title: Weekly monitoring of children with asthma for infections and illness during common cold seasons.
abstract: BACKGROUND
  Exacerbations of childhood asthma and rhinovirus infections both peak during the spring and fall, suggesting that viral infections are major contributors to seasonal asthma morbidity.
  
  
  OBJECTIVE
  We sought to evaluate rhinovirus infections during peak seasons in children with asthma and to analyze relationships between viral infection and illness severity.
  
  
  METHODS
  Fifty-eight children aged 6 to 8 years with asthma provided 5 consecutive weekly nasal lavage samples during September and April; symptoms, medication use, and peak flow were recorded. Rhinoviruses were identified by using multiplex PCR and partial sequencing of viral genomes.
  
  
  RESULTS
  Viruses were detected in 36% to 50% of the specimens, and 72% to 99% of the viruses were rhinoviruses. There were 52 different strains (including 16 human rhinovirus C) among the 169 rhinovirus isolates; no strains were found in more than 2 collection periods, and all but 2 children had a respiratory tract infection. Virus-positive weeks were associated with greater cold and asthma symptom severity (P < .0001 and P = .0002, respectively). Furthermore, virus-positive illnesses had increased duration and severity of cold and asthma symptoms and more frequent loss of asthma control (47% vs 22%, P = .008). Although allergen-sensitized versus nonsensitized children had the same number of viral infections, the former had 47% more symptomatic viral illnesses (1.19 vs 0.81 per month, P = .03).
  
  
  CONCLUSIONS
  Rhinovirus infections are nearly universal in children with asthma during common cold seasons, likely because of a plethora of new strains appearing each season. Illnesses associated with viruses have greater duration and severity. Finally, atopic asthmatic children experienced more frequent and severe virus-induced illnesses.
authors.affiliation: Department of Pediatrics, University of Wisconsin, Madison, WI 53792-4108, USA.
authors.forename: Jaime P
authors.initials: JP
authors.lastname: Olenec
authors.forename: Woo Kyung
authors.initials: WK
authors.lastname: Kim
authors.forename: Wai-Ming
authors.initials: WM
authors.lastname: Lee
authors.forename: Fue
authors.initials: F
authors.lastname: Vang
authors.forename: Tressa E
authors.initials: TE
authors.lastname: Pappas
authors.forename: Lisa E P
authors.initials: LE
authors.lastname: Salazar
authors.forename: Michael D
authors.initials: MD
authors.lastname: Evans
authors.forename: Jack
authors.initials: J
authors.lastname: Bork
authors.forename: Kathleen
authors.initials: K
authors.lastname: Roberg
authors.forename: Robert F
authors.initials: RF
authors.lastname: Lemanske
authors.forename: James E
authors.initials: JE
authors.lastname: Gern
mesh_terms: D001249:Asthma / Q000150:complications* / Q000503:physiopathology*; D002648:Child; D003139:Common Cold / Q000150:complications / Q000175:diagnosis / Q000453:epidemiology / Q000821:virology; D005260:Female; D006801:Humans; D008297:Male; D018670:Monitoring, Ambulatory; D016133:Polymerase Chain Reaction / Q000379:methods; D012141:Respiratory Tract Infections / Q000150:complications / Q000175:diagnosis / Q000453:epidemiology / Q000821:virology; D012229:Rhinovirus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D012621:Seasons; D012720:Severity of Illness Index; D013997:Time Factors; D014777:Virus Diseases / Q000150:complications / Q000175:diagnosis / Q000453:epidemiology / Q000821:virology
references.citation: PLoS One. 2007 Oct 03;2(10):e966
references.pmid: 17912345
references.citation: BMJ. 1995 May 13;310(6989):1225-9
references.pmid: 7767192
references.citation: J Allergy Clin Immunol. 2004 Aug;114(2):239-47
references.pmid: 15316497
references.citation: J Infect Dis. 1987 Jul;156(1):43-9
references.pmid: 3036962
references.citation: Am J Epidemiol. 1985 Nov;122(5):830-46
references.pmid: 2996330
references.citation: Clin Infect Dis. 2003 Jun 15;36(12):1523-32
references.pmid: 12802751
references.citation: Am J Respir Crit Care Med. 1996 Sep;154(3 Pt 1):654-60
references.pmid: 8810601
references.citation: J Allergy Clin Immunol. 2009 Jan;123(1):98-104.e1
references.pmid: 19027147
references.citation: J Infect Dis. 1977 Jul;136(1):109-11
references.pmid: 886201
references.citation: Thorax. 2006 May;61(5):376-82
references.pmid: 16384881
references.citation: Lancet. 2008 Sep 20;372(9643):1100-6
references.pmid: 18805338
references.citation: J Allergy Clin Immunol. 2005 Jan;115(1):132-8
references.pmid: 15637559
references.citation: J Clin Virol. 2007 Jun;39(2):67-75
references.pmid: 17482871
references.citation: Am J Respir Crit Care Med. 1999 Mar;159(3):785-90
references.pmid: 10051251
references.citation: J Allergy Clin Immunol. 2006 Mar;117(3):557-62
references.pmid: 16522453
references.citation: Virol J. 2007 May 03;4:40
references.pmid: 17477878
references.citation: J Clin Microbiol. 2007 Aug;45(8):2626-34
references.pmid: 17537928
references.citation: Science. 2009 Apr 3;324(5923):55-9
references.pmid: 19213880