Respiratory syncytial virus (RSV) is an enveloped, single-stranded RNA virus belonging to the family of paramyxoviridae and a human pathogen in the genus Pneumovirus.1
Most RSV infections cause mild to moderate upper respiratory illness and cold-like symptoms. However, in certain high-risk pediatric patients, RSV may cause serious lower respiratory tract disease.
About the photograph: Electron photomicrograph of budding virion (129) used to indicate location and chain length of the RSV proteins. (Peter Collins, 1989; Fields Virology, 2nd ed, 1990).
In the absence of adequate infection-control practices, RSV can spread very rapidly in the hospital environment and other settings. RSV transmission can occur by contact with large droplet aerosols or fomites and by contact with infectious secretions through hand contamination and self-inoculation of the eyes, nose, and mouth.
RSV transmission may be prevented by frequent hand washing by parents and healthcare providers, isolating infants
from people with upper respiratory infections, and avoiding crowds during the RSV season.4
The start and end of RSV season can vary year to year, state to state, and can even vary within communities in the same region.6,7 Throughout much of the US, the RSV season begins in the fall and runs into spring—although year-round RSV activity has been reported in Florida and Puerto Rico.6-10 Local historical data can help determine the start and end of RSV season in a geographic region.5,6
Before determining the start and end of RSV season, it's important to consider different sources of surveillance data, such as:
In NREVSS, the onset week in an area (national, region, or state) is defined as the first of 2 consecutive weeks when the weekly percentage of all specimens testing positive for RSV antigen in all reporting laboratories in the area is ≥10%. The offset is the end of the last 2 consecutive weeks when the weekly percentage positive exceeds 10%. Visit CDC NREVSS for reports to stay updated on RSV activity in your region.
Synagis is indicated for the prevention of serious lower respiratory tract disease caused by respiratory syncytial virus (RSV) in children at high risk of RSV disease. Safety and efficacy were established in children with bronchopulmonary dysplasia (BPD), infants with a history of premature birth (≤35 weeks gestational age), and children with hemodynamically significant congenital heart disease (CHD). The recommended dose of Synagis is 15 mg/kg of body weight given monthly by intramuscular injection. The first dose of Synagis should be administered prior to commencement of the RSV season and the remaining doses should be administered monthly throughout the RSV season. Children who develop an RSV infection should continue to receive monthly doses throughout the RSV season.
The efficacy of Synagis at doses less than 15 mg/kg, or of dosing less frequently than monthly throughout the RSV season, has not been established.
Synagis is contraindicated in children who have had a previous significant hypersensitivity reaction to Synagis. Cases of anaphylaxis and anaphylactic shock, including fatal cases, have been reported following initial exposure or re-exposure to Synagis. Other acute hypersensitivity reactions, which may be severe, have also been reported on initial exposure or re-exposure to Synagis. The relationship between these reactions and the development of antibodies to Synagis is unknown. If a significant hypersensitivity reaction occurs with Synagis, its use should be permanently discontinued. If a mild hypersensitivity reaction occurs, clinical judgment should be used regarding cautious readministration of Synagis. As with any intramuscular injection, Synagis should be given with caution to children with thrombocytopenia or any coagulation disorder. Palivizumab may interfere with immunological-based RSV diagnostic tests, such as some antigen detection-based assays.
Adverse reactions occurring greater than or equal to 10% and at least 1% more frequently than placebo are fever and rash. In post-marketing reports, cases of severe thrombocytopenia (platelet count <50,000/microliter) and injection site reactions have been reported.