Asthmatic patients do not have an increased risk of rhinovirus infection but are more likely to develop severe lower respiratory symptoms if they do become infected.
Dr Jonathan Corne and colleagues at the Department of Respiratory Medicine, Nottingham University Hospital, Nottingham, England said their study does not support the popular conception that people with asthma are more susceptible to colds than people without the disease.
The clinicians said that detecting differences in rhinovirus infections between asthmatics and healthy individuals would help elucidates pathogenesis of asthma exacerbations. Reverse transcriptase polymerase chain reactions have shown a five-fold increase in their sensitivity for detection of rhinoviruses.
Dr Corne recruited 76 cohabiting couples; one person in each couple had atopic asthma, the other did not. Participants completed daily diary cards of upper-respiratory-tract (URT) and lower-respiratory-tract (LRT) symptoms. In addition, all participants measured their peak expiratory flow twice daily. Every two weeks, nasal aspirates were taken and examined for rhinovirus. Mixed models were used to compare risks of infection between groups, and clinicians also compared the severity and duration of infections.
The researchers analyzed 753 nasal samples and found rhinovirus detected in 10.1 percent (38/378) of samples from participants with asthma, and 8.5 percent (32/375) of samples from healthy participants.
When the clinicians adjusted for confounding factors, they found that asthma did not significantly increase the risk of infection. Rhinovirus infection was associated more frequently with LRT infection in participants with asthma (12 of 28 infections) than in healthy individuals (four of 23 infections).
Symptoms of LRT associated with rhinovirus infection were substantially more severe and longer-lasting in participants with asthma than in healthy participants. The two groups did not differ in frequency, severity, or duration of URT infections or symptoms associated with rhinovirus infection…