What pathogen is responsible for the majority of bronchiolitis cases?

Respiratory syncytial virus (RSV) is the primary pathogen linked to most cases of bronchiolitis, particularly in infants and young children. This virus is known for its ability to infect and inflame the small airways (bronchioles) in the lungs, leading to the clinical presentation of bronchiolitis, which typically includes wheezing, coughing, and difficulty breathing.

The prevalence of RSV as the causative agent is particularly significant during the winter months, coinciding with seasonal outbreaks. RSV tends to be more severe in infants, especially those under six months of age, resulting in a substantial number of hospitalizations. Understanding the role of RSV is crucial for clinical management and for parents, as it highlights the importance of supportive care during viral respiratory infections in pediatric populations.

Other pathogens, such as Streptococcus pneumoniae, the influenza virus, and parainfluenza virus, can cause respiratory illnesses, but they are less commonly associated with the specific diagnosis of bronchiolitis when compared to RSV, making it important for clinicians to recognize its predominant role.