Comparison of directigen RSV with viral isolation and direct immunofluorescence for the identification of respiratory syncytial virus

Abstract

An enzyme immunoassay membrane test (Directigen RSV) for the detection of respiratory syncytial virus in clinical specimens was compared prospectively with isolation in cell culture and direct immunofluorescence (IF). A total of 315 nasopharyngeal wash specimens from pediatric patients were examined. Directigen RSV was 86.1% sensitive and 91.3% specific for specimens positive by isolation in cell culture and/or IF, with 88.6% agreement. The false-positive rate was 16%; 2 of 20 specimens giving false-positive reactions by Directigen RSV were true-positives by blocking assay. Twenty-seven specimens (8.5%) whose results were initially uninterpretable by Directigen RSV due to filtration difficulties were diluted and upon retesting produced acceptable results. Sixty-three viral isolates and/or IF identifications of virus antigens representing seven virus groups other than respiratory syncytial virus were also found; cross-reactions between Directigen RSV and other viruses were not observed. Directigen RSV will be useful as an immediate procedure and in facilities lacking a comprehensive virology laboratory.

Prospective evaluation of a dot-blot enzyme immunoassay (Directigen RSV) for the antigenic detection of respiratory syncytial virus from nasopharyngeal aspirates of paediatric patients

“…Of the different rapid diagnostic methods available for RSV, enzyme immunoassay systems provide high sensitivity and specificity, as well as being appropriate for routine use, with results available in < 15 min [5,10,11]. The present prospective study of the ColorPAC assay demonstrated acceptable levels of sensitivity (80.9%) and specificity (97.5%).…”

“…Statistical analysis was carried out by performing Student's t-test on paired data. All p values were two-tailed and were considered significant if < 0.05 [10].…”

Stability of respiratory syncytial virus antigen due to buffer treatment for direct detection in nasopharyngeal specimens with enzyme immunoassay

“…Since RSV is a labile virus and loses the infectivity during transport or storage, many test systems (e.g., radioimmunoassay, immunofluorescence test (IFT), immunoperoxidase assay, enzyme immunoassay (EIA), enzyme immunomembrane filter assay) have been described and have been compared for rapiddetectionofRSV infections (2,4,5,9,10,13-l5,l7-22, 24,26,27,29,[31][32][33][34][35][36][37]. However, in our opinion some tests have certain drawbacks for practical application: (i) IFT is often difficult and time-consuming in preparing the slides, and the subjective reading of the stained cells require trained and experienced personnel; furthermore, no automatisation is possible (5); (ii) the need for sonification of the specimens for testing in EIA (2); (iii) and/or overnight incubation for testing in EIA (2); (iv) or the use of cell cultures, e.g., for shell-vial test (18).…”

Differential diagnoses of influenza A virus, influenza B virus, and respiratory syncytial virus infections by direct immunofluorescence using mixtures of monoclonal antibodies of different isotypes

“…Direct immunofluorescence (DIF) and enzyme immunosorbent assay have commonly been applied for rapid detection of influenza viruses and RSV (5). Enzyme immunomembrane filter assays are available commercially and require less than 15 min to complete (10,13,14). DIF offers the advantages of being able to assess specimen quality and to test for multiple viruses in the same specimen.…”

“…Murine MAbs that were prepared and are used in this laboratory for the diagnosis of influenza A and B viruses (13) and of RSV (14) were typed by the Isotype Ab-STAT-I test (Sang-Stat Medical Corporation, Menlo Park, Calif.). The MAbs used for influenza A and B viruses were found to be murine immunoglobulin G1 (IgG1) and IgG2b, respectively; two MAbs were pooled for detection of RSV and were typed as IgG2a and IgG3.…”