Rapid detection of respiratory syncytial virus by a biotin-enhanced immunoassay: test performance by laboratory technologists and housestaff.

A biotin-enhanced enzyme immunoassay (EIA) for respiratory syncytial virus (RSV) antigen detection (TESTPACK RSV) was prospectively compared with virus isolation in cell culture and immunofluorescence. Of 156 nasopharyngeal swab specimens from infants with respiratory symptoms, 81 (52%) yielded RSV in culture. Compared with culture the sensitivity of the EIA was 95% and specificity was 92%; the specificity increased to 97% with a blocking assay. Compared with immunofluorescence the sensitivity of EIA was 92% and specificity was 93%. In order to assess the performance of TESTPACK RSV as a bedside test, nasopharyngeal swabs from 49 children were tested by EIA at the bedside by housestaff and by immunofluorescence in the laboratory; the sensitivity of the EIA was lower (78%) while specificity remained high (95%). Inclusion of older children may have resulted in diminished sensitivity. The TESTPACK RSV is a simple, rapid test that performs well and is easily adaptable to an office setting. Further evaluation of the test in older children may be required.