Respiratory Syncytial Virus Infection in Infants and Young Children

Epidemiology of RSV Bronchiolitis

RSV is the predominant viral pathogen causing bronchiolitis, with the highest incidence occurring between December and March in North America, though regional variations exist 1
Approximately 90% of children are infected with RSV within the first 2 years of life, and up to 40% will experience lower respiratory tract infection during their initial infection 1
RSV infection does not confer permanent immunity, with reinfections occurring throughout life 1
RSV bronchiolitis leads to more than 90,000 hospitalizations annually in the United States 4
Mortality from RSV has decreased significantly over time, from approximately 4,500 deaths annually in 1985 to around 390 deaths in 1999 4

Initial symptoms of rhinitis and cough, which may progress to lower respiratory symptoms 1
Tachypnea, wheezing, rales/crackles are common clinical findings 1, 4
Use of accessory respiratory muscles and/or nasal flaring are signs of increased respiratory effort 1, 4
Increased respiratory effort, particularly in severe cases 1

Palivizumab (a monoclonal antibody) is recommended for prophylaxis in high-risk infants, including those born before 29 weeks' gestation, those with chronic lung disease of prematurity, and those with hemodynamically significant heart disease 5