Pediatric Respiratory Syncytial Virus: Risk Factors and Treatment Options

New investigational therapeutics are undergoing clinical development.

Respiratory syncytial virus (RSV) is a leading viral cause of acute lower respiratory infections and associated deaths among infants and children worldwide, underlying an estimated 33.8 million infections among children younger than age 5 years in 2005.1,2 Globally, only pneumococcal pneumonia and H. influenzae type b appear to claim the lives of more infants and children than RSV, and* RSV is the only one of these three diseases for which a vaccine is not yet available.1-3

In temporal climates, RSV infections vary seasonally. In most of the US, outbreaks peak during the winter and reach a nadir during the summer months.4 The US Centers for Disease Control and Prevention (CDC) reported that for 2013 and 2014, the onset of RSV season varied regionally, from October to January, and that Florida’s RSV season begins earlier and lasts longer than is the case in other states.4 Healthcare-associated or hospital-acquired RSV is a recognized problem and the CDC has issued recommendations for preventing the spread of RSV in healthcare settings.5

Nearly all infants are infected the first time before their 5th birthday, leading to 2.1 million outpatient visits annually among children younger than age 5 years, and approximately 150,000 hospitalizations annually among children younger than age 2 years.5,6 The elderly are also vulnerable, with an estimated 177,000 RSV-associated hospitalizations and 14,000 deaths annually in the US among people age 65 years or older.4

Symptoms typically appear within a week of exposure, and initially include appetite loss, runny nose, and not infrequently, sore throat, with subsequent development of sneezing, coughing, and fever, and in some cases, respiratory wheeze.4

Overall, up to 40% of infants and young children infected with RSV develop pneumonia or bronchiolitis; risks are higher for prematurely-born infants, and infants and children with chronic cardiopulmonary disease, immunosuppression, or Down syndrome.4,7

Definitive diagnosis involves laboratory testing, usually using antigen detection tests but increasingly including more sensitive PCR assays.4

RSV bronchiolitis typically self-resolves in 90% of children after three weeks, but severe cases require supportive care.6 Treatment is nonspecific and supportive. If neecssary, infants are treated with supplemental oxygen and mucus suctioning; in severe cases, intubation and mechanical ventilation may be necessary.4