Methods
We performed a retrospective cohort study that included all infants with one or more wheezing episodes who were younger than two years old in tertiary centers in Rionegro, Colombia, between January 2019 and December 2019.  The municipality of Rionegro had a total population of 101,046 inhabitants, with two tertiary referral hospitals(8). Inclusion criteria were defined as children younger than two years of age admitted to the pediatric ward diagnosed with a wheezing episode. Patients without lower respiratory compromises, with positive bacterial cultures on admission or a confirmed whooping cough (culture or PCR) were excluded. The study protocol was approved by the Institutional Review Board of the University of Antioquia (No 18/2015).