Laboratory Testing

Several different types of laboratory tests are commercially available for diagnosis of RSV infection. Rapid diagnostic assays performed on respiratory specimens are available commercially. Most clinical laboratories currently utilize antigen detection tests. 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.

Sensitivity of virus isolation from respiratory secretions in cell culture varies among laboratories. Experienced laboratorians should be consulted for optimal results.

RT-PCR assays are now commercially available. The sensitivity of these assays is equal to or exceeds the sensitivity of virus isolation and antigen detections methods. Highly sensitive RT-PCR assays should be considered particularly when testing adults, because they may have low viral loads in their respiratory specimens.

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