Respiratory Syncytial Virus Infection (RSV)

Respiratory syncytial (sin-SISH-uhl) virus

ost clinical laboratories currently utilize antigen detection tests, and many supplement antigen testing with cell culture. Compared with culture, the sensitivity of antigen detection tests generally ranges from 80% to 90%. Antigen detection tests and culture are generally reliable in young children but less useful in older children and adults. Because of its thermolability, the sensitivity of RSV isolation in cell culture from respiratory secretions can vary among laboratories. Experienced laboratorians should be consulted for optimal results.

RT-PCR assays are now commercially available for RSV. The sensitivity of these assays often exceeds the sensitivity of virus isolation and antigen detections methods. Use of highly sensitive RT-PCR assays should be considered, particularly when testing older children and adults because they may have low viral loads in their respiratory specimens.

Serologic tests are less frequently used for routine diagnosis. Although useful for seroprevalence and epidemiologic studies, a diagnosis using paired acute- and convalescent-phase sera to demonstrate a significant rise in antibody titer to RSV cannot be made in time to guide patient care.

American Academy of Pediatrics (AAP) Guidelines for Infants and Children at Risk for Severe Illness Due to RSV Infection
According to the AAP1, palivizumab prophylaxis may be considered for the following infants and children

Infants born at 28 weeks’ gestation or earlier during RSV season, whenever that occurs during the first 12 months of life
Infants born at 29–32 weeks’ gestation if they are younger than 6 months of age at the start of the RSV season
Infants born at 32–35 weeks’ gestation who are younger than 3 months of age at the start of the RSV season or who are born during RSV season if they have at least one of the following 2 risk factors: 1) infant attends child care; 2) infant has a sibling younger than 5 years of age
Infants and children younger than 2 years with cyanotic or complicated congenital heart disease
Infants and children younger than 2 years who have been treated for chronic lung disease within 6 months of the start of the RSV season.
Infants born before 35 weeks of gestation who have either congenital abnormalities of the airway or neuromuscular disease that compromises handling of respiratory secretions