Corne JM, Marshall C, Smith S, et al. Lancet. 2002;359:831–834
Purpose of Study.
Rhinovirus infections cause a significant proportion of asthma exacerbations. The aim of this study was to determine if people with asthma are more susceptible to rhinovirus infections than people without asthma.
The study participants were 76 cohabiting and nonsmoking couples, 1 who had asthma and at least 1 positive skin test, and 1 who was neither atopic nor asthmatic.
From September to December, each subject recorded peak expiratory flow twice daily and categorized any upper and lower respiratory tract symptoms as mild (1), moderate (2) or severe (3) once daily. Nasal aspirates were obtained every 2 weeks for rhinovirus reverse transcriptase-polymerase chain reaction (RT-PCR); each member of a couple had nasal aspirates collected within 24 hours of the other. Clinical illness was defined as a symptom score above the individual’s median score for at least 3 days, preceded and followed by symptom scores below the median score. Any illnesses beginning within 7 days before or 2 days after rhinovirus isolation was classified as being associated with that infection.
After adjusting for the use of inhaled corticosteroids and sex, the 2 groups did not differ significantly with respect to risk of rhinovirus infection (odds ratio [OR]: 1.15; 95% confidence interval [CI]: 0.71–1.87) or severity (P = .38) or duration (P = .66) of upper respiratory tract symptoms. With their first rhinovirus infection, subjects with asthma had more lower respiratory tract symptoms (P = .051), more severe (P = .001) and longer (P = .005) duration of lower respiratory tract symptoms, and greater mean fall in peak flow (P = .03) than subjects without asthma. Risk of infection was slightly but not significantly higher in asthmatics using continuous inhaled corticosteroids (OR: 1.15; 95% CI: 0.60–2.19). Sex was not associated with susceptibility to rhinovirus infection (OR: 0.87; 95% CI: 0.53–1.42).
People with atopic asthma are not at greater risk of rhinovirus infection than those without atopy and asthma, but have more frequent, more severe, and longer lasting lower respiratory tract symptoms with rhinovirus infections.
Many recent studies have focused on the lower respiratory tract symptoms occurring during rhinovirus infections, in an effort to determine the mechanisms of rhinovirus-induced asthma symptoms. This study’s detailed characterization of the upper and lower respiratory tract symptoms in asthmatics and nonasthmatics will be helpful in determining the degree of extrapolation to asthmatic individuals that can be applied to studies done in nonasthmatics. In addition, the increased morbidity from rhinovirus-induced lower respiratory tract symptoms in asthmatics described in this study illustrates the importance of rhinovirus prevention in this population.