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.