title: Dual infection of infants by human metapneumovirus and human respiratory syncytial virus is strongly associated with severe bronchiolitis.
abstract: The association between severe bronchiolitis and dual infection by human metapneumovirus (hMPV) and human respiratory syncytial virus (hRSV) was investigated in <2-year-old infants with bronchiolitis who were admitted to the hospital during the 2001-2002 winter season. hMPV in nasopharyngeal aspirate and/or cells and fluid collected by nonbronchoscopic bronchoalveolar lavage was detected by reverse transcriptase-polymerase chain reaction (RT-PCR). hRSV was detected in nasopharyngeal aspirate and/or cells and fluid collected by nonbronchoscopic bronchoalveolar lavage by enzyme immunoassay, tissue culture, and RT-PCR. Dual infection with hMPV and hRSV confers a 10-fold increase in relative risk (RR) of admission to a pediatric intensive-care unit for mechanical ventilation (RR, 10.99 [95% confidence interval, 5.0-24.12]; P<.001, by Fisher exact test). Dual infection by hMPV and hRSV is associated with severe bronchiolitis.
authors.affiliation: Department of Child Health, University of Liverpool, Liverpool, United Kingdom. m.g.semple@liv.ac.uk
authors.forename: Malcolm G
authors.initials: MG
authors.lastname: Semple
authors.forename: Angela
authors.initials: A
authors.lastname: Cowell
authors.forename: Winfred
authors.initials: W
authors.lastname: Dove
authors.forename: Julie
authors.initials: J
authors.lastname: Greensill
authors.forename: Paul S
authors.initials: PS
authors.lastname: McNamara
authors.forename: Claire
authors.initials: C
authors.lastname: Halfhide
authors.forename: Paul
authors.initials: P
authors.lastname: Shears
authors.forename: Rosalind L
authors.initials: RL
authors.lastname: Smyth
authors.forename: C Anthony
authors.initials: CA
authors.lastname: Hart
mesh_terms: D001990:Bronchiolitis, Viral / Q000503:physiopathology / Q000821:virology*; D001992:Bronchoalveolar Lavage Fluid / Q000821:virology; D002675:Child, Preschool; D006801:Humans; D007124:Immunoenzyme Techniques; D007223:Infant; D007231:Infant, Newborn; D029121:Metapneumovirus / Q000235:genetics / Q000302:isolation & purification*; D009305:Nasopharynx / Q000821:virology; D018184:Paramyxoviridae Infections / Q000150:complications* / Q000821:virology; D018357:Respiratory Syncytial Virus Infections / Q000150:complications* / Q000821:virology; D018113:Respiratory Syncytial Virus, Human / Q000235:genetics / Q000302:isolation & purification*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012720:Severity of Illness Index