Abstract: Abstract: Objective To investigate the prevalence of year-round respiratory viral infection in children with lower re⁃ spiratory tract infection (LRTI), and the relationship between respiratory viral infection and allergen sensitization in exacer⁃ bating asthma. Methods A total of 231 hospitalized children with acute LRTI were investigated from May 2013 to April 2014. The 5 most common respiratory viruses were isolated from nasopharyngeal aspirate using multiplex reverse transcrip⁃ tion-polymerase chain reaction, including respiratory syncytial virus (RSV), adenovirus (AV), parainfluenza virus (PIV), in⁃ fluenza virus (IFV) and rhinovirus (RV). Atopic sensitization was defined if more than 1 serum specific immunoglobulin E level measured using immunofluorescence experiment was over 0.35 IU/mL. Results RSV was the most common pathogen of bronchiolitis in hospitalized children through the year. RV or IFV infections were more prevalent in asthma exacerbations compared to other LRTIs. AV was more likely to cause pneumonia. RV and IFV were associated with asthma exacerbations in children with atopic sensitization, but not in nonatopic children. Conclusion RV and IFV are associated with hospital⁃ ization for asthma exacerbation in children with atopic sensitization.

Key words: asthma, allergens, orthomyxoviridae, rhinovirus, child, lower respiratory infection