1. What is bronchitis in babies? Baby bronchitis refers to inflammation of the bronchial mucosa that occurs in infants and young children, mainly manifesting as cough, wheezing, dyspnea and other symptoms. It is common in infants and young children between 3 months and 3 years old, especially in winter and spring. 2. Causes of bronchitis in babies 1. Viral infection: such as influenza virus, adenovirus, etc.; 2. Bacterial infection: such as Streptococcus pneumoniae, Haemophilus influenzae