New estimates show that the burden of respiratory syncytial virus, or RSV, among children aged younger than 2 years in the outpatient setting is higher than previously reported, and children aged younger than 6 months are particularly high risk.
Joana Lively, MPH, an epidemiologist in the CDC’s Division of Viral Disease, and colleagues used previously unpublished data from the New Vaccine Surveillance Network (NVSN) to estimate rates of RSV-associated ED and pediatric practice visits among children aged younger than 24 months between 2004 and 2009. The analysis included 3,339 children from Nashville, Tennessee; Rochester, New York; and Cincinnati, Ohio. Among them, 1,532 were tested for RSV in EDs and 1,724 were tested in pediatric practices, with 21% and 18% testing positive for RSV, respectively.
Lively and colleagues said the average annual RSV infection rates among children aged younger than 2 years was 59.6 (95% CI, 50.9-68.3) and 205.7 (95% CI, 169.5-241.9) per 1,000 children for ED and pediatric practice visits, respectively.
In the ED, rates of RSV increased after birth, peaking at a rate of 116 (95% CI, 99.3-132.7) per 1,000 children at 4 months of age. In pediatric practices, the peak rate was 289.2 (95% CI, 241.1-337.2) per 1,000 children at 5 months of age.
The researchers said the new estimates for children aged younger than 24 months in ED and primary care settings suggest that the RSV burden in this age group might be approximately 1.5-fold higher than what they had previously reported.
“The study findings reiterate the importance of RSV as a cause of outpatient visits for children under 2 years of age,” Lively told Infectious Diseases in Children. “It particularly highlights the large burden in infants under 6 months of age and may help guide the potential use of novel maternal vaccines and RSV-specific antibody products that are under development.” – by Bruce Thiel
Disclosures: The authors report no relevant financial disclosures.