Prospective, monocentric, case-control and transversal study Primary end-point: correlation between serum KL-6 level and severity of the bronchiolitis, evaluated by a clinical scoring system established at the time of the admission in Paediatric Emergency Unit Secondary end-points: respiratory virus detected by EIA and RT-PCR, phylogenetic study of rhinovirus, length of hospitalisation, immediate morbidity and mortality, risk of asthma at the age of three years old.
