Detection of pathogenic bacteria during rhinovirus infection is associated with increased respiratory symptoms and asthma exacerbations.
BACKGROUND
Detection of either viral or bacterial pathogens is associated with wheezing in children; however, the influence of both bacteria and viruses on illness symptoms has not been described.


OBJECTIVE
We evaluated bacterial detection during the peak rhinovirus season in children with and without asthma to determine whether an association exists between bacterial infection and the severity of rhinovirus-induced illnesses.


METHODS
Three hundred eight children (166 with asthma and 142 without asthma) aged 4 to 12 years provided 5 consecutive weekly nasal samples during September and scored cold and asthma symptoms daily. Viral diagnostics and quantitative PCR for Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis were performed on all nasal samples.


RESULTS
Detection rates were 53%, 17%, and 11% for H influenzae, S pneumoniae, and M catarrhalis, respectively, with detection of rhinovirus increasing the risk of detecting bacteria within the same sample (odds ratio [OR], 2.0; 95% CI, 1.4-2.7; P < .0001) or the following week (OR, 1.6; 95% CI, 1.1-2.4; P = .02). In the absence of rhinovirus, S pneumoniae was associated with increased cold symptoms (mean, 2.7 [95% CI, 2.0-3.5] vs 1.8 [95% CI, 1.5-2.2]; P = .006) and moderate asthma exacerbations (18% [95% CI, 12% to 27%] vs 9.2% [95% CI, 6.7% to 12%]; P = .006). In the presence of rhinovirus, S pneumoniae was associated with increased moderate asthma exacerbations (22% [95% CI, 16% to 29%] vs 15% [95% CI, 11% to 20%]; P = .01). Furthermore, M catarrhalis detected alongside rhinovirus increased the likelihood of experiencing cold symptoms, asthma symptoms, or both compared with isolated detection of rhinovirus (OR, 2.0 [95% CI, 1.0-4.1]; P = .04). Regardless of rhinovirus status, H influenzae was not associated with respiratory symptoms.


CONCLUSIONS
Rhinovirus infection enhances detection of specific bacterial pathogens in children with and without asthma. Furthermore, these findings suggest that M catarrhalis and S pneumoniae contribute to the severity of respiratory tract illnesses, including asthma exacerbations.
Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Ind. Electronic address: kloepfer@iu.edu.
Kirsten M
KM
Kloepfer
Department of Pediatrics, University of Wisconsin-Madison, Madison, Wis.
Wai Ming
WM
Lee
Department of Pediatrics, University of Wisconsin-Madison, Madison, Wis.
Tressa E
TE
Pappas
Department of Pediatrics, University of Wisconsin-Madison, Madison, Wis.
Theresa J
TJ
Kang
Department of Medicine, University of Wisconsin-Madison, Madison, Wis.
Rose F
RF
Vrtis
Department of Biostatistics and Medical Informatics, University of Wisconsin-Madison, Madison, Wis.
Michael D
MD
Evans
Department of Biostatistics and Medical Informatics, University of Wisconsin-Madison, Madison, Wis.
Ronald E
RE
Gangnon
Department of Pediatrics, University of Wisconsin-Madison, Madison, Wis.
Yury A
YA
Bochkov
Department of Pediatrics, University of Wisconsin-Madison, Madison, Wis; Department of Medicine, University of Wisconsin-Madison, Madison, Wis.
Daniel J
DJ
Jackson
Department of Pediatrics, University of Wisconsin-Madison, Madison, Wis; Department of Medicine, University of Wisconsin-Madison, Madison, Wis.
Robert F
RF
Lemanske
Department of Pediatrics, University of Wisconsin-Madison, Madison, Wis; Department of Medicine, University of Wisconsin-Madison, Madison, Wis.
James E
JE
Gern
D001249:Asthma / Q000150:complications / Q000235:genetics / Q000382:microbiology / Q000821:virology; D001419:Bacteria / Q000235:genetics / Q000302:isolation & purification; D001424:Bacterial Infections / Q000235:genetics / Q000382:microbiology*; D002648:Child; D002675:Child, Preschool; D004269:DNA, Bacterial / Q000235:genetics*; D005260:Female; D006801:Humans; D008297:Male; D010850:Picornaviridae Infections / Q000235:genetics / Q000382:microbiology; D016133:Polymerase Chain Reaction; D012229:Rhinovirus
D004269:DNA, Bacterial
Rhinovirus; asthma; bacteria