Rhinovirus Species in Acute Respiratory Tract Infections and the Risk of Asthma in Children.

BACKGROUND

Rhinoviruses (RV) are the most common pathogens causing respiratory tract infections, and early childhood RV wheezing illnesses are a known risk factor for childhood asthma. The role of acute upper respiratory tract infections (URTI) caused by different RV species in asthma development is not well known.

METHODS

We conducted a nested case-control study in a birth cohort of 923 children followed prospectively from birth to age 7 years. Nasal swab samples collected during acute respiratory tract infections (ARI) at age 0-24 months were analyzed by PCR, and RV-positive samples were genotyped. Each case with asthma at age 7 years was matched with three cohort children without asthma. Conditional logistic regression was used to test associations between RV wheezing illnesses or RV URTIs and asthma risk.

RESULTS

We identified 56 cases and 168 matched controls. In total, 807 RV-positive samples were successfully classified. Wheezing illnesses caused by RV-A and RV-C at age 0-24 months were associated with an increased risk of asthma at age 7 years (for RV-A, odds ratio [OR]: 1.60, 95% confidence interval [CI]: 1.05-2.43, p = 0.03; for RV-C, OR: 1.66, 95% CI: 1.11-2.49, p = 0.01). RV-A, RV-B, or RV-C positive URTIs were not associated with asthma risk.

CONCLUSION

Both RV-A and RV-C -induced early wheezing illnesses were associated with an increased risk of childhood asthma. Acute URTIs caused by RV-A, RV-B, or RV-C were not associated with asthma risk.