
authors.affiliation: Laboratoire de Virologie, Domaine Rockefeller, Hospices Civils de Lyon, 69373 Lyon Cedex 08, Lyon, France. genevieve.billaud@chu-lyon.fr
authors.forename: Geneviève
authors.initials: G
authors.lastname: Billaud
authors.forename: Florence
authors.initials: F
authors.lastname: Morfin
authors.forename: Astrid
authors.initials: A
authors.lastname: Vabret
authors.forename: Anne
authors.initials: A
authors.lastname: Boucher
authors.forename: Yves
authors.initials: Y
authors.lastname: Gillet
authors.forename: Nicolas
authors.initials: N
authors.lastname: Crassard
authors.forename: Claire
authors.initials: C
authors.lastname: Galambrun
authors.forename: Olivier
authors.initials: O
authors.lastname: Ferraris
authors.forename: Loïc
authors.initials: L
authors.lastname: Legrand
authors.forename: Michèle
authors.initials: M
authors.lastname: Aymard
authors.forename: Bruno
authors.initials: B
authors.lastname: Lina
authors.forename: François
authors.initials: F
authors.lastname: Freymuth
authors.forename: Danielle
authors.initials: D
authors.lastname: Thouvenot
mesh_terms: D000328:Adult; D001483:Base Sequence; D002460:Cell Line; D002648:Child; D017931:DNA Primers; D006801:Humans; D009305:Nasopharynx / Q000821:virology; D029482:Parainfluenza Virus 4, Human / Q000235:genetics / Q000302:isolation & purification; D010614:Pharynx / Q000821:virology; D012137:Respiratory System / Q000821:virology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019351:Rubulavirus Infections / Q000453:epidemiology*; D013048:Specimen Handling / Q000379:methods
chemical_list: D017931:DNA Primers