Evaluation of a rapid diagnostic test for respiratory syncytial virus (RSV): potential for bedside diagnosis

Abstract

Objective: Rapid detection of respiratory syncytial virus (RSV) infection can assist clinicians in decisions regarding antiviral therapy with ribavirin as well as instituting infection control measures. The Abbott TestPack RSV is a rapid RSV detection immunoassay that can be performed on respiratory secretions in 20 to 30 minutes without special laboratory equipment. The purpose of this study was to evaluate housestaff performance of the TestPack RSV at bedside as compared with laboratory testing of aliquots of the same specimen by tissue culture inoculation, direct fluorescent antibody (DFA) testing and TestPack RSV.

Methods: During the 1991 through 1992 RSV season, 137 nasopharyngeal aspirates or washes obtained from pediatric patients < 4 years of age suffering from acute respiratory disease were assayed by the Food and Drug Administration-approved TestPack RSV as well as conventional tube culture and DFA testing.

Results: 66 of 137 (48%) specimens were positive for RSV as defined by: isolation and DFA-positive (n = 48) and DFA testing positive with negative culture (n = 18); blocking assay experiments using TestPack RSV confirmed culture-negative DFA-positive specimens as positive in 8/8 instances in which material for retesting was available. Using these definitions, the sensitivity and specificity for the assays were: housestaff TestPack RSV: 92%, 93%; laboratory TestPack RSV: 97%, 98%; virus isolation: 72%, 100%.

Conclusion: From these data, it appears that the TestPack RSV EIA in the field setting is reliable, although laboratory confirmation of results is important.