Human parainfluenza virus type 4 infections: a report of 20 cases from 1998 to 2002.
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.
Billaud
Geneviève
G
Laboratoire de Virologie, Domaine Rockefeller, Hospices Civils de Lyon, 69373 Lyon Cedex 08, Lyon, France. genevieve.billaud@chu-lyon.fr
Morfin
Florence
F
Vabret
Astrid
A
Boucher
Anne
A
Gillet
Yves
Y
Crassard
Nicolas
N
Galambrun
Claire
C
Ferraris
Olivier
O
Legrand
Loïc
L
Aymard
Michèle
M
Lina
Bruno
B
Freymuth
François
F
Thouvenot
Danielle
D
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
D017931:DNA Primers