Detection of respiratory syncytial virus in nasopharyngeal secretions by 24-well plate precentrifugation assay using a monoclonal antibody against F protein

Background. Respiratory syncytial virus (RSV) is responsible for 50% of all bronchiolitis and 25% of pneumonia cases during the first month of life. D etection of the RSV antigen by immunofluorescence in exfoliated nasal epith elium or by other methods in nasopharyngeal swabs is useful in the potentia lly infected patient because results are available within a few hours. in c ontrast, RSV antigen detection in cell culture may require as much as 3 wee ks. Methods. Three methods for detection of respiratory syncytial virus in 131 clinical respiratory specimens from patients with acute respiratory disease and bronchiolitis were compared utilizing the following: a precentrifugati on immunofluorescence assay using Hep-2 cells, indirect immunofluorescence assay, and conventional tube cell culture using Hep-2 cells. Results. Respiratory syncytial virus was identified in 36 specimens by the three methods previously described. The virus was recovered in 41 (31.3%) s amples by precentrifugation immunofluorescence assay, 40 (30.5%) were ident ified by the immunofluorescence technique, and 38 (29.0%) cases were positi ve by conventional cell culture. The sensitivity of the precentrifugation a ssay in relation to the immunofluorescence technique was 90%, the specifici ty 94.5%, and the agreement, 96.2%. A positive predictive value of 90.2% wa s obtained. Sensitivity, specificity, agreement, and positive predictive va lues obtained by the precentrifugation assay variant compared to the conven tional cell were 90.8%, 94.5%, 93.1%, and 87.8%, respectively. Conclusions. The precentrifugation immunofluorescence assay method was as s ensitive as the remainder of the methods used in our study and represents a valid alternative for rapid detection of respiratory syncytial virus in cl inical samples. (C) 2000 IMSS. Published by Elsevier Science Inc.