Risk factors for severe bronchiolitis caused by respiratory virus infections among Mexican children in an emergency department

Robledo-Aceves, Mireya; Moreno-Peregrina, María de Jesús; Velarde-Rivera, Fernando; Ascencio-Esparza, Elba; Preciado-Figueroa, Francisco M.; Caniza, Miguela A.; Escobedo-Melendez, Griselda

Inclusion criteria included diagnosis of severe bronchiolitis, age 2 years or younger, date of birth during the study period, birthplace in Jalisco, Mexico, and respiratory virus detected in nasopharyngeal aspirate. Exclusion criteria included previous hospitalization for bronchiolitis, previous use of bronchodilators or corticosteroids, the lack of clinical symptoms of respiratory infections and/or demographic data, birthplace outside the catchment area, and absence of respiratory virus isolated in nasopharynx aspirate. Healthy children 2 years or younger, with no history of respiratory symptoms or previous hospitalizations during the past 6 months, who were born in the catchment area and received care from the Preventative Medicine department in our hospital were included as a healthy control group.