Respiratory viral infections in children with asthma: do they matter and can we prevent them?

Ahanchian, Hamid; Jones, Carmen M; Chen, Yueh-sheng; Sly, Peter D

Asthma is a major public health problem with a huge social and economic burden affecting 300 million people worldwide [1] . Viral respiratory infections are the major cause of acute asthma exacerbations and contribute to asthma inception in high risk young children with susceptible genetic background. A history of wheeze associated with respiratory viral infections early in life is one of the major risk factors for the later development of asthma [2] [3] [4] [5] [6] [7] , together with sensitization to aeroallergens in early life and a family history of asthma and allergies, reflecting a genetic predisposition. Respiratory viral infections are also the principal cause of asthma exacerbations in children and adults [8] [9] [10] [11] [12] [13] . However, the question of whether viral infections "select" susceptible hosts or whether viral infections may induce asthma de novo by "damaging" airways is not settled. In other words, do viruses cause or simply unmask asthma?