SDI in partnership with MedImmune, has announced the publication of a ground-breaking study on the variances of the respiratory syncytial virus (RSV) season between major U.S. metropolitan areas. The study is published in the December issue of The Pediatric Infectious Disease Journal.

RSV is the most common cause of respiratory infections in infants and young children and is the leading cause of hospitalization in children less than 24 months of age. Each year, an estimated 125,000 infants in the United States are hospitalized with severe RSV infections. Those at the greatest risk for severe disease or death include high-risk premature infants and those with compromised respiratory, cardiac, or immune systems. The virus is transmitted from person to person through the air and from contact with infected surfaces, and it predominantly circulates during fall and winter months in the Northern Hemisphere.

The published study findings demonstrated that there is significant variability in the onset and duration of RSV activity between metropolitan areas located within the same region. For example, in the three-year study, greater than 73 percent of all the measured metropolitan areas revealed at least one week of significant RSV activity outside of the traditional American Academy of Pediatrics (AAP)-defined season for RSV activity (or outbreaks) in their region, which is typically November through March. In addition, the study found that the Southern region experienced the longest duration and earliest conclusion of RSV activity while the Midwest region exhibited the latest season commencement and peak. Portions of Florida demonstrated year-round RSV outbreaks.