Respiratory viral infection in lower airways of asymptomatic children.
OBJECTIVE
The aim of this study was to determine if asthmatic children have viruses more commonly detected in lower airways during asymptomatic periods than normal children.


METHODS
Fifty-five asymptomatic children attending elective surgical procedures (14 with stable asthma, 41 normal controls) underwent non-bronchoscopic bronchoalveolar lavage. Differential cell count and PCR for 13 common viruses were performed.


RESULTS
Nineteen (35%) children were positive for at least one virus, with adenovirus being most common. No differences in the proportion of viruses detected were seen between asthmatic and normal 'control' children. Viruses other than adenovirus were associated with higher neutrophil counts, suggesting that they caused an inflammatory response in both asthmatics and controls (median BAL neutrophil count, 6.9% for virus detected vs. 1.5% for virus not detected, p = 0.03).


CONCLUSIONS
Over one-third of asymptomatic children have a detectable virus (most commonly adenovirus) in the lower airway; however, this was not more common in asthmatics. Viruses other than adenovirus were associated with elevated neutrophils suggesting that viral infection can be present during relatively asymptomatic periods in asthmatic children.
Thavagnanam
S
S
Respiratory Research Group, Centre for Infection and Immunity, Queen's University of Belfast, Belfast, UK.
Christie
S N
SN
Doherty
G M
GM
Coyle
P V
PV
Shields
M D
MD
Heaney
L G
LG
D000256:Adenoviridae / Q000302:isolation & purification; D000293:Adolescent; D001249:Asthma / Q000821:virology*; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology / Q000821:virology; D016022:Case-Control Studies; D002452:Cell Count; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D016133:Polymerase Chain Reaction; D012141:Respiratory Tract Infections / Q000821:virology*; D014780:Viruses / Q000235:genetics / Q000302:isolation & purification*