Respiratory syncytial virus (RSV) infection is ubiquitous with almost all 
infants having been infected by 2 years of age and lifelong repeated infections 
common. It is the second largest cause of mortality, after malaria, in infants 
outside the neonatal period and causes up to 200,000 deaths per year worldwide. 
RSV results in clinical syndromes that include upper respiratory tract 
infections, otitis media, bronchiolitis (up to 80% of cases) and lower 
respiratory tract disease including pneumonia and exacerbations of asthma or 
viral-induced wheeze. For the purposes of this review we will focus on RSV 
bronchiolitis in infants in whom the greatest disease burden lies. For infants 
requiring hospital admission, the identification of the causative respiratory 
virus is used to direct cohorting or isolation and infection control procedures 
to minimize nosocomial transmission. Nosocomial RSV infections are associated 
with poorer clinical outcomes, including increased mortality, the need for 
mechanical ventilation and longer length of hospital stay. Numerous clinical 
guidelines for the management of infants with bronchiolitis have been published, 
although none are specific for RSV bronchiolitis. Ribavirin is the only licensed 
drug for the specific treatment of RSV infection but due to drug toxicity and 
minimal clinical benefit it has not been recommended for routine clinical use. 
There is currently no licensed vaccine to prevent RSV infection but passive 
immunoprophylaxis using a monoclonal antibody, palivizumab, reduces the risk of 
hospitalization due to RSV infection by 39-78% in various high-risk infants 
predisposed to developing severe RSV disease. The current management of RSV 
bronchiolitis is purely supportive, with feeding support and oxygen 
supplementation until the infant immune system mounts a response capable of 
controlling the disease. The development of a successful treatment or 
prophylactic agent has the potential to revolutionize the care and outcome for 
severe RSV infections in the world's most vulnerable infants.