Introduction:
Acute viral bronchiolitis (AVB) is the leading cause of hospitalization among infants in developed and developing countries and associated with significant morbidity1-4. AVB is defined as the first episode of wheezing in a child younger than 12-24 months with physical findings of a viral respiratory infection and has no other explanation for the wheezing (pneumonia or atopy)3,4. The common clinical presentation includes prodrome of rhinorrhea, cough, low-grade fever, followed by paroxysmal cough, dyspnea, chest retractions, wheezing, and lung hyperinflation with patchy atelectasis on chest radiograph. Respiratory syncytial virus (RSV) is the main cause of AVB worldwide and accounts for 30-80% of cases. Other viruses implicated are influenza viruses, parainfluenza viruses (PIV 1-3), human metapneumovirus (hMPV), rhinovirus, enterovirus, adenovirus, and bocavirus2,4-11. AVB is characterized by acute inflammation, edema, and necrosis of epithelial cells lining of small airways, increased mucus production, and bronchospasm4,12. The severity of AVB varies from asymptomatic exposures to severe lower respiratory tract infection leading to emergency room (ER) visit, Pediatric intensive care unit (PICU) admission, and sometimes mortality4. The reason for variable course in children is not well understood but it is believed that in children with severe disease, the enhanced inflammatory response may be a contributing factor rather than virus induced cytopathy.13. Children with RSV infection in early life have a higher risk of developing asthma and recurrent wheezing in later childhood4,14,15
The literature on clinical characteristics, viral profile, intensive care needs, and outcome of infants with AVB is limited. Therefore, this prospective observational study was planned to investigate clinico-virological profile, treatment details, intensive care needs, and outcome infants with AVB.