Evidence of a causal role of winter virus infection during infancy in early childhood asthma.
BACKGROUND
Bronchiolitis during infancy is associated with an increased risk of childhood asthma. Whether winter viral infections cause asthma or are a manifestation of a predisposition to asthma development is unknown.


OBJECTIVE
To study the relationship of winter virus infection during infancy and the development of childhood asthma.


METHODS
We studied over 95,000 infants born between 1995 and 2000 and followed through 2005 who were enrolled in the Tennessee Medicaid program from birth through early childhood to determine whether infant birth in relationship to the winter virus peak alters the risk of developing early childhood asthma.


RESULTS
Among 95,310 children studied during five winter virus seasons from birth through early childhood, the risk of developing asthma tracked with the timing of infant birth in relationship to the winter virus peak. Infant birth approximately 4 months before the winter virus peak carried the highest risk, with a 29% increase in odds of developing asthma compared with birth 12 months before the peak (adjusted odds ratio, 1.29; 95% confidence interval, 1.19-1.40). Infant age at the winter virus peak was comparable to or greater than other known risk factors for asthma.


CONCLUSIONS
Timing of birth in relationship to winter virus season confers a differential and definable risk of developing early childhood asthma, establishing winter virus seasonality as a causal factor in asthma development. Delay of exposure or prevention of winter viral infection during early infancy could prevent asthma.
Wu
Pingsheng
P
Division of Allergy, Pulmonary and Critical Care Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-8300, USA.
Dupont
William D
WD
Griffin
Marie R
MR
Carroll
Kecia N
KN
Mitchel
Edward F
EF
Gebretsadik
Tebeb
T
Hartert
Tina V
TV
D001249:Asthma / Q000209:etiology*; D001990:Bronchiolitis, Viral / Q000150:complications*; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D016017:Odds Ratio; D010850:Picornaviridae Infections / Q000150:complications*; D018357:Respiratory Syncytial Virus Infections / Q000150:complications; D012229:Rhinovirus; D012307:Risk Factors; D012621:Seasons
Arch Dis Child. 1997 Apr;76(4):315-9
9166022
J Pediatr. 2001 Mar;138(3):311-7
11241035
Bull World Health Organ. 2004 Dec;82(12):914-22
15654405
Am J Dis Child. 1986 Jun;140(6):543-6
3706232
Am J Respir Crit Care Med. 1999 Mar;159(3):785-90
10051251
Am J Respir Crit Care Med. 2000 May;161(5):1501-7
10806145
J Am Geriatr Soc. 2000 Jun;48(6):651-7
10855601
Pediatr Pulmonol. 2006 Oct;41(10):962-71
16871628
Am J Med. 2005 Mar;118(3):285-91
15745727
J Infect Dis. 2001 Jan 1;183(1):16-22
11076709
J Allergy Clin Immunol. 2004 Dec;114(6):1275-7
15577822
Pediatr Allergy Immunol. 2005 Aug;16(5):386-92
16101930
BMJ. 1995 May 13;310(6989):1225-9
7767192
J Pediatr. 2000 Dec;137(6):865-70
11113845
Pediatr Infect Dis J. 2003 Feb;22(2 Suppl):S76-82
12671456
Pediatrics. 2007 Jun;119(6):1104-12
17545377
J Exp Med. 2002 Nov 18;196(10):1381-6
12438429
Clin Exp Allergy. 1989 Nov;19(6):643-8
2598104
J Pediatr. 1986 Nov;109(5):776-80
3772657
Am J Obstet Gynecol. 2003 Dec;189(6):1705-12
14710102
Am J Respir Crit Care Med. 2001 Mar;163(3 Pt 2):S2-6
11254543
J Allergy Clin Immunol. 2003 Jan;111(1):66-71
12532098
N Engl J Med. 1981 Oct 8;305(15):841-6
6168908
Vaccine. 1998 Apr;16(6):564-8
9569466
Nat Med. 2008 Jun;14(6):633-40
18488036
J Pediatr. 2007 Jul;151(1):34-42, 42.e1
17586188
Am J Respir Crit Care Med. 2005 Jan 15;171(2):137-41
15516534
J Virol. 2005 Feb;79(4):2050-7
15681407
Pediatr Infect Dis J. 2000 Jul;19(7):635-41
10917222
Am J Epidemiol. 1991 Jun 1;133(11):1135-51
2035517
Clin Exp Allergy. 1992 Nov;22(11):1026-31
1468028
J Allergy Clin Immunol. 2005 Apr;115(4):668-74; quiz 675
15805982
Am J Respir Crit Care Med. 2007 Jan 15;175(2):108-19
17053206
J Clin Virol. 2005 Nov;34(3):161-9
16126001
Pediatrics. 1995 Apr;95(4):500-5
7700748
Acta Paediatr Jpn. 1994 Aug;36(4):371-4
7941998
Pediatrics. 2008 Jul;122(1):58-64
18595987