Detection of respiratory syncytial, parainfluenza type 2, and adenovirus antigens by radioimmunoassay and enzyme immunoassay on nasopharyngeal specimens from children with acute respiratory disease.

Four-layer antispecies radioimmunoassay (RIA) and enzyme immunoassay (EIA) procedures were developed for the detection of respiratory syncytial virus (RSV), parainfluenza type 2 virus, and adenovirus antigens in nasopharyngeal specimens from children hospitalized for acute respiratory disease. Polystyrene beads (RIA) or flat-bottomed polystyrene microtiter plates (EIA) were used as the solid phases, guinea pig anti-virus immunoglobulins were used as the captive antibodies, rabbit anti-virus immunoglobulins were used as the secondary antibodies, and 125I-labeled sheep anti-rabbit (RIA) or horseradish peroxidase-labeled swine anti-rabbit (EIA) immunoglobulins were used as the indicator antibodies. A comparison of the EIAs and RIAs with routinely used immunofluorescence (IF) techniques was made with 164 nasopharyngeal specimens collected from children with acute respiratory disease. Only 3 of 66 RSV IF-positive specimens were negative in RSV RIA, and of 83 RSV, parainfluenza type 2 virus, and adenovirus IF-negative specimens, 1 was positive in RSV RIA. Of 4 parainfluenza type 2 virus IF-positive and 11 adenovirus IF-positive specimens, each was positive in corresponding RIAs, and all 83 IF-negative specimens were negative in parainfluenza type 2 virus and adenovirus RIAs. The results of the RSV, parainfluenza type 2, and adenovirus EIAs confirmed the results of corresponding RIAs in each selected case tested. The RIAs and EIAs were found to be as specific and sensitive as IF techniques, and more practical in the rapid detection of respiratory viruses in nasopharyngeal secretions.