Detection of respiratory syncytial virus in nasopharyngeal secretions by ELISA: comparison with fluorescent antibody technique.

Samples of nasopharyngeal secretions (NPS) obtained from 140 infants and children with acute respiratory disease were examined for the presence of respiratory syncytial (RS) virus by ELISA. An antiserum produced in rabbits against RS-virus polypeptides was used both as the "capture" antibody and as conjugate in a double-antibody sandwich technique. RS virus was detected by ELISA in specimens of NPS obtained from 72 (51%) of the patients. By comparison RS virus was shown to be present in 86 (61%) of the patients when the immunofluorescent antibody (IF) technique was employed. Samples obtained from 78 of the 140 patients were also examined by inoculation into tissue cultures, and RS-virus was isolated from 47 patients. RS virus was detected by ELISA in 37 (79%) and by IF technique in 43 (91%) of these 47 patients. The IF technique was found to be more sensitive than ELISA, especially in patients older than 9 months and for the examination of specimens of NPS containing only a small percentage of RS-virus antigen-positive cells.