Association of respiratory picornaviruses with acute bronchiolitis in French infants

BackgroundHuman rhinoviruses and enteroviruses (Picornaviridae) are suspected to be major viral etiological causes of bronchiolitis in infants.ObjectivesIn the present study, we assessed the potential role of the respiratory picornaviruses as causative agents of bronchiolitis in French infants.Study designFrom September 2001 to June 2002, we prospectively selected 192 infants ≤36 months of age and hospitalized for acute bronchiolitis. The detection of common respiratory viruses (respiratory syncytial virus, influenza virus A and B, parainfluenza virus 1, 2, 3 and adenovirus) was performed using classical immunofluorescence antigen and cell-culture detection assays on nasopharyngeal aspirates whereas the detection of human metapneumovirus (HMPV) was performed by a real-time RT-PCR assay. The presence of rhinovirus and/or enterovirus was assessed in respiratory samples by a picornavirus RT-PCR detection assay followed by a differential Southern blotting procedure.ResultsA potential causative virus was detected in 72.5% of the 192 study infants. RSV (30%), rhinovirus (21%), enterovirus (9%), infuenza virus A (6%) and human metapneumovirus (4%) were the most frequent causative agents detected. Rhinoviruses or enteroviruses were detected as the only evidence of respiratory viral tract infection in 57 (30%) of 192 infants, whereas rhinovirus or enterovirus occurred in mixed viral infection detected in 25 (13%) of 192 study cases (30% versus 13%, p < 10−3).ConclusionsOur data suggest that respiratory picornaviruses are one of the leading etiological causes of bronchiolitis in French infants. These findings highlight the need to implement a rapid picornavirus RT-PCR detection assay for the clinical diagnosis of respiratory infections in pediatric patients with bronchiolitis.